Radiology Research and Practice The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Image Guidance in Radiation Therapy: Techniques and Applications Wed, 17 Dec 2014 12:22:49 +0000 In modern day radiotherapy, the emphasis on reduction on volume exposed to high radiotherapy doses, improving treatment precision as well as reducing radiation-related normal tissue toxicity has increased, and thus there is greater importance given to accurate position verification and correction before delivering radiotherapy. At present, several techniques that accomplish these goals impeccably have been developed, though all of them have their limitations. There is no single method available that eliminates treatment-related uncertainties without considerably adding to the cost. However, delivering “high precision radiotherapy” without periodic image guidance would do more harm than treating large volumes to compensate for setup errors. In the present review, we discuss the concept of image guidance in radiotherapy, the current techniques available, and their expected benefits and pitfalls. Shikha Goyal and Tejinder Kataria Copyright © 2014 Shikha Goyal and Tejinder Kataria. All rights reserved. Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging? Wed, 10 Dec 2014 00:10:16 +0000 Objective(s). The major challenge encountered to decrease the milliamperes (mA) level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI) prototype comprising a low mA X-ray source and a novel microlens-based sensor relative to current imaging technologies. Study Design. A LDXI in static (group 1) and dynamic (group 2) modes was compared to medical fluoroscopy (group 3), digital intraoral radiography (group 4), and CBCT scan (group 5) using a dental phantom. Results. The Mann-Whitney test showed no statistical significance in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds) between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5. Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with microlens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future. Arnav R. Mistry, Daniel Uzbelger Feldman, Jie Yang, and Eric Ryterski Copyright © 2014 Arnav R. Mistry et al. All rights reserved. Multisite Kinetic Modeling of 13C Metabolic MR Using [1-13C]Pyruvate Mon, 08 Dec 2014 11:45:13 +0000 Hyperpolarized 13C imaging allows real-time in vivo measurements of metabolite levels. Quantification of metabolite conversion between [1-13C]pyruvate and downstream metabolites [1-13C]alanine, [1-13C]lactate, and [13C]bicarbonate can be achieved through kinetic modeling. Since pyruvate interacts dynamically and simultaneously with its downstream metabolites, the purpose of this work is the determination of parameter values through a multisite, dynamic model involving possible biochemical pathways present in MR spectroscopy. Kinetic modeling parameters were determined by fitting the multisite model to time-domain dynamic metabolite data. The results for different pyruvate doses were compared with those of different two-site models to evaluate the hypothesis that for identical data the uncertainty of a model and the signal-to-noise ratio determine the sensitivity in detecting small physiological differences in the target metabolism. In comparison to the two-site exchange models, the multisite model yielded metabolic conversion rates with smaller bias and smaller standard deviation, as demonstrated in simulations with different signal-to-noise ratio. Pyruvate dose effects observed previously were confirmed and quantified through metabolic conversion rate values. Parameter interdependency allowed an accurate quantification and can therefore be useful for monitoring metabolic activity in different tissues. Pedro A. Gómez Damián, Jonathan I. Sperl, Martin A. Janich, Oleksandr Khegai, Florian Wiesinger, Steffen J. Glaser, Axel Haase, Markus Schwaiger, Rolf F. Schulte, and Marion I. Menzel Copyright © 2014 Pedro A. Gómez Damián et al. All rights reserved. In Vivo MR Microneurography of the Tibial and Common Peroneal Nerves Sun, 07 Dec 2014 08:23:14 +0000 MR microneurography is a noninvasive technique that provides visualization of the microanatomy of peripheral nerves, otherwise available only with histopathology. The objective of this study was to present a protocol to visualize the microstructure of peripheral nerves in vivo, using a 3T MRI scanner with a clinical set of coils and sequences. The tibial and the common peroneal nerves of healthy volunteers were imaged above the medial malleolus and at the level of the fibular head, respectively. The acquired images provided details about the internal structure of peripheral nerves, with visualization of the fascicles, the interfascicular fat, the epineurium, and the perineurium. MR microneurography can be performed in a clinical setting with acceptable imaging times and can be a potentially powerful tool that complements standard MR neurography. Paolo F. Felisaz, Eric Y. Chang, Irene Carne, Stefano Montagna, Francesco Balducci, Giulia Maugeri, Anna Pichiecchio, Fabrizio Calliada, Maurizia Baldi, and Stefano Bastianello Copyright © 2014 Paolo F. Felisaz et al. All rights reserved. Bilateral Obturator Hernia Diagnosed by Computed Tomography: A Case Report with Review of the Literature Wed, 03 Dec 2014 07:43:09 +0000 Obturator hernia is a rare form of abdominal hernia and a diagnostic challenge. It is commonly seen in elderly thin females. Its diagnosis is often delayed with resultant increased morbidity and mortality due to bowel ischemia/gangrene. It