Contrast enhanced ultrasound should be the initial radiological investigation to characterise focal liver lesions

Contrast enhanced ultrasound (CEUS) involves the administration of a microbubble contrast agent followed by a US scan to evaluate the liver lesion through all phases of enhancement. Although technical difficulty and operator dependence can be encountered, CEUS is thought to be superior to conventional US and CT. This study aims to determine how effective CEUS is at characterising focal liver lesions and to establish its role in the diagnostic algorithm.

All patients who underwent a liver CEUS performed by a single consultant radiologist were identified over a 5 year period. The CEUS report, CT, MRI and/or PET report, histopathology report and case notes were reviewed.

127 patients were included. CEUS correctly identified 71 of 77 malignant lesions and all of the benign liver lesions. The sensitivity of CEUS for detecting and correctly characterising a malignant FLL is therefore 92% with a specificity of 100%.

Our study shows that CEUS has a high sensitivity and specificity for characterising focal liver lesions. CEUS has advantages over CT and MRI of a high degree of safety, good patient tolerance and often availability at the time of initial detection. We therefore suggest that CEUS should be used as the initial study in the characterisation of FLLs. The study should be followed, as appropriate, by CT and MRI or PET studies. Biopsy, with its risks of tumour seeding and false negative results should only be considered after review of the imaging studies and full MDT discussion.