BioMed Research International: Radiology The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Interfractional Variations of Tumor Centroid Position and Tumor Regression during Stereotactic Body Radiotherapy for Lung Tumor Sun, 07 Dec 2014 10:44:34 +0000 Purpose. To determine interfractional changes of lung tumor centroid position and tumor regression during stereotactic body radiation therapy (SBRT). Methods and Materials. 34 patients were treated by SBRT in 4-5 fractions to a median dose of 50 Gy. The CT scans acquired for verification were registered with simulation CT scans. The gross target volume (GTV) was contoured on all verification CT scans and compared to the initial GTV in treatment plan system. Results. The mean (standard deviation, SD) three-dimension vector shift was  mm. The mean interfractional variations of tumor centroid position were  mm in anterior-posterior (AP) direction,  mm in superior-inferior (SI) direction, and  mm in right-left (RL) direction. Large interfractional variations (5 mm) were observed in 5 fractions (3.3%) in RL direction, 16 fractions (10.5%) in SI direction, and 36 fractions (23.5%) in AP direction. Tumor volume did not decrease significantly during lung SBRT. Conclusions. Small but insignificant tumor volume regression was observed during lung SBRT. While the mean interfractional variations of tumor centroid position were minimal in three directions, variations more than 5 mm account for approximately a third of all, indicating additional margin for PTV, especially in AP direction. Yanan Sun, Yufei Lu, Siguo Cheng, Wei Guo, Ke Ye, Huiyun Zhao, Xiaoli Zheng, Dingjie Li, Shujuan Wang, Chengliang Yang, and Hong Ge Copyright © 2014 Yanan Sun et al. All rights reserved. Quantification of an External Motion Surrogate for Quality Assurance in Lung Cancer Radiation Therapy Sun, 30 Nov 2014 07:43:32 +0000 The purpose of this work was to validate the stability of the end exhale position in deep expiration breath hold (DEBH) technique for quality assurance in stereotactic lung tumor radiation therapy. Furthermore, a motion analysis was performed for 20 patients to evaluate breathing periods and baseline drifts based on an external surrogate. This trajectory was detected using stereo infrared (IR) cameras and reflective body markers. The respiratory waveform showed large interpatient differences in the end exhale position during irradiation up to 18.8 mm compared to the global minimum. This position depends significantly on the tumor volume. Also the baseline drifts, which occur mostly in posterior direction, are affected by the tumor size. Breathing periods, which depend mostly on the patient age, were in a range between 2.4 s and 7.0 s. Fifteen out of 20 patients, who showed a reproducible end exhale position with a deviation of less than 5 mm, might benefit from DEBH due to smaller planning target volumes (PTV) compared to free breathing irradiation and hence sparing of healthy tissue. Patients with larger uncertainties should be treated with more complex motion compensation techniques. Jens Wölfelschneider, Tobias Brandt, Sebastian Lettmaier, Rainer Fietkau, and Christoph Bert Copyright © 2014 Jens Wölfelschneider et al. All rights reserved. Differentiation of Benign Angiomatous and Microcystic Meningiomas with Extensive Peritumoral Edema from High Grade Meningiomas with Aid of Diffusion Weighted MRI Sun, 16 Nov 2014 07:51:57 +0000 Objective. To determine whether angiomatous and microcystic meningiomas which mimic high grade meningiomas based on extent of peritumoral edema can be reliably differentiated as low grade tumors using normalized apparent diffusion coefficient (ADC) values. Methods. Preoperative magnetic resonance imaging (MRI) of seventy patients with meningiomas was reviewed. Morphologically, the tumors were divided into 3 groups. Group 1 contained 12 pure microcystic, 3 pure angiomatoid and 7 mixed angiomatoid and microcystic tumors. Group 2 included World Health Organization (WHO) grade II and WHO grade III tumors, of which 28 were atypical and 9 were anaplastic meningiomas. Group 3 included WHO grade I tumors of morphology different than angiomatoid and microcystic. Peritumoral edema, normalized ADC, and cerebral blood volume (CBV) were obtained for all meningiomas. Results. Edema index of tumors in group 1 and group 2 was significantly higher than in group 3. Normalized ADC value in group 1 was higher than in group 2, but not statistically significant between groups 1 and 3. CBV values showed no significant group differences. Conclusion. A combination of peritumoral edema index and normalized ADC value is a novel approach to preoperative differentiation between true aggressive meningiomas and mimickers such as angiomatous and microcystic meningiomas. Avetis Azizyan, Paula Eboli, Doniel Drazin, James Mirocha, Marcel M. Maya, and Serguei Bannykh Copyright © 2014 Avetis Azizyan et al. All rights reserved. Partial Splenic Embolization with Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma Accompanied by Thrombocytopenia Mon, 15 Sep 2014 00:00:00 +0000 Background. Thrombocytopenia often makes the introduction of systemic treatment difficult in patients with cirrhosis and hepatocellular carcinoma (HCC). We retrospectively evaluated the long-term effects of partial splenic embolization (PSE) with transarterial chemoembolization (TACE) in patients with HCC patients accompanied by thrombocytopenia. Patients and Methods. Twenty-one patients with HCC complicated by severe thrombocytopenia (platelet count, <5.0 × 104/mm3) were treated with PSE and TACE. Both the safety and platelet-increasing effect was evaluated in these patients. Results. Seventeen of 21 patients (81.0%) showed increased platelet counts to ≥5.0 × 104/mm3. Subsequently, 13 patients (61.9%) successfully received systemic chemotherapy. Platelet counts and serum levels of total bilirubin, as well as neutrophil counts, improved significantly one month after treatment. However, serum levels of albumin and hemoglobin decreased significantly one month after treatment. Severe adverse events, including acute liver failure and portal vein thrombus, were observed in two patients. Conclusion. PSE with selective TACE made it possible for patients with HCC and severe thrombocytopenia to receive systemic chemotherapy. Although PSE with TACE was safe and tolerable for most patients, the extent of PSE with TACE in a wide area of the liver may increase the risk for fatal liver failure. Yoshihiko Ooka, Tetsuhiro Chiba, Sadahisa Ogasawara, Tenyu Motoyama, Eiichiro Suzuki, Akinobu Tawada, Fumihiko Kanai, and Osamu Yokosuka Copyright © 2014 Yoshihiko Ooka et al. All rights reserved. Perfusion in the Tissue Surrounding Pancreatic Cancer and the Patient’s Prognosis Thu, 11 Sep 2014 08:58:24 +0000 Objective. The objective was to investigate the relationship between prognosis in case of pancreatic cancer and perfusion in tissue surrounding pancreatic cancer using perfusion CT. Methods. We enrolled 17 patients diagnosed with inoperable pancreatic adenocarcinoma. All patients were examined by perfusion CT and then underwent chemotherapy using gemcitabine. The time density curve (TDC) of each CT pixel was analyzed to calculate area under the curve (AUC) and blood flow (BF) using a mathematical algorithm based on the single-compartment model. To measure the AUC and BF of tumor ( and ) and peritumoral tissue ( and ), regions of interest were manually placed on the cancer and in pancreatic tissue within 10 mm of proximal pancreatic parenchyma. Survival days from the date of perfusion CT were recorded. Correlation between AUC or BF and survival days was assessed. Results. We found a significant correlation between or and survival days ( or 0.0005). Higher or values were associated with shorter survival. We found no significant correlation between or and survival. Conclusions. Our results suggest that assessments of perfusion in pancreatic tissue within 10 mm of proximal pancreatic parenchyma may be useful in predicting prognosis. Yoshihiro Nishikawa, Yoshihisa Tsuji, Hiroyoshi Isoda, Yuzo Kodama, and Tsutomu Chiba Copyright © 2014 Yoshihiro Nishikawa et al. All rights reserved. Volume Change and Liver Parenchymal Signal Intensity in Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging after Portal Vein Embolization prior to Hepatectomy Thu, 11 Sep 2014 07:40:41 +0000 Purpose. To investigate the liver volume change and the potential of early evaluation by contrast-enhanced magnetic resonance imaging (MRI) using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) after portal vein embolization (PVE). Materials and Methods. Retrospective evaluations of computed tomography (CT) volumetry of total liver and nonembolized areas were performed before and 3 weeks after PVE in 37 cases. The percentage of future liver remnant (%FLR) and the change ratio of %FLR (%FLR ratio) were calculated. Prospective evaluation of signal intensities (SIs) was performed to estimate the role of Gd-EOB-DTPA-enhanced MRI as a predictor of hypertrophy in 16 cases. The SI contrast between embolized and nonembolized areas was calculated 1 week after PVE. The change in SI contrast before and after PVE (SI ratio) was also calculated in 11 cases. Results. %FLR ratio significantly increased, and SI ratio significantly decreased (both ). There were significant negative correlations between %FLR and SI contrast and between %FLR and SI ratio (both ). Conclusion. Hypertrophy in the nonembolized area after PVE was indicated by CT volumetry, and measurement of SI contrast and SI ratio in Gd-EOB-DTPA-enhanced MRI early after PVE may be useful to predict the potential for hepatic hypertrophy. Ayako Akiba, Satoru Murata, Takahiko Mine, Shiro Onozawa, Tetsuro Sekine, Yasuo Amano, Youichi Kawano, Eiji Uchida, and Shin-ichiro Kumita Copyright © 2014 Ayako Akiba et al. All rights reserved. Improved Efficacy of Transcatheter Arterial Chemoembolization Using Warmed Miriplatin for Hepatocellular Carcinoma Mon, 08 Sep 2014 07:03:20 +0000 The aim of this study was to evaluate the efficacy and safety of transcatheter arterial chemoembolization (TACE) using warmed and nonwarmed miriplatin for hepatocellular carcinoma. Eighty patients (117 nodules), treated between January 2010 and June 2013, were evaluated. Thirty-two and 85 nodules were treated with nonwarmed and warmed miriplatin, respectively. The efficacy of TACE was evaluated on a per nodule basis according to treatment effect (TE). Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.0. TE grades were significantly improved in the warmed group compared to the nonwarmed group (nonwarmed: TE 4, 12.5%; TE 3, 0%; TE 2, 15.6%; TE 1, 71.9%; warmed: TE 4, 34.1%; TE 3, 5.9%; TE 2, 9.4%; TE 1, 50.6%; ) . Multivariate analysis revealed significant impact of warming miriplatin on objective response rate (odds ratio, 12.35; 95% confidence interval, 2.90–90.0; ). CTCAE grades of elevated aspartate and alanine transaminase after TACE were significantly higher in the warmed group ( and 0.0068, resp.); however, all adverse events were only transient. The use of warmed miriplatin in TACE significantly improved TE without causing serious complications. Daisuke Yasui, Satoru Murata, Shiro Onozawa, Takahiko Mine, Tatsuo Ueda, Fumie Sugihara, Chiaki Kawamoto, Eiji Uchida, and Shin-ichiro Kumita Copyright © 2014 Daisuke Yasui et al. All rights reserved. Patched Targeting Peptides for Imaging and Treatment of Hedgehog Positive Breast Tumors Mon, 08 Sep 2014 06:41:50 +0000 High tumor hedgehog expression is correlated with poor prognosis in invasive ductal carcinoma. Peptides which bind the patched receptor have recently been reported to have a growth inhibitory effect in tumors with activated hedgehog signaling. We sought to examine growth inhibition with these peptides in breast cancer cells and use these peptides as molecular imaging probes to follow changes in hedgehog expression after chemotherapy. Significant growth inhibition was observed in breast cancer cell lines treated with PTCH-blocking peptides. Significant in vitro uptake was observed with both FITC- and 99mTc-EC-peptide conjugates. In vivo imaging studies displayed greater accumulation of 99mTc-labeled peptides within tumors as compared to adjacent muscle tissue. Patched receptor expression increased after treatment and this correlated with an increase in tumor radiotracer uptake. These studies suggest that peptides which bind the sonic hedgehog docking site in patched receptor correlate with patched expression and can be used to image patched in vivo. Further, our data suggest that radiolabeled peptides may enable us to examine the activity of the hedgehog signaling pathway and to evaluate response to anti-cancer therapies. Daniel Smith, Fanlin Kong, David Yang, Richard Larson, Jennifer Sims-Mourtada, and Wendy A. Woodward Copyright © 2014 Daniel Smith et al. All rights reserved. Highlighting the Structure-Function Relationship of the Brain with the Ising Model and Graph Theory Thu, 04 Sep 2014 00:00:00 +0000 With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model) or global dynamics (e.g., the Ising model) have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions. T. K. Das, P. M. Abeyasinghe, J. S. Crone, A. Sosnowski, S. Laureys, A. M. Owen, and A. Soddu Copyright © 2014 T. K. Das et al. All rights reserved. Design of CGMP Production of 18F- and 68Ga-Radiopharmaceuticals Tue, 02 Sep 2014 12:32:43 +0000 Objective. Radiopharmaceutical production process must adhere to current good manufacturing process (CGMP) compliance to ensure the quality of precursor, prodrug (active pharmaceutical ingredient, API), and the final drug product that meet acceptance criteria. We aimed to develop an automated system for production of CGMP grade of PET radiopharmaceuticals. Methods. The hardware and software of the automated synthesizer that fit in the hot cell under cGMP requirement were developed. Examples of production yield and purity for 68Ga-DOTATATE and 18F-FDG at CGMP facility were optimized. Analytical assays and acceptance criteria for cGMP grade of 68Ga-DOTATATE and 18F-FDG were established. Results. CGMP facility for the production of PET radiopharmaceuticals has been established. Radio-TLC and HPLC analyses of 68Ga-DOTATATE and 18F-FDG showed that the radiochemical purity was 92% and 96%, respectively. The products were sterile and pyrogenic-free. Conclusion. CGMP compliance of radiopharmaceuticals has been reviewed. 