The Role of Ultrasound in the Diagnosis of Hepatic Steatosis in Morbidly Obese Patients

Background: Hepatic steatosis is prevalent in obese patients. Although it requires histology for diagnosis, ultrasound may indicate its presence. We evaluated the importance of ultrasound in the diagnosis of steatosis in morbidly obese patients, and considered its clinical relevance for patients with BMI of 35-40 kg/m² without co-morbidities. Methods: 187 morbidly obese patients submitted to bariatric surgery were prospectively studied. All patients had ultrasound before the operation, and hepatic biopsies during the operation, which were compared. Results: The prevalence of steatosis histologically was 91.4%. The sensitivity and specificity of ultrasound in diagnosing steatosis was 49.1% and 75%, respectively,with a positive predictive value of 95.4%. Conclusion: The biopsies found a very high prevalence of steatosis in the studied population. The ultrasound results yielded a high positive predictive value (95.4%), suggesting its use as a diagnostic tool for this co-morbidity in morbidly obese patients.The low sensitivity of the method could be related to the lack of objective criteria for the ultrasound diagnosis of steatosis, and probably, technical problems in performing ultrasound in such patients. We believe that in patients with a BMI of 35-40 kg/m² without other comorbidities, the ultrasound finding of steatosis could be of value as an indication for bariatric surgery.