Acoustic liver biopsy in patients with hepatitis C and advanced liver fibrosis using endoscopic ultrasound.

Background: Transabdominal ultrasound cannot be used to quantitate fibrosis in patients with advanced liver fibrosis due to variability in the abdominal wall thickness and composition. This variability can be eliminated by using endoscopic ultrasound.

Aim: The purpose of this study was to determine the amount of fibrosis in the liver of hepatitis C patients with advanced fibrosis using endoscopic ultrasound.

Methods: Endoscopic ultrasound images of the liver were recorded by keeping the gain, contrast, frequency, magnification and acoustic power constant on the ultrasound processor. Videotaped images of the liver were digitized on Image-Pro Plus software. Using adobe Photoshop, a histogram was produced to quantitate the luminosity of the five areas of interest per image. Quantification of the ultrasound images were done by two independent investigators blinded to the Ishak liver fibrosis score. The mean luminosity of the ultrasound images were compared with the Ishak fibrosis score. The study was performed in seven patients (mean age 54 years; 3 male, 4 female) with hepatitis C and advanced liver fibrosis.

Results: The correlation between the two independent investigators for the ultrasound images was 0.93. The correlation between the mean luminosity on ultrasound images to the Ishak fibrosis score was r = 0.77, r = 0.72 and r = 0.73 for the most hyperechoic area of interest, total hyperechoic area and for the entire liver, respectively.

Conclusion: A new technique was developed that uses endoscopic ultrasound to evaluate the degree of fibrosis in patients with advanced liver fibrosis. There is a good correlation between the luminosity on endoscopic ultrasound and the Ishak fibrosis score.