68Ga-DOTATATE and 18F-FDG were synthesized with high radiochemical yield under CGMP process. Yen-Ting Chi, Pei-Chun Chu, Hao-Yu Chao, Wei-Chen Shieh, and Chuck C. Chen Copyright © 2014 Yen-Ting Chi et al. All rights reserved. Abnormal Functional Resting-State Networks in ADHD: Graph Theory and Pattern Recognition Analysis of fMRI Data Sun, 31 Aug 2014 00:00:00 +0000 The framework of graph theory provides useful tools for investigating the neural substrates of neuropsychiatric disorders. Graph description measures may be useful as predictor variables in classification procedures. Here, we consider several centrality measures as predictor features in a classification algorithm to identify nodes of resting-state networks containing predictive information that can discriminate between typical developing children and patients with attention-deficit/hyperactivity disorder (ADHD). The prediction was based on a support vector machines classifier. The analyses were performed in a multisite and publicly available resting-state fMRI dataset of healthy children and ADHD patients: the ADHD-200 database. Network centrality measures contained little predictive information for the discrimination between ADHD patients and healthy subjects. However, the classification between inattentive and combined ADHD subtypes was more promising, achieving accuracies higher than 65% (balance between sensitivity and specificity) in some sites. Finally, brain regions were ranked according to the amount of discriminant information and the most relevant were mapped. As hypothesized, we found that brain regions in motor, frontoparietal, and default mode networks contained the most predictive information. We concluded that the functional connectivity estimations are strongly dependent on the sample characteristics. Thus different acquisition protocols and clinical heterogeneity decrease the predictive values of the graph descriptors. Anderson dos Santos Siqueira, Claudinei Eduardo Biazoli Junior, William Edgar Comfort, Luis Augusto Rohde, and João Ricardo Sato Copyright © 2014 Anderson dos Santos Siqueira et al. All rights reserved. Motion Freeze for Respiration Motion Correction in PET/CT: A Preliminary Investigation with Lung Cancer Patient Data Thu, 28 Aug 2014 15:05:43 +0000 Purpose. Respiratory motion presents significant challenges for accurate PET/CT. It often introduces apparent increase of lesion size, reduction of measured standardized uptake value (SUV), and the mismatch in PET/CT fusion images. In this study, we developed the motion freeze method to use 100% of the counts collected by recombining the counts acquired from all phases of gated PET data into a single 3D PET data, with correction of respiration by deformable image registration. Methods. Six patients with diagnosis of lung cancer confirmed by oncologists were recruited. PET/CT scans were performed with Discovery STE system. The 4D PET/CT with the Varian real-time position management for respiratory motion tracking was followed by a clinical 3D PET/CT scan procedure in the static mode. Motion freeze applies the deformation matrices calculated by optical flow method to generate a single 3D effective PET image using the data from all the 4D PET phases. Results. The increase in SUV and decrease in tumor size with motion freeze for all lesions compared to the results from 3D and 4D was observed in the preliminary data of lung cancer patients. In addition, motion freeze substantially reduced tumor mismatch between the CT image and the corresponding PET images. Conclusion. Motion freeze integrating 100% of the PET counts has the potential to eliminate the influences induced by respiratory motion in PET data. Tzung-Chi Huang, Kuei-Ting Chou, Yao-Ching Wang, and Geoffrey Zhang Copyright © 2014 Tzung-Chi Huang et al. All rights reserved. Radiofrequency Thermoablation of HCC Larger Than 3 cm and Less Than 5 cm Proximal to the Gallbladder without Gallbladder Isolation: A Single Center Experience Thu, 28 Aug 2014 07:04:08 +0000 Radiofrequency ablation (RFA) is an effective minimally invasive treatment for nonsurgical hepatocellular carcinoma (HCC), but ablation of tumors close to the gallbladder could be associated with several complications. We report our experience on the treatment of HCC close to the gallbladder with RFA. Eight RFA procedures were performed in eight patients with HCC larger than 3 cm and less than 5 cm close to the gallbladder. In all cases, a percutaneous approach was used. There were no major complications. Only in two patients a minimal wall thickening of the gallbladder was observed. Contrast enhanced computed tomography carried out after 30 days from the first procedure showed complete necrosis in seven patients (87%). Only one patient had local recurrence at 11 months of followup. Although limited, our experience suggests that, after careful preprocedural planning, in experienced hands and with appropriate technology, percutaneous RFA could be safely performed even for lesions larger than 3 cm located in close adjacency to the gallbladder. Antonio Orlacchio, Fabrizio Chegai, Costantino Del Giudice, Mariangela Massaccesi, Elisa Costanzo, Elena Di Caprera, and Giovanni Simonetti Copyright © 2014 Antonio Orlacchio et al. All rights reserved. Visual Learning Alters the Spontaneous Activity of the Resting Human Brain: An fNIRS Study Thu, 28 Aug 2014 00:00:00 +0000 Resting-state functional connectivity (RSFC) has been widely used to investigate spontaneous brain activity that exhibits correlated fluctuations. RSFC has been found to be changed along the developmental course and after learning. Here, we investigated whether and how visual learning modified the resting oxygenated hemoglobin (HbO) functional brain connectivity by using functional near-infrared spectroscopy (fNIRS). We demonstrate that after five days of training on an orientation discrimination task constrained to the right visual field, resting HbO functional connectivity and directed mutual interaction between high-level visual cortex and frontal/central areas involved in the top-down control were significantly modified. Moreover, these changes, which correlated with the degree of perceptual learning, were not limited to the trained left visual cortex. We conclude that the resting oxygenated hemoglobin functional connectivity could be used as a predictor of visual learning, supporting the involvement of high-level visual cortex and the involvement of frontal/central cortex during visual perceptual learning. Haijing Niu, Hao Li, Li Sun, Yongming Su, Jing Huang, and Yan Song Copyright © 2014 Haijing Niu et al. All rights reserved. New Imaging Strategies Using a Motion-Resistant Liver Sequence in Uncooperative Patients Wed, 27 Aug 2014 08:07:47 +0000 MR imaging has unique benefits for evaluating the liver because of its high-resolution capability and ability to permit detailed assessment of anatomic lesions. In uncooperative patients, motion artifacts can impair the image quality and lead to the loss of diagnostic information. In this setting, the recent advances in motion-resistant liver MR techniques, including faster imaging protocols (e.g., dual-echo magnetization-prepared rapid-acquisition gradient echo (MP-RAGE), view-sharing technique), the data under-sampling (e.g., gradient recalled echo (GRE) with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), single-shot echo-train spin-echo (SS-ETSE)), and motion-artifact minimization method (e.g., radial GRE with/without k-space-weighted image contrast (KWIC)), can provide consistent, artifact-free images with adequate image quality and can lead to promising diagnostic performance. Understanding of the different motion-resistant options allows radiologists to adopt the most appropriate technique for their clinical practice and thereby significantly improve patient care. Bong Soo Kim, Kyung Ryeol Lee, and Myeng Ju Goh Copyright © 2014 Bong Soo Kim et al. All rights reserved. In Vitro Demonstration of Focused Ultrasound Thrombolysis Using Bifrequency Excitation Wed, 27 Aug 2014 07:33:13 +0000 Focused ultrasound involving inertial cavitation has been shown to be an efficient method to induce thrombolysis without any pharmacological agent. However, further investigation of the mechanisms involved and further optimization of the process are still required. The present work aims at studying the relevance of a bifrequency excitation compared to a classical monofrequency excitation to achieve thrombolysis without any pharmacological agent. In vitro human blood clots were placed at the focus of a piezoelectric transducer. Efficiency of the thrombolysis was assessed by weighing each clot before and after sonication. The efficiencies of mono- (550 kHz) and bifrequency (535 and 565 kHz) excitations were compared for peak power ranging from 70 W to 220 W. The thrombolysis efficiency appears to be correlated to the inertial cavitation activity quantified by passive acoustic listening. In the conditions of the experiment, the power needed to achieve 80% of thrombolysis with a monofrequency excitation is reduced by the half with a bifrequency excitation. The thermal effects of bifrequency and monofrequency excitations, studied using MR thermometry measurements in turkey muscle samples where no cavitation occurred, did not show any difference between both types of excitations when using the same power level. Izella Saletes, Bruno Gilles, Vincent Auboiroux, Nadia Bendridi, Rares Salomir, and Jean-Christophe Béra Copyright © 2014 Izella Saletes et al. All rights reserved. CT Findings in Acute, Subacute, and Chronic Ischemic Colitis: Suggestions for Diagnosis Wed, 27 Aug 2014 06:45:06 +0000 Purpose. This paper aims at evaluating CT findings of occlusive and nonocclusive ischemic colitis (IC), in correlation with the etiology and the different phases of the disease. Materials and Methods. CT examination and clinical history of 32 patients with proven IC were retrospectively reviewed. The CT findings were analyzed according to the different phases of the disease (acute, subacute, and chronic). Results. Among the 32 CT examinations performed in the acute phase, 62.5% did not present signs of occlusion of the superior mesenteric artery (SMA) or inferior mesenteric artery (IMA), whereas IMA occlusion was detected in 37.5% of CT examinations. In the acute phase, the presence of pericolic fluid was found in 100% of patients undergoing progressive resorption from acute to subacute phase if an effective reperfusion occurred; the bowel wall thickening was observed in 28.1% patients in acute phase and in 86.4% patients evaluated in subacute phase. The unthickened colonic wall was found in all conditions where ischemia was not followed by effective reperfusion (71.9% of cases), and it was never found in chronic phase, when the colon appeared irregularly thickened. Conclusion. CT allows determining the morphofunctional alterations associated with the IC discriminating the occlusive forms from the nonocclusive forms. CT, furthermore, allows estimating the timing of ischemic damage. Francesca Iacobellis, Daniela Berritto, Dominik Fleischmann, Giuliano Gagliardi, Antonio Brillantino, Maria Antonietta Mazzei, and Roberto Grassi Copyright © 2014 Francesca Iacobellis et al. All rights reserved. Early Glottic Cancer: Role of MRI in the Preoperative Staging Thu, 14 Aug 2014 09:06:44 +0000 Introduction. Clinical staging is the most important time in management of glottic cancer in early stage (I-II). We have conducted a prospective study to evaluate if magnetic resonance imaging (MRI) is more accurate than computed tomography (CT) about tumoral extension, to exactly choose the most appropriate surgical approach, from organ preservation surgery to demolitive surgery. Materials and Methods. This prospective study was conducted on 26 male patients, with suspected laryngeal neoplasia of glottic region. The images of MRI and CT were analyzed to define the expansion of glottic lesion to anterior commissure, laryngeal cartilages, subglottic and/or supraglottic site, and paraglottic space. The results of MRI and CT were compared with each other and with the pathology report. Results. CT accuracy was 70% with low sensitivity but with high specific value. MRI showed a diagnostic accuracy in 80% of cases, with a sensitivity of 100% and high specificity. Statistical analysis showed that MRI has higher correlation than CT with the pathology report. Conclusion. Our study showed that MRI is more sensitive than CT in the preoperative staging of early glottic cancer, to select exactly the eligible patients in conservative surgery of the larynx, as supracricoid laryngectomy and cordectomy by CO2 laser. Eugenia Allegra, Pierpaolo Ferrise, Serena Trapasso, Orazio Trapuzzano, Antonio Barca, Stefania Tamburrini, and Aldo Garozzo Copyright © 2014 Eugenia Allegra et al. All rights reserved. CT Perfusion in the Characterisation of Renal Lesions: An Added Value to Multiphasic CT Wed, 13 Aug 2014 00:00:00 +0000 Objective. To prospectively evaluate if computed