The purpose of this study was to assess the value of diffusion-weighted magnetic resonance imaging (DWI) in detecting esophageal cancer and assessing lymph-node status, compared with histopathological results. DWI was prospectively performed in 24 consecutive patients with esophageal cancer, using the diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) sequence. DWIBS images were fused with T2-weighted images, and independently and blindly evaluated by three board-certified radiologists, regarding primary tumor detectability and lymph-node status. Apparent diffusion coefficients (ADCs) of the primary tumor and lymph nodes were also measured. Average primary tumor detection rate was 49.4%, average patient-based sensitivity and specificity for the detection of lymph-node metastasis were 77.8 and 55.6%, and average lymph-node group-based sensitivity and specificity were 39.4 and 92.6%. There were no interobserver differences among the three readers (P < 0.0001). Mean ADC of detected primary tumors was 1.26 +/- 0.29x10(-3) mm(2)/s. Mean ADC of metastatic lymph nodes (1.46 +/- 0.35x10(-3) mm(2)/s) was significantly higher (P < 0.0001) than that of nonmetastatic lymph nodes (1.15 +/- 0.24 mm(2)/s), but ADCs of both groups overlapped. In conclusion, this study suggests that DWI only has a limited role in detecting esophageal cancer and nodal staging.

The present study was conducted to clarify the diagnostic accuracy of 18F-fluoro-2-deoxy-D-glucose (18FDG) positron emission tomography (PET)/computed tomography (CT) in the staging in pediatric sarcomas. Fifty pediatric patients with histologically proven sarcomas who underwent 18FDG PET/CT before treatment were evaluated retrospectively for the detection of nodal and distant metastases. Diagnostic accuracy of 18FDG PET/CT in detecting nodal and distant metastases was compared with that of 18FDG PET and conventional imaging (CI). The images were reviewed and a diagnostic consensus was reached by 3 observers. REFERENCE standard was histologic examination in 15 patients and confirmation of an obvious progression in size of the lesions on follow-up examinations. Nodal metastasis was correctly assessed in 48 patients (96%) with PET/CT, in contrast to 43 patients (86%) with PET, and 46 patients (92%) with CI. Diagnostic accuracies of nodal metastasis in 3 modalities were similar. Using PET/CT, distant metastasis was correctly assigned in 43 patients (86%), whereas interpretation based on PET alone or CI revealed distant metastasis in 33 patients (66%) and 35 patients (70%), respectively. Diagnostic accuracy of distant metastasis with PET/CT was significantly higher than that of PET (P=0.002) or CI (P=0.008). False negative results regarding distant metastasis by PET/CT in 7 patients (14%) were caused by subcentimetric lesions (n=4), bone marrow lesion (n=2), and soft tissue lesions (n=1). PET/CT is more accurate and probably more cost-effective than PET alone or CI regarding distant metastasis in pediatric sarcomas.

SPIO-enhanced MR imaging at 3.0 T provided better diagnostic performance for detection of hepatic metastases than 1.5 T.