is mistakenly diagnosed as femoral or inguinal hernia on USG. Computed tomography is diagnostic and is a valuable tool for preoperative diagnosis. This report presents a case of 70-year-old thin female presenting with intestinal obstruction due to left sided obstructed obturator hernia. USG showed small bowel obstruction and an obstructed left sided femoral hernia. CT scan of abdomen and pelvis with inguinal and upper thigh region disclosed left sided obturator hernia. It also detected clinically occult right sided obturator hernia. Early diagnosis and surgical treatment contribute greatly in reducing the morbidity and mortality rate. Sanjay M. Khaladkar, Anubhav Kamal, Sahil Garg, and Vigyat Kamal Copyright © 2014 Sanjay M. Khaladkar et al. All rights reserved. Influenceable and Avoidable Risk Factors for Systemic Air Embolism due to Percutaneous CT-Guided Lung Biopsy: Patient Positioning and Coaxial Biopsy Technique—Case Report, Systematic Literature Review, and a Technical Note Mon, 10 Nov 2014 00:00:00 +0000 Following the first case of a systemic air embolism due to percutaneous CT-guided lung biopsy in our clinic we analysed the literature regarding this matter in view of influenceable or avoidable risk factors. A systematic review of literature reporting cases of systemic air embolism due to CT-guided lung biopsy was performed to find out whether prone positioning might be a risk factor regarding this issue. In addition, a technical note concerning coaxial biopsy practice is presented. Prone position seems to have relevance for the development and/or clinical manifestation of air embolism due to CT-guided lung biopsy and should be considered a risk factor, at least as far as lesions in the lower parts of the lung are concerned. Biopsies of small or cavitary lesions in coaxial technique should be performed using a hemostatic valve. Gernot Rott and Frieder Boecker Copyright © 2014 Gernot Rott and Frieder Boecker. All rights reserved. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Accuracy in the Staging of Non-Small Cell Lung Cancer: Review and Cost-Effectiveness Wed, 05 Nov 2014 09:42:56 +0000 Aim of the performed clinical study was to compare the accuracy and cost-effectiveness of PET/CT in the staging of non-small cell lung cancer (NSCLC). Material and Methods. Cross-sectional and prospective study including 103 patients with histologically confirmed NSCLC. All patients were examined using PET/CT with intravenous contrast medium. Those with disease stage ≤IIB underwent surgery (). Disease stage was confirmed based on histology results, which were compared with those of PET/CT and positron emission tomography (PET) and computed tomography (CT) separately. 63 patients classified with ≥IIIA disease stage by PET/CT did not undergo surgery. The cost-effectiveness of PET/CT for disease classification was examined using a decision tree analysis. Results. Compared with histology, the accuracy of PET/CT for disease staging has a positive predictive value of 80%, a negative predictive value of 95%, a sensitivity of 94%, and a specificity of 82%. For PET alone, these values are 53%, 66%, 60%, and 50%, whereas for CT alone they are 68%, 86%, 76%, and 72%, respectively. Incremental cost-effectiveness of PET/CT over CT alone was €17,412 quality-adjusted life-year (QALY). Conclusion. In our clinical study, PET/CT using intravenous contrast medium was an accurate and cost-effective method for staging of patients with NSCLC. Nieves Gómez León, Sofía Escalona, Beatriz Bandrés, Cristobal Belda, Daniel Callejo, and Juan Antonio Blasco Copyright © 2014 Nieves Gómez León et al. All rights reserved. Evaluation of Contrast Extravasation as a Diagnostic Criterion in the Evaluation of Arthroscopically Proven HAGL/pHAGL Lesions Mon, 03 Nov 2014 07:13:47 +0000 Purpose. The validity of preoperative MRI in diagnosing HAGL lesions is debated. Various investigations have produced mixed results with regard to the utility of MRI. The purpose of this investigation is to apply a novel method of diagnosing HAGL/pHAGL lesions by looking at contrast extravasation and to evaluate the reliability of such extravasation of contrast into an extra-articular space as a sign of HAGL/pHAGL lesion. Methods. We utilized specific criteria to define contrast extravasation. We evaluated these criteria in 12 patients with arthroscopically proven HAGL/pHAGL lesion. We also evaluated these criteria in a control group. Results. Contrast extravasation occurred in over 83% of arthroscopically positive cases. Contrast extravasation as a diagnostic criterion in the evaluation of HAGL/pHAGL lesions demonstrated a high interobserver degree of agreement. Conclusions. In conclusion, extra-articular contrast extravasation may serve as a valid and reliable sign of HAGL and pHAGL lesions, provided stringent criteria are maintained to assure that the contrast lies in an extra-articular location. In cases where extravasation is not present, the “J” sign, though nonspecific, may be the only evidence of subtle HAGL and pHAGL lesions. Level of Evidence. Level IV, Retrospective Case-Control series. Catherine Maldjian, Vineet Khanna, James Bradley, and Richard Adam Copyright © 2014 Catherine Maldjian et al. All rights reserved. Whole Prostate Volume and Shape Changes with the Use of an Inflatable and Flexible Endorectal Coil Mon, 13 Oct 2014 07:25:10 +0000 Purpose. To determine to what extent an inflatable endorectal coil (ERC) affects whole prostate (WP) volume and shape during prostate MRI. Materials and Methods. 