tomography perfusion (CTp) could be a useful tool in addition to multiphasic CT in renal lesion characterisation. Materials and Methods. Fifty-eight patients that were scheduled for surgical resection of a renal mass with a suspicion of renal cell carcinoma (RCC) were enrolled. Forty-one out of 58 patients underwent total or partial nephrectomy after CTp examination, and a pathological analysis was obtained for a total of 49 renal lesions. Perfusion parameters and attenuation values at multiphasic CT for both lesion and normal cortex were analysed. All the results were compared with the histological data obtained following surgery. Results. PS and MTT values were significantly lower in malignant lesions than in the normal cortex ( and , resp.); PS, MTT, and BF values were also statistically different between oncocytomas and malignant lesions. According to ROC analysis, the accuracy, sensitivity, and specificity to predict RCC were 95.92%, 100%, and 66.7%, respectively, for CTp whereas they were 89.80%, 93.35%, and 50%, respectively, for multiphasic CT. Conclusion. A significant difference between renal cortex and tumour CTp parameter values may suggest a malignant renal lesion. CTp could represent an added value to multiphasic CT in differentiating renal cells carcinoma from oncocytoma. Francesco Giuseppe Mazzei, Maria Antonietta Mazzei, Nevada Cioffi Squitieri, Chiara Pozzessere, Lorenzo Righi, Alfredo Cirigliano, Susanna Guerrini, Domenico D’Elia, Maria Raffaella Ambrosio, Aurora Barone, Maria Teresa del Vecchio, and Luca Volterrani Copyright © 2014 Francesco Giuseppe Mazzei et al. All rights reserved. Reduced Time CT Perfusion Acquisitions Are Sufficient to Measure the Permeability Surface Area Product with a Deconvolution Method Tue, 12 Aug 2014 00:00:00 +0000 Objective. To reduce the radiation dose, reduced time CT perfusion (CTp) acquisitions are tested to measure permeability surface (PS) with a deconvolution method. Methods and Materials. PS was calculated with repeated measurements while truncating the time density curve (TDC) at different time values in 14 CTp studies using CTp 4D software (GE Healthcare, Milwaukee, WI, US). The median acquisition time of CTp studies was 59.35 sec (range 49–92 seconds). To verify the accuracy of the deconvolution algorithm, a variation of the truncated PS within the error measurements was searched, that is, within 3 standard deviations from the mean nominal error provided by the software. The test was also performed for all the remaining CTp parameters measured. Results. PS maximum variability happened within 25 seconds. The PS became constant after 40 seconds for the majority of the active tumors (10/11), while for necrotic tissues it was consistent within 1% after 50 seconds. A consistent result lasted for all the observed CTp parameters, as expected from their analytical dependance. Conclusion. 40-second acquisition time could be an optimal compromise to obtain an accurate measurement of the PS and a reasonable dose exposure with a deconvolution method. Francesco Giuseppe Mazzei, Luca Volterrani, Susanna Guerrini, Nevada Cioffi Squitieri, Eleonora Sani, Gloria Bettini, Chiara Pozzessere, and Maria Antonietta Mazzei Copyright © 2014 Francesco Giuseppe Mazzei et al. All rights reserved. Development of a Hybrid Magnetic Resonance and Ultrasound Imaging System Thu, 07 Aug 2014 09:04:43 +0000 A system which allows magnetic resonance (MR) and ultrasound (US) image data to be acquired simultaneously has been developed. B-mode and Doppler US were performed inside the bore of a clinical 1.5 T MRI scanner using a clinical 1–4 MHz US transducer with an 8-metre cable. Susceptibility artefacts and RF noise were introduced into MR images by the US imaging system. RF noise was minimised by using aluminium foil to shield the transducer. A study of MR and B-mode US image signal-to-noise ratio (SNR) as a function of transducer-phantom separation was performed using a gel phantom. This revealed that a 4 cm separation between the phantom surface and the transducer was sufficient to minimise the effect of the susceptibility artefact in MR images. MR-US imaging was demonstrated in vivo with the aid of a 2 mm VeroWhite 3D-printed spherical target placed over the thigh muscle of a rat. The target allowed single-point registration of MR and US images in the axial plane to be performed. The system was subsequently demonstrated as a tool for the targeting and visualisation of high intensity focused ultrasound exposure in the rat thigh muscle. Victoria Sherwood, John Civale, Ian Rivens, David J. Collins, Martin O. Leach, and Gail R. ter Haar Copyright © 2014 Victoria Sherwood et al. All rights reserved. Patients with Poor Response to Antipsychotics Have a More Severe Pattern of Frontal Atrophy: A Voxel-Based Morphometry Study of Treatment Resistance in Schizophrenia Wed, 23 Jul 2014 11:05:22 +0000 Approximately 30% of schizophrenia patients do not respond adequately to the therapy. Previous MRI studies have suggested that drug treatment resistance is associated with brain morphological abnormalities, although region-of-interest analysis of MR studies from nonresponder and responder patients failed to demonstrate a statistically significant difference between these two schizophrenia subgroups. We have used a voxel-based analysis of segmented MR studies to assess structural cerebral differences in 20 nonresponder and 15 responder patients and 16 age-matched normal volunteers. Differences between the three groups emerged bilaterally mainly at the level of the superior and middle frontal gyri, primarily due to reduced grey matter volumes in nonresponders, as compared to both normal volunteers and responder patients. Post hoc direct comparison between the two schizophrenia subgroups demonstrated significantly reduced grey matter volumes in middle frontal gyrus bilaterally, in the dorsolateral aspects of left superior frontal gyrus extending into postcentral gyrus and in the right medial temporal cortex. Our results extend and integrate previous findings suggesting a more severe atrophy in nonresponder schizophrenia patients, compared to responder patients, mainly at the level of the superior and middle frontal gyri. Longitudinal studies in drug-naïve patients are needed to assess the role of these associations. Mario Quarantelli, Olga Palladino, Anna Prinster, Vittorio Schiavone, Barbara Carotenuto, Arturo Brunetti, Angela Marsili, Margherita Casiello, Giovanni Muscettola, Marco Salvatore, and Andrea de Bartolomeis Copyright © 2014 Mario Quarantelli et al. All rights reserved. Role of CT Perfusion in Monitoring and Prediction of Response to Therapy of Head and Neck Squamous Cell Carcinoma Mon, 21 Jul 2014 09:46:46 +0000 This review aims to summarize the technique and clinical applications of CT perfusion (CTp) of head and neck cancer. The most common pathologic type (90%) of head and neck cancer is squamous cell carcinoma (HNSCC): its diagnostic workup relies on CT and MRI, as they provide an accurate staging for the disease by determining tumour volume, assessing its extension, and detecting of lymph node metastases. Compared with conventional CT and MRI, CTp allows for obtaining measures of tumour vascular physiology and functional behaviour, and it has been demonstrated to be a feasible and useful tool in predicting local outcomes in patients undergoing radiation therapy and chemotherapy and may help monitor both treatments. Lorenzo Preda, Sonia Francesca Calloni, Marco Elvio Manlio Moscatelli, Maria Cossu Rocca, and Massimo Bellomi Copyright © 2014 Lorenzo Preda et al. All rights reserved. Alteration of Interictal Brain Activity in Patients with Temporal Lobe Epilepsy in the Left Dominant Hemisphere: A Resting-State MEG Study Mon, 21 Jul 2014 00:00:00 +0000 Resting MEG activities were compared between patients with left temporal lobe epilepsy (LTLE) and normal controls. Using SAMg2, the activities of MEG data were reconstructed and normalized. Significantly elevated SAMg2 signals were found in LTLE patients in the left temporal lobe and medial structures. Marked decreases of SAMg2 signals were found in the wide extratemporal lobe regions, such as the bilateral visual cortex. The study also demonstrated a positive correlation between the seizure frequency and brain activities of the abnormal regions after the multiple linear regression analysis. These results suggested that the aberrant brain activities not only were related to the epileptogenic zones, but also existed in other extratemporal regions in patients with LTLE. The activities of the aberrant regions could be further damaged with the increase of the seizure frequency. Our findings indicated that LTLE could be a multifocal disease, including complex epileptic networks and brain dysfunction networks. Haitao Zhu, Jinlong Zhu, Tiezhu Zhao, Yong Wu, Hongyi Liu, Ting Wu, Lu Yang, Yuanjie Zou, Rui Zhang, and Gang Zheng Copyright © 2014 Haitao Zhu et al. All rights reserved. Automated Synthesis of 18F-Fluoropropoxytryptophan for Amino Acid Transporter System Imaging Sun, 20 Jul 2014 11:19:02 +0000 Objective. This study was to develop a cGMP grade of [18F]fluoropropoxytryptophan (18F-FTP) to assess tryptophan transporters using an automated synthesizer. Methods. Tosylpropoxytryptophan (Ts-TP) was reacted with K18F/kryptofix complex. After column purification, solvent evaporation, and hydrolysis, the identity and purity of the product were validated by radio-TLC (1M-ammonium acetate : methanol = 4 : 1) and HPLC (C-18 column, methanol : water = 7 : 3) analyses. In vitro cellular uptake of 18F-FTP and 18F-FDG was performed in human prostate cancer cells. PET imaging studies were performed with 18F-FTP and 18F-FDG in prostate and small cell lung tumor-bearing mice (3.7 MBq/mouse, iv). Results. Radio-TLC and HPLC analyses of 18F-FTP showed that the Rf and Rt values were 0.9 and 9 min, respectively. Radiochemical purity was >99%. The radiochemical yield was 37.7% (EOS 90 min, decay corrected). Cellular uptake of 18F-FTP and 18F-FDG showed enhanced uptake as a function of incubation time. PET imaging studies showed that 18F-FTP had less tumor uptake than 18F-FDG in prostate cancer model. However, 18F-FTP had more uptake than 18F-FDG in small cell lung cancer model. Conclusion. 18F-FTP could be synthesized with high radiochemical yield. Assessment of upregulated transporters activity by 18F-FTP may provide potential applications in differential diagnosis and prediction of early treatment response. I-Hong Shih, Xu-Dong Duan, Fan-Lin Kong, Michael D. Williams, Kevin Yang, Yin-Han Zhang, and David J. Yang Copyright © 2014 I-Hong Shih et al. All rights reserved. Magnetic Resonance Imaging for the Normal Mesostenium and Involvement of the Mesostenium in Acute Pancreatitis Sun, 20 Jul 2014 09:11:45 +0000 The main point of this paper is to study MRI findings of the normal mesostenium and the involvement of the mesostenium in acute pancreatitis and to discuss the relationship between the involvement of the mesostenium and the severity of acute pancreatitis. In clinical practice, the mesenterical involvement in acute pancreatitis was often observed on MRI in daily works, which was little recorded in the reported studies. We conducted the current study to assess the mesenterical involvement in acute pancreatitis with MRI. We found that the mesenterical involvement of acute pancreatitis patients is common on MRI. The mesenterical involvement has a positive correlation with the MR severity index and the Acute Physiology and Chronic Healthy Evaluation II scoring system. It has been shown that MR can be used to visualize mesenterical involvement, which is a supplementary indicator in evaluating the severity of acute pancreatitis and local and systemic complications. Xiao Xiao Chi, Xiao Ming Zhang, Tian Wu Chen, Wei Tang, Bo Xiao, Yi Fan Ji, and Xiao Hua Huang Copyright © 2014 Xiao Xiao Chi et al. All rights reserved. Total Bolus Extraction Method Improves Arterial Image Quality in Dynamic CTAs Derived from Whole-Brain CTP Data Wed, 16 Jul 2014 11:54:55 +0000 Background and Purposes. The 320-detector row CT scanner enables visualization of whole-brain hemodynamic information (dynamic CT angiography (CTA) derived from CT perfusion scans). However, arterial image quality in dynamic CTA (dCTA) is inferior to arterial image quality in standard CTA. This study evaluates whether the arterial image quality can be improved by using a total bolus extraction (ToBE) method. Materials and Methods. DCTAs of 15 patients, who presented with signs of acute cerebral ischemia, were derived from 320-slice CT perfusion scans using both the standard subtraction method and the proposed ToBE method. Two neurointerventionalists blinded to the scan type scored the arterial image quality on a 5-point scale in the 4D dCTAs in consensus. Arteries were divided into four categories: (I) large extradural, (II) intradural (large, medium, and small), (III) communicating arteries, and (IV) cerebellar and ophthalmic arteries. Results. Quality of extradural and intradural arteries was significantly higher in the ToBE dCTAs than in the standard dCTAs (extradural , large intradural , medium intradural , and small intradural ). Conclusion. The 4D dCTAs derived with the total bolus extraction (ToBE) method provide hemodynamic information combined with improved arterial image quality as compared to standard 4D dCTAs. Elyas Ghariq, Adriënne M. Mendrik, Peter W. A. Willems, Raoul M. S. Joemai, Eidrees Ghariq, Evert-jan Vonken, Matthias J. P. van Osch, and Marianne A. A. van Walderveen Copyright © 2014 Elyas Ghariq et al. All rights reserved. KPG Index versus OPG Measurements: A Comparison between 3D and 2D Methods in Predicting Treatment Duration and Difficulty Level for Patients with Impacted Maxillary Canines Wed, 09 Jul 2014 13:26:36 +0000 Aim. The aim of this study was to test the agreement between orthopantomography (OPG) based 2D measurements and the KPG index, a new index based on 3D Cone Beam Computed Tomography (CBCT) images, in predicting orthodontic treatment duration and difficulty level of impacted maxillary canines. Materials and Methods. OPG and CBCT images of 105 impacted canines were independently scored by three orthodontists at and after 1 month (), using the KPG index and the following 2D methods: distance from cusp tip and occlusal plane, cusp tip position in relation to the lateral incisor, and canine inclination. Pearson’s coefficients were used to evaluate the degree of agreement and the with Yates correction test was used to assess the independence between them. Results. Inter- and intrarater reliability were higher with KPG compared to 2D methods. Pearson’s coefficients showed a statistically significant association between all the indexes, while the with Yates correction test resulted in a statistically significant rejection of independency only for one 2D index. Conclusions. 