Contrast‐enhanced voiding urosonography: A new, radiation‐free, alternative method for imaging of urinary bladder and urethra in healthy dogs

Abstract

Contrast‐enhanced voiding urosonography (CE‐VUS) has been generally considered as a promising tool to diagnose vesicoureteral reflux and abnormalities in lower urinary tract in human patients, especially in children. The purpose of this prospective study is to evaluate the quality of images of the urinary bladder and urethra obtained by CE‐VUS using a second‐generation ultrasound contrast agent (SonoVue®) in healthy dogs and to investigate the safety profile of SonoVue® after intravesical administration. Eighty‐four CE‐VUS examinations with SonoVue® were successfully performed in both unsedated (39/84) and sedated (45/84) dogs. Contrast‐enhanced voiding urosonography examination of urinary bladder was technically successful in all (84/84) dogs. The image quality was not considered adequate in five (5/84) dogs including three dogs in whom layering of contrast media during filling phase was observed and two dogs with premature destruction of microbubbles. In these five dogs, the problem was readily recognized and corrected such that the procedure was still successfully undertaken. The assessment of the urethra during spontaneous micturition was successfully performed in all (84/84) dogs in whom voiding was elicited during the examination. No side effects were observed after intravesical application of SonoVue®. This study demonstrates that CE‐VUS is a feasible and valuable technique to evaluate low urinary tract morphology and function in dogs. Based on our review of the literature, there are no published reports about the use of this method in dogs.

Diagnosis of traumatic urethral stricture in a canine patient with contrast‐enhanced voiding urosonography : A case report

“…9 However, the requirement for anesthesia, and the high cost of the procedure impede the application of CT and MRI studies in clinical practice. 3,9 The selection of imaging methods should depend on the etiology, US imaging and improves its diagnostic performance, reducing the need for CT and other diagnostic procedures in dogs who need lower urinary tract evaluation. 1,3 Additionally, the use of UCA can improve the reliability of US.…”

“…However, to perform classic urethrography procedures, sedation or general anesthesia is required, and this is the main limitation of these examinations, especially in critically ill patients. Recently, the use of CE‐VUS and contrast‐enhanced retrograde sonourethrography offered a very accurate depiction of urethral width during the filling of the urethral lumen 3,7 …”

“…Compared with the other imaging methods (RUG, VCUG, CT urography, and MRI), sedation or general anesthesia may not be required for the CE‐VUS examination 3 . Furthermore, CE‐VUS is a fast and cheap diagnostic method, and it does not expose the patient to ionizing radiation 2,3 …”

“…This second-generation UCA is the most used and consists of phospholipid-stabilized microbubbles filled with sulfur hexafluoride. [1][2][3] The safety of IV and intravesical administration of UCA in humans, especially in children, has been established in the literature. 2,4 In veterinary medicine, studies investigated the safety profile of IV and intravesical administration of Sonovue.…”

Diagnostic yield of uroendoscopy compared to ultrasonography for evaluating lower urinary tract disorders in dogs

“…17 Other techniques such as transrectal US and contrast enhanced transperineal US are more sensitive for lesions of the intrapelvic urethra and adjacent structures, however, these techniques were not employed in this study, affecting the agreement between uroendoscopy and US in these dogs. 18,19 The absence of abnormalities on uroendoscopy in stranguric dogs should be considered relevant, as this allows the clinician to exclude a mechanical obstruction as the reason for the clinical signs. Contrast urethrography could also be considered for these cases, but we did not evaluate that imaging modality in this study.…”