Ozkurt Huseyin, Keskiner Firat, Karatag Ozan, Alkim Canan, Erturk Sukru Mehmet, Basak Muzaffer
Department of Radiology, Sisli Etfal Education and Research Hospital, Istanbul, Turkey.
Department of Radiology, Canakkale Onsekiz Mart University, Faculty of Medicine, Canakkale, Turkey.
Iran J Radiol. 2014 Jan;11(1):e3555. doi: 10.5812/iranjradiol.3555. Epub 2014 Jan 30.
Hepatic fibrosis is a typical complication of chronic liver diseases resulting in cirrhosis that remains a major public health problem worldwide. Liver biopsy is currently the gold standard for diagnosing and staging hepatic fibrosis. Percutaneous liver biopsy; however, is an invasive procedure with risks of complications. Therefore, there is need for alternative non-invasive techniques to assess liver fibrosis and chronic liver diseases. In recent years, MRI techniques, including diffusion weighted imaging (DWI), have been developed for in vivo quantification of liver fibrosis.
The purpose of this study is to evaluate the utility of diffusion weighted MRI in the diagnosis and quantification of the degree of hepatic fibrosis and to investigate the influence of b-value.
Twenty-four patients (13 males, 11 females), with a mean age of 46 years (36-73 years) diagnosed as chronic hepatitis and histopathologically proven liver fibrosis and 22 other patients (8 males, 14 females) with no clinical or biochemical findings of liver disease, with a mean age of 51.2 years (32-75 years) were included in the study. All patients with chronic hepatitis underwent percutaneous liver biopsy by an experienced hepatologist without sonographic guidance. The Knodell histology activity index (HAI) for grading of necroinflammatory changes and Metavir scoring system for staging of the liver fibrosis were used to record the severity of the disease. All patients were examined with a 1.5 Tesla MRI system and the patients underwent diffusion weighted imaging (DWI) with a routine hepatic MRI protocol. Different b-values including 250, 500, 750, and 1000 sec/mm (2) were used to calculate apparent diffusion coefficients.
We detected decreased apparent diffusion coefficient values in patients with hepatic fibrosis compared to patients without chronic hepatitis and there was a trend toward decrease in hepatic apparent diffusion coefficient values with an increasing degree of fibrosis.
Our findings suggest that hepatic apparent diffusion coefficient measurement with a b-value of 750 sec/mm (2) or greater is useful in accurate quantification of liver fibrosis and necroinflammation.
肝纤维化是慢性肝病的典型并发症，可导致肝硬化，这在全球范围内仍然是一个主要的公共卫生问题。肝活检是目前诊断和分期肝纤维化的金标准。然而，经皮肝活检是一种侵入性操作，存在并发症风险。因此，需要替代性的非侵入性技术来评估肝纤维化和慢性肝病。近年来，包括扩散加权成像（DWI）在内的磁共振成像（MRI）技术已被开发用于肝纤维化的体内定量分析。
本研究旨在评估扩散加权MRI在肝纤维化诊断及程度定量分析中的应用价值，并探讨b值的影响。
本研究纳入了24例患者（男性13例，女性11例），平均年龄46岁（36 - 73岁），诊断为慢性肝炎且经组织病理学证实存在肝纤维化；以及22例其他患者（男性8例，女性14例），平均年龄51.2岁（32 - 75岁），无肝脏疾病的临床或生化表现。所有慢性肝炎患者均由经验丰富的肝病专家在无超声引导的情况下进行经皮肝活检。采用Knodell组织学活动指数（HAI）对坏死性炎症变化进行分级，采用Metavir评分系统对肝纤维化进行分期，以记录疾病的严重程度。所有患者均使用1.5特斯拉MRI系统进行检查，并按照常规肝脏MRI协议接受扩散加权成像（DWI）检查。使用包括250、500、750和1000 sec/mm²在内的不同b值来计算表观扩散系数。
与无慢性肝炎的患者相比，我们检测到肝纤维化患者的表观扩散系数值降低，并且随着纤维化程度的增加，肝脏表观扩散系数值有下降趋势。
我们的研究结果表明，使用b值为750 sec/mm²或更高的肝脏表观扩散系数测量有助于准确量化肝纤维化和坏死性炎症。