2D indexes for predicting impacted maxillary canines treatment duration and difficulty sometimes are discordant; a 3D index like the KPG index could be useful in solving these conflicts. Domenico Dalessandri, Marco Migliorati, Luca Visconti, Luca Contardo, Chung How Kau, and Conchita Martin Copyright © 2014 Domenico Dalessandri et al. All rights reserved. Therapeutic Potential of Tacrolimus on Acute Myocardial Infarction in Minipigs: Analysis with Serial Cardiac Magnetic Resonance and Changes at Histological and Protein Levels Wed, 09 Jul 2014 00:00:00 +0000 This study investigates the therapeutic potential of intracoronary tacrolimus against acute myocardial infarction (AMI) in minipigs with serial cardiac magnetic resonance (CMR) and changes at histological and protein levels. Twelve minipigs subjected to permanent left anterior descending artery ligation were randomized as tac-treated group (, with intracoronary tacrolimus treatment) and controls . CMR with cine and late gadolinium enhancement (LGE) studies were performed on postoperative days 2, 5, and 21. There were no significant differences in left ventricular function (LVF), contractility, and LGE between the two groups on day 2. On day 5, the tac-treated group showed a significantly higher ejection fraction, smaller infarct, and lower day-5/day-2 infarct ratio than controls. On day 21, the controls demonstrated further deterioration of LVF and infarct. Contrastingly, the tac-treated animals demonstrated preservation of LVF, contractility, significantly smaller infarct, and lower day-21/day-2 infarct ratios compared with those on day 5 and controls. The in vivo CMR results were correlated with in vitro findings on histology, immunostaining, and Western blotting which revealed significantly less fibrosis, higher vascularities, less CD68+ and CD40+ inflammatory cells, lower expressions of inflammatory (MMP-9, NF-B, and TNF-), and apoptotic (Bax, Caspase-3, c-PARP) biomarkers, respectively, in tac-treated AMI minipigs than controls. Sheung-Fat Ko, Hon-Kan Yip, Steve Leu, Chen-Chang Lee, Jiunn-Jye Sheu, Chia-Chang Lee, Shu-Hang Ng, Chung-Cheng Huang, Min-Chi Chen, and Cheuk-Kwan Sun Copyright © 2014 Sheung-Fat Ko et al. All rights reserved. A Low-Interaction Automatic 3D Liver Segmentation Method Using Computed Tomography for Selective Internal Radiation Therapy Thu, 03 Jul 2014 11:48:19 +0000 This study introduces a novel liver segmentation approach for estimating anatomic liver volumes towards selective internal radiation treatment (SIRT). The algorithm requires minimal human interaction since the initialization process to segment the entire liver in 3D relied on a single computed tomography (CT) slice. The algorithm integrates a localized contouring algorithm with a modified k-means method. The modified k-means segments each slice into five distinct regions belonging to different structures. The liver region is further segmented using localized contouring. The novelty of the algorithm is in the design of the initialization masks for region contouring to minimize human intervention. Intensity based region growing together with novel volume of interest (VOI) based corrections is used to accomplish the single slice initialization. The performance of the algorithm is evaluated using 34 liver CT scans. Statistical experiments were performed to determine consistency of segmentation and to assess user dependency on the initialization process. Volume estimations are compared to the manual gold standard. Results show an average accuracy of 97.22% for volumetric calculation with an average Dice coefficient of 0.92. Statistical tests show that the algorithm is highly consistent and independent of user initialization ( and Fleiss’ ). Mohammed Goryawala, Seza Gulec, Ruchir Bhatt, Anthony J. McGoron, and Malek Adjouadi Copyright © 2014 Mohammed Goryawala et al. All rights reserved. MR Imaging Findings in Alcoholic and Nonalcoholic Acute Wernicke’s Encephalopathy: A Review Tue, 24 Jun 2014 10:18:22 +0000 Wernicke’s encephalopathy (WE) is a severe neurological syndrome caused by thiamine (vitamin B1) deficiency and clinically characterized by the sudden onset of mental status changes, ocular abnormalities, and ataxia. Apart from chronic alcoholism, the most common cause of WE, a lot of other conditions causing malnutrition and decreasing thiamine absorption such as gastrointestinal surgical procedures and hyperemesis gravidarum must be considered as predisposing factors. Due to its low prevalence and clinical heterogeneity, WE is often misdiagnosed, leading to persistent dysfunctions and, in some cases, to death. Nowadays, MR imaging of the brain, showing T2 and FLAIR hyperintensities in typical (thalami, mammillary bodies, tectal plate, and periaqueductal area) and atypical areas (cerebellum, cranial nerve nuclei, and cerebral cortex), is surely the most important and effective tool in the diagnostic assessment of WE. The aim of this paper is to propose a state of the art of the role of MR imaging in the early diagnosis of this complex disease. Gaetana Manzo, Angela De Gennaro, Attilio Cozzolino, Antonietta Serino, Giacomo Fenza, and Andrea Manto Copyright © 2014 Gaetana Manzo et al. All rights reserved. Altered Modular Organization of Functional Connectivity Networks in Cirrhotic Patients without Overt Hepatic Encephalopathy Thu, 05 Jun 2014 14:14:52 +0000 Minimal hepatic encephalopathy (MHE) is associated with changes in functional connectivity. To investigate the patterns of modular changes of the functional connectivity in the progression of MHE, resting-state functional magnetic resonance imaging was acquired in 24 MHE patients, 31 cirrhotic patients without minimal hepatic encephalopathy (non-HE), and 38 healthy controls. Newman’s metric, the modularity value, was maximized and compared in three groups. Topological roles with the progression of MHE were illustrated by intra- and intermodular connectivity changes. Results showed that the value of MHE patients was significantly lower than that of controls rather than that of non-HE patients , which was correlated with neuropsychological test scores rather than the ammonia level and Child-Pugh score. Less intrasubcortical connections and more isolated subcortical modules were found with the progression of MHE. The non-HE patients had the same numbers of connect nodes as controls and had more hubs compared with MHE patients and healthy controls. Our findings supported that both intra- and intermodular connectivity, especially those related to subcortical regions, were continuously impaired in cirrhotic patients. The adjustments of hubs and connector nodes in non-HE patients could be a compensation for the decreased modularity in their functional connectivity networks. Gang Zheng, Liping Zhang, Long Jiang Zhang, Qiang Li, Zhiying Pan, Xue Liang, Donghong Shi, and Guang Ming Lu Copyright © 2014 Gang Zheng et al. All rights reserved. Biomedical Imaging: Role and Opportunities of Medical Imaging in the “Omics” Era Wed, 04 Jun 2014 09:31:26 +0000 Tzu-Chen Yen, Dimitris Visvikis, Tinsu Pan, and Yu-Hua Dean Fang Copyright © 2014 Tzu-Chen Yen et al. All rights reserved. Intrinsic Functional Connectivity Networks in Healthy Elderly Subjects: A Multiparametric Approach with Structural Connectivity Analysis Thu, 29 May 2014 16:16:34 +0000 Intrinsic functional connectivity magnetic resonance imaging (iFCMRI) provides an encouraging approach for mapping large-scale intrinsic connectivity networks (ICNs) in the “resting” brain. Structural connections as measured by diffusion tensor imaging (DTI) are a major constraint on the identified ICNs. This study aimed at the combined investigation of ten well-defined ICNs in healthy elderly subjects at single subject level as well as at the group level, together with the underlying structural connectivity. IFCMRI and DTI data were acquired in twelve subjects (68 ± 7 years) at a 3T scanner and were studied using the tensor imaging and fiber tracking software package. The seed-based iFCMRI analysis approach was comprehensively performed with DTI analysis, following standardized procedures including an 8-step processing of iFCMRI data. Our findings demonstrated robust ICNs at the single subject level and conclusive brain maps at the group level in the healthy elderly sample, supported by the complementary fiber tractography. The findings demonstrated here provide a methodological framework for future comparisons of pathological (e.g., neurodegenerative) conditions with healthy controls on the basis of multiparametric functional connectivity mapping. Martin Gorges, Hans-Peter Müller, Albert C. Ludolph, Volker Rasche, and Jan Kassubek Copyright © 2014 Martin Gorges et al. All rights reserved. Advances in Miniaturized Instruments for Genomics Thu, 29 May 2014 07:41:01 +0000 In recent years, a lot of demonstrations of the miniaturized instruments were reported for genomic applications. They provided the advantages of miniaturization, automation, sensitivity, and specificity for the development of point-of-care diagnostics. The aim of this paper is to report on recent developments on miniaturized instruments for genomic applications. Based on the mature development of microfabrication, microfluidic systems have been demonstrated for various genomic detections. Since one of the objectives of miniaturized instruments is for the development of point-of-care device, impedimetric detection is found to be a promising technique for this purpose. An in-depth discussion of the impedimetric circuits and systems will be included to provide total consideration of the miniaturized instruments and their potential application towards real-time portable imaging in the “-omics” era. The current excellent demonstrations suggest a solid foundation for the development of practical and widespread point-of-care genomic diagnostic devices. Cihun-Siyong Alex Gong and Kin Fong Lei Copyright © 2014 Cihun-Siyong Alex Gong and Kin Fong Lei. All rights reserved. Considering Angle Selection When Using Ultrasound Electrode Displacement Elastography to Evaluate Radiofrequency Ablation of Tissues Tue, 27 May 2014 06:35:41 +0000 Percutaneous radiofrequency ablation (RFA) is a minimally invasive treatment to thermally destroy tumors. Ultrasound-based electrode-displacement elastography is an emerging technique for evaluating the region of RFA-induced lesions. The angle between the imaging probe and the RFA electrode can influence electrode-displacement elastography when visualizing the ablation zone. We explored the angle effect on electrode-displacement elastography to measure the ablation zone. Phantoms embedded with meatballs were fabricated and then ablated using an RFA system to simulate RFA-induced lesions. For each phantom, a commercial ultrasound scanner with a 7.5 MHz linear probe was used to acquire raw image data at different angles, ranging from 30° to 90° at increments of 10°, to construct electrode-displacement images and facilitate comparisons with tissue section images. The results revealed that the ablation regions detected using electrode-displacement elastography were highly correlated with those from tissue section images when the angle was between 30° and 60°. However, the boundaries of lesions were difficult to distinguish, when the angle was larger than 60°. The experimental findings suggest that angle selection should be considered to achieve reliable electrode-displacement elastography to describe ablation zones. Jingjing Xia, Qiang Li, Pin-Yu Chen, Zhuhuang Zhou, Chiao-Yin Wang, Hao-Li Liu, Jianfu Teng, and Po-Hsiang Tsui Copyright © 2014 Jingjing Xia et al. All rights reserved. A Functional Polymorphism of the MAOA Gene Modulates Spontaneous Brain Activity in Pons Sun, 25 May 2014 12:31:18 +0000 Objective. To investigate the effects of a functional polymorphism of the monoamine oxidase A (MAOA) gene on spontaneous brain activity in healthy male adolescents. Methods. Thirty-one healthy male adolescents with the low-activity MAOA genotype (MAOA-L) and 25 healthy male adolescents with the high-activity MAOA genotype (MAOA-H) completed the 11-item Barratt Impulsiveness Scale (BIS-11) questionnaire and were subjected to resting-state functional magnetic resonance imaging (rs-fMRI) scans. The amplitude of low-frequency fluctuation (ALFF) of the blood oxygen level-dependent (BOLD) signal was calculated using REST software. ALFF data were related to BIS scores and compared between genotype groups. Results. Compared with the MAOA-H group, the MAOA-L group showed significantly lower ALFFs in the pons. There