76例胆道梗阻的影像学分析

目的：探讨半傅立叶单次激发快速自旋回波序列（HASTE）磁共振胆管成像（MRCP）对胰、胆管疾病的临床诊断价值,并与其他序列及影像学检查比较。方法：通过Siemens1.5T Vision Plus扫描仪,采用自控阵表面线圈,加脂肪抑制和图像预饱和技术,以HASTE序列重T2加权相多层扫描,进行三维重建,多角度多方位观察。结果：本组76例病人,胰胆管良性梗阻16例,表现为胆总管近端扩张,远端逐渐变细,边缘光滑,全层无中断,呈不全梗阻,胰腺的良性梗阻表现为“管道穿通征”阳性;恶性梗阻28例,梗阻端形态以截断状最多见,其次为乳头状和“鼠尾征”。另外胰头癌和壶腹癌可见“双管征”即梗阻平面以上胆总管和胰管均扩张。本组MRCP的敏感性、特异性和准确性分别为91.0％、96.5％、94.7％。确诊率：MRCP94.7％,超声77.7％,CT76.3%,ERCP（逆行内镜胰胆管成像）90.0％。结论：HASTE MRCP作为无创性技术,成像速度快,空间分辨率高,能完整显示胰胆管系统结构,优于ERCP和PTC,是目前理想的成像方法。初步认为,“双管征”多见于恶性梗阻,“管道穿通征”见于良性梗阻,可作为鉴别良恶性梗阻的重要指征。

Obstructive diseases of the biliary tree: an imaging analysis of 76 cases]

OBJECTIVE: To test the value of magnetic resonance cholangiopancreatography (MRCP) with half-Fourier acquisition single-shot (HASTE) sequence in the diagnosis of the biliary obstructive diseases in comparison with other imaging examinations. METHODS: Altogether 76 patients with pancreaticobiliary duct diseases underwent MRCP on Siemens 1.5T Vision Plus scanner, and a heavily T2-weighted HASTE was obtained during a breath-hold. The findings of MRCP images were analyzed and compared with those of ultrasound, CT, (endoscopic retrograde cholangiopancreatography ERCP) or PTC. RESULTS: The sensitivity, specificity and accuracy of MRCP were 91.0%, 96.50%, and 94.00% respectively in detecting both benign and malignant obstructions. The diagnostic accuracy of MRCP was close to ERCP, and obviously superior to CT and ultrasound (P<0.05). Benign obstructions were characterized by dilatation of proximal end of the common bile duct (CBD) and gradual stenosis in the distal CBD with tapered margin without interruptions, known as "duct-penetrating sign". It was most commonly seen that malignant obstructive ends presented "truncated form" and "rat-tail" form. CONCLUSION: T2-weighted HASTE is the T2 optional noninvasive technique with excellent accuracy in diagnosing biliary obstruction and defining their causes. The degree of biliary dilation, the pattern of obstructive ends and the "double duct sign"and "duct-penetrating sign" may serve as important indicators for differentiating benign and malignant obstructions.