title: Is it better to use two elastographic methods for liver fibrosis assessment?
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Gastroenterology and Hepatology, University of Medicine and Pharmacy Timişoara, 10 Iosif Bulbuca Bv. 300736 Timisoara, Romania. isporea@umft.ro
authors: Ioan
authors: I
authors: Sporea
authors: Roxana
authors: R
authors: Şirli
authors: Alina
authors: A
authors: Popescu
authors: Simona
authors: S
authors: Bota
authors: Radu
authors: R
authors: Badea
authors: Monica
authors: M
authors: Lupşor
authors: Mircea
authors: M
authors: Focşa
authors: Mirela
authors: M
authors: Dănilă
mesh_terms: D000328:Adult; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D019698:Hepatitis C, Chronic / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results