From the Departments of Diagnostic Radiology and Oncology (I.Y.), Pediatrics, Perinatal and Maternal Medicine (N.M.), Esophagogastric Surgery (T.K., Y.T.), and Pathology (E.I., D.K., Y.E.), Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Department of Physiology, Keio University School of Medicine, Tokyo, Japan (K.H., H.O.); and Central Institute for Experimental Animals, Kawasaki, Kanagawa, Japan (K.H.).
Radiology. 2014 Jul;272(1):164-73. doi: 10.1148/radiol.14132170. Epub 2014 Mar 21.
To determine the feasibility of diffusion-tensor magnetic resonance (MR) imaging and tractography as a means of evaluating the depth of mural invasion by esophageal carcinomas.
This study was approved by the institutional review board, and written informed consent was obtained from each patient. Twenty esophageal specimens, each containing a carcinoma, were studied with a 7.0-T MR imaging system equipped with a four-channel phased-array surface coil. Diffusion-tensor MR images were obtained with a field of view of 50-60 mm × 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 MR images were compared with the histopathologic findings as the reference standard. The differences in diffusion-tensor MR imaging parameters between the carcinoma and the layers of the esophageal wall were statistically analyzed by using the Dunnett test.
In all 20 carcinomas (100%), the diffusion-weighted images, apparent diffusion coefficient (ADC) maps, fractional anisotropy (FA) maps, λ1 maps, and direction-encoded color FA maps made it possible to determine the depth of tumor invasion of the esophageal wall that was observed during histopathologic examination. The λ1 maps showed the best contrast between the carcinomas and the layers of the esophageal wall. The carcinomas had both lower ADC values and lower FA values than the normal esophageal wall; thus, the carcinomas were clearly demarcated from the normal esophageal wall. Diffusion-tensor tractography images were also useful for determining the depth of tumor invasion of the esophageal wall.
Diffusion-tensor MR imaging and tractography are feasible in esophageal specimens and provide excellent morphologic data for the evaluation of mural invasion by esophageal carcinomas.
旨在确定弥散张量磁共振（MR）成像和轨迹技术评估食管癌壁浸润深度的可行性。
本研究经机构审查委员会批准，并获得每位患者的书面知情同意。20 个包含食管癌的食管标本在配备四通道相控阵表面线圈的 7.0-T MR 成像系统上进行研究。弥散张量 MR 图像的视野为 50-60mm×25-30mm，矩阵为 256×128，层厚 1mm，b 值为 1000sec/mm²，在七个非共线方向上施加运动探测梯度。MR 图像与组织病理学发现作为参考标准进行比较。使用 Dunnett 检验对癌与食管壁各层之间的弥散张量 MR 成像参数差异进行统计学分析。
在 20 例（100%）癌中，弥散加权图像、表观扩散系数（ADC）图、各向异性分数（FA）图、λ1 图和方向编码彩色 FA 图均能确定在组织病理学检查中观察到的食管壁肿瘤浸润深度。λ1 图显示癌与食管壁各层之间的对比度最佳。癌的 ADC 值和 FA 值均低于正常食管壁，因此癌与正常食管壁清晰区分。弥散张量轨迹图也有助于确定食管壁肿瘤浸润的深度。
弥散张量 MR 成像和轨迹技术在食管标本中是可行的，可为评估食管癌壁浸润提供优异的形态学数据。
