Portilha Maria Antónia, Pedro Marcos Teixeira, Ruivo Catarina, Semedo Luís Curvo, Marques Cristina, Alves Filipe Caseiro
Clínica Universitária de Radiologia, Hospitais da Universidade de Coimbra, Coimbra, Portugal.
Acta Med Port. 2011 Dec;24 Suppl 2:531-8. Epub 2011 Dec 31.
Gadoxetic acid (Gd-EOB-DTPA) is a contrast media used in magnetic resonance imaging (MRI) for the detection and characterization of hepatic lesions. It shows combined properties of extracellular and biliary excretion, with 50% of the administered dose eliminated by the hepatobiliary pathway. One of its applications, therefore, is the characterization of focal hepatic lesions, including those of hepatocellular nature, such as focal nodular hyperplasia and hepatocellular adenoma. Patients with focal nodular hyperplasia (FNH) are usually asymptomatic and rarely reveal complications. In other hand, hepatocellular adenoma may suffer complications, such as intraperitoneal or intratumoral (sometimes massive) bleeding and the possible progression to malignancy.
To determine the value of MRI with Gd-EOB-DTPA in characterizing hepatic lesions, particularly in the differentiation between HNF and AHC.
A retrospective study was carried out by investigating cases of FNH and HCA referred for MR evaluation with Gd-EOB-DTPA in the Department of Radiology of the University Hospitals of Coimbra (HUC) between August 2009 and December 2010. We evaluated 32 patients, 24 with FNH and 8 AHC. The diagnosis was established by histology, follow-up or agreement between imaging methods. In order to evaluate the enhancement after contrast administration in the hepatobiliary phase, we calculated the values of Signal-to-noise ratio (SNR), Contrast-to-noise ratio (CNS) and percentage of enhancement. Statistical analysis was performed with SPSS, version 18, and the tests were evaluated at a significance level of 5%.
The SNR and CNR after contrast is significantly different for the two types of lesion (p <0.001 and p = 0.03, respectively), with higher values for both parameters in the group of focal nodular hyperplasia. As for the % of enhancement, there is a statistically significant difference between groups (p = 0.006), again with the FNH group presenting higher values. There are significant differences in both groups among the studies pre-and post-contrast for the CNR (FNH: p <0.001; adenoma: p = 0.017), but for the SNR of the lesion the difference manifests in the HNF group (p <0,001); the CNR values increase in FNH and decrease in hepatocellular adenoma, while for the SNR of the lesion post-contrast values are higher than pre-contrast, in both groups.
Magnetic resonance imaging with hepatospecific contrast is a valuable method for characterization of benign hepatic lesions, helping to differentiate FNH from HCA, based on the different patterns of uptake and retention of Gd-EOB-DTPA.
钆塞酸二钠（Gd-EOB-DTPA）是一种用于磁共振成像（MRI）的造影剂，用于检测和鉴别肝脏病变。它具有细胞外和胆汁排泄的综合特性，给药剂量的50%通过肝胆途径清除。因此，其应用之一是鉴别局灶性肝脏病变，包括肝细胞性病变，如局灶性结节性增生和肝细胞腺瘤。局灶性结节性增生（FNH）患者通常无症状，很少出现并发症。另一方面，肝细胞腺瘤可能出现并发症，如腹腔内或肿瘤内（有时大量）出血以及可能进展为恶性肿瘤。
确定使用钆塞酸二钠的MRI在鉴别肝脏病变，特别是在FNH和AHC鉴别诊断中的价值。
对2009年8月至2010年12月在科英布拉大学医院（HUC）放射科接受钆塞酸二钠MR评估的FNH和HCA病例进行回顾性研究。我们评估了32例患者，其中24例为FNH，8例为AHC。诊断通过组织学、随访或成像方法之间的一致性确定。为了评估肝胆期造影剂注射后的强化情况，我们计算了信噪比（SNR）、对比噪声比（CNS）和强化百分比的值。使用SPSS 18版进行统计分析，检验在5%的显著性水平下进行评估。
两种类型病变造影后的SNR和CNR有显著差异（分别为p<0.001和p = 0.03），局灶性结节性增生组这两个参数的值更高。至于强化百分比，两组之间有统计学显著差异（p = 0.006），同样是FNH组的值更高。两组在造影前和造影后研究中的CNR均有显著差异（FNH：p<0.001；腺瘤：p = 0.0- 17），但病变的SNR差异在FNH组中表现明显（p<0.001）；FNH的CNR值增加，肝细胞腺瘤的CNR值降低，而对于病变的SNR，两组造影后的值均高于造影前。
使用肝特异性造影剂的磁共振成像是鉴别良性肝脏病变的有价值方法，基于钆塞酸二钠摄取和滞留的不同模式有助于区分FNH和HCA。
