Feasibility for detecting liver metastases in dogs using gadobenate dimeglumine-enhanced magnetic resonance imaging

Early detection of liver metastases may improve the prognosis for successful treatment in dogs with primary tumors. Hepatobiliary-specific contrast agents have been shown to allow an increase in magnetic resonance imaging (MRI) detection of liver metastases in humans. The purpose of this prospective study was to test the feasibility for using one of these agents, gadobenate dimeglumine, to detect liver metastases in dogs. Ten consecutive dogs known to have a primary tumor were recruited for inclusion in the study. All dogs were scanned using the same protocol that included a T2-weighted respiratory-triggered sequence, T1 VIBE, diffusion-weighted imaging, and 3D-FLASH before and after dynamic injection of gadobenate dimeglumine contrast medium. Delayed imaging was performed less than 30 min after injection and up to 60 min in two cases. Histological analysis of liver lesions identified in delayed phases was performed for each case and confirmed metastatic origin. In all cases, lesion number detected in hepatobiliary contrast-enhanced sequences was statistically higher than in other sequences. Optimal lesion detection occurred with a 3D-FLASH sequence acquired in the transverse plane and less than 30 min after injection. Findings indicated that gabobenate dimeglumine enhanced MRI is a feasible technique for detecting liver metastases in dogs.