Yamada Ichiro, Yoshino Norio, Hikishima Keigo, Miyasaka Naoyuki, Yamauchi Shinichi, Uetake Hiroyuki, Yasuno Masamichi, Saida Yukihisa, Tateishi Ukihide, Kobayashi Daisuke, Eishi Yoshinobu
Department of Diagnostic Radiology and Nuclear Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Oral and Maxillofacial Radiology, Tokyo Medical and Dental University, Tokyo, Japan.
Magn Reson Imaging. 2017 May;38:174-181. doi: 10.1016/j.mri.2016.12.028. Epub 2017 Jan 5.
In this study, we aimed to evaluate the feasibility of determining the mural invasion depths of colorectal carcinomas using high-spatial-resolution (HSR) quantitative T2 mapping on a 3-T magnetic resonance (MR) scanner.
Twenty colorectal specimens containing adenocarcinomas were imaged on a 3-T MR system equipped with a 4-channel phased-array surface coil. HSR quantitative T2 maps were acquired using a spin-echo sequence with a repetition time/echo time of 7650/22.6-361.6ms (16 echoes), 87×43.5-mm field of view, 2-mm section thickness, 448×224 matrix, and average of 1. HSR fast-spin-echo T2-weighted images were also acquired. Differences between the T2 values (ms) of the tumor tissue, colorectal wall layers, and fibrosis were measured, and the MR images and histopathologic findings were compared.
In all specimens (20/20, 100%), the HSR quantitative T2 maps clearly depicted an 8-layer normal colorectal wall in which the T2 values of each layer differed from those of the adjacent layer(s) (P<0.001). Using this technique, fibrosis (73.6±9.4ms) and tumor tissue (104.2±6.4ms) could also be clearly differentiated (P<0.001). In 19 samples (95%), the HSR quantitative T2 maps and histopathologic data yielded the same findings regarding the tumor invasion depth.
Our results indicate that 3-T HSR quantitative T2 mapping is useful for distinguishing colorectal wall layers and differentiating tumor and fibrotic tissues. Accordingly, this technique could be used to determine mural invasion by colorectal carcinomas with a high level of accuracy.
在本研究中，我们旨在评估在3-T磁共振（MR）扫描仪上使用高空间分辨率（HSR）定量T2成像测定结直肠癌壁内浸润深度的可行性。
20个含有腺癌的结直肠标本在配备有4通道相控阵表面线圈的3-T MR系统上成像。使用重复时间/回波时间为7650/22.6 - 361.6 ms（16个回波）、视野为87×43.5 mm、层厚2 mm、矩阵为448×224且平均次数为1的自旋回波序列采集HSR定量T2图。还采集了HSR快速自旋回波T2加权图像。测量肿瘤组织、结直肠壁各层和纤维化的T2值（ms）之间的差异，并比较MR图像和组织病理学结果。
在所有标本中（20/20，100%），HSR定量T2图清晰显示出正常的8层结直肠壁，其中各层的T2值与相邻层不同（P<0.001）。使用该技术，纤维化（73.6±9.4 ms）和肿瘤组织（104.2±6.4 ms）也能清晰区分（P<0.001）。在19个样本（95%）中，HSR定量T2图和组织病理学数据在肿瘤浸润深度方面得出了相同的结果。
我们 的结果表明，3-T HSR定量T2成像有助于区分结直肠壁各层以及区分肿瘤和纤维化组织。因此，该技术可用于高精度地确定结直肠癌的壁内浸润情况。
