胆汁流动伪影的MR胆胰管成像表现

Findings of bile flow artifacts on MR cholangiopancreatography

目的探讨MR胆胰管成像（MRCP）上胆汁流动伪影的影像表现。方法回顾性分析85例胆总管正常和95例胆总管扩张患者的MRCP资料，在MRCP原始薄层图像上观察记录胆汁流动伪影的表现，采用x^2。检验对各组胆汁流动伪影的发生率进行比较，采用Spearman等级相关分析检验胆总管直径和伪影表现形式的关系。结果胆总管正常组流动伪影发生率38．8％（33／85），扩张组流动伪影发生率83．2％（79／95），差异有统计学意义（x^2=37．512，P=0．000）。胆总管直径（φ）≤4mm时无流动伪影，4mm〈φ≤8mm时，流动伪影主要表现为单线征（52．6％，30／57）。胆总管轻度扩张时，流动伪影主要表现为三线征（85．7％，36／42）；中度扩张时主要表现为多线征（84．6％，22／26），各组问表现差异有统计学意义（x^2=284．561，P=0．000）。随胆总管直径增加，伪影的表现形式不同，二者有相关性（r=0．553，P=0．000）。结论胆总管正常组可以发生流动伪影；胆总管扩张组流动伪影发生率高于正常组；胆汁流动伪影的表现形式与胆总管直径有相关性。

Objective To explore the findings of bile flow artifacts （BFA） on MR cholangiopancreatography（MRCP）. Methods Eighty five patients with normal common bile duct （CBD） and 95 patients with dilated CBD who had MRCP examination were studied retrospectively. Findings of BFA on original thin images of MRCP were recorded. Date were tested by Chi-square test and Spearman coefficient of rank correlation analysis. Results The rate of BFA in CBD with normal group was 38.8% （33/85） , in dilated group was 83.2% （79/95）, there was statistically significant difference between them（ x^2 = 37. 512, P = 0. 000 ）. BFA was not observed when the diameter of CBD was no more than 4 ram. BFA was partly observed when the diameter of CBD was 4 mm〈 φ≤ 8 mm, singlestring sign was predominant findings （52. 6% ,30/57）. Three-string sign was predominant findings in CBD with slight-dilated group （85.7%, 36/42）. Multi-string sign was predominant findings in CBD with medium-dilated group（84. 6% ,22/26）. There was statistically significant difference between each groups （ x^2 = 284. 561, P = 0. 000 ） . BFA had different manifestations with CBD of different diameter, there was relative between them （ r = 0. 553, P = 0. 000）. Conclusion BFA can occur in CBD with normal diameter. CBD with dilated group has higher rate of BFA than CBD with normal diameter. Manifestations of BFA are relative with the diameter of CBD.