was a significant correlation between the BIS scores and the ALFF values in the pons for MAOA-L group, but not for the MAOA-H group. Further regression analysis showed a significant genotype by ALFF values interaction effect on BIS scores. Conclusions. Lower spontaneous brain activity in the pons of the MAOA-L male adolescents may provide a neural mechanism by which boys with the MAOA-L genotype confers risk for impulsivity and aggression. Hui Lei, Xiaocui Zhang, Xin Di, Hengyi Rao, Qingsen Ming, Jibiao Zhang, Xiao Guo, Yali Jiang, Yidian Gao, Jinyao Yi, Xiongzhao Zhu, and Shuqiao Yao Copyright © 2014 Hui Lei et al. All rights reserved. A Novel Method for Intraoral Access to the Superior Head of the Human Lateral Pterygoid Muscle Sun, 18 May 2014 00:00:00 +0000 Background. The uncoordinated activity of the superior and inferior parts of the lateral pterygoid muscle (LPM) has been suggested to be one of the causes of temporomandibular joint (TMJ) disc displacement. A therapy for this muscle disorder is the injection of botulinum toxin (BTX), of the LPM. However, there is a potential risk of side effects with the injection guide methods currently available. In addition, they do not permit appropriate differentiation between the two bellies of the muscle. Herein, a novel method is presented to provide intraoral access to the superior head of the human LPM with maximal control and minimal hazards. Methods. Computational tomography along with digital imaging software programs and rapid prototyping techniques were used to create a rapid prototyped guide to orient BTX injections in the superior LPM. Results. The method proved to be feasible and reliable. Furthermore, when tested in one volunteer it allowed precise access to the upper head of LPM, without producing side effects. Conclusions. The prototyped guide presented in this paper is a novel tool that provides intraoral access to the superior head of the LPM. Further studies will be necessary to test the efficacy and validate this method in a larger cohort of subjects. Aleli Tôrres Oliveira, Anderson Aparecido Camilo, Paulo Roberto Valle Bahia, Antonio Carlos Pires Carvalho, Marcos Fabio DosSantos, Jorge Vicente Lopes da Silva, and André Antonio Monteiro Copyright © 2014 Aleli Tôrres Oliveira et al. All rights reserved. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling Thu, 15 May 2014 15:27:47 +0000 To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values. Xiufeng Li, Subhendra N. Sarkar, David E. Purdy, and Richard W. Briggs Copyright © 2014 Xiufeng Li et al. All rights reserved. Tract-Based Spatial Statistics: Application to Mild Cognitive Impairment Mon, 12 May 2014 10:12:55 +0000 Rationale and Objectives. The primary objective of the current investigation was to characterize white matter integrity in different subtypes of mild cognitive impairment (MCI) using tract-based spatial statistics of diffusion tensor imaging. Materials and Methods. The study participants were divided into 4 groups of 30 subjects each as follows: cognitively healthy controls, amnestic MCI, dysexecutive MCI, and Alzheimer’s disease (AD). All subjects underwent a comprehensive neuropsychological assessment, apolipoprotein E genotyping, and 3-tesla MRI. The diffusion tensor was reconstructed and then analyzed using tract-based spatial statistics. The changes in brain white matter tracts were also examined according to the apolipoprotein E ε4 status. Results. Compared with controls, amnestic MCI patients showed significant differences in the cerebral white matter, where changes were consistently detectable in the frontal and parietal lobes. We found a moderate impact of the apolipoprotein E ε4 status on the extent of white matter disruption in the amnestic MCI group. Patients with AD exhibited similar but more extensive alterations, while no significant changes were observed in dysexecutive MCI patients. Conclusion. The results from this study indicate that amnestic MCI is the most likely precursor to AD as both conditions share significant white matter damage. By contrast, dysexecutive MCI seems to be characterized by a distinct pathogenesis. Yau-Yau Wai, Wen-Chuin Hsu, Hon-Chung Fung, Jiann-Der Lee, Hsiao-Lung Chan, Ming-Lun Tsai, Yu-Chun Lin, Yih-Ru Wu, Leslie Ying, and Jiun-Jie Wang Copyright © 2014 Yau-Yau Wai et al. All rights reserved. Figure of Image Quality and Information Capacity in Digital Mammography Thu, 08 May 2014 12:49:36 +0000 Objectives. In this work, a simple technique to assess the image quality characteristics of the postprocessed image is developed and an easy to use figure of image quality (FIQ) is introduced. This FIQ characterizes images in terms of resolution and noise. In addition information capacity, defined within the context of Shannon’s information theory, was used as an overall image quality index. Materials and Methods. A digital mammographic image was postprocessed with three digital filters. Resolution and noise were calculated via the Modulation Transfer Function (MTF), the coefficient of variation, and the figure of image quality. In addition, frequency dependent parameters such as the noise power spectrum (NPS) and noise equivalent quanta (NEQ) were estimated and used to assess information capacity. Results. FIQs for the “raw image” data and the image processed with the “sharpen edges” filter were found 907.3 and 1906.1, correspondingly. The information capacity values were and  bits/mm2. Conclusion. It was found that, after the application of the postprocessing techniques (even commercial nondedicated software) on the raw digital mammograms, MTF, NPS, and NEQ are improved for medium to high spatial frequencies leading to resolving smaller structures in the final image. Christos M. Michail, Nektarios E. Kalyvas, Ioannis G. Valais, Ioannis P. Fudos, George P. Fountos, Nikos Dimitropoulos, Grigorios Koulouras, Dionisis Kandris, Maria Samarakou, and Ioannis S. Kandarakis Copyright © 2014 Christos M. Michail et al. All rights reserved. Evaluation of Inhibitory Effect of Recreational Drugs on Dopaminergic Terminal Neuron by PET and Whole-Body Autoradiography Tue, 29 Apr 2014 11:02:36 +0000 There is little investigation for the functional roles of peripheral dopamine. [18F]FDOPA has been used in cancer imaging (i.e., neuroendocrine and tumors pancreatic tumors) and neuroimaging (i.e., Parkinson’s disease and Huntington’s disease). Here, we accessed side effects of recreational drugs such as ketamine, cocaine, and methamphetamine on dopamine neurons in peripheral organs by using positron emission tomography (PET) imaging and quantitative whole-body autoradiography (QWBAR) with [18F]FDOPA. The images were applied for the measurement of specific binding ratios (SBRs) of striatum with the cerebellum as the reference region. Clear striatal [18F]FDOPA-derived radioactivity was observed. Moderate level of radiotracer accumulation was presented in the mucosal layers of the stomach and small intestine. The medulla layers of kidney had higher radioactivity than that of the cortex. Blocking images markedly eliminated the specific binding of [18F]FDOPA in the striatum and in peripheral organs such as stomachs, intestines, and kidney. Ketamine showed the highest inhibitory effect on striatal [18F]FDOPA-derived radioactivity followed by cocaine and methamphetamine. The current results demonstrated a useful crossing-validating tool that enhances the capability of [18F]FDOPA for further investigations of the alteration of dopaminergic neurons in the brain disorder or cancer diseases in peripheral tissues. Skye Hsin-Hsien Yeh, Ming-Hsien Lin, Fan-Lin Kong, Chi-Wei Chang, Li-Chung Hwang, Chien-Feng Lin, Jeng-Jong Hwang, and Ren-Shyan Liu Copyright © 2014 Skye Hsin-Hsien Yeh et al. All rights reserved. Early Treatment Response Monitoring Using 2-Deoxy-2-[18F]fluoro-D-glucose Positron Emission Tomography Imaging during Fractionated Radiotherapy of Head Neck Cancer Xenografts Mon, 28 Apr 2014 09:24:38 +0000 Background. To determine the optimal timing and analytic method of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (PET) imaging during fractionated radiotherapy (RT) to predict tumor control. Methods. Ten head neck squamous cell carcinoma xenografts derived from the UT-14-SCC cell line were irradiated with 50 Gy at 2 Gy per day over 5 weeks. Dynamic PET scans were acquired over 70 minutes at baseline (week 0) and weekly for seven weeks. PET data were analyzed using standard uptake value (SUV), retention index (RI), sensitivity factor (SF), and kinetic index (Ki). Results. Four xenografts had local failure (LF) and 6 had local control. Eighty scans from week 0 to week 7 were analyzed. RI and SF after 10 Gy appeared to be the optimal predictors for LF. In contrast, SUV and Ki during RT were not significant predictors for LF. Conclusion. RI and SF of PET obtained after the first week of fractionated RT were the optimal methods and timing to predict tumor control. Jiayi Huang, John L. Chunta, Mitual Amin, David Y. Lee, Inga S. Grills, Ching-Yee Oliver Wong, Brian Marples, Di Yan, and George D. Wilson Copyright © 2014 Jiayi Huang et al. All rights reserved. GRE T2-Weighted MRI: Principles and Clinical Applications Wed, 16 Apr 2014 13:39:56 +0000 The sequence of a multiecho gradient recalled echo (GRE) T2-weighted imaging (T2WI) is a relatively new magnetic resonance imaging (MRI) technique. In contrast to T2 relaxation, which acquires a spin echo signal, T2 relaxation acquires a gradient echo signal. The sequence of a GRE T2WI requires high uniformity of the magnetic field. GRE T2WI can detect the smallest changes in uniformity in the magnetic field and can improve the rate of small lesion detection. In addition, the T2 value can indirectly reflect changes in tissue biochemical components. Moreover, it can be used for the early diagnosis and quantitative diagnosis of some diseases. This paper reviews the principles and clinical applications as well as the advantages and disadvantages of GRE T2WI. Meng Yue Tang, Tian Wu Chen, Xiao Ming Zhang, and Xiao Hua Huang Copyright © 2014 Meng Yue Tang et al. All rights reserved. The Role of Imaging in Radiation Therapy Planning: Past, Present, and Future Thu, 10 Apr 2014 06:44:02 +0000 The use of ionizing radiation for cancer treatment has undergone extraordinary development during the past hundred years. The advancement of medical imaging has been critical in helping to achieve this change. The invention of computed tomography (CT) was pivotal in the development of treatment planning. Despite some disadvantages, CT remains the only three-dimensional imaging modality used for dose calculation. Newer image modalities, such as magnetic resonance (MR) imaging and positron emission tomography (PET), are also used secondarily in the treatment-planning process. MR, with its better tissue contrast and resolution than those of CT, improves tumor definition compared with CT planning alone. PET also provides metabolic information to supplement the CT and MR anatomical information. With emerging molecular imaging techniques, the ability to visualize and characterize tumors with regard to their metabolic profile, active pathways, and genetic markers, both across different tumors and within individual, heterogeneous tumors, will inform clinicians regarding the treatment options most likely to benefit a patient and to detect at the earliest time possible if and where a chosen therapy is working. In the post-human-genome era, multimodality scanners such as PET/CT and PET/MR will provide optimal tumor targeting information. Gisele C. Pereira, Melanie Traughber, and Raymond F. Muzic Jr. Copyright © 2014 Gisele C. Pereira et al. All rights reserved. Rational Design of a Triple Reporter Gene for Multimodality Molecular Imaging Mon, 07 Apr 2014 12:31:51 +0000 Multimodality imaging using noncytotoxic triple fusion (TF) reporter genes is an important application for cell-based tracking, drug screening, and therapy. The firefly luciferase (fl), monomeric red fluorescence protein (mrfp), and truncated herpes simplex virus type 1 thymidine kinase SR39 mutant (ttksr39) were fused together to create TF reporter gene constructs with different order. The enzymatic activities of TF protein in vitro and in vivo were determined by luciferase reporter assay, -FEAU cellular uptake experiment, bioluminescence imaging, and micropositron emission tomography (microPET). The TF construct expressed in H1299 cells possesses luciferase activity and red fluorescence. The tTKSR39 activity is preserved in TF protein and mediates high levels of -FEAU accumulation and significant cell death from ganciclovir (GCV) prodrug activation. In living animals, the luciferase and tTKSR39 activities of TF protein have also been successfully validated by multimodality imaging systems. The red fluorescence signal is relatively weak for in vivo imaging but may expedite FACS-based selection of TF reporter expressing cells. We have developed an optimized triple fusion reporter construct DsRedm-fl-ttksr39 for more effective and sensitive in vivo animal imaging using fluorescence, bioluminescence, and PET imaging modalities, which may facilitate different fields of biomedical research and applications. Ya-Ju Hsieh, Luen Hwu, Chien-Chih Ke, Skye Hsin-Hsien Yeh, Chien-Feng Lin, Fu-Du Chen, Hsin-Ell Wang, Kang-Ping Lin, Ran-Chou Chen, and Ren-Shyan Liu Copyright © 2014 Ya-Ju Hsieh et al. All rights reserved. Acute Ethanol-Induced Changes in Edema and Metabolite Concentrations in Rat Brain Tue, 25 Mar 2014 09:10:25 +0000 The aim of this study is to describe the acute effects of EtOH on brain edema and cerebral metabolites, using diffusion weight imaging (DWI) and proton magnetic resonance spectroscopy (1H-MRS) at a 7.0T MR and