Monzawa Shuichi, Ichikawa Tomoaki, Nakajima Hiroto, Kitanaka Yuki, Omata Kosaku, Araki Tsutomu
Department of Radiology, Yamanashi Hospital, Kofu, Yamanashi, Japan.
AJR Am J Roentgenol. 2007 Jan;188(1):147-53. doi: 10.2214/AJR.05.0512.
The purpose of this retrospective study was to determine the usefulness of delayed phase imaging for detecting small (< or = 2 cm) hepatocellular carcinomas (HCCs) in patients with liver cirrhosis.
Triphasic (arterial, portal venous, and delayed phases) dynamic CT was performed in 33 patients with 48 HCCs proven histopathologically and in 65 control subjects. Arterial, portal venous, and delayed phase images were obtained 30 seconds, 68-70 seconds, and 5 minutes after the start of contrast material injection, respectively. Three blinded observers reviewed the images independently and evaluated tumor attenuation. Diagnostic performance for the combination of phases was assessed using receiver operating characteristic (ROC) curve analysis.
On arterial phase images, 28 of the 48 HCCs were hyperattenuating, nine were isoattenuating, and 11 were hypoattenuating. On portal venous phase images, three tumors were hyperattenuating, 17 were isoattenuating, and 28 were hypoattenuating. On delayed phase images, five tumors were isoattenuating, and 43 were hypoattenuating. The mean sensitivity for the combination of arterial and portal venous phase imaging was 86.8%, that for the combination of arterial and delayed phase imaging was 90.3%, and that for the combination of all three phase imaging was 93.8%. The area underneath composite ROC curve (A(Z)) for the combination of all three phase imaging (A(Z) = 0.940) was significantly higher than that for the combination of arterial and portal venous phase imaging (A(Z) = 0.917) and for the combination of arterial and delayed phase imaging (A(Z) = 0.922).
Delayed phase imaging is useful for detecting small HCCs and should be included in dynamic CT examinations of patients with liver cirrhosis.
本回顾性研究旨在确定延迟期成像在检测肝硬化患者小（≤2 cm）肝细胞癌（HCC）中的作用。
对33例经组织病理学证实患有48个HCC的患者以及65名对照者进行了三期（动脉期、门静脉期和延迟期）动态CT检查。分别在注入对比剂开始后30秒、68 - 70秒和5分钟获得动脉期、门静脉期和延迟期图像。三名盲法观察者独立审查图像并评估肿瘤密度。使用受试者操作特征（ROC）曲线分析评估各期联合的诊断性能。
在动脉期图像上，48个HCC中28个呈高密度，9个等密度，11个低密度。在门静脉期图像上，3个肿瘤呈高密度，17个等密度，28个低密度。在延迟期图像上，5个肿瘤等密度，43个低密度。动脉期和门静脉期成像联合的平均敏感性为86.8%，动脉期和延迟期成像联合的为90.3%，三期成像联合的为93.8%。三期成像联合的复合ROC曲线下面积（A(Z)=0.940）显著高于动脉期和门静脉期成像联合的（A(Z)=0.917）以及动脉期和延迟期成像联合的（A(Z)=0.922）。
延迟期成像对检测小HCC有用，应纳入肝硬化患者的动态CT检查中。
