Carmina Duran MD, Abstract Co-Author: Nothing to Disclose

Luis Riera Soler MD, Presenter: Nothing to Disclose

Núria Rojo Sanchis, Abstract Co-Author: Nothing to Disclose

Anna Torremadé Ayats, Abstract Co-Author: Nothing to Disclose

Jordi M. Puig-Domingo MD, Abstract Co-Author: Nothing to Disclose

To assess the usefulness of voiding urosonography (VUS) for the evaluation of the upper urinary tract and urethra, in particular for the diagnosis and characterization of posterior urethral valves (and subtypes) and anterior urethral valves.

From October 2005 through April 2009, we performed 667 contrast-enhanced VUS examinations, using a multifrequency (6–4 MHz) convex transducer to study the entire urinary tract including the urethra (transperineal and/or transpelvic approach). To perform VUS, we used a specific harmonic imaging mode based on pulse inversion with a predetermined low (0.16–0.22) MI and administered a galactose-based contrast agent. During voiding, attention was focused on the presence of posterior urethral dilation, poor distention of the valve area, and reduced caliber of the anterior urethra. Thickness and irregularity of the bladder walls were also noted.

We performed VUS in 450 boys: 6(aged 2 days to 7 years old) had obstructive urethral pathology (posterior urethral valves (PUV), n=5; anterior urethral valves (AUV), n=1). Of these, 5 patients presenting prenatal oligohydramnios and hydronephrosis were studied 2 days after birth and diagnosed with PUVs. In these 5 patients, VUS found: thickening (> 4 mm if empty bladder, > 8mm if full bladder) and diverticula of bladder walls in 100%, posterior urethral dilatation (11-14mm +/- SD) in 100%, poor distension of the valve area in 4 cases, and transitory dilatation of the valve area in the fifth. In the other case (a 7-year-old boy finally diagnosed with AUV), VUS performed for difficulty in urinating found an abrupt change in the width (with proximal dilatation) of the pendulous urethra, secondary to a valve seen as a linear filling defect along the ventral wall. These findings were confirmed with VCUG and after surgery in 5 patients. One case, a boy with Prune-Belly syndrome was lost to follow-up. Vesicoureteral reflux was detected in 4 of the 5 patients with PUVs.  

VUS can replace VCUG for the diagnosis, characterization, postoperative follow-up of obstructive urethral pathology and thus obviate irradiation of the patient’s pelvis and gonads.

Used together with prenatal and clinical data, VUS enables accurate early diagnosis of obstructive urethral pathology and thus facilitates the immediate treatment essential for this pathology.

Duran, C, Riera Soler, L, Rojo Sanchis, N, Torremadé Ayats, A, Puig-Domingo, J, Voiding Urosonography: The Best Imaging Study for Obstructive Urethral Pathology in Boys.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8010771.html