GADOLINIUM ZEOLITE AS AN ORAL CONTRAST AGENT FOR MAGNETIC-RESONANCE-IMAGING

The purpose of this study was to evaluate efficacy and safety of a gad olinium (Gd) zeolite suspension as an oral MRI contrast agent, Serial dilutions of GADO-LITE(R) Oral Suspension '1,2-300 mu g of Gd(III)/ml) were prepared, MRI (T1 and T2 weighted) of standards and dogs (precon trast and postcontrast) were performed, Toxicity and Gd absorption wer e also assessed, Subsequently, 30 normal male adult volunteers were di vided into six groups of five subjects each, Gd zeolite po suspension was administered before and after MRI in volumes and concentrations ra nging from 250 to 1500 mt; 6 to 60 mu g of Gd+3/mL, The images were ra ted (efficacy score) by a blinded reader, Vital signs, blood chemistri es and urinalysis were recorded, Gadolite Oral Suspension produced exc ellent enhancement of the dog gastrointestinal [GI) tract. No toxicity or absorption of Gd was observed in dogs receiving doses up to 4 time s the anticipated human dose daily for 14 consecutive days, In clinica l trials, Gd zeolite significantly improved the efficacy scores for al l groups and all pulsing sequences (all P values < .05), Efficacy scor es and signal intensities generally increased with concentration and v olume, No Gd was detected in blood or urine specimens, No significant adverse events were reported, Gd zeolite is a promising contrast mediu m for enhancement of the GI tract in MRI.