相位阵列线圈高分辨MRI显示肛管和肛周结构及其意义

The demonstration of the normal anal canal and perianal structures by high-resolution magnetic resonance imaging with a phased-array coil

目的:探讨应用体外相位阵列线圈高分辨MRI技术对肛管和肛周结构显示的可行性及其价值。方法:应用体外圆形极化相位阵列脊柱线圈对20例健康志愿者进行了高分辨MR扫描,扫描序列包括轴位T1WI,轴位、矢状和冠状平面T2WI及Gd-DTPA增强扫描的T1WI,轴位和冠状扫描平面分别垂直和平行于肛管的长轴。结果:肛管的粘膜、粘膜下层、肛门括约肌及会阴部结构如会阴体、会阴浅横肌、球海绵体肌、坐骨海绵体肌等在T2WI上均可清楚显示。男性和女性的肛管结构存在差异,女性外括约肌的前部明显短于后部,会阴体较男性大,而男性的球海绵体肌较女性厚。结论:体外相位阵列线圈高分辨MRI技术可清楚显示肛管和肛周结构的正常解剖,可为肛管区域病变的正确诊断和治疗提供较精确的解剖信息。

Objective ：To evaluate the feasibility and value of a high-resolution magnetic resonance imaging（MRI） technique with a phased-array coil in demonstrating in full the anal canal and perianal structures. Methods： with an circularly polarized phase array coil （T1 and T2 -weighted turbo spin echo） were performed in 20 healthy volunteers. Axial T1W, axial, sagittal and coronal T2W and Gd-DTPA contrast-enhanced T1W images were obtained. It was important that axial and coronal angle was respectively perpendicular and parallel to the long axis of the anal canal. Results： Mucosa and submucosa of the anal canal, anal sphincters, as well some perineal structures such as perineal body, superficial transverse perineal muscle, bulbospongiosus and ischiocavemosus were clearly shown on T2W images. Male anal canal was different from females＇. The anterior external sphincter was shorter than its posterior part in women. The perineal body was thicker in women than in men and the bulbospongiosus was thicker in men than women. Conclusions： High-resolution MRI technique with a phased-array coil provides information for the normal anatomy of the anal canal and perianal structures. The results suggest useful applications in the diagnosis and management of anal diseases.