79 consecutive patients underwent T2W MRI at 3T first with a 6-channel surface coil and then with the combination of a 16-channel surface coil and ERC in the same imaging session. WP volume was assessed by manually contouring the prostate in each T2W axial slice. PSA density was also calculated. The maximum anterior-posterior (AP), left-right (LR), and craniocaudal (CC) prostate dimensions were measured. Changes in WP prostate volume, PSA density, and prostate dimensions were then evaluated. Results. In 79 patients, use of an ERC yielded no significant change in whole prostate volume (, ) and PSA density (). However, use of an ERC significantly decreased the AP dimension of the prostate by (), increased LR dimension by (), and increased the CC dimension by (). Conclusion. Use of an ERC in prostate MRI results in the shape deformation of the prostate gland with no significant change in the volume of the prostate measured on T2W MRI. Therefore, WP volumes calculated on ERC MRI can be reliably used in clinical workflow. Murat Osman, Haytham Shebel, Sandeep Sankineni, Marcelino L. Bernardo, Dagane Daar, Bradford J. Wood, Peter A. Pinto, Peter L. Choyke, Baris Turkbey, and Harsh K. Agarwal Copyright © 2014 Murat Osman et al. All rights reserved. Assessment of Condylar Changes in Patients with Temporomandibular Joint Pain Using Digital Volumetric Tomography Sun, 21 Sep 2014 07:10:52 +0000 Objective. To evaluate the efficiency of DVT in comparison with OPG in the assessment of bony condylar changes in patients of TMJ pain. Methods. 100 temporomandibular joints of 62 patients with the complaint of temporomandibular joint pain were included in the study. DVT and OPG radiographs were taken for all the 100 joints. Three observers interpreted the DVT and OPG radiograph for the bony changes separately for two times with an interval of one week. The bony changes seen in the condyle were given coding from 0 to 6. (0: Normal, 1: Erosion, 2: Flattening, 3: Osteophyte, 4: Sclerosis, 5: Resorption, and 6: other changes). Interobserver and intraobserver variability was assessed with one-way ANOVA statistics. Z test was used to see the significant difference between OPG and DVT. Results. In the present study the interexaminer reliability for OPG and DVT was 0.903 and 0.978, respectively. Intraexaminer reliability for OPG and DVT was 0.908 and 0.980, respectively. The most common condylar bony change seen in OPG and DVT was erosion followed by flattening and osteophyte. There was significant difference between OPG and DVT in detecting erosion and osteophytes. The other changes observed in our study were Ely’s cyst, pointed condyle, and bifid condyle. All the bony changes are more commonly seen in females than males. Conclusion. DVT provides more valid and accurate information on condylar bony changes. The DVT has an added advantage of lesser radiation exposure to the patient and cost effectiveness and could be easily accessible in a dental hospital. Ujwala Shivarama Shetty, Krishna N. Burde, Venkatesh G. Naikmasur, and Atul P. Sattur Copyright © 2014 Ujwala Shivarama Shetty et al. All rights reserved. Aortoenteric Fistula as a Complication of Open Reconstruction and Endovascular Repair of Abdominal Aorta Sun, 14 Sep 2014 09:29:12 +0000 The paper intends to present a review of imaging characteristics of secondary aortoenteric fistula (AEF). Mechanical injury, infection, and adherence of a bowel segment to the aorta or aortic graft are major etiologic factors of AEF after open aortic repair. The pathogenesis of AEF formation after endovascular abdominal aortic repair is related to mechanical failure of the stent-graft, to stent graft infection, and to persistent pressurization of the aneurysmal sac. The major clinical manifestations of AEF comprise haematemesis, melaena, abdominal pain, sepsis, and fever. CT is the initial diagnostic modality of choice in a stable patient. However, the majority of reported CT appearances are not specific. In case of equivocal CT scans and clinical suspicion of AEF, scintigraphy, 67Ga citrate scans or 18F-FDG PET/CT is useful. Diagnostic accuracy of endoscopy in evaluation of AEF is low; nevertheless it allows to evaluate other than AEF etiologies of gastrointestinal bleeding. Without adequate therapy, AEF is lethal. Conventional surgical treatment is associated with high morbidity and mortality. The endovascular repair may be an option in hemodynamically unstable and high-risk surgical patients. We also illustrate an example of a secondary AEF with highly specific albeit rare radiologic picture from our institution. Marek Tagowski, Hendryk Vieweg, Christian Wissgott, and Reimer Andresen Copyright © 2014 Marek Tagowski et al. All rights reserved. Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults Mon, 08 Sep 2014 07:47:24 +0000 Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall. João Palas, António P. Matos, Vasco Mascarenhas, Vasco Herédia, and Miguel Ramalho Copyright © 2014 João Palas et al. All rights reserved. Evaluation of Hemodynamics in Focal Steatosis and Focal Spared Lesion of the Liver Using Contrast-Enhanced Ultrasonography with Sonazoid Mon, 04 Aug 2014 00:00:00 +0000 We aim to investigate the hemodynamics in focal steatosis and focal spared lesion of the liver using contrast-enhanced ultrasonography (CEUS) with Sonazoid. The subjects were 47 patients with focal steatosis and focal spared lesion. We evaluated enhancement patterns (hyperenhancement, isoenhancement, and hypoenhancement) in the vascular phase and the presence or absence of a hypoechoic area in the postvascular phase for these lesions using CEUS. Of the 24 patients with focal steatosis, the enhancement pattern was isoenhancement in 19 and hypoenhancement in 5. Hypoechoic areas were noted in the postvascular phase in 3 patients. Of the 23 patients with focal spared lesions, the enhancement pattern was isoenhancement in 18 and hyperenhancement in 5. No hypoechoic areas were noted in the postvascular phase in any patient. The hemodynamics in focal steatosis and focal spared lesions in nondiffuse fatty liver can be observed using low-invasive procedures in real-time by CEUS. It was suggested that differences in the dynamics of enhancement in the vascular phase of CEUS were influenced by the fat deposits in the target lesion, the surrounding liver parenchyma, and the third inflow. Kazue Shiozawa, Manabu Watanabe, Takashi Ikehara, Michio Kogame, Mie Shinohara, Masao Shinohara, Koji Ishii, Yoshinori Igarashi, Hiroyuki Makino, and Yasukiyo Sumino Copyright © 2014 Kazue Shiozawa et al. All rights reserved. Rapid Automated Target Segmentation and Tracking on 4D Data without Initial Contours Sun, 03 Aug 2014 13:04:22 +0000 Purpose. To achieve rapid automated delineation of gross target volume (GTV) and to quantify changes in volume/position of the target for radiotherapy planning using four-dimensional (4D) CT. Methods and Materials. Novel morphological processing and successive localization (MPSL) algorithms were designed and implemented for achieving autosegmentation. Contours automatically generated using MPSL method were compared with contours generated using state-of-the-art deformable registration methods (using and MIMVista software). Metrics such as the Dice similarity coefficient, sensitivity, and positive predictive value (PPV) were analyzed. The target motion tracked using the centroid of the GTV estimated using MPSL method was compared with motion tracked using deformable registration methods. Results. MPSL algorithm segmented the GTV in 4DCT images in seconds per phase ( resolution) as compared to seconds per phase for deformable registration based methods in 9 cases. Dice coefficients between MPSL generated GTV contours and manual contours (considered as ground-truth) were . In comparison, the Dice coefficients between ground-truth and contours generated using deformable registration based methods were 0.909 ± 0.051. Conclusions. The MPSL method achieved similar segmentation accuracy as compared to state-of-the-art deformable registration based segmentation methods, but with significant reduction in time required for GTV segmentation. Venkata V. Chebrolu, Daniel Saenz, Dinesh Tewatia, William A. Sethares, George Cannon, and Bhudatt R. Paliwal Copyright © 2014 Venkata V. Chebrolu et al. All rights reserved. Endovascular Embolisation of Visceral Artery Pseudoaneurysms Tue, 15 Jul 2014 00:00:00 +0000 Objective. To evaluate the technical success, safety, and outcome of endovascular embolization procedure in management of visceral artery pseudoaneurysms. Materials and Methods. 46 patients were treated for 53 visceral pseudoaneurysms at our institution. Preliminary diagnostic workup in all cases was performed by contrast enhanced abdominal CT scan and/or duplex ultrasound. In all patients, embolization was performed as per the standard departmental protocol. For data collection, medical records and radiology reports of all patients were retrospectively reviewed. Technical success, safety, and outcome of the procedure were analyzed. Results. Out of 46 patients, 13 were females and 33 were males. Mean patient age was years and mean pseudoaneurysm size was  mm. Technical success rate for endovascular visceral pseudoaneurysm coiling was 93.47% . Complication rate was 6.52% . Followup was done for a mean duration of months (0.5–69 months). Complete resolution of symptoms or improvement in clinical condition was seen in 36 patients (80%) out of those 45 in whom procedure was technically successful. Conclusion. Results of embolization of visceral artery pseudoaneurysms with coils at our center showed high success rate and good short term outcome. Yasir Jamil Khattak, Tariq Alam, Rana Hamid Shoaib, Raza Sayani, Tanveer-ul Haq, and Muhammad Awais Copyright © 2014 Yasir Jamil Khattak et al. All rights reserved. Gestational Trophoblastic Disease: A Multimodality Imaging Approach with Impact on Diagnosis and Management Sun, 13 Jul 2014 10:57:29 +0000 Gestational trophoblastic disease is a condition of uncertain etiology, comprised of hydatiform mole (complete and partial), invasive mole, choriocarcinoma, and placental site trophoblastic tumor. It arises from abnormal proliferation of trophoblastic tissue. Early diagnosis of gestational trophoblastic disease and its potential complications is important for timely and successful management of the condition with preservation of fertility. Initial diagnosis is based on a multimodality approach: encompassing clinical features, serial quantitative β-hCG titers, and pelvic ultrasonography. Pelvic magnetic resonance imaging (MRI) is sometimes used as a problem-solving tool to assess the depth of myometrial invasion and extrauterine disease spread in equivocal and complicated cases. Chest radiography, body computed tomography (CT), and brain MRI have been recommended as investigative tools for overall disease staging. Angiography has a role in management of disease complications and metastases. Efficacy of PET (positron emission tomography) and PET/CT in