deSouza N M, Puni R, Kmiot W A, Bartram C I, Hall A S, Bydder G M
Robert Steiner Magnetic Resonance Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, England.
J Comput Assist Tomogr. 1995 Sep-Oct;19(5):745-51. doi: 10.1097/00004728-199509000-00010.
The anal sphincter was imaged with MR using an internal coil to demonstrate its anatomy, contrast enhancement patterns, and appearance in disease.
A cylindrical saddle geometry coil was placed in the anal canal. Sixteen volunteers and 18 patients were examined. Imaging was performed on a 0.5 T Picker Asset MRI scanner in all the volunteers and nine patients and on a 1.0 T Picker HPQ Vista in nine patients. Then T1- and T2-weighted SE, T1-weighted GE and STIR images transverse to the sphincter, and T1-weighted SE images parallel to the sphincter in the coronal oblique plane were obtained. Intravenous gadopentetate dimeglumine (0.1 mmol/kg) was given to 2 normal subjects for dynamic studies and 10 patients for conventional postcontrast imaging.
The coils were easy to insert and well tolerated and provided high spatial resolution. The internal sphincter had a higher signal intensity than the external sphincter on all sequences but particularly on STIR images. Brisk contrast enhancement of the internal sphincter was seen. Sphincteric abscesses and fistulous tracks were identified in three patients and confirmed at surgery. Sphincter defects were seen in three patients with past obstetric trauma, and these were also confirmed at surgery. Sphincter atrophy was seen in three patients with idiopathic fecal soiling.
MRI of the anal sphincter with an internal coil provides excellent visualization of normal anatomy and may be of considerable value in diagnosis.
使用内置线圈对肛门括约肌进行磁共振成像，以显示其解剖结构、对比增强模式及在疾病中的表现。
将圆柱形鞍形线圈置于肛管内。对16名志愿者和18名患者进行检查。所有志愿者及9名患者在0.5T的Picker Asset MRI扫描仪上成像，另外9名患者在1.0T的Picker HPQ Vista上成像。然后获取与括约肌垂直的T1加权和T2加权SE、T1加权GE及STIR图像，以及在冠状斜面上与括约肌平行的T1加权SE图像。对2名正常受试者给予静脉注射钆喷酸葡胺（0.1 mmol/kg）进行动态研究，对10名患者进行常规增强后成像。
线圈易于插入且耐受性良好，提供了高空间分辨率。在所有序列上，内括约肌的信号强度均高于外括约肌，尤其是在STIR图像上。可见内括约肌有明显的对比增强。在3名患者中发现了括约肌脓肿和瘘管，并经手术证实。在3名有既往产科创伤的患者中发现了括约肌缺陷，也经手术证实。在3名特发性大便失禁患者中发现了括约肌萎缩。
使用内置线圈对肛门括约肌进行磁共振成像可清晰显示正常解剖结构，在诊断中可能具有重要价值。
