PURPOSE: To demonstrate the feasibility of diffusion-tensor magnetic resonance imaging (MRI) and tractography as a means of evaluating the individual layers of the normal esophageal wall by using esophageal specimens containing carcinoma. MATERIALS AND METHODS: Twelve esophageal specimens each containing a carcinoma that were preserved in formalin were studied with a 7.0-T small-bore MR system equipped with a four-channel phased-array surface coil. Diffusion-tensor MR images were obtained with a field of view of 50-60 × 25-30 mm, matrix of 256 × 128, section thickness of 1 mm, b value of 1000 sec/mm(2) , and motion-probing gradient in seven noncollinear directions. The diffusion-weighted images, apparent diffusion coefficient (ADC) maps, fractional anisotropy (FA) maps, direction-encoded color FA maps, and tractographic images in the 12 esophageal specimens were compared with the histopathologic findings, which served as the gold standard. RESULTS: The diffusion-weighted images, ADC maps, FA maps, and direction-encoded color FA maps depicted the normal esophageal wall in all 12 specimens (100%) as consisting of eight layers, which clearly corresponded to the tissue layers of the esophageal wall. The ADC, FA, λ1 , λ2 , and λ3 values of each layer of the normal esophageal wall were significantly different from the corresponding values of the adjacent layer or layers of the esophageal wall. Diffusion-tensor tractographic images were able to selectively display the layers of the normal esophageal wall. CONCLUSION: By looking at the normal part of esophageal specimens containing carcinoma, we have demonstrated that diffusion-tensor MRI and tractography are capable of depicting the individual tissue layers of the normal esophageal wall.
PURPOSE: To demonstrate the feasibility of diffusion-tensor magnetic resonance imaging (MRI) and tractography as a means of evaluating the individual layers of the normal esophageal wall by using esophageal specimens containing carcinoma. MATERIALS AND METHODS: Twelve esophageal specimens each containing a carcinoma that were preserved in formalin were studied with a 7.0-T small-bore MR system equipped with a four-channel phased-array surface coil. Diffusion-tensor MR images were obtained with a field of view of 50-60 × 25-30 mm, matrix of 256 × 128, section thickness of 1 mm, b value of 1000 sec/mm(2) , and motion-probing gradient in seven noncollinear directions. The diffusion-weighted images, apparent diffusion coefficient (ADC) maps, fractional anisotropy (FA) maps, direction-encoded color FA maps, and tractographic images in the 12 esophageal specimens were compared with the histopathologic findings, which served as the gold standard. RESULTS: The diffusion-weighted images, ADC maps, FA maps, and direction-encoded color FA maps depicted the normal esophageal wall in all 12 specimens (100%) as consisting of eight layers, which clearly corresponded to the tissue layers of the esophageal wall. The ADC, FA, λ1 , λ2 , and λ3 values of each layer of the normal esophageal wall were significantly different from the corresponding values of the adjacent layer or layers of the esophageal wall. Diffusion-tensor tractographic images were able to selectively display the layers of the normal esophageal wall. CONCLUSION: By looking at the normal part of esophageal specimens containing carcinoma, we have demonstrated that diffusion-tensor MRI and tractography are capable of depicting the individual tissue layers of the normal esophageal wall.