Manfredi R, Maresca G, De Gaetano A M, De Franco A, Marano P
Istituto di Radiologia, Università Cattolica del Sacro Cuore, Policlinico A. Gemelli, Roma.
Radiol Med. 1995 Sep;90(3):250-61.
This study was aimed at assessing the accuracy of Magnetic Resonance Imaging (MRI) in the characterization of focal liver masses. We prospectively examined 51 patients with focal liver masses: the morphological features were investigated with different pulse sequences and the functional characteristics were studied after the i.v. administration of Gd-DTPA (2 mmol/kg). MR findings were compared with those of gold standard methods, i.e., percutaneous biopsy, surgery or, for hemangiomas, 99mTc-labelled blood cell liver scintigraphy. All hemangiomas presented with typical features: signal intensity was very high on long TE images (> 140 msec) and a globular enhancement pattern, with centripetal progression, was observed after dynamic studies. This signal pattern on T2-weighted images is highly indicative of hemangioma. Five of 7 focal nodular hyperplasias (71%) were isointense with hepatic parenchyma on all pulse sequences; the central scar was observed in 5/7 cases on short TR/TE images and in all cases on long TR/TE images in 16/17 cases (94%). High signal intensity on T1-weighted images was statistically significant for HCC. A pseudocapsule was observed in 12 cases (70%). A mosaic pattern on T2-weighted images was observed in 3 cases. Seventy-four per cent of HCCs exhibited signal enhancement during the arterial phase of the dynamic study. Metastases presented a uniform pattern, i.e., they were hypointense on T1-weighted and hyperintense on T2-weighted images in 12/13 cases (92%). A central hypointense area on T2-weighted images is indicative of coagulative necrosis. A lesion with these morphological features and hypovascular signal is suggestive of metastasis.
本研究旨在评估磁共振成像（MRI）对肝脏局灶性肿块特征的诊断准确性。我们前瞻性地检查了51例肝脏局灶性肿块患者：采用不同脉冲序列研究其形态学特征，并在静脉注射钆喷酸葡胺（Gd-DTPA，2 mmol/kg）后研究其功能特征。将MRI结果与金标准方法（即经皮活检、手术，对于血管瘤则与99mTc标记血细胞肝脏闪烁显像）的结果进行比较。所有血管瘤均表现出典型特征：在长TE图像（>140毫秒）上信号强度非常高，动态研究后观察到呈向心性强化的球状强化模式。T2加权图像上的这种信号模式高度提示血管瘤。7例局灶性结节性增生中有5例（71%）在所有脉冲序列上与肝实质等信号；5/7例在短TR/TE图像上观察到中央瘢痕，16/17例（94%）在长TR/TE图像上所有病例均观察到中央瘢痕。T1加权图像上的高信号强度对肝细胞癌具有统计学意义。12例（70%）观察到假包膜。3例在T2加权图像上观察到镶嵌样模式。74%的肝细胞癌在动态研究的动脉期表现出信号增强。转移瘤表现出均匀的模式，即12/13例（92%）在T1加权图像上呈低信号，在T2加权图像上呈高信号。T2加权图像上的中央低信号区提示凝固性坏死。具有这些形态学特征和低血供信号的病变提示转移瘤。
