Brief Article
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World J Gastroenterol. Sep 7, 2011; 17(33): 3824-3829
Published online Sep 7, 2011. doi: 10.3748/wjg.v17.i33.3824
Is it better to use two elastographic methods for liver fibrosis assessment?
Ioan Sporea, Roxana Şirli, Alina Popescu, Simona Bota, Radu Badea, Monica Lupşor, Mircea Focşa, Mirela Dănilă
Ioan Sporea, Roxana Şirli, Alina Popescu, Simona Bota, Mirela Dănilă, Department of Gastroenterology and Hepatology, University of Medicine and Pharmacy Timişoara, 10 Iosif Bulbuca Bv., 300736 Timisoara, Romania
Radu Badea, Monica Lupşor, Department of Medical Imaging, 3rd Medical Clinic, University of Medicine and Pharmacy, Cluj-Napoca, 21-23 Croitorilor str., 400162 Cluj-Napoca, Romania
Mircea Focşa, Department of Biophysics and Medical Informatics, University of Medicine and Pharmacy Timisoara, 14 Tudor Vladimirescu str., 300173 Timisoara, Romania
Author contributions: Sporea I wrote the paper, and designed and supervised the study; Şirli R, Popescu A, Bota S, Badea R, Lupşor M and Dănilă M performed research; Focşa M, Bota S and Şirli R analyzed the data; Şirli R revised the manuscript.
Correspondence to: Dr. Ioan Sporea, Professor, Department of Gastroenterology and Hepatology, University of Medicine and Pharmacy Timişoara, 10 Iosif Bulbuca Bv., 300736 Timişoara, Romania.
Telephone: +40-256-309455 Fax: +40-256-488003
Received: December 4, 2010
Revised: March 25, 2011
Accepted: April 1, 2011
Published online: September 7, 2011

AIM: 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.

CONCLUSION: 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.

Keywords: Transient elastography, Acoustic radiation force impulse elastography, Liver stiffness, Combined methods