CONTRAST-ENHANCED MAGNETIC-RESONANCE UROGRAPHY - FIRST EXPERIMENTAL RESULTS WITH A POLYMERIC GADOLINIUM BLOODPOOL AGENT

RATIONALE AND OBJECTIVES. The authors investigated the feasibility of contrast-enhanced excretory magnetic resonance urography to visualize the nonobstructed urinary tract with a macromolecular gadolinium-based bloodpool agent. METHODS. Excretory magnetic resonance imaging was pe rformed in seven pigs using a T-1-weighted three dimensional fast-fiel d-echo sequence before and up to 120 minutes after administration of a gadolinium bloodpool prototype agent. RESULTS. During the first 15 mi nutes after injection, the urographic effect was predominantly poor. V isualization of the entire urinary tract was excellent in four pigs an d incomplete but satisfactory in three 105 minutes after injection. Fu rosemide application was tested in one case, which improved image qual ity effectively. Corresponding to the physiological excretion rate, si gnal measurements in the renal parenchyma revealed a gradual decrease of the initially distinct contrast enhancement. CONCLUSIONS. T-1-weigh ted contrast-enhanced magnetic resonance urography using a polymeric g adolinium blood-pool allows detailed visualization of the normal urina ry tract, while information about the excretory function is obtained s imultaneously. However, application of a diuretic seems to be essentia l to prevent lengthy examination duration.