the evaluation of recurrent or metastatic disease has not been adequately investigated yet. This paper discusses the imaging features of gestational trophoblastic disease on various imaging modalities and the role of different imaging techniques in the diagnosis and management of this entity. Sunita Dhanda, Subhash Ramani, and Meenkashi Thakur Copyright © 2014 Sunita Dhanda et al. All rights reserved. Performing Chest X-Rays at Inspiration in Uncooperative Children: The Effect of Exercises with a Training Program for Radiology Technicians Wed, 09 Jul 2014 07:31:49 +0000 Objective. It is difficult to acquire a chest X-ray of a crying infant at maximum inspiration. A computer program was developed for technician training. Method. Video clips of 3 babies were used and the moment of deepest inspiration was determined in the single-frame view. 12 technicians simulated chest radiographs at normal video speed by pushing a button. The computer program stopped the video and calculated the period of time to the optimal instant for a chest X-ray. Demonstration software can be tested at website online. Every technician simulated 10 chest X-rays for each of the 3 video clips. The technicians then spent 40 minutes practicing performing chest X-rays at optimal inspiration. The test was repeated after 5, 20, and 40 minutes of practice. Results. 6 participants showed a significant improvement after exercises (collective 1). Deviation from the optimal instant for taking an X-ray at inspiration decreased from 0.39 to 0.22 s after 40 min of practice. 6 technicians showed no significant improvement (collective 2). Deviation decreased from a low starting value of 0.25 s to 0.21 s. Conclusion. The tested computer program improves the ability of radiology technicians to take a chest X-ray at optimal inspiration in a crying child. Heinz-Jakob Langen, Christiane Kohlhauser-Vollmuth, Corinna Sengenberger, Johann Bielmeier, Renate Jocher, and Martina Eschmann Copyright © 2014 Heinz-Jakob Langen et al. All rights reserved. Differential Diagnoses of Overgrowth Syndromes: The Most Important Clinical and Radiological Disease Manifestations Mon, 09 Jun 2014 10:55:31 +0000 Overgrowth syndromes comprise a heterogeneous group of diseases that are characterized by excessive tissue development. Some of these syndromes may be associated with dysfunction in the receptor tyrosine kinase (RTK)/PI3K/AKT pathway, which results in an increased expression of the insulin receptor. In the current review, four overgrowth syndromes were characterized (Proteus syndrome, Klippel-Trenaunay-Weber syndrome, Madelung’s disease, and neurofibromatosis type I) and illustrated using cases from our institution. Because these syndromes have overlapping clinical manifestations and have no established genetic tests for their diagnosis, radiological methods are important contributors to the diagnosis of many of these syndromes. The correlation of genetic discoveries and molecular pathways that may contribute to the phenotypic expression is also of interest, as this may lead to potential therapeutic interventions. Letícia da Silva Lacerda, Úrsula David Alves, José Fernando Cardona Zanier, Dequitier Carvalho Machado, Gustavo Bittencourt Camilo, and Agnaldo José Lopes Copyright © 2014 Letícia da Silva Lacerda et al. All rights reserved. Continuous Dynamic Registration of Microvascularization of Liver Tumors with Contrast-Enhanced Ultrasound Mon, 02 Jun 2014 06:11:10 +0000 Aim. To evaluate the diagnostic value of quantification of liver tumor microvascularization using contrast-enhanced ultrasound (CEUS) measured continuously from the arterial phase to the late phase (3 minutes). Material and Methods. We present a retrospective analysis of 20 patients with malignant () or benign () liver tumors. The tumors had histopathologically been proven or clearly identified using contrast-enhanced reference imaging with either 1.5 T MRI (liver specific contrast medium) or triphase CT and follow-up. CEUS was performed using a multifrequency transducer (1–5 MHz) and a bolus injection of 2.4 mL sulphur hexafluoride microbubbles. A retrospective perfusion analysis was performed to determine TTP (time-to-peak), RBV (regional blood volume), RBF (regional blood flow), and Peak. Results. Statistics revealed a significant difference () between benign and malignant tumors in the RBV, RBF, and Peak but not in TTP (). Receiver operating curves (ROC) were generated for RBV, RBF, Peak, and TTP with estimated ROC areas of 0.97, 0.96, 0.98, and 0.76, respectively. Conclusion. RBV, RBF, and Peak continuously measured over a determined time period of 3 minutes could be of valuable support in differentiating malignant from benign liver tumors. Lukas Philipp Beyer, Benedikt Pregler, Isabel Wiesinger, Christian Stroszczynski, Philipp Wiggermann, and Ernst-Michael Jung Copyright © 2014 Lukas Philipp Beyer et al. All rights reserved. Technical Considerations of Phosphorous-32 Bremsstrahlung SPECT Imaging after Radioembolization of Hepatic Tumors: A Clinical Assessment with a Review of Imaging Parameters Thu, 27 Mar 2014 11:08:47 +0000 Background. Bremsstrahlung (BS) imaging during radioembolization (RE) confirms the deposition of radiotracer in hepatic/extrahepatic tumors. The aim of this study is to demonstrate 32P images and to optimize the imaging parameters. Materials and Methods. Thirty-nine patients with variable types of hepatic tumors, treated with the intra-arterial injection of 32P, were included. All patients underwent BS SPECT imaging 