Magnetic resonance imaging procedure for pelvic fracture urethral injuries and recto urethral fistulas: A simplified protocol.

Abstract

The urethral gap in pelvic fracture urethral injury (PFUI) is traditionally assessed using voiding cystourethrogram (VCUG) and retrograde urethrogram (RGU). Magnetic resonance imaging (MRI) is performed in complex cases. We assessed the refined "Joshi" MRI protocol to evaluate complex urethral defects after PFUI. A prospective study was conducted at our center from January 2018 to January 2020, involving patients aged >18 years with PFUI, suitable for MRI, and those who gave consent to perform standard RGU, VCUG, and MRI using standard and "Joshi" protocol. Forty men were included in the study. Distance between urethral/prostatic stumps was measured. Image quality was scored by four radiologists and four urologists. The surgical approach and type of PFUI repair were noted. We also established the need for inferior pubectomy by assessing the position of the posterior urethra (membranous) in relation to a horizontal line drawn from the lower edge of the pubic bone anteriorly to the rectum posteriorly in a sagittal image. The mean age was 30 years (SD, 5.25; range, 21-43), and the time from injury to imaging was 4 months (3-10 months); 40% of the men underwent crural separation, 57.5%, inferior pubectomy, and 2.5%, crural rerouting. There was a difference of 0.3 to 1.1 cm in the urethral gap measurements between MR images using the standard versus "Joshi" technique. MRI identified complex injuries such as rectourethral fistula, the need for inferior pubectomy, and the orientation of the posterior urethra. Urologists' and radiologists' satisfaction scores for the MR images were satisfactory to excellent. If the posterior urethra was over the defined mark, there was a 100% likelihood of inferior pubectomy (23/40 patients). MR image acquisition using the "Joshi" protocol provided high-quality anatomical information in PFUI cases to assist with surgical planning.