Diffusion‐weighted MRI for hepatocellular carcinoma screening in chronic liver disease: Direct comparison with ultrasound screening

Ultrasound is a widely utilized method of screening patients with chronic liver disease for hepatocellular carcinoma ( HCC ). However, the sensitivity of ultrasound for small tumours is limited. We have prospectively compared ultrasound screening with diffusion‐weighted ( DWI ) MRI for detecting HCC . Methods Patients with chronic liver disease referred for ultrasound screening underwent a liver ultrasound and a liver MRI comprising free breathing DWI . Each test was independently read to determine the accuracy of each modality for detecting HCC . Results One hundred and ninety‐two patients were recruited and HCC was diagnosed in six patients (3%); all of whom were detected at ultrasound screening, and five detected at MRI screening. Ultrasound had false‐positive studies 20 times (10%) while DWI MRI had three false‐positive examinations (2%) p≥0.05. The sensitivity, specificity, positive predictive value and negative predictive values for ultrasound are 100%, 90%, 23% and 100%, respectively, while for MRI are 83%, 98%, 63% and 99%. Conclusion In patients with chronic liver disease undergoing surveillance for hepatocellular carcinoma, DWI MRI screening shows similar sensitivity to screening ultrasound but with a significantly lower false‐positive rate.