Inter-observer agreement for detection and grading of hepatic steatosis- An ultrasound based study

Objectives: To determine the inter observer agreement of ultrasound diagnosis of the severity and grading of steatosis in patients with HCV.Methods: Patients with HCV were evaluated, from March 2008-August 2010 at Radiology department, Dow Medical College and Civil Hospital Karachi, with ultrasound for detection and grading of steatosis and fibrosis using a standardized set of criteria. The same sets of images were reviewed by the same radiologists 5 years later (2015) for determining the agreement in the grading. Kappa (k) statistics were utilized. Present results were compared with that of the pilot study conducted in 2007 on 100 images.Results: 452 set of images were reviewed by three radiologists, designated A, B and C. The inter observer agreement was satisfactory to good with k=0.8 for no steatosis, 0.4 for mild steatosis, 0.7 for moderate steatosis and 0.9 for severe steatosis. The inter-observer agreement in the pilot study in 2007 had shown k – values of 0.81 for no steatosis, 0.5 for mild steatosis, 0.8 for moderate steatosis and 0.9 for severe steatosis.Conclusions: The studied criteria for ultrasound diagnosis and grading of hepatic steatosis had persistently good inter-observer agreement for absence, and moderate to severe grades of steatosis. The agreement was low for mild steatosis.