24–72 h after tracer administration, using low energy high resolution (LEHR) (18 patients) or medium energy general purpose (MEGP) (21 patients) collimators. A grading scale from 1 to 4 was used to express the compatibility of the 32P images with those obtained from CT/MRI. Results. Although the image quality obtained with the MEGP collimator was visually and quantitatively better than with the LEHR (76% concordance score versus 71%, resp.), there was no statistically significant difference between them. Conclusion. The MEGP collimator is the first choice for BS SPECT imaging. However, if the collimator change is time consuming (as in a busy center) or an MEGP collimator is not available, the LEHR collimator could be practical with acceptable images, especially in a SPECT study. In addition, BS imaging is a useful method to confirm the proper distribution of radiotherapeutic agents and has good correlation with anatomical findings. Elahe Pirayesh, Mahasti Amoui, Shahram Akhlaghpoor, Shahnaz Tolooee, Maryam Khorrami, Hossain PoorBeigi, Shahab Sheibani, and Majid Assadi Copyright © 2014 Elahe Pirayesh et al. All rights reserved. Changes in Renal Function in Elderly Patients Following Intravenous Iodinated Contrast Administration: A Retrospective Study Mon, 24 Mar 2014 00:00:00 +0000 Background. Contrast-induced nephropathy (CIN) is a recognised complication of intravascular administration of iodinated contrast media (ICM). Previous studies suggest a higher incidence in the elderly, but no large study has assessed this to date. We set out to assess changes in creatinine in elderly inpatients following computed tomography (CT) examination and compare those who received intravenous contrast to those who did not. Methods. Using the Radiology Information System in two teaching hospitals, inpatients over the age of seventy who had a CT examination and a baseline creatinine were identified and their follow-up creatinine levels were analysed. Elderly inpatients who underwent a noncontrast CT over the same period were used as controls. Results. 677 elderly inpatients who received ICM were compared with 487 controls. 9.2% of patients who received ICM developed acute kidney injury (AKI) compared to 3.5% of inpatient controls (). Patients with higher baseline eGFR had a higher incidence of post-CT AKI. Conclusions. The incidence of post-CT AKI is higher in patients who received IV ICM compared to those who did not; the difference may be partly attributable to contrast-induced nephropathy. This suggests that the incidence of CIN in the elderly may not be as high as previously thought. Ali Alsafi, Zaid Alsafi, Amish Lakhani, and Nicola H. Strickland Copyright © 2014 Ali Alsafi et al. All rights reserved. Carotid Artery Stenosis: Comparison of 3D Time-of-Flight MR Angiography and Contrast-Enhanced MR Angiography at 3T Sun, 23 Mar 2014 09:04:58 +0000 Purpose. The aim of this study was to assess the correlation of 3D time-of-flight MR angiography (TOF MRA) and contrast-enhanced MR angiography (CEMRA) for carotid artery stenosis evaluation at 3T. Material and Methods. Twenty-three patients (5?f, 18?m; mean age 61?y, age range 45–78?y) with internal carotid artery stenosis detected with ultrasonography were examined on a 3.0T MR system. The MR examination included both 3D TOF MRA and CEMRA of the carotid arteries. MR images were evaluated independently by two board-certified radiologists. Stenosis evaluation was based on a five-point scale. Stenosis grades determined by TOF and CEMRA were compared using Spearman’s rank correlation coefficient and the Wilcoxon test. Cohen’s Kappa was used to evaluate interrater reliability. Results. CEMRA detected stenosis in 24 (52%) of 46 carotids evaluated, while TOF detected stenosis in 27 (59%) of 46 carotids. TOF MRA yielded significantly higher results for stenosis grade in comparison to CEMRA (). Interrater agreement was very good for both TOF MRA () and CEMRA (). Conclusion. At 3T, 3D TOF MRA should not be used as replacement for contrast-enhanced MRA of the carotid arteries, as it results in significantly higher stenosis grades. Ivan Platzek, Dominik Sieron, Philipp Wiggermann, and Michael Laniado Copyright © 2014 Ivan Platzek et al. All rights reserved. Dislocability of Localization Devices for Nonpalpable Breast Lesions: Experimental Results Thu, 06 Mar 2014 09:22:35 +0000 Purpose. For accurate resection of nonpalpable malignant breast lesions with a tumor-free resection rim, an exact and stable wire localization is essential. We tested the resistance towards traction force of different localization devices used in our clinic for breast lesions in two types of tissue. Materials and Methods. Eight different commercially available hook-wire devices were examined for resistance towards traction force using an analogue spring scale. Results. Most systems showed a high level of movement already under small traction force. Retractable systems with round hooks such as the Bard DuaLok , the Fil d’Ariane, and the RPLN Breast Localization Device withstood less traction force than the other systems. However, the Bard DuaLok system was very resistant towards a small traction force of 50 g when compared to the other systems. The Ultrawire Breast Localization Device withstood the most traction force in softer tissue and Kopans Breast Lesion Localization Needle withstood the most force in harder tissue. Conclusion. The Ultrawire Breast Localization Device and Kopans Breast Lesion Localization Needle withstood the most traction force. In