Introduction The estimation of liver fibrosis in patients chronically infected with hepatitis B or C is crucial in determining the prognosis, surveillance, and treatment decisions. Liver biopsy is still the gold-standard for assessing liver fibrosis. However, it is susceptible to variability in interpretation and carries an associated morbidity and mortality. ARFI elastography is a novel, non-invasive technology incorporated into conventional B-mode ultrasonography that is used to assess liver fibrosis.
Aim To compare ultrasound elastography stiffness scores in patients with chronic hepatitis B or C disease with concomitantly acquired histopathology specimen scores.
Method A total of 80 patients underwent ARFI elastography, real time ultrasound examination of the liver and concomitant ultrasound guided biopsy between January 2010 and December 2010. Of these patients, 34 patients had chronic viral hepatitis (18 Hepatitis B, 16 Hepatitis C). All liver biopsies were carried out to aid the management of the patients. The ARFI elastographies and the liver biopsies were carried out by a single operator. Elastography scores were obtained (using a Siemens Acuson S2000 and 4C1 probe 4 MHz transducer) in the same anatomical region of the liver as the biopsy which was taken using a Biopince 18 gauge Menghini type needle. All liver histology was graded for fibrosis using the Ishak fibrosis staging system.
Results Four out of 34 patients with chronic viral hepatitis were excluded as two did not have elastography scores recorded and two did not have their liver histology graded for fibrosis. Of the patients who were included, 15 had chronic hepatitis B and 15 had chronic hepatitis C. The mean age of the patients was 40.0 years and the number of male patients was 24. The mean ARFI elastography score and mean Ishak staging were 1.59 and 1.63 respectively. A direct correlation was found between ARFI elastography measurements and Ishak staging (Spearman's rank correlation =0.31). The negative predictive value for fibrosis using ARFI elastography was 94%.
Conclusion A significant correlation between ARFI elastography measurements and liver histology is seen in this study carried out on consecutive unselected cases in a secondary care setting. ARFI elastography is an accurate non-invasive method of excluding liver fibrosis in patients with chronic viral hepatitis. The technology is widely applicable as the software can be integrated into a conventional ultrasound system and an elastography examination can be carried out during a routine screening ultrasound scan of the liver.