Myers Robert P, Elkashab Magdy, Ma Mang, Crotty Pam, Pomier-Layrargues Gilles
Division of GAstroenterology, Department of Medicine, University of Calgary, Alberta.
Can J Gastroenterol. 2010 Nov;24(11):661-70. doi: 10.1155/2010/153986.
Liver stiffness measurement (LSM) using transient elastography (TE) is a promising tool for the noninvasive assessment of hepatic fibrosis.
To determine the feasibility and performance of TE in a North American cohort of patients with chronic liver disease.
LSMs were obtained using TE in 260 patients with chronic hepatitis B or C, or nonalcoholic fatty liver disease from four Canadian hepatology centres. The accuracy of TE compared with liver biopsy for the prediction of significant fibrosis (Metavir fibrosis score of F2 or greater), bridging fibrosis (Metavir fibrosis score of F3 or greater) and cirrhosis (Metavir fibrosis score of F4 ) was assessed using area under ROC curves (AUROCs), and compared with the aspartate aminotransferase-to-platelet ratio index. The influence of alanine aminotransferase (ALT) levels and other factors on liver stiffness was determined using linear regression analyses.
failure of TE occurred in 2.7% of patients, while liver biopsies were inadequate for staging in 0.8%. Among the remaining 251 patients, the AUROCs of TE for Metavir fibrosis scores of F2 and F3 or greater, and F4 were 0.74 (95% CI 0.68 to 0.80), 0.89 (95% CI 0.84 to 0.94), and 0.94 (95% CI 0.90 to 0.97), respectively. LSM was more accurate than the aminotransferase-to-platelet ratio index for bridging fibrosis (AUROC 0.78) and cirrhosis (AUROC 0.88), but not significant fibrosis (AUROC 0.76). At a cut-off of 11.1 kPa, the sensitivity, specificity, and positive and negative predictive values for cirrhosis (prevalence 11%) were 96%, 81%, 39% and 99%, respectively. For significant fibrosis (prevalence 53%), a cut-off of 7.7 kPa was 68% sensitive and 69% specific, and had a positive predictive value of 70% and a negative predictive value of 65%. Liver stiffness was independently associated with ALT, body mass index and steatosis. The optimal LSM cut-offs for cirrhosis were 11.1 kPa and 11.5 kPa in patients with ALT levels lower than 100 U⁄L and 100 U⁄L or greater, respectively. For fibrosis scores of F2 or greater, these figures were 7.0 kPa and 8.6 kPa, respectively.
the major role of TE is the exclusion of bridging fibrosis and cirrhosis. However, TE cannot replace biopsy for the diagnosis of significant fibrosis. Because liver stiffness may be influenced by significant ALT elevation, body mass index and⁄or steatosis, tailored liver stiffness cut-offs may be necessary to account for these factors.
使用瞬时弹性成像（TE）进行肝脏硬度测量（LSM）是一种用于肝纤维化无创评估的有前景的工具。
确定TE在北美慢性肝病患者队列中的可行性和性能。
在来自四个加拿大肝病中心的260例慢性乙型或丙型肝炎、或非酒精性脂肪性肝病患者中使用TE获得LSM。使用ROC曲线下面积（AUROCs）评估TE与肝活检相比预测显著纤维化（Metavir纤维化评分F2或更高）、桥接纤维化（Metavir纤维化评分F3或更高）和肝硬化（Metavir纤维化评分F4）的准确性，并与天冬氨酸转氨酶与血小板比值指数进行比较。使用线性回归分析确定丙氨酸转氨酶（ALT）水平和其他因素对肝脏硬度的影响。
2.7%的患者TE检查失败，而0.8%的患者肝活检分期不充分。在其余251例患者中，TE对Metavir纤维化评分F2、F3或更高以及F4的AUROCs分别为0.74（95%CI 0.68至0.80）、0.89（95%CI 0.84至0.94）和0.94（95%CI 0.90至0.97）。对于桥接纤维化（AUROC 0.78）和肝硬化（AUROC 0.88），LSM比转氨酶与血小板比值指数更准确，但对于显著纤维化（AUROC 0.76）并非如此。在临界值为11.1 kPa时，肝硬化（患病率11%）的敏感性、特异性、阳性和阴性预测值分别为96%、81%、39%和99%。对于显著纤维化（患病率53%），临界值7.7 kPa的敏感性为68%，特异性为69%，阳性预测值为70%，阴性预测值为65%。肝脏硬度与ALT、体重指数和脂肪变性独立相关。在ALT水平低于100 U/L和100 U/L或更高的患者中，肝硬化的最佳LSM临界值分别为11. kPa和11.5 kPa。对于纤维化评分F2或更高，这些数字分别为7.0 kPa和8.6 kPa。
TE的主要作用是排除桥接纤维化和肝硬化。然而，TE不能替代活检用于显著纤维化的诊断。由于肝脏硬度可能受ALT显著升高、体重指数和/或脂肪变性影响，可能需要根据这些因素调整肝脏硬度临界值。