general retractable systems withstand less traction force than nonretractable systems. David Kaul, Eva Fallenberg, Felix Diekmann, Volker Budach, and Martin Maurer Copyright © 2014 David Kaul et al. All rights reserved. Computed Tomography Colonography Technique: The Role of Intracolonic Gas Volume Wed, 18 Dec 2013 17:06:56 +0000 Introduction. Poor distention decreases the sensitivity and specificity of CTC. The total volume of gas administered will vary according to many factors. We aim to determine the relationship between the volume of retained gas at the time of image acquisition and colonic distention and specifically the presence of collapsed bowel segments at CTC. Materials and Methods. All patients who underwent CTC over a 12-month period at a single institution were included in the study. Colonic luminal distention was objectively scored by 2 radiologists using an established 4-point scale. Quantitative analysis of the volume of retained gas at the time of image acquisition was conducted using the threshold 3D region growing function of OsiriX. Results. 108 patients were included for volumetric analysis. Mean retained gas volume was 3.3 L. 35% (38/108) of patients had at least one collapsed colonic segment. Significantly lower gas volumes were observed in the patients with collapsed colonic segments when compared with those with fully distended colons 2.6 L versus 3.5 L (). Retained volumes were significantly higher for the 78% of patients with ileocecal reflux at 3.4 L versus 2.6 L without ileocecal reflux (). Conclusion. Estimation of intraluminal gas volume at CTC is feasible using image segmentation and thresholding tools. An average of 3.5 L of retained gas was found in diagnostically adequate CTC studies with significantly lower mean gas volume observed in patients with collapsed colonic segments. Patrick D. McLaughlin, Kevin P. Murphy, Lee Crush, Owen J. O'Connor, Joseph P. Coyle, Cressida R. Brennan, Attiya Suhail, Denis Kelly, and Michael M. Maher Copyright © 2013 Patrick D. McLaughlin et al. All rights reserved. Impact of Gas Delivery Systems on Imaging Studies of Human Cerebral Blood Flow Wed, 11 Dec 2013 15:24:25 +0000 Purpose. To compare a semiopen breathing circuit with a non-rebreathing (Hudson mask) for MRI experiments involving gas delivery. Methods and Materials. Cerebral blood flow (CBF) was measured by quantitative phase contrast angiography of the internal carotid and basilar arteries in 18 volunteers (20–31 years). In 8 subjects, gases were delivered via a standard non-rebreathing (Hudson mask). In 10 subjects, gases were delivered using a modified “Mapleson A” semiopen anesthetic gas circuit and mouthpiece. All subjects were given 100% O2, medical air, and carbogen gas (95% O2 and 5% CO2) delivered at 15 L/min in a random order. Results. The Hudson mask group showed significant increases in CBF in response to increased FiCO2 compared to air (+9.8%). A small nonsignificant reduction in CBF (−2.4%) was seen in response to increased inspired concentrations of oxygen (FiO2). The Mapleson A group showed significantly larger changes in CBF in response to both increased inspired concentrations of carbon dioxide (FiCO2) (+32.2%, ) and FiO2 (−14.6%, ). Conclusions. The use of an anaesthetic gas delivery circuit avoids entrainment of room air and rebreathing effects that may otherwise adversely affect the experimental results. John R. Cain, Laura M. Parkes, Peter Eadsforth, Susan C. Beards, and Alan Jackson Copyright © 2013 John R. Cain et al. All rights reserved. Role of Barium Esophagography in Patients with Locally Advanced Esophageal Cancer: Evaluation of Response to Neoadjuvant Chemoradiotherapy Wed, 04 Dec 2013 17:15:42 +0000 Purpose. This retrospective study examined the usefulness of barium esophagography, focusing on the luminal stenosis, in the response evaluation of neoadjuvant chemoradiotherapy (NACRT) in patients with esophageal cancer. Materials and Methods. Thirty-four patients with primary advanced esophageal cancer (≥T2) who were treated with NACRT before surgical resection were analyzed. All patients underwent barium esophagography before and after NACRT. The tumor length, volume, and percent esophageal stenosis (PES) before and after NACRT were measured. These values and their changes were compared between histopathologic responders () and nonresponders (). Results. Posttreatment tumor length and PES in responders (4.5 cm ± 1.1 and 33.0% ± 18.5) were significantly smaller than those in nonresponders (5.8 cm ± 1.9 and 48.0% ± 12.9) (). Regarding posttherapeutic changes, the decrease in PES in responders (31.5% ± 13.9) was significantly greater than that in nonresponders (14.4% ± 10.7) (). The best decrease in PES cutoff with which to differentiate between responders and nonresponders was 18.8%, which yielded a sensitivity of 91% and a specificity of 75%. Conclusions. Decrease in PES is a good parameter to differentiate responders from nonresponders for NACRT. Barium esophagography is useful in response evaluation to NACRT in patients with locally advanced esophageal cancer. Daisuke Tsurumaru, Kiyohisa Hiraka, Masahiro Komori, Yoshiyuki Shioyama, Masaru Morita, and Hiroshi Honda Copyright © 2013 Daisuke Tsurumaru et al. All rights reserved. Whole Body Microwave Irradiation for Improved Dacarbazine Therapeutical Action in Cutaneous Melanoma Mouse Model Tue, 26 Nov 2013 14:51:59 +0000 A cutaneous melanoma mouse model was used to test the efficacy of a new therapeutical approach that uses low doses of cytostatics in