Stevens S D, Heiken J P, Brunt E, Hanto D W, Flye M W
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110.
AJR Am J Roentgenol. 1991 Dec;157(6):1195-8. doi: 10.2214/ajr.157.6.1950864.
Recent reports indicate that the presence or absence of a periportal low-attenuation rim ("periportal collar" sign) on CT scans is of variable reliability in predicting rejection after liver transplantation. To study this matter further, we reviewed 178 CT scans in 68 patients (74 allografts) after hepatic transplantation. One hundred twenty-one scans were obtained within 7 days of liver biopsy. The presence or absence of a central or peripheral periportal collar on these scans was correlated with the presence or absence of acute rejection found at biopsy. A central periportal collar was defined as an abnormally large amount of low-attenuation material surrounding the main portal vein, the right portal vein, or the left portal vein. A peripheral periportal collar was defined as a low-attenuation area surrounding a portal vein branch distal to the left or right portal veins. A weak, but statistically significant correlation between the presence of a peripheral periportal collar and acute allograft rejection was shown in patients in whom CT scans were obtained within 3 days of biopsy. However, the sensitivity, specificity, accuracy, and positive predictive value of the presence of a peripheral collar in this group were 60%, 67%, 64%, and 63%, respectively. The sensitivity, specificity, accuracy, and positive predictive value of the presence of a central collar in patients scanned within 3 days of biopsy were 74%, 35%, 54%, and 52%, respectively. Negative predictive values of peripheral and central collars were 65% and 59%, respectively. Our study shows that a periportal collar is seen more commonly in patients with recently transplanted allografts (mean interval after transplantation, 46 days for peripheral collars and 57 days for central collars) and in patients with ascites. The presence of a central or peripheral periportal collar on CT is not sufficiently sensitive, specific, or accurate to reliably diagnose or exclude acute allograft rejection.
近期报告表明，CT扫描上是否存在肝门周围低密度边缘（“肝门周围套圈”征）在预测肝移植后排斥反应方面的可靠性不一。为进一步研究此问题，我们回顾了68例患者（74个同种异体移植物）肝移植后的178次CT扫描。121次扫描是在肝活检后7天内进行的。这些扫描上是否存在中央或外周肝门周围套圈与活检时发现的急性排斥反应的有无相关。中央肝门周围套圈定义为围绕主门静脉、右门静脉或左门静脉的异常大量低密度物质。外周肝门周围套圈定义为位于左或右门静脉远端的门静脉分支周围的低密度区域。在活检后3天内进行CT扫描的患者中，外周肝门周围套圈的存在与急性同种异体移植物排斥反应之间存在微弱但具有统计学意义的相关性。然而，该组中外周套圈存在的敏感性、特异性、准确性和阳性预测值分别为60%、67%、64%和63%。活检后3天内进行扫描的患者中，中央套圈存在的敏感性、特异性、准确性和阳性预测值分别为74%、35%、54%和52%。外周和中央套圈的阴性预测值分别为65%和59%。我们的研究表明，肝门周围套圈在近期接受同种异体移植的患者（移植后平均间隔时间，外周套圈为46天，中央套圈为57天）和腹水患者中更常见。CT上中央或外周肝门周围套圈的存在在可靠诊断或排除急性同种异体移植物排斥反应方面不够敏感、特异或准确。
