Brancatelli Giuseppe, Baron Richard L, Peterson Mark S, Marsh Wallis
Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St., Pittsburgh, PA 15213, USA.
AJR Am J Roentgenol. 2003 Apr;180(4):1007-14. doi: 10.2214/ajr.180.4.1801007.
The purpose of our study was to determine the specificity of helical CT for depiction of hepatocellular carcinoma in a population of patients with cirrhosis.
Single-detector helical CT screening was undertaken in 1329 patients with cirrhosis who were referred for transplantation. The patients underwent one or more helical CT examinations over 30 months and were followed up for an additional 19 months or until transplantation. We predominantly used unenhanced and biphasic contrast-enhanced techniques with infusions of 2.5-5.0 mL/sec. Four hundred thirty patients underwent transplantation within this period. Liver specimens were sectioned at 1-cm intervals, with direct comparison of imaging and pathologic findings and histologic confirmations of all lesions. Prospective preoperative helical CT reports were used for the primary data analysis. A retrospective unblinded review was undertaken to determine characteristics of false-positive lesions diagnosed as hepatocellular carcinoma.
Thirty-five patients (8%) had false-positive diagnoses for hepatocellular carcinoma based on helical CT. Twenty of these patients (5%) showed hypoattenuating lesions seen during one of the three helical CT examination phases. Fifteen patients (3%) had hyperattenuating lesions seen during the arterial phase. Among the 15 hyperattenuating lesions, CT revealed the causes to be transient benign hepatic enhancement (n = 3), hemangiomas (n = 2), fibrosis (n = 2), peliosis (n = 1), volume averaging (n = 1), low-grade dysplastic nodule (n = 1), or undetermined (n = 5). Of the 20 hypoattenuating lesions, the causes were shown to be fibrosis (n = 8), focal fat (n = 4), infarcted regenerative nodules (n = 2), regenerative nodules (n = 1), fluid trapped at the dome of the liver (n = 1), hemangioma (n = 1), or undetermined (n = 3). Follow-up helical CT in 13 (72%) of 18 patients allowed a change in the diagnosis of hepatocellular carcinoma to a finding of no cancer present.
Helical CT screening for hepatocellular carcinoma in patients with cirrhosis has a substantial false-positive detection rate. Although most of lesions were hypoattenuating, a few hyperenhancing arterial phase lesions were proven not to be hepatocellular carcinoma. An awareness of imaging characteristics and follow-up imaging can help radiologists avoid a mistaken diagnosis in many patients.
我们研究的目的是确定螺旋CT在肝硬化患者群体中对肝细胞癌的诊断特异性。
对1329例因移植而转诊的肝硬化患者进行单排螺旋CT筛查。这些患者在30个月内接受了一次或多次螺旋CT检查，并额外随访19个月或直至移植。我们主要采用非增强和双期对比增强技术，注射速率为2.5 - 5.0 mL/秒。在此期间，430例患者接受了移植。肝脏标本每隔1厘米切片，将影像学和病理结果直接对比，并对所有病变进行组织学确认。前瞻性术前螺旋CT报告用于主要数据分析。进行回顾性非盲法复查以确定诊断为肝细胞癌的假阳性病变的特征。
35例患者（8%）基于螺旋CT被误诊为肝细胞癌。其中20例患者（5%）在三个螺旋CT检查阶段之一出现低密度病变。15例患者（3%）在动脉期出现高密度病变。在这15个高密度病变中，CT显示其原因分别为短暂性良性肝脏强化（n = 3）、血管瘤（n = 2）、纤维化（n = 2）、肝紫癜（n = 1）、容积效应（n = 1）、低度发育异常结节（n = 1）或未明确（n = 5）。在20个低密度病变中，其原因分别为纤维化（n = 8）、局灶性脂肪（n = 4）、梗死性再生结节（n = 2）、再生结节（n = 1）、肝顶部积液（n = 1）、血管瘤（n = 1）或未明确（n = 3）。18例患者中有13例（72%）进行了随访螺旋CT检查，结果显示肝细胞癌的诊断转变为未发现癌症。
对肝硬化患者进行肝细胞癌的螺旋CT筛查有相当高的假阳性检出率。虽然大多数病变为低密度，但少数动脉期强化的病变被证实并非肝细胞癌。了解影像学特征并进行随访成像有助于放射科医生在许多患者中避免误诊。
