Urinary bladder injuries are classified based on intraperitoneal versus extraperitoneal location. Intraperitoneal lacerations are associated with a higher risk of sepsis and tend to be large and are therefore treated with prompt surgical exploration and repair. In contrast, extraperitoneal bladder ruptures are commonly managed conservatively via simple catheter drainage with healing commonly achieved between 10 days and 3 weeks. However, lower urinary tract injuries are an exception to the rule which also require emergent intervention. The subject of this case report is an 8-year old girl that suffered lacerations to the bladder neck, bladder trigone, and pelvic floor during a motor vehicle collision. The initial contrast-enhanced phase demonstrated bladder wall thickening and intraluminal blood clot. Bladder rupture was not directly apparent until the patient was called back for a delayed scan of the pelvis which showed contrast extravasation from the trigone pooling around retroperitoneal spaces including the mesorectal fascia surrounding the rectum and the presacral space. Although these are not intraperitoneal locations, the radiologist should be aware that lacerations involving the bladder neck and lower urinary tract warrant immediate surgical consultation. Lower urinary tract injuries are sufficiently uncommon that an experienced urologist may encounter only a handful during their career. This case report highlights the anatomic spaces in the pelvis that are necessary to troubleshoot the likely location of a bladder injury and that the lack of intraperitoneal pooling of contrast should not distract from the emergent nature of this rare injury. The common association of lower urinary tract injury with pelvic floor disruption is also highlighted in this case as the patient had lacerations and pooling of contrast extending along the vagina and into the labia. Finally, the importance of delayed excretory phase imaging in the setting of pelvic trauma is emphasized to allow for the prompt diagnosis of bladder trauma. Read More

Meeting name: SPR 2022 Annual Meeting & Postgraduate Course , 2022

Authors: Infante Juan

Keywords: trauma, bladder, pelvic anatomy

Renal dysfunction in a transplant kidney is a common clinical problem which is usually attributed to either rejection or arterial stenosis. While the overall incidence of transplant renal artery stenosis is low, the question of stenosis remains after Doppler examinations although abnormal Doppler ultrasounds are often later proven to be false positives. In the author's experience, these false positive cases are almost always associated with high correction angles (at or near 60 degrees). Conversely, repeating a positive Doppler study by maneuvering the transducer to produce a lower correction angle often resolves the apparently elevated velocity. A contributing factor to the usage of high correction angles is the actual angle of takeoff of the transplant renal artery relative to the external iliac artery. This can make performing the study with a low correction angle a physically challenging task for the sonographer. Nevertheless, proper effort when scanning these cases is indicated to save the patients from unnecessary follow-up studies and possibly unnecessary invasive procedures. This educational exhibit aims to address the following learning points: 1) The basis for avoiding high correction angles can be traced to back to basic trigonometric principles which we must keep in mind during image acquisition and interpretation 2) The mechanism for false positive Doppler studies in post-transplant renal artery stenosis is often an unnecessarily high Doppler correction angle 3) Repeating a positive Doppler study with the aim of minimizing the correction angle through optimal probe placement can help avoid unnecessary further testing including possibly invasive procedures 4) The angle of takeoff and variable trajectories of transplant renal arteries can pose difficult physical and cognitive problems for the ultrasound operator Read More

Meeting name: SPR 2022 Annual Meeting & Postgraduate Course , 2022

Authors: Infante Juan

Keywords: renal artery stenosis, renal transplant, Doppler