MICTURATING CYSTOURETHROGRAPHY BY MR-IMAG ING USING RADIAL K-SPACE SAMPLING

Purpose: To investigate the feasibility of micturating cystourethrogra phy (MCU) by means of real-time MR imaging with radial k-space samplin g. Methods: The MR-MCU was performed in 7 adult male patients subseque nt to a gadolinium(Gd)-DTPA-enhanced excretory MR-urography. The Gd-en hancement of the urethra was visualized by MR-fluoroscopy using a T-1- weighted gradient-echo-sequence with radial k-space sampling and a sli ce thickness of 10 mm. Results: The proposed technique allowed in all 7 patients a dynamic realtime imaging of the Gd-flow inside the urethr a during micturition. The normal anatomy of the entire course of the u rethra was demonstrated in each patient, while simultaneously the rela tion to the prostate and pelvic floor became visible. Furthermore, the urinary bladder could be assessed by interactive repositioning of the slice orientation in any preferred direction. The ureters could also be visualized due to the persisting Gd-enhancement of the upper urinar y tract after the preceding MR-urography. Conclusions: MR-MCU using Cd -DTPA and radial k-space data acquisition is a novel imaging modality for a real-time visualization of the urethra during micturition withou t radiation exposure. This method also allows the assessment of the bl adder, the pelvic floor, and the Gd-filled upper urinary tract which s uggests a potential for the diagnosis of vesicoureteral reflux and uri nary incontinence.