to define changes in apparent diffusion coefficient (ADC) values and the concentration of metabolites in the rat brain after acute EtOH intoxication. ADC values in each ROI decreased significantly at 1 h and 3 h after ethanol administration. ADC values in frontal lobe were decreased significantly compared with other regions at 3 h. For EtOH/Cr+PCr and cerebral metabolites (Cho, Tau, and Glu) differing over time, no significant differences for Ins, NAA, and Cr were observed in frontal lobes. Regression analysis revealed a significant association between TSEtOH/Cr+PCr and TSCho, TSTau, TSGlu, and TSADC. The changes of ADC values in different brain regions reflect the process of the cytotoxic edema in vivo. The characterization of frontal lobes metabolites changes and the correlations between TSEtOH/Cr+PCr and TSCho, TSTau, and TSGlu provide a better understanding for the biological mechanisms in neurotoxic effects of EtOH on the brain. In addition, the correlations between TSEtOH/Cr+PCr and TSADC will help us to understand development of the ethanol-induced brain cytotoxic edema. Huimin Liu, Wenbin Zheng, Gen Yan, Baoguo Liu, Lingmei Kong, Yan Ding, Zhiwei Shen, Hui Tan, and Guishan Zhang Copyright © 2014 Huimin Liu et al. All rights reserved. Development and Evaluation of an Open-Source Software Package “CGITA” for Quantifying Tumor Heterogeneity with Molecular Images Mon, 17 Mar 2014 08:18:09 +0000 Background. The quantification of tumor heterogeneity with molecular images, by analyzing the local or global variation in the spatial arrangements of pixel intensity with texture analysis, possesses a great clinical potential for treatment planning and prognosis. To address the lack of available software for computing the tumor heterogeneity on the public domain, we develop a software package, namely, Chang-Gung Image Texture Analysis (CGITA) toolbox, and provide it to the research community as a free, open-source project. Methods. With a user-friendly graphical interface, CGITA provides users with an easy way to compute more than seventy heterogeneity indices. To test and demonstrate the usefulness of CGITA, we used a small cohort of eighteen locally advanced oral cavity (ORC) cancer patients treated with definitive radiotherapies. Results. In our case study of ORC data, we found that more than ten of the current implemented heterogeneity indices outperformed SUVmean for outcome prediction in the ROC analysis with a higher area under curve (AUC). Heterogeneity indices provide a better area under the curve up to 0.9 than the SUVmean and TLG (0.6 and 0.52, resp.). Conclusions. CGITA is a free and open-source software package to quantify tumor heterogeneity from molecular images. CGITA is available for free for academic use at Yu-Hua Dean Fang, Chien-Yu Lin, Meng-Jung Shih, Hung-Ming Wang, Tsung-Ying Ho, Chun-Ta Liao, and Tzu-Chen Yen Copyright © 2014 Yu-Hua Dean Fang et al. All rights reserved. Pushing CT and MR Imaging to the Molecular Level for Studying the “Omics”: Current Challenges and Advancements Thu, 13 Mar 2014 09:48:00 +0000 During the past decade, medical imaging has made the transition from anatomical imaging to functional and even molecular imaging. Such transition provides a great opportunity to begin the integration of imaging data and various levels of biological data. In particular, the integration of imaging data and multiomics data such as genomics, metabolomics, proteomics, and pharmacogenomics may open new avenues for predictive, preventive, and personalized medicine. However, to promote imaging-omics integration, the practical challenge of imaging techniques should be addressed. In this paper, we describe key challenges in two imaging techniques: computed tomography (CT) and magnetic resonance imaging (MRI) and then review existing technological advancements. Despite the fact that CT and MRI have different principles of image formation, both imaging techniques can provide high-resolution anatomical images while playing a more and more important role in providing molecular information. Such imaging techniques that enable single modality to image both the detailed anatomy and function of tissues and organs of the body will be beneficial in the imaging-omics field. Hsuan-Ming Huang and Yi-Yu Shih Copyright © 2014 Hsuan-Ming Huang and Yi-Yu Shih. All rights reserved. Automatic Detection and Quantification of Acute Cerebral Infarct by Fuzzy Clustering and Histographic Characterization on Diffusion Weighted MR Imaging and Apparent Diffusion Coefficient Map Wed, 12 Mar 2014 16:58:04 +0000 Determination of the volumes of acute cerebral infarct in the magnetic resonance imaging harbors prognostic values. However, semiautomatic method of segmentation is time-consuming and with high interrater variability. Using diffusion weighted imaging and apparent diffusion coefficient map from patients with acute infarction in 10 days, we aimed to develop a fully automatic algorithm to measure infarct volume. It includes an unsupervised classification with fuzzy C-means clustering determination of the histographic distribution, defining self-adjusted intensity thresholds. The proposed method attained high agreement with the semiautomatic method, with similarity index 89.9 ± 6.5%, in detecting cerebral infarct lesions from 22 acute stroke patients. We demonstrated the accuracy of the proposed computer-assisted prompt segmentation method, which appeared promising to replace the laborious, time-consuming, and operator-dependent semiautomatic segmentation. Jang-Zern Tsai, Syu-Jyun Peng, Yu-Wei Chen, Kuo-Wei Wang, Hsiao-Kuang Wu, Yun-Yu Lin, Ying-Ying Lee, Chi-Jen Chen, Huey-Juan Lin, Eric Edward Smith, Poh-Shiow Yeh, and Yue-Loong Hsin Copyright © 2014 Jang-Zern Tsai et al. All rights reserved. Current Opportunities and Challenges of Magnetic Resonance Spectroscopy, Positron Emission Tomography, and Mass Spectrometry Imaging for Mapping Cancer Metabolism In Vivo Mon, 03 Mar 2014 00:00:00 +0000 Cancer is known to have unique metabolic features such as Warburg effect. Current cancer therapy has moved forward from cytotoxic treatment to personalized, targeted therapies, with some that could lead to specific metabolic changes, potentially monitored by imaging methods. In this paper we addressed the important aspects to study cancer metabolism by using image techniques, focusing on opportunities and challenges of magnetic resonance spectroscopy (MRS), dynamic nuclear polarization (DNP)-MRS, positron emission tomography (PET), and mass spectrometry imaging (MSI) for mapping cancer metabolism. Finally, we highlighted the future possibilities of an integrated in vivo PET/MR imaging systems, together with an in situ MSI tissue analytical platform, may become the ultimate technologies for unraveling and understanding the molecular complexities in some aspects of cancer metabolism. Such comprehensive imaging investigations might provide information on pharmacometabolomics, biomarker discovery, and disease diagnosis, prognosis, and treatment response monitoring for clinical medicine. Gigin Lin and Yuen-Li Chung Copyright © 2014 Gigin Lin and Yuen-Li Chung. All rights reserved. Establishment of a Swine Model for Validation of Perfusion Measurement by Dynamic Contrast-Enhanced Magnetic Resonance Imaging Thu, 27 Feb 2014 06:39:47 +0000 The aim of the study was to develop a suitable animal model for validating dynamic contrast-enhanced magnetic resonance imaging perfusion measurements. A total of 8 pigs were investigated by DCE-MRI. Perfusion was determined on the hind leg musculature. An ultrasound flow probe placed around the femoral artery provided flow measurements independent of MRI and served as the standard of reference. Images were acquired on a 1.5 T MRI scanner using a 3D T1-weighted gradient-echo sequence. An arterial catheter for local injection was implanted in the femoral artery. Continuous injection of adenosine for vasodilation resulted in steady blood flow levels up to four times the baseline level. In this way, three different stable perfusion levels were induced and measured. A central venous catheter was used for injection of two different types of contrast media. A low-molecular weight contrast medium and a blood pool contrast medium were used. A total of 6 perfusion measurements were performed with a time interval of about 20–25 min without significant differences in the arterial input functions. In conclusion the accuracy of DCE-MRI-based perfusion measurement can be validated by comparison of the integrated perfusion signal of the hind leg musculature with the blood flow values measured with the ultrasound flow probe around the femoral artery. Anika Sauerbrey, Stefan Hindel, Marc Maaß, Christine Krüger, Andreas Wissmann, Martin Kramer, Benno Nafz, and Lutz Lüdemann Copyright © 2014 Anika Sauerbrey et al. All rights reserved. Performance Enhancement of a Web-Based Picture Archiving and Communication System Using Commercial Off-the-Shelf Server Clusters Thu, 20 Feb 2014 16:42:29 +0000 The rapid development of picture archiving and communication systems (PACSs) thoroughly changes the way of medical informatics communication and management. However, as the scale of a hospital’s operations increases, the large amount of digital images transferred in the network inevitably decreases system efficiency. In this study, a server cluster consisting of two server nodes was constructed. Network load balancing (NLB), distributed file system (DFS), and structured query language (SQL) duplication services were installed. A total of 1 to 16 workstations were used to transfer computed radiography (CR), computed tomography (CT), and magnetic resonance (MR) images simultaneously to simulate the clinical situation. The average transmission rate (ATR) was analyzed between the cluster and noncluster servers. In the download scenario, the ATRs of CR, CT, and MR images increased by 44.3%, 56.6%, and 100.9%, respectively, when using the server cluster, whereas the ATRs increased by 23.0%, 39.2%, and 24.9% in the upload scenario. In the mix scenario, the transmission performance increased by 45.2% when using eight computer units. The fault tolerance mechanisms of the server cluster maintained the system availability and image integrity. The server cluster can improve the transmission efficiency while maintaining high reliability and continuous availability in a healthcare environment. Yan-Lin Liu, Cheng-Ting Shih, Yuan-Jen Chang, Shu-Jun Chang, and Jay Wu Copyright © 2014 Yan-Lin Liu et al. All rights reserved. Respiratory-Gated MRgHIFU in Upper Abdomen Using an MR-Compatible In-Bore Digital Camera Wed, 29 Jan 2014 13:31:41 +0000 Objective. To demonstrate the technical feasibility and the potential interest of using a digital optical camera inside the MR magnet bore for monitoring the breathing cycle and subsequently gating the PRFS MR thermometry, MR-ARFI measurement, and MRgHIFU sonication in the upper abdomen. Materials and Methods. A digital camera was reengineered to remove its magnetic parts and was further equipped with a 7 m long USB cable. The system was electromagnetically shielded and operated inside the bore of a closed 3T clinical scanner. Suitable triggers were generated based on real-time motion analysis of the images produced by the camera (resolution pixels, 30 fps). Respiratory-gated MR-ARFI prepared MRgHIFU ablation was performed in the kidney and liver of two sheep in vivo, under general anaesthesia and ventilator-driven forced breathing. Results. The optical device demonstrated very good MR compatibility. The current setup permitted the acquisition of motion artefact-free and high resolution MR 2D ARFI and multiplanar interleaved PRFS thermometry (average SNR 30 in liver and 56 in kidney). Microscopic histology indicated precise focal lesions with sharply delineated margins following the respiratory-gated HIFU sonications. Conclusion. The proof-of-concept for respiratory motion management in MRgHIFU using an in-bore digital camera has been validated in vivo. Vincent Auboiroux, Lorena Petrusca, Magalie Viallon, Arnaud Muller, Sylvain Terraz, Romain Breguet, Xavier Montet, Christoph D. Becker, and Rares Salomir Copyright © 2014 Vincent Auboiroux et al. All rights reserved. Differential Regulation of Ferritin Subunits and Iron Transport Proteins: An Effect of Targeted Hepatic X-Irradiation Thu, 12 Dec 2013 08:57:05 +0000 The current study aimed to investigate radiation-induced regulation of iron proteins including ferritin subunits in rats. Rat livers were selectively irradiated in vivo at 25 Gy. This dose can be used to model radiation effects to the liver without inducing overt radiation-induced liver disease. Sham-irradiated rats served as controls. Isolated hepatocytes were irradiated at 8 Gy. Ferritin light polypeptide (FTL) was detectable in the serum of sham-irradiated rats with an increase after irradiation. Liver irradiation increased hepatic protein expression of both ferritin subunits. A rather early increase (3 h) was observed for hepatic TfR1 and Fpn-1 followed by a decrease at 12 h. The increase in TfR2 persisted over the observed time. Parallel to the elevation of AST levels, a significant increase (24 h) in hepatic iron content was measured. Complete blood count analysis showed a significant decrease in leukocyte number with an early increase in neutrophil granulocytes and a decrease in lymphocytes. In vitro, a significant increase in ferritin subunits at mRNA level was detected after irradiation which was further induced with a combination treatment of irradiation and acute phase cytokine. Irradiation can directly alter the expression of ferritin subunits and this response can be strongly influenced by radiation-induced proinflammatory cytokines. FTL