Quillin S P, Atilla S, Brown J J, Borrello J A, Yu C Y, Pilgram T K
Mallinckrodt Institute of Radiology, St. Louis, MO 63110, USA.
Magn Reson Imaging. 1997;15(3):275-85. doi: 10.1016/s0730-725x(96)00226-3.
This study aimed to determine the overall accuracy of known enhancement patterns for the characterization of a large series of focal hepatic masses on dynamic contrast-enhanced magnetic resonance (MR) images. Breath-hold T1-weighted images of the liver acquired before intravenous gadolinium administration and serially over 6-10 min after contrast injection were acquired in < 25 a using FLASH or rapid spin-echo pulse sequences. A total of 311 proven focal hepatic masses in 128 patients were analyzed, including 192 malignant lesions (166 metastases and 26 hepatomas) and 119 benign lesions (48 cavernous hemangiomas, 45 hepatic cysts, and 26 other abnormalities). The lesions were evaluated for a variety of characteristics independently by two reviewers who were blinded to results. Cavernous hemangiomas showed early peripheral nodular enhancement (80% sensitivity and 99% specificity) and hepatic cysts showed no enhancement (100% sensitivity and 95% specificity). Hepatic metastases showed variable, moderate enhancement (47% by one reviewer and 74% by the other). Metastatic lesions from hypervascular primary neoplasms displayed peak enhancement during the hepatic artery dominant (bolus) phase, while other malignant neoplasms showed later peak enhancement (72% sensitivity and 77% specificity). Five metastatic foci with early homogeneous enhancement showed a delayed peripheral washout of contrast (rim sign), while no nonmetastatic foci displayed this finding (3% sensitivity and 100% specificity). Characteristic enhancement patterns of focal hepatic lesions were described in a large series of patients. This study confirms results of previous investigators who have shown that early nodular peripheral enhancement was highly specific for hemangiomas and lack of enhancement was highly specific for hepatic cysts. Hypervascular metastatic foci show earlier peak enhancement than other malignant lesions. Some (2-3%) metastatic lesions display a peripheral washout of contrast on serial images, with 100% specificity.
本研究旨在确定已知强化模式在动态对比增强磁共振（MR）图像上对一大系列肝脏局灶性肿块进行特征性诊断的总体准确性。在<25岁的患者中，使用快速小角度激发（FLASH）或快速自旋回波脉冲序列，在静脉注射钆之前采集屏气肝脏T1加权图像，并在注射造影剂后6 - 10分钟内连续采集。对128例患者的共311个经证实的肝脏局灶性肿块进行了分析，包括192个恶性病变（166个转移瘤和26个肝癌）和119个良性病变（48个海绵状血管瘤、45个肝囊肿和26个其他异常）。两位对结果不知情的阅片者独立评估病变的各种特征。海绵状血管瘤表现为早期周边结节状强化（敏感性80%，特异性99%），肝囊肿无强化（敏感性100%，特异性95%）。肝转移瘤表现为强化程度各异，中等强化（一位阅片者为47%，另一位为74%）。来自富血供原发肿瘤的转移瘤在肝动脉主导（团注）期出现强化峰值，而其他恶性肿瘤强化峰值出现较晚（敏感性72%，特异性77%）。5个早期均匀强化的转移灶表现为造影剂延迟周边廓清（边缘征），而非转移灶未出现此表现（敏感性3%，特异性100%）。本研究描述了一大系列患者肝脏局灶性病变的特征性强化模式。本研究证实了先前研究者的结果，即早期结节状周边强化对血管瘤具有高度特异性，无强化对肝囊肿具有高度特异性。富血供转移灶比其他恶性病变强化峰值出现更早。一些（2 - 3%）转移瘤在序列图像上表现为造影剂周边廓清，特异性为100%。