conjunction with mild whole body microwave exposure of 2.45 GHz in order to enhance cytostatics antitumoral effect. Materials and Methods. A microwave exposure system for C57BL/6 mouse whole body microwave irradiation was designed; groups of 40 mice (males and females) bearing experimental tumours were subjected to a combined therapy comprising low doses of dacarbazine in combination with mild whole body irradiation. Clinical parameters and serum cytokine testing using xMAP technology were performed. Results. The group that was subjected to combined therapy, microwave and cytostatic, had the best clinical evolution in terms of overall survival, tumour volume, and metastatic potential. At day 14 the untreated group had 100% mortality, while in the combined therapy group 40% of mice were surviving. Quantifying serum IL-1β, IL-6, IL-10, IL-12 (p70), IFN-γ, GM-CSF, TNF-α, MIP-1α, MCP-1, and KC during tumorigenesis and therapy found that the combined experimental therapy decreases all the inflammatory cytokines, except chemokine MCP-1 that was found increased, suggesting an increase of the anti-tumoral immune response triggered by the combined therapy. The overall metastatic process is decreased in the combined therapy group. Monica Neagu, Carolina Constantin, Diana Martin, Lucian Albulescu, Nicusor Iacob, and Daniel Ighigeanu Copyright © 2013 Monica Neagu et al. All rights reserved. The Spleen Revisited: An Overview on Magnetic Resonance Imaging Mon, 25 Nov 2013 14:33:22 +0000 Despite being well visualized by different cross-sectional imaging techniques, the spleen is many times overlooked during the abdominal examination. The major reason is the low frequency of splenic abnormalities, the majority consisting of incidental findings. There has been a steady increase in the number of performed abdominal magnetic resonance imaging (MRI) studies; therefore, it is important to be familiar to the major MRI characteristics of disease processes involving the spleen, in order to interpret the findings correctly, reaching whenever possible the appropriate diagnosis. The spleen may be involved in several pathologic conditions like congenital diseases, trauma, inflammation, vascular disorders and hematologic disorders, benign and malignant tumors, and other disease processes that focally or diffusely affect the spleen. This paper presents a description and representative MRI images for many of these disorders. João Palas, António P. Matos, and Miguel Ramalho Copyright © 2013 João Palas et al. All rights reserved. Lumbar Facet Joint Arthritis Is Associated with More Coronal Orientation of the Facet Joints at the Upper Lumbar Spine Wed, 23 Oct 2013 10:00:40 +0000 We retrospectively analyzed CT scans of 620 individuals, who presented to our traumatology department between 2008 and 2010. Facet joint (FJ) arthritis was present in 308 (49.7%) individuals with a mean grade of 1. It was seen in 27% of individuals ≤40 years and in 75% of individuals ≥41 years () as well as in 52% of females and 49% of males (). Mean FJ orientation was 30.4° at L2/3, 38.7° at L3/4, 47° at L4/5, and 47.3° at L5/S1. FJ arthritis was significantly associated with more coronal (increased degree) FJ orientation at L2/3 () with a cutoff point at ≥32°. FJs were more coronally oriented (48.8°) in individuals ≤40 years and more sagittally oriented (45.6°) in individuals ≥41 years at L5/S1 (). Mean FJ asymmetry was 4.89° at L2/3, 6.01° at L3/4, 6.67° at L4/5, and 7.27° at L5/S1, without a significant difference for FJ arthritis. FJ arthritis is common, increases with age, and affects both genders equally. More coronally oriented FJs (≥32°) in the upper lumbar spine may be an individual risk factor for development of FJ arthritis. Thorsten Jentzsch, James Geiger, Stefan M. Zimmermann, Ksenija Slankamenac, Thi Dan Linh Nguyen-Kim, and Clément M. L. Werner Copyright © 2013 Thorsten Jentzsch et al. All rights reserved. Stereoscopic Visualization of Diffusion Tensor Imaging Data: A Comparative Survey of Visualization Techniques Tue, 22 Oct 2013 10:31:01 +0000 Diffusion tensor imaging (DTI) data has traditionally been displayed as a grayscale functional anisotropy map (GSFM) or color coded orientation map (CCOM). These methods use black and white or color with intensity values to map the complex multidimensional DTI data to a two-dimensional image. Alternative visualization techniques, such as maps utilize enhanced graphical representation of the principal eigenvector by means of a headless arrow on regular nonstereoscopic (VM) or stereoscopic display (VMS). A survey of clinical utility of patients with intracranial neoplasms was carried out by 8 neuroradiologists using traditional and nontraditional methods of DTI display. Pairwise comparison studies of 5 intracranial neoplasms were performed with a structured questionnaire comparing GSFM, CCOM, VM, and VMS. Six of 8 neuroradiologists favored maps over traditional methods of display (GSFM and CCOM). When comparing the stereoscopic (VMS) and the non-stereoscopic (VM) modes, 4 favored VMS, 2 favored VM, and 2 had no preference. In conclusion, processing and visualizing DTI data stereoscopically is technically feasible. An initial survey of users indicated that based display methodology with or without stereoscopic visualization seems to be preferred over traditional methods to display DTI data. Osama Raslan, James Matthew Debnam, Leena Ketonen, Ashok J. Kumar, Dawid Schellingerhout, and Jihong Wang Copyright © 2013 Osama Raslan et al. All rights reserved.