Manganese Dipyridoxyl Diphosphate: A New Paramagnetic Hepatobiliary Contrast Agent for Magnetic Resonance Imaging of the Liver — Clinical Results in 20 Patients

Abstract

Particularly the introduction of new hepatobiliary contrast agents, such as manganese dipyridoxyl diphosphate (Mn-DPDP), gadolinium benzyloxy-proprionic-tetraacetic acid (Gd-BOPTA), and Fe-EHPG and the development of fast gradient-recalled echo (GRE) sequences in breath-hold technique promise to improve the performance of magnetic resonance imaging (MRI) over the more familiar ultrasound (US) and computed tomography (CT) [3, 5] in differentiating between pathological and normal liver tissue. Mn-DPDP has a significantly higher affinity for hepatocytes than the routinely used gadolinium diethylene triamine pentaacetate (Gd-DTPA), which undergoes nonspecific extracellular distribution and predominantly renal excretion [7]. The synthesis and characterization of Mn-DPDP are described by Rocklage et al. [6, 7]. Toxicity studies reported by Elizondo et al. [1] suggest that Mn-DPDP is safe at the doses necessary for clinical imaging. Lim et al. [4] reported, upon initial human trials, that Mn-DPDP exhibits long-lasting preferential uptake by hepatocytes. In this phase II study we describe the Mn-DPDP uptake and morphological appearance of normal and pathological liver tissue.