The duplicated collecting system of the urinary tract: embryology, imaging appearances and clinical considerations

Duplication anomalies of the urinary collecting system are common and can be discovered and characterized with multiple imaging modalities. The embryology, imaging manifestations and clinical ramifications of duplicated ureters and renal collecting systems vary from a normal anatomical variant to urological pathology and are discussed and illustrated in this review.

Variation in the level of detail in pediatric voiding cystourethrogram reports

INTRODUCTION

Voiding cystourethrogram (VCUG) provides a wealth of data on urinary tract function and anatomy, but few standards exist for reporting VCUG findings.

OBJECTIVE

We aimed to assess variability in VCUG reports and to test our hypothesis that VCUG reports from pediatric facilities and pediatric radiologists are more complete than those performed at other facilities or by non-pediatric radiologists.

STUDY DESIGN

We analyzed original VCUG reports from children enrolled in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial. A 23-item checklist was created and used to evaluate reporting of technical (e.g. catheter size), anatomic (e.g. vesicoureteral reflux (VUR) presence and grade, bladder shape), and functional information (e.g. bladder emptying). Radiologists were classified as pediatric or non-pediatric radiologists. Facilities were categorized as to whether they were a free-standