Abdol-Mohammad Kajbafzadeh1, Mehrzad Mehdizadeh2, Zahra Aryan1, Maryam Ebadi1, Shadi Abdar Esfahani3, Laleh Montaser-Kouhsari1, Azadeh Elmi4, Saman Shafaat Talab4, Zhina Sadeghi5. 1. Pediatric Urology Research Center, Pediatric Center of Excellence, Tehran University of Medical Sciences, No. 32, 2nd Floor, 7th Street Saadat-Abad Ave, Tehran, 1998714616 Iran. 2. Pediatric Radiology Department, Pediatric Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran. 3. Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA USA. 4. Division of Abdominal Imaging and Interventional Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, White 270, Boston, MA 02114 USA. 5. Department of Urology, University Hospitals of Case Medical Center, Case Western Reserve University, Cleveland, OH 44106 USA.
Abstract
BACKGROUND: Despite advances in urologic imaging, the paucity of an optimal technique that accurately clarifies obstructive and nonobstructive hydroureter exists. OBJECTIVE: This study was conducted to introduce a novel and modified ultrasonographic technique, known as drainage-related ultrasonography (DRUS), discriminating obstructive and nonobstructive, nonrefluxing hydroureter. MATERIALS AND METHODS: A total of 358 children (mean age, 3.7 years) with 418 nonrefluxing hydroureter were included. These children were composed of two groups of obstructive nonrefluxing (141 children with 157 dilated ureters) and nonobstructive, nonrefluxing (217 children with 261 hydroureter). The definite diagnosis regarding the subtype of hydroureter was derived from appropriate investigation. The maximum diameter of the dilated ureter, which was observed on ultrasonography, was recorded before and after 3 h of catheterization, as D1 and D2, respectively. To assess the D ratio, a formula was developed, that is, [(|D1 - D2|)/D1] × 100. Values were recorded and cutoff points were set to discriminate between subtypes. RESULTS: Obstructive versus nonobstructive subtypes of nonrefluxing hydroureter were clarified with 78.5 % sensitivity and 83.4 % specificity, by setting a cutoff point of 22 % for the D ratio. Regardless of the cutoff point assigned to the reduction in D (D2 compared with D1), DRUS revealed 93.9 % sensitivity, 80.6 % specificity, 63.2 % positive predictive value, and 97.4 % negative predictive value in discriminating upper from lower obstruction. CONCLUSION: DRUS affords favorable results in terms of differentiating between obstructive and nonobstructive, nonrefluxing hydroureter, as well as between upper and lower obstruction in obstructive cases. It has the potential to become an efficient imaging modality in the diagnostic algorithm of hydroureter.
BACKGROUND: Despite advances in urologic imaging, the paucity of an optimal technique that accurately clarifies obstructive and nonobstructive hydroureter exists. OBJECTIVE: This study was conducted to introduce a novel and modified ultrasonographic technique, known as drainage-related ultrasonography (DRUS), discriminating obstructive and nonobstructive, nonrefluxing hydroureter. MATERIALS AND METHODS: A total of 358 children (mean age, 3.7 years) with 418 nonrefluxing hydroureter were included. These children were composed of two groups of obstructive nonrefluxing (141 children with 157 dilated ureters) and nonobstructive, nonrefluxing (217 children with 261 hydroureter). The definite diagnosis regarding the subtype of hydroureter was derived from appropriate investigation. The maximum diameter of the dilated ureter, which was observed on ultrasonography, was recorded before and after 3 h of catheterization, as D1 and D2, respectively. To assess the D ratio, a formula was developed, that is, [(|D1 - D2|)/D1] × 100. Values were recorded and cutoff points were set to discriminate between subtypes. RESULTS: Obstructive versus nonobstructive subtypes of nonrefluxing hydroureter were clarified with 78.5 % sensitivity and 83.4 % specificity, by setting a cutoff point of 22 % for the D ratio. Regardless of the cutoff point assigned to the reduction in D (D2 compared with D1), DRUS revealed 93.9 % sensitivity, 80.6 % specificity, 63.2 % positive predictive value, and 97.4 % negative predictive value in discriminating upper from lower obstruction. CONCLUSION: DRUS affords favorable results in terms of differentiating between obstructive and nonobstructive, nonrefluxing hydroureter, as well as between upper and lower obstruction in obstructive cases. It has the potential to become an efficient imaging modality in the diagnostic algorithm of hydroureter.
Authors: José de Bessa; Francisco Tibor Dénes; Maria Cristina Chammas; Luciana Cerri; Edison Daniel Schneider Monteiro; Carlos Alberto Buchpiguel; Giovanni Guido Cerri; Miguel Srougi Journal: J Pediatr Urol Date: 2008-01-14 Impact factor: 1.830