Esophageal carcinoma: Evaluation with q-space diffusion-weighted MR imaging ex vivo.

PURPOSE: To determine the usefulness of q-space MR imaging as means of evaluating the depth of mural invasion, the histologic grades, and lymph node metastasis in esophageal carcinomas. METHODS: Twenty esophageal specimens each containing a carcinoma were studied with a 7.0 Tesla MR imaging system. q-Space MR images were obtained with a 50-60 mm × 25-30 mm field of view, 256 × 128 matrix, 2 mm section thickness, 10 b values ranging from 0 to 7163 s/mm(2) , and a motion-probing gradient in the y-direction, and the MR images were compared with the histopathologic findings. RESULTS: The mean displacement maps, probability for zero displacement maps, and kurtosis maps in all 20 carcinomas (100%) made it possible to identify the depth of tumor invasion of the esophageal wall. These q-space MR imaging parameters were significantly correlated with the histologic grades of the esophageal carcinomas (P < 0.01), and also significantly correlated with their nuclear-cytoplasmic ratios (P < 0.01 or P < 0.001) and tumor cellularity (cell density) (P < 0.01 or P < 0.001). The q-space MR imaging parameters were also capable of differentiating between the metastatic lymph nodes and nonmetastatic lymph nodes (P < 0.01). CONCLUSION: q-Space MR imaging ex vivo provides excellent diagnostic accuracy for evaluating mural invasion by esophageal carcinomas, the histologic grades of esophageal carcinomas, and lymph node metastasis by esophageal carcinomas.