Pennisi F, Farina R, Politi G, Lombardo R, Puleo S
Istituto di Radiologia, Università degli Studi, Catania.
Radiol Med. 1998 Dec;96(6):579-87.
The differential diagnosis of focal hepatic lesions is still studied by diagnostic imaging operators. A big step forward in the field of ultrasound (US) has come from the color Doppler mode permitting accurate studies of the vascularization of focal hepatic lesions. Echocontrast agents have further improved color Doppler sensitivity to slow flows and have permitted to visualize intralesional vascular signals which were missed at B-mode US. New data have thus been acquired which can be integrated with flowmetric findings to help make the correct differential diagnosis with a fair safety margin. We studied the pathognomonic US pattern for each type of lesion.
We examined 55 patients with single hepatic lesions which had already been typified: they were 10 hepatic angiomas, 3 focal nodular hyperplasias (FNH), 2 hepatic adenomas, 20 hepatocarcinomas and 20 hepatic metastases. Color Doppler investigations were performed on each patient before and after the intravenous (i.v.) administration of an echocontrast agent (Levovist, Schering AG, Berlin, Germany). For each lesion we studied the morphological characteristics, the resistance index (RI) of intralesional arterial vessels, the hepatic perfusion index and the maximum speed in intralesional vessels.
Contrast-enhanced US showed no intralesional signals or afferent branches in 8 hepatic angiomas, which however exhibited some peripheral vascularization; weak intralesional vascular signals were demonstrated in 2 cavernous angiomas. Intralesional signals, as well as peripheral vascularization, were detected in the 3 FNH cases, which also exhibited a centripetal afferent branch; the hepatic perfusion index in these lesions never exceeded .25. The two hepatic adenomas had similar color flowmetry to FNH also after i.v. contrast agent administration, except for the contripetal afferent vessel which was not seen. In the 20 hepatocarcinomas, contrast-enhanced images showed numerous intralesional signals and afferent branches which, with the peripheral vascularization, resulted in a basket-like pattern. Flowmetry of intralesional arterial vessels showed an irregular systodiastolic range, with RI = .32 +/- .5 in 12 lesions and high in the remaining 8 lesions (RI = .82 +/- 10). The hepatic perfusion index was .65 +/- 10 in all patients. In 14 of the 20 hepatic metastases, B-mode US showed no intralesional signals except for 6 metastases from colorectal carcinoma, and contrast-enhanced findings were about the same. The hepatic perfusion index at flowmetry ranged .30 to .45 in all patients.
诊断影像工作者仍在研究肝脏局灶性病变的鉴别诊断。超声（US）领域的一大进步来自彩色多普勒模式，它能准确研究肝脏局灶性病变的血管化情况。超声造影剂进一步提高了彩色多普勒对缓慢血流的敏感性，并能显示B超下遗漏的病灶内血管信号。由此获得的新数据可与血流测量结果相结合，以帮助在有合理安全边际的情况下做出正确的鉴别诊断。我们研究了每种病变类型的特征性超声表现。
我们检查了55例已明确类型的肝脏单发病变患者：其中10例为肝血管瘤，3例为局灶性结节性增生（FNH），2例为肝腺瘤，20例为肝癌，20例为肝转移瘤。在静脉注射（i.v.）超声造影剂（声诺维，先灵公司，柏林，德国）前后对每位患者进行彩色多普勒检查。对于每个病变，我们研究了其形态特征、病灶内动脉血管的阻力指数（RI）、肝脏灌注指数以及病灶内血管的最大速度。
超声造影显示8例肝血管瘤病灶内无信号或无传入分支，但有一些周边血管化；2例海绵状血管瘤显示微弱的病灶内血管信号。3例FNH病例检测到病灶内信号以及周边血管化，还显示有向心性传入分支；这些病变的肝脏灌注指数从未超过0.25。2例肝腺瘤在静脉注射造影剂后也有与FNH相似的彩色血流表现，但未见向心性传入血管。在20例肝癌中，超声造影图像显示大量病灶内信号和传入分支，加上周边血管化，形成篮状模式。病灶内动脉血管的血流测量显示收缩期和舒张期范围不规则，12个病灶的RI = 0.32 ± 0.05，其余8个病灶较高（RI = 0.82 ± 0.10）。所有患者的肝脏灌注指数为0.65 ± 0.10。在20例肝转移瘤中的14例，B超显示病灶内无信号，除了6例结直肠癌转移瘤，超声造影结果大致相同。所有患者血流测量时的肝脏灌注指数范围为0.30至0.45。
