Martí-Bonmatí Luis, Alberich-Bayarri Angel, Sánchez-González Javier
Radiology Department, Hospital Quirón, Avenida Blasco Ibáñez 14, 46010, Valencia, Spain.
Abdom Imaging. 2012 Apr;37(2):180-7. doi: 10.1007/s00261-011-9762-5.
Diffuse liver diseases have a definitive radiological importance due to the ability of MR imaging to demonstrate abnormalities before the patient is symptomatic or the liver damage is advanced. Biopsy procedures are invasive, may lead to complications and have a sample bias. Imaging biomarkers target to fat, water, and iron tissue concentrations may be considered as hepatic virtual biopsies. There is a need to identify a rapid and practicable method to accurately quantify liver steatosis, differentiate steatohepatitis from simple steatosis, grade the necroinflammatory activity, calculate the liver iron burden and monitor overload progression. MR is used in the evaluation of diffuse liver disorders with accurate approaches such as the use of chemical shift, Dixon vector analysis, turbo spin echo fat suppression, and T2* gradient echo techniques. These methods are influenced by some factors like proportional ambiguity, T1 and T2* effects on signal decay, adding a significant bias in the combined fat-water-iron quantification. A GRE multi-echo chemical shift sequence was configured to independently calculate fat, water, and iron parametric liver images. It is now necessary to conduct a pilot project in order to validate this method in a group of subjects without and with different grades of fat, water, and iron liver changes.
由于磁共振成像（MR成像）能够在患者出现症状或肝脏损伤进展之前显示异常，弥漫性肝病具有明确的放射学重要性。活检程序具有侵入性，可能导致并发症并存在样本偏差。针对脂肪、水和铁组织浓度的成像生物标志物可被视为肝脏虚拟活检。需要确定一种快速且可行的方法，以准确量化肝脂肪变性，区分脂肪性肝炎与单纯性脂肪变性，对坏死性炎症活动进行分级，计算肝脏铁负荷并监测过载进展。MR被用于评估弥漫性肝脏疾病，采用了诸如化学位移、狄克逊矢量分析、快速自旋回波脂肪抑制和T2梯度回波技术等精确方法。这些方法受到一些因素的影响，如比例模糊性、T1和T2对信号衰减的影响，在脂肪-水-铁联合定量中增加了显著偏差。配置了一个梯度回波多回波化学位移序列来独立计算脂肪、水和铁的肝脏参数图像。现在有必要开展一个试点项目，以便在一组没有以及有不同程度脂肪、水和铁肝脏变化的受试者中验证该方法。
