Comparison of the diagsnotic performance of CT angiography and contrast-enhanced US in hepatic artery occlusion after liver transplantation

Purpose To evaluate the diagnostic performance of computed tomographic angiography(CTA) and contrast-enhanced US(CEUS) and compare the two modalities to diagnose significant hepatic artery occlusion (HAO). Materials and Methods The institutional review board approved this study, with a waiver of informed consent. Among 3117 adult liver transplantations performed over 8 years, 329 recipients were suspected of having HAO using Doppler US. After exclusion of recipients having either CTA or CEUS, 139 recipients were included in the study. CTA and CEUS were retrospectively reviewed using the criterion used in previous studies (CTA, ≥50% stenosis at the anastomosis; CEUS, no HA enhancement, or delayed and discontinuous enhancement). Accuracies of CTA and CEUS were compared using McNemar test. Results CEUS showed statistical significant better accuracy and specificity than CTA in patients with Doppler US abnormality after liver transplantation (accuracy 89.2% vs 98.3%, p=0.0005; specificity, 83.2% vs 100%, p=0.0001). CTA had 15 false positive diagnoses, and CEUS had one false negative diagnosis. Conclusion CEUS showed higher specificity and positive predictive value than CTA and should be the preferred second-line imaging tool for the diagnosis of HAO in patients with Doppler US abnormality.