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/mm², 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. Magn Reson Med 73:2262-2273, 2015.