Richard H. Marshall MD, Presenter: Nothing to Disclose

Marna J. Eissa MD, Abstract Co-Author: Nothing to Disclose

Edward I. Bluth MD, Abstract Co-Author: Author, Thieme Medical Publishers, Inc

Nancy Davis MD, Abstract Co-Author: Nothing to Disclose

Liver steatosis has been linked to alcoholic and non-alcoholic liver disease as well as chronic HCV infection.  Liver biopsy has been used as the primary method to quantify liver steatosis in suspected patients. The purpose of this study is to determine if the US HRI can be used to selectively reduce the number of unecessary liver biopsies.

101 patients who had recently undergone US guided liver biopsy at our institution were selected for this study.  Requirements included a single image containing both the liver and the right kidney, creatinine <1.3 and no liver or renal masses.  HRI was calculated for each study based on a modification of methods developed by Webb et al and Soder et al using freeware available through the NIH website.  A board certified pathologist analized each biopsy specimin and quantified the amount of steatosis.  The HRI was then compared to histologically based steatosis percentage.

Our HRI data showed a strong correlation to percentage of fat (0.71, p<0.0001). Patients were grouped into two categories based on percentage of fat less than or greater than 5%. An HRI of 1.34 or greater had a 92% sensitivity for identifying fat greater than 5% (histologic grade I or higher), specificity 62%, PPV 0.593 and and NPV of 0.93. If this method was used prospectively for selecting patients for biopsy in this sample, 41% of biopsies could have been avoided.

HRI can be used to reduce liver biopsies by approximately 41% in  patients with suspected steatosis and without renal disease, referred for biopsy in an academic medical center for standard accepted indications.  The estimated prevalence of NAFLD is approximately 40 million people in the US and at our institution the cost per biopsy is $3600.  Applying this universally to patients with the same indications and exclusions, the benefit of this non-invasive screening test could save upwards of $51 billion annually in the US in unnecessary healthcare expenditures.

HRI can be easily calculated without extra cost for software or equipment.  Based on the prevalence of NAFLD, HRI can be used to save billions of dollars annually.

Marshall, R, Eissa, M, Bluth, E, Davis, N, Cost Savings and Patient Benefit in Using the Ultrasound Hepatorenal Index (HRI) as a Screening Tool to Prevent Unnecessary Liver Biopsy in Patients with Suspected Steatosis.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9007417.html