肝脏螺旋CT动态增强扫描时肝动脉期肝实质一过性异常强化的研究

目的　研究肝脏螺旋CT动态增强扫描时肝动脉期肝实质一过性异常强化 (transienthepaticabnormalenhancement,THAE)的表现特征 ,探讨其产生原因及临床意义。方法　 1999年 1月至2 0 0 1年 9月 92 6例患者因各种原因接受了肝脏或上腹部螺旋CT扫描。CT扫描常规先作全肝或上腹部螺旋CT平扫 ;注射对比剂开始后 2 5～ 3 0s行肝动脉期扫描 ,65～ 70s行门静脉期扫描 ;对部分病例还行病灶局部延迟扫描 ,延迟时间为 3、5及 10～ 15min。肝动脉期共检出 82例 (男 72例 ,女 10例 ;年龄 2 6～ 78岁 )具有THAE ,着重对其在平扫和增强各期图像上的表现、与肝内或肝外病灶的关系以及门静脉系统情况做详细观察和记录。结果　 82例 (8 9% )共有 12 2处肝动脉期THAE ,其中 110处(90 2 % )平扫未显示THAE区域密度异常 ,12处 (9 8% )呈稍低密度 ;所有 12 2处THAE在肝动脉期都为均匀的高密度影 ;在门静脉期 ,10 9处 (89 3 % )转为等密度而不能分辨 ,余 13处 (10 7% )为均匀稍高密度影 (其中 10处作了延迟扫描 ,均转为等密度 )。 83处 (68 0 % )THAE呈边缘光滑的楔形或扇形 ,2 9处呈不规则形 (2 3 8% ) ,余为其他形状。THAE紧贴肝内肿瘤或其他病灶的有 46处 (3 7 7% ) ,邻近肝外肿瘤或其他病灶 2 0处 (16 4% ) ,余 5 6处 (45

A study on the transient hepatic abnormal enhancement in the hepatic arterial phase during dynamic contrast-enhanced spiral CT

Objective To define the features of transient hepatic abnormal enhancement (THAE) in the hepatic arterial phase (HAP) during dynamic contrast enhanced spiral CT, and to investigate the causes of THAE and emphasize its importance in CT scanning of the liver Methods In 32 months, spiral CT studies of the liver or upper abdomen in 926 patients with various causes were performed Unenhanced spiral CT images were routinely obtained before injection of contrast material, then spiral CT scans were performed during the HAP(25-30 seconds) and the portal venous phase (PVP) (65-70 seconds), respectively, and delayed phase scans of the local lesion in some patients were also acquired 3, 5 , and 10-15 minutes after the initiation of injection Eighty two patients (72 men, 10 women; age range, 26-78 years) were identified to have THAE The appearances of THAEs and the lesions in unenhanced and all of enhanced imaging (HAP, PVP, and delayed phase imaging for the local lesion) were carefully analyzed Results There were 122 THAEs in the 82 (8 9%) patients In unenhanced imaging, most ( n =110, 90 2%) of THAEs showed no attenuating abnormality, while some of them ( n =12, 9 8%) were faintly hypoattenuating All of 122 THAEs in HAP imaging showed homogeneous hyperattenuating, and they changed to isoattenuating ( n =109, 89 3%) or slightly hyperattenuating ( n =13, 10 7%, among them, 10 THAEs with delayed phase imaging changed to isoattenuating) in PVP imaging The morphology of THAE in HAP imaging was wedge shaped or fan shaped in 83 (68 0%), irregular shape in 29 (23 8%), and others in 10 (8 2%) THAEs There were 46 (37 7%) THAEs to be located right next to hepatic tumors or other lesions, 20 (16 4%) THAEs close to tumors or other lesions bordering on the livers, and 56 (45 9%) THAEs far from tumors or other lesions both inside and outside the livers In PVP imaging, the portal vein (or its left branch) or splenic vein displayed marked stenosis or obstruction (i e, not enhanced by contrast media) in 29 patients, in whom there were 50 THAEs which were mostly located in the left lobes ( P <0 01) and they could be demonstrated as segmental or lobar hyperattenuating in HAP imaging Conclusion In HAP of dynamic contrast enhanced spiral CT, THAE may not be unusual The features of THAE could distinguish it from liver parenchymal lesions The cause of THAE is varied It is highly important to recognize and to distinguish THAE, which could increase the level of diagnosing diseases both inside and outside liver and avoid unsuitable biopsy or treatment