Comparing PET/MRI with PET/CT for Pretreatment Staging of Gastric Cancer

Figure 4

(a) A 75-year-old man with gastric carcinoma diagnosed as lymph node metastasis. (A) The axial CT image shows an enlarged lymph node (arrow) next to the lesion (arrowhead). (B, D) A fusion PET/MRI and PET/CT image shows the enlarged lymph node with FDG uptake and an SUVmax of 3.4 (arrow). (C) One T2-weighted axial image shows a mild-high signal intensity enlarged lymph node (arrow) next to the antrum. (E) One PET image when an obviously avid FDG uptake was observed (arrow). (F) One diffusion-weighted image shows the enlarged lymph node with high signal intensity (arrow), suggesting diffusion restriction. With the aid of these images, indicating a metastatic lymph node, a preoperative diagnosis of N+ could be made. (b) A 67-year-old man with gastric carcinoma diagnosed as a short diameter 5 mm perigastric metastatic lymph node (arrow). The lymph node near the lesser curvature of the stomach is not found as a metastasis lesion on the CT and PET (A, C, D) and no increased FDG uptake (B). It can be diagnosed through diffusion-weighted imaging () and T2-weighted saturated fat imaging due to its high signal intensity on both modalities (E, F).

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