RATIONALE AND OBJECTIVE: To approach the concept of magnetic resonance (MR) imaging-monitored micturating cystourethrography (MRMCU) by using gadolinium-enhanced real-time MR fluoroscopy. METHODS: MRMCU was performed in 21 male patients (27-76 years) subsequent to gadolinium excretory MR urography. Patients were examined in supine position at 1.5 T. For MR fluoroscopy of the urethra during micturition, we used a T1-weighted single-slice gradient-echo sequence with continuous radial k-space acquisition. Image reconstruction was obtained with the sliding-window technique reaching a frame rate of 25/s. The image plane was guided interactively through the urethra, the bladder and the ureters without stopping the scan. RESULTS: Two patients were unable to void in supine position. With MR fluoroscopy, the flow of gadolinium-enhanced urine through the urethra was visualized in 19 patients, in 14 of whom with complete demonstration of the urethral anatomy subdivided into 5 segments. Four urethral segments were identified in 1 patient, 3 segments in 2 patients, 2 segments in 3 patients, and 1 segment in 1 patient. MRMCU demonstrated changes in the urethral anatomy and the urine flow in 2 patients with a neobladder and in 1 patient with hypertrophy of the prostate. Subject to the limitation of antegrade gadolinium application, interactive MRMCU allowed to determine whether the ureters were enhanced by gadolinium or not. CONCLUSION: Gadolinium-enhanced MR fluoroscopy using radial k-space acquisition has achieved complete demonstration of the segmental anatomy of the urethra in 74% of the male adult patients who were able to accomplish micturition. Although MR fluoroscopy was able to visualize the gadolinium-enhanced ureters, the current data do not permit to conclude that MRMCU can demonstrate vesicoureteral reflux, especially in children.
RATIONALE AND OBJECTIVE: To approach the concept of magnetic resonance (MR) imaging-monitored micturating cystourethrography (MRMCU) by using gadolinium-enhanced real-time MR fluoroscopy. METHODS:MRMCU was performed in 21 male patients (27-76 years) subsequent to gadolinium excretory MR urography. Patients were examined in supine position at 1.5 T. For MR fluoroscopy of the urethra during micturition, we used a T1-weighted single-slice gradient-echo sequence with continuous radial k-space acquisition. Image reconstruction was obtained with the sliding-window technique reaching a frame rate of 25/s. The image plane was guided interactively through the urethra, the bladder and the ureters without stopping the scan. RESULTS: Two patients were unable to void in supine position. With MR fluoroscopy, the flow of gadolinium-enhanced urine through the urethra was visualized in 19 patients, in 14 of whom with complete demonstration of the urethral anatomy subdivided into 5 segments. Four urethral segments were identified in 1 patient, 3 segments in 2 patients, 2 segments in 3 patients, and 1 segment in 1 patient. MRMCU demonstrated changes in the urethral anatomy and the urine flow in 2 patients with a neobladder and in 1 patient with hypertrophy of the prostate. Subject to the limitation of antegrade gadolinium application, interactive MRMCU allowed to determine whether the ureters were enhanced by gadolinium or not. CONCLUSION:Gadolinium-enhanced MR fluoroscopy using radial k-space acquisition has achieved complete demonstration of the segmental anatomy of the urethra in 74% of the male adult patients who were able to accomplish micturition. Although MR fluoroscopy was able to visualize the gadolinium-enhanced ureters, the current data do not permit to conclude that MRMCU can demonstrate vesicoureteral reflux, especially in children.
Authors: Owen J Arthurs; Andrea D Edwards; Ilse Joubert; Martin J Graves; Pat A K Set; David J Lomas Journal: Eur Radiol Date: 2011-04-17 Impact factor: 5.315
Authors: Marco Di Girolamo; Simone Mariani; Giulia Marta Barelli; Elisa Rosati; Alberto Trucchi; Andrea Laghi Journal: Abdom Radiol (NY) Date: 2021-12-06