Shear Wave Elastography as a Reliable Tool to Assess Liver Fibrosis.

Introduction: Chronic liver diseases are very frequent in daily practice, due to chronic infection with hepatitis viruses C or B, or due to other aetiologies, such as alcoholic steatohepatitis or non-alcoholic steatohepatitis. Others like autoimmune hepatitis or primary biliary cirrhosis are also often diagnosed. A proper evaluation of the liver brosis is of value for treatment, prognosis assessment and follow-up. Liver biopsy was the “goldstandard” for liver brosis evaluation. A problem with liver biopsy is that the specimen obtained represents roughly 1/50,000 of the total liver volume and brosis is not evenly distributed throughout the liver. Hence, considering these limitations of liver biopsies, non-invasive methods for the evaluation of liver disease severity is an alternative. Aim: 1. To calculate shear wave velocity in suspected cases of liver brosis. 2. To correlate elastography ndings with histopathology. Materials and methods: This study was conducted on 45 patients at Ramaiah hospitals from November 2017 to June 2019 and included all patients suspected to have liver disease undergoing liver function tests, elastography and liver biopsy at our Institute. Patients with gross ascites and focal liver lesions were excluded. Results: Out of the 45 subjects that were evaluated on elastography, 25 cases showed values less than 1.35 m/s indicating that these cases had either no evidence of brosis or mild brosis. There was 100 % positive correlation in all the 25 cases on comparison of elastography ndings with biopsy. +Of the 4 cases proven to have grade II brosis on histopathology, 6 cases showed values between 1.35 to 1.55 m/s on elastography. 2 cases showed false positive results which later on turned out to be subjects with no brosis on histopathology. Of the 7 cases proven to have grade III brosis on histopathology, all 7 cases showed values between 1.55 to 1.80 m/s on elastography which is considered the cut off value for grade III brosis. Hence, there was 100% positive correlation. Of the 9 cases proven to have grade IV brosis on histopathology, all 9 cases showed values more than 1.80 m/s on elastography which is considered the cut off value for grade IV brosis. Hence, there was 100% positive correlation. Conclusion: Elastography is a reliable screening tool for the liver brosis grading. It is better than the blood indices in distinguishing signicant brosis, severe brosis & cirrhosis of liver. The distinction of these stages affects the treatment plan and also monitoring of response to treatment. Elastography has advantages of being a non-invasive, reliable & dependable test as against the liver biopsy. When used as a screening modality, it can obviate the need for liver biopsy