can be used as a serum marker for early phase radiation-induced liver damage. Naila Naz, Shakil Ahmad, Silke Cameron, Federico Moriconi, Margret Rave-Fränk, Hans Christiansen, Clemens Friedrich Hess, Giuliano Ramadori, and Ihtzaz A. Malik Copyright © 2013 Naila Naz et al. All rights reserved. The Importance and Perspective of Magnetic Resonance Imaging in the Evaluation of Endometriosis Wed, 20 Nov 2013 15:00:32 +0000 MR imaging is becoming increasingly important in the assessment of patients with endometriosis. Its multiplanar capabilities and superior soft tissue contrast are particularly useful in the detection of deep infiltrating endometriotic implants. Endometriosis, defined as the presence of endometrial glands and stroma outside the endometrium, is among the most common gynaecological disorders affecting women in their reproductive age. The diagnosis and evaluation of the extension of endometriosis are difficult only with physical examination and laparoscopy. According to the authors’ personal experience, a special MRI technique and some imaging guidelines regarding different anatomical localizations of endometriosis are discussed. This review is a brief presentation of current evidence on the diagnostic accuracy of MRI in the evaluation of endometriosis concerning other diagnostic methods, the limitations of MRI and its essential usefulness for preoperative diagnosis of deep pelvic endometriosis, and future perspectives in monitoring this disease. Agnieszka Bianek-Bodzak, Edyta Szurowska, Sambor Sawicki, and Marcin Liro Copyright © 2013 Agnieszka Bianek-Bodzak et al. All rights reserved. Cone Beam Computed Tomographic Analysis of the Shape, Height, and Location of the Mandibular Lingula in a Population of Children Wed, 20 Nov 2013 15:00:28 +0000  Objectives. This is the first study to identify and classify the different morphological shapes of the mandibular lingula (ML) in children using cone-beam computed tomography (CBCT). Material and Methods. A retrospective study was performed to evaluate the shape, height, and location of the ML in relation to the surrounding structures using CBCT images of mandibles obtained from 269 children. The shape of the ML was classified into triangular, truncated, nodular, or assimilated types. The location was determined by five distances. The height of the lingula was also measured from the lingular tip to the mandibular foramen. Results. A nodular shape of the ML was most commonly found (48.3%, ) followed by truncated (23.4%, ), assimilated (14.4%, ), and triangular (13.7%, ). The mean distance of ML from the anterior and posterior borders of mandibular ramus was  mm and  mm, respectively. In the majority of the mandibles studied, the ML was located above the occlusal plane. Conclusion. The present study provides new information to the literature concerning the shape, height, and location of the lingula in a Turkish pediatric population. This finding may assist clinicians to localize the lingula and avoid intraoperative complications. Ahmet Ercan Sekerci, Kenan Cantekin, and Mustafa Aydinbelge Copyright © 2013 Ahmet Ercan Sekerci et al. All rights reserved. Similar-Case-Based Optimization of Beam Arrangements in Stereotactic Body Radiotherapy for Assisting Treatment Planners Sat, 02 Nov 2013 14:30:18 +0000 Objective. To develop a similar-case-based optimization method for beam arrangements in lung stereotactic body radiotherapy (SBRT) to assist treatment planners. Methods. First, cases that are similar to an objective case were automatically selected based on geometrical features related to a planning target volume (PTV) location, PTV shape, lung size, and spinal cord position. Second, initial beam arrangements were determined by registration of similar cases with the objective case using a linear registration technique. Finally, beam directions of the objective case were locally optimized based on the cost function, which takes into account the radiation absorption in normal tissues and organs at risk. The proposed method was evaluated with 10 test cases and a treatment planning database including 81 cases, by using 11 planning evaluation indices such as tumor control probability and normal tissue complication probability (NTCP). Results. The procedure for the local optimization of beam arrangements improved the quality of treatment plans with significant differences () in the homogeneity index and conformity index for the PTV, V10, V20, mean dose, and NTCP for the lung. Conclusion. The proposed method could be usable as a computer-aided treatment planning tool for the determination of beam arrangements in SBRT. Taiki Magome, Hidetaka Arimura, Yoshiyuki Shioyama, Katsumasa Nakamura, Hiroshi Honda, and Hideki Hirata Copyright © 2013 Taiki Magome et al. All rights reserved. Effect of Alcohol on Diffuse Axonal Injury in Rat Brainstem: Diffusion Tensor Imaging and Aquaporin-4 Expression Study Sun, 27 Oct 2013 11:10:27 +0000 The aim of this study is to assess the effects of alcohol on traumatic brain injury by using diffusion tensor imaging (DTI) and evaluate aquaporin-4(AQP4) expression changes in rat brainstems following acute alcohol intoxication with diffuse axonal injury (DAI). We further investigated the correlation between the AQP4 expression and DTI in the brain edema. Eighty-five rats were imaged before and after injury at various stages. DTI was used to measure brainstem apparent diffusion coefficient (ADC) and fractional anisotropy (FA), with immunostaining being used to determine AQP4 expression. After acute alcoholism with DAI, ADC values of the brainstem first decreased within 6 h and then elevated. FA values began to decline by 1 h, reaching a minimum at 24 h after trauma. There was a negative correlation between ADC values and brainstem AQP4 expression at 6 h and positive correlation at 6 h to 24 h. Changes of ADC and FA values in DAI with acute alcoholism indicate the effects of ethanol on brain edema and the severity of axonal injury. The correlations between ADC values and the brainstem AQP4 expression at different time points suggest that AQP4 expression follows an adaptative profile to the severity of brain edema. Lingmei Kong, Gengpeng Lian, Wenbin Zheng, Huimin Liu, Haidu Zhang, and Ruowei Chen Copyright © 2013 Lingmei Kong et al. All rights reserved. Design and Validation of an Augmented Reality System for Laparoscopic Surgery in a Real Environment Wed, 23 Oct 2013 09:09:42 +0000 Purpose. This work presents the protocol carried out in the development and validation of an augmented reality system which was installed in an operating theatre to help surgeons with trocar placement during laparoscopic surgery. The purpose of this validation is to demonstrate the improvements that this system can provide to the field of medicine, particularly surgery. Method. Two experiments that were noninvasive for both the patient and the surgeon were designed. In one of these experiments the augmented reality system was used, the other one was the control experiment, and the system was not used. The type of operation selected for all cases was a cholecystectomy due to the low degree of complexity and complications before, during, and after the surgery. The technique used in the placement of trocars was the French technique, but the results can be extrapolated to any other technique and operation. Results and Conclusion. Four clinicians and ninety-six measurements obtained of twenty-four patients (randomly assigned in each experiment) were involved in these experiments. The final results show an improvement in accuracy and variability of 33% and 63%, respectively, in comparison to traditional methods, demonstrating that the use of an augmented reality system offers advantages for trocar placement in laparoscopic surgery. F. López-Mir, V. Naranjo, J. J. Fuertes, M. Alcañiz, J. Bueno, and E. Pareja Copyright © 2013 F. López-Mir et al. All rights reserved. Glutamine/Glutamate Metabolism Studied with Magnetic Resonance Spectroscopic Imaging for the Characterization of Adrenal Nodules and Masses Wed, 02 Oct 2013 17:53:36 +0000 Purpose. To assess glutamine/glutamate (Glx) and lactate (Lac) metabolism using proton magnetic resonance spectroscopic imaging (1H-MRS) in order to differentiate between adrenal gland nodules and masses (adenomas, pheochromocytomas, carcinomas, and metastases). Materials and Methods. Institutional review board approval and informed consent were obtained. A total of 130 patients (47 men) with 132 adrenal nodules/masses were prospectively assessed ( years). A multivoxel system was used with a two-dimensional point-resolved spectroscopy/chemical-shift imaging sequence. Spectroscopic data were interpreted by visual inspection and peak amplitudes of lipids (Lip), choline (Cho), creatine (Cr), Lac, and Glx. Lac/Cr and Glx/Cr were calculated. Glx/Cr was assessed in relation to lesion size. Results. Statistically significant differences were observed in Glx/Cr results between adenomas and pheochromocytomas (), however, with a low positive predictive value (PPV). Glx levels were directly proportional to lesion size in carcinomas. A cutoff point of 1.44 was established for the differentiation between carcinomas larger versus smaller than 4 cm, with 75% sensitivity, 100% specificity, 100% PPV, and 80% accuracy. Lac/Cr results showed no differences across lesions. A cutoff point of −6.5 for Lac/Cr was established for carcinoma diagnosis. Conclusion. Glx levels are directly proportional to lesion size in carcinomas. A cutoff point of −6.5 Lac/Cr differentiates carcinomas from noncarcinomas. Suzan M. Goldman, Thiago F. Nunes, Homero J. F. Melo, Claudio Dalavia, Denis Szejnfeld, Claudio Kater, Cassio Andreoni, Jacob Szejnfeld, and Sergio A. Ajzen Copyright © 2013 Suzan M. Goldman et al. All rights reserved. Risk Management in Magnetic Resonance: Failure Mode, Effects, and Criticality Analysis Thu, 19 Sep 2013 08:26:32 +0000 The aim of the study was to perform a risk management procedure in “Magnetic Resonance Examination” process in order to identify the critical phases and sources of radiological errors and to identify potential improvement projects including procedures, tests, and checks to reduce the error occurrence risk. In this study we used the proactive analysis “Failure Mode Effects Criticality Analysis,” a qualitative and quantitative risk management procedure; has calculated Priority Risk Index (PRI) for each activity of the process; have identified, on the PRI basis, the most critical activities and, for them, have defined improvement projects; and have recalculated the PRI after implementation of improvement projects for each activity. Time stop and audits are performed in order to control the new procedures. The results showed that the most critical tasks of “Magnetic Resonance Examination” process were the reception of the patient, the patient schedule drafting, the closing examination, and the organization of activities. Four improvement projects have been defined and executed. PRI evaluation after improvement projects implementation has shown that the risk decreased significantly following the implementation of procedures and controls defined in improvement projects, resulting in a reduction of the PRI between 43% and 100%. Antonella Petrillo, Roberta Fusco, Vincenza Granata, Salvatore Filice, Nicola Raiano, Daniela Maria Amato, Maria Zirpoli, Alessandro di Finizio, Mario Sansone, Anna Russo, Eugenio Maria Covelli, Tonino Pedicini, and Maria Triassi Copyright © 2013 Antonella Petrillo et al. All rights reserved. Estimation of the Lateral Ventricles Volumes from a 2D Image and Its Relationship with Cerebrospinal Fluid Flow Mon, 16 Sep 2013 13:35:16 +0000 Purpose. This work suggests a fast estimation method of the lateral ventricles volume from a 2D image and then determines if this volume is correlated with the cerebrospinal fluid flow at the aqueductal and cerebral levels in neurodegenerative diseases. Materials and Methods. FForty-five elderly patients suffering from Alzheimer’s disease (19), normal pressure hydrocephalus (13), and vascular dementia (13) were involved and underwent anatomical and phase contrast MRI scans. Lateral ventricles and stroke volumes were assessed on anatomical and phase contrast scans, respectively. A common reference plane was used to calculate the lateral ventricles’ area on 2D images. Results. The largest volumes were observed in hydrocephalus patients. The linear regression between volumes and areas was computed, and a strong positive correlation was detected (). A derived equation was determined to represent the volumes for any given area. On the other hand, no significant correlations were detected between ventricles and stroke volumes (). Conclusion. Lateral ventricles volumes are significantly proportional to the 2D reference section area and could be used for patients’ follow-up even if 3D images are unavailable. The cerebrospinal fluid fluctuations in brain disorders may depend on many physiological parameters other than the ventricular morphology. Chaarani Bader, Capel Cyrille, Zmudka Jadwiga, Daouk Joel, Anthony Fichten, Gondry-Jouet Catherine, Bouzerar Roger, and Balédent Olivier Copyright © 2013 Chaarani Bader et al. All rights reserved. Postmortem Computed Tomography Imaging in the Investigation of Nontraumatic Death in Infants and Children Wed, 04 Sep 2013 13:31:05 +0000 Objective. To determine the accuracy of postmortem computed tomography (PMCT) for the assessment of causes in nontraumatic deaths in children. Study Design. We enrolled cases of nontraumatic deaths of infants and children who underwent PMCT at a single center. The presumed cause of death determined by PMCT was prospectively compared with the clinical and pathological diagnoses of deaths. Results. Thirty-eight cases were enrolled for analysis. Among them, seven cases also underwent conventional medical autopsy. PMCT revealed an identifiable cause of death in accordance with the clinical diagnosis of death in 16 cases of the 38 cases (the concordance rate was 42%) and in accordance with the autopsy cause of death in four of the seven autopsy cases (the concordance rate was 57%). Among eight cases with unknown cause of death by clinical diagnosis, four cases (50%) were identified with cardiac tamponade as a cause of death (one case) and intracranial hemorrhage suggesting abuse (3 cases). Conclusions. PMCT seems to be a promising technique that might serve as a substitute for conventional medical autopsy and give us the complementary information to clinical diagnoses particularly in cases of child abuse. Larger multicenter trials are worthwhile to validate the general feasibility of PMCT. Yukihiro Noda, Ken Yoshimura, Shoji Tsuji, Atsushi Ohashi, Hirohide Kawasaki, Kazunari Kaneko, Shigeki Ikeda, Hiroaki Kurokawa, and Noboru Tanigawa Copyright © 2013 Yukihiro Noda et al. All rights reserved. Congenital and Acquired Abnormalities of the Corpus Callosum: A Pictorial Essay Tue, 06 Aug 2013 09:17:49 +0000 The purpose of this review is to illustrate the wide spectrum of lesions in the corpus callosum, both congenital and acquired: developmental abnormalities, phakomatoses, neurometabolic disorders, demyelinating diseases, infection and inflammation, vascular lesions, neoplasms, traumatic and iatrogenic injury, and others. Cases include fetuses, children, and adults with rich iconography from the authors’ own archive. Katarzyna Krupa and Monika Bekiesinska-Figatowska Copyright © 2013 Katarzyna Krupa and Monika Bekiesinska-Figatowska. All rights reserved. Qualitative and Quantitative Hippocampal MRI Assessments in Intractable Epilepsy Mon, 29 Jul 2013 08:32:39 +0000 Aims. To acquire normative data of hippocampal volumes and T2 relaxation times, to evaluate and compare qualitative and quantitative assessments in evaluating hippocampi in patients with different durations of intractable epilepsy, and to propose an imaging protocol based on performance of these techniques. Methods. MRI analysis was done in 50 nonepileptic controls and 30 patients with intractable epilepsy on 1.5T scanner. Visual assessment and hippocampal volumetry were done on oblique coronal IR/T2W and T1W MP-RAGE images, respectively. T2 relaxation times were measured using 16-echo Carr-Purcell-Meiboom-Gill sequence. Volumetric data was normalized for variation in head size between individuals. Patients were divided into temporal () and extratemporal () groups based on clinical and EEG localization. Results. In controls, right hippocampal volume was slightly more than the left with no effect of age or gender. In TLE patients, hippocampal volumetry provided maximum concordance with EEG. Visual assessment of unilateral pathology concurred well with measured quantitative values but poorly in cases with bilateral pathologies. There were no significant differences of mean values between extratemporal group and controls group. Quantitative techniques detected mild abnormalities, undetected on visual assessment. Conclusions. Quantitative techniques are more sensitive to diagnose bilateral and mild unilateral hippocampal abnormalities. Paramdeep Singh, Rupinderjeet Kaur, Kavita Saggar, Gagandeep Singh, and Amarpreet Kaur Copyright © 2013 Paramdeep Singh et al. All rights reserved. Magnetic Resonance Sialography Findings of Submandibular Ducts Imaging Thu, 25 Jul 2013 10:13:38 +0000 Purpose. We aimed to assess the problem solving capability of magnetic resonance sialography (MR sialography), a noninvasive method for imaging submandibular gland ducts and determining duct-related pathologies, by comparing diseased and healthy cases. Materials and Methods. We conducted radiological assessment on a total of 60 submandibular glands (mean age 44.7) in 20 cases and 10 volunteers. MR sialography examinations were conducted with single-shot fast spin-echo sequence by using a surface coil placed on the submandibular gland. Each gland was evaluated in terms of the length, width and stricture of the main duct, as well as the difference between the intraparenchymal duct width, and the main duct width. Statistical analysis was performed. Results. In the MR sialography the primary duct mean length was determined as 51 mm (40–57 mm) in all submandibular glands. On the MR sialography imaging, the visualization ratio of the ductal system of submandibular gland was evaluated in the cases and volunteers. Conclusion. MR sialography is an effective and a noninvasive method in imaging submandibular gland ducts, demonstrating the presence, location and degree of stricture/dilatation, and elucidating the disease etiology. Nezahat Karaca Erdoğan, Canan Altay, Nesibe Özenler, Tuğba Bozkurt, Engin Uluç, Berna Dirim Mete, and İsmail Özdemir Copyright © 2013 Nezahat Karaca Erdoğan et al. All rights reserved. Assessment of Hemodynamics in a Rat Model of Liver Cirrhosis with Precancerous Lesions Using Multislice Spiral CT Perfusion Imaging Thu, 20 Jun 2013 13:26:39 +0000 Rationale and Objectives. To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. Materials and Methods. Male Wistar rats were randomly divided into the control group () and the precancerous liver cirrhosis group (). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. Results. High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, ; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion () but significantly decreased hepatic portal perfusion and mean transit time (). Conclusion. Multislice spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions. Guolin Ma, Rongjie Bai, Huijie Jiang, Xuejia Hao, Zaisheng Ling, and Kefeng Li Copyright © 2013 Guolin Ma et al. All rights reserved. Simultaneous Reduction in Noise and Cross-Contamination Artifacts for Dual-Energy X-Ray CT Wed, 19 Jun 2013 11:34:58 +0000 Purpose. Dual-energy CT imaging tends to suffer from much lower signal-to-noise ratio than single-energy CT. In this paper, we propose an improved anticorrelated noise reduction (ACNR) method without causing cross-contamination artifacts. Methods. The proposed algorithm diffuses both basis material density images (e.g., water and iodine) at the same time using a novel correlated diffusion algorithm. The algorithm has been compared to the original ACNR algorithm in a contrast-enhanced, IRB-approved patient study. Material density accuracy and noise reduction are quantitatively evaluated by the percent density error and the percent noise reduction. Results. Both algorithms have significantly reduced the noises of basis material density images in all cases. The average percent noise reduction is 69.3% and 66.5% with the ACNR algorithm and the proposed algorithm, respectively. However, the ACNR algorithm alters the original material density by an average of 13% (or 2.18 mg/cc) with a maximum of 58.7% (or 8.97 mg/cc) in this study. This is evident in the water density images as massive cross-contaminations are seen in all five clinical cases. On the contrary, the proposed algorithm only changes the mean density by 2.4% (or 0.69 mg/cc) with a maximum of 7.6% (or 1.31 mg/cc). The cross-contamination artifacts are significantly minimized or absent with the proposed algorithm. Conclusion. The proposed algorithm can significantly reduce image noise present in basis material density images from dual-energy CT imaging, with minimized cross-contaminations compared to the ACNR algorithm. Baojun Li, Baohong Li, Jack Luo, Peng Tang, Jiandong Mao, and Xiaoye Wu Copyright © 2013 Baojun Li et al. All rights reserved. Improvements in the Quantitative Assessment of Cerebral Blood Volume and Flow with the Removal of Vessel Voxels from MR Perfusion Images Mon, 18 Mar 2013 09:48:00 +0000 Objective. To improve the quantitative assessment of cerebral blood volume (CBV) and flow (CBF) in the brain voxels from MR perfusion images. Materials and Methods. Normal brain parenchyma was automatically segmented with the time-to-peak criteria after cerebrospinal fluid removal and preliminary vessel voxel removal. Two scaling factors were calculated by comparing the relative CBV and CBF of the segmented normal brain parenchyma with the absolute values in the literature. Using the scaling factors, the relative values were converted to the absolute CBV and CBF. Voxels with either CBV > 8 mL/100 g or CBF > 100 mL/100 g/min were characterized as vessel voxels and were excluded from the quantitative measurements. Results. The segmented brain parenchyma with normal perfusion was consistent with the angiographic findings for each patient. We confirmed the necessity of dual thresholds including CBF and CBV for proper removal of vessel voxels. The scaling factors were 0.208 ± 0.041 for CBV, and 0.168 ± 0.037, 0.172 ± 0.037 for CBF calculated using standard and circulant singular value decomposition techniques, respectively. Conclusion. The automatic scaling and vessel removal techniques provide an alternative method for obtaining improved quantitative assessment of CBV and CBF in patients with thromboembolic cerebral arterial disease. Michael Mu Huo Teng, I-Chieh Cho, Yi-Hsuan Kao, Chi-Shuo Chuang, Fang-Ying Chiu, and Feng-Chi Chang Copyright © 2013 Michael Mu Huo Teng et al. All rights reserved. Differential Temporal Evolution Patterns in Brain Temperature in Different Ischemic Tissues in a Monkey Model of Middle Cerebral Artery Occlusion Tue, 02 Oct 2012 13:42:41 +0000 Brain temperature is elevated in acute ischemic stroke, especially in the ischemic penumbra (IP). We attempted to investigate the dynamic evolution of brain temperature in different ischemic regions in a monkey model of middle cerebral artery occlusion. The brain temperature of different ischemic regions was measured with proton magnetic resonance spectroscopy (1H MRS), and the evolution processes of brain temperature were compared among different ischemic regions. We found that the normal (baseline) brain temperature of the monkey brain was 37.16°C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16°C higher than the baseline; however, this increase was region dependent, with 1.72°C in the IP, 1.08°C in the infarct core, and 0.62°C in the oligemic region. After recanalization, the brain temperature of the infarct core showed a pattern of an initial decrease accompanied by a subsequent increase. However, the brain temperature of the IP and oligemic region showed a monotonously and slowly decreased pattern. Our study suggests that in vivo measurement of brain temperature could help to identify whether ischemic tissue survives. Zhihua Sun, Jing Zhang, Yingmin Chen, Yunting Zhang, Xuejun Zhang, Hong Guo, and Chunshui Yu Copyright © 2012 Zhihua Sun et al. All rights reserved. Quantifying Tumor Vascular Heterogeneity with Dynamic Contrast-Enhanced Magnetic Resonance Imaging: A Review Tue, 26 Apr 2011 14:44:53 +0000 Tumor microvasculature possesses a high degree of heterogeneity in its structure and function. These features have been demonstrated to be important for disease diagnosis, response assessment, and treatment planning. The exploratory efforts of quantifying tumor vascular heterogeneity with DCE-MRI have led to promising results in a number of studies. However, the methodological implementation in those studies has been highly variable, leading to multiple challenges in data quality and comparability. This paper reviews several heterogeneity quantification methods, with an emphasis on their applications on DCE-MRI pharmacokinetic parametric maps. Important methodological and technological issues in experimental design, data acquisition, and analysis are also discussed, with the current opportunities and efforts for standardization highlighted. Xiangyu Yang and Michael V. Knopp Copyright © 2011 Xiangyu Yang and Michael V. Knopp. All rights reserved. An Evaluation of Cellular Neural Networks for the Automatic Identification of Cephalometric Landmarks on Digital Images Thu, 10 Sep 2009 11:15:46 +0000 Several efforts have been made to completely automate cephalometric analysis by automatic landmark search. However, accuracy obtained was worse than manual identification in every study. The analogue-to-digital conversion of X-ray has been claimed to be the main problem. Therefore the aim of this investigation was to evaluate the accuracy of the Cellular Neural Networks approach for automatic location of cephalometric landmarks on softcopy of direct digital cephalometric X-rays. Forty-one, direct-digital lateral cephalometric radiographs were obtained by a Siemens Orthophos DS Ceph and were used in this study and 10 landmarks (N, A Point, Ba, Po, Pt, B Point, Pg, PM, UIE, LIE) were the object of automatic landmark identification. The mean errors and standard deviations from the best estimate of cephalometric points were calculated for each landmark. Differences in the mean errors of automatic and manual landmarking were compared with a 1-way analysis of variance. The analyses indicated that the differences were very small, and they were found at most within 0.59 mm. Furthermore, only few of these differences were statistically significant, but differences were so small to be in most instances clinically meaningless. Therefore the use of X-ray files with respect to scanned X-ray improved landmark accuracy of automatic detection. Investigations on softcopy of digital cephalometric X-rays, to search more landmarks in order to enable a complete automatic cephalometric analysis, are strongly encouraged. Rosalia Leonardi, Daniela Giordano, and Francesco Maiorana Copyright © 2009 Rosalia Leonardi et al. All rights reserved.