Department of Gastroenterology and Hepatology, University of Medicine and Pharmacy Timişoara, 10 Iosif Bulbuca Bv. 300736 Timisoara, Romania.
World J Gastroenterol. 2011 Sep 7;17(33):3824-9. doi: 10.3748/wjg.v17.i33.3824.
To find out if by combining 2 ultrasound based elastographic methods: acoustic radiation force impulse (ARFI) elastography and transient elastography (TE), we can improve the prediction of fibrosis in patients with chronic hepatitis C.
Our study included 197 patients with chronic hepatitis C. In each patient, we performed, in the same session, liver stiffness (LS) measurements by means of TE and ARFI, respectively, and liver biopsy (LB), assessed according to the Metavir score. 10 LS measurements were performed both by TE and ARFI; median values were calculated and expressed in kilopascals (kPa) and meters/second (m/s), respectively. Only TE and ARFI measurements with IQR < 30% and SR ≥ 60% were considered reliable.
On LB 13 (6.6%) patients had F0, 32 (16.2%) had F1, 52 (26.4%) had F2, 47 (23.9%) had F3, and 53 (26.9%) had F4. A direct, strong correlation was found between TE measurements and fibrosis (r = 0.741), between ARFI and fibrosis (r = 0.730) and also between TE and ARFI (r = 0.675). For predicting significant fibrosis (F ≥ 2), for a cut-off of 6.7 kPa, TE had 77.5% sensitivity (Se) and 86.5% specificity (Sp) [area under the receiver operating characteristic curve (AUROC) 0.87] and for a cut-off of 1.2 m/s, ARFI had 76.9% Se and 86.7% Sp (AUROC 0.84). For predicting cirrhosis (F = 4), for a cut-off of 12.2 kPa, TE had 96.2% Se and 89.6% Sp (AUROC 0.97) and for a cut-off of 1.8 m/s, ARFI had 90.4% Se and 85.6% Sp (AUROC 0.91). When both elastographic methods were taken into consideration, for predicting significant fibrosis (F ≥ 2), (TE ≥ 6.7 kPa and ARFI ≥ 1.2 m/s) we obtained 60.5% Se, 93.3% Sp, 96.8% positive predictive value (PPV), 41.4% negative predictive value (NPV) and 68% accuracy, while for predicting cirrhosis (TE ≥ 12.2 kPa and ARFI ≥ 1.8 m/s) we obtained 84.9% Se, 94.4% Sp, 84.9% PPV, 94.4% NPV and 91.8% accuracy.
TE used in combination with ARFI is highly specific for predicting significant fibrosis; therefore when the two methods are concordant, liver biopsy can be avoided.
探讨联合应用两种基于超声的弹性成像技术：声辐射力脉冲（ARFI）弹性成像和瞬时弹性成像（TE）是否能提高对慢性丙型肝炎患者纤维化的预测能力。
本研究纳入了 197 例慢性丙型肝炎患者。在同一检查中，分别采用 TE 和 ARFI 进行肝脏硬度（LS）测量，同时进行肝脏活检（LB），并根据 Metavir 评分进行评估。TE 和 ARFI 分别进行了 10 次 LS 测量，计算并分别以千帕（kPa）和米/秒（m/s）表示中位数。仅考虑 IQR＜30%和 SR≥60%的 TE 和 ARFI 测量值是可靠的。
LB 显示，13 例（6.6%）患者为 F0，32 例（16.2%）为 F1，52 例（26.4%）为 F2，47 例（23.9%）为 F3，53 例（26.9%）为 F4。TE 测量值与纤维化之间存在直接、强烈的相关性（r=0.741），ARFI 与纤维化之间存在直接、强烈的相关性（r=0.730），TE 与 ARFI 之间也存在直接、强烈的相关性（r=0.675）。对于预测显著纤维化（F≥2），TE 的截断值为 6.7 kPa 时，具有 77.5%的灵敏度（Se）和 86.5%的特异性（Sp）[受试者工作特征曲线（ROC）下面积（AUROC）为 0.87]，ARFI 的截断值为 1.2 m/s 时，具有 76.9%的 Se 和 86.7%的 Sp（AUROC 为 0.84）。对于预测肝硬化（F=4），TE 的截断值为 12.2 kPa 时，具有 96.2%的 Se 和 89.6%的 Sp（AUROC 为 0.97），ARFI 的截断值为 1.8 m/s 时，具有 90.4%的 Se 和 85.6%的 Sp（AUROC 为 0.91）。当同时考虑两种弹性成像方法时，对于预测显著纤维化（F≥2）（TE≥6.7 kPa 和 ARFI≥1.2 m/s），我们获得了 60.5%的 Se、93.3%的 Sp、96.8%的阳性预测值（PPV）、41.4%的阴性预测值（NPV）和 68%的准确率；对于预测肝硬化（TE≥12.2 kPa 和 ARFI≥1.8 m/s），我们获得了 84.9%的 Se、94.4%的 Sp、84.9%的 PPV、94.4%的 NPV 和 91.8%的准确率。
TE 联合 ARFI 对预测显著纤维化具有高度特异性；因此，当两种方法一致时，可以避免进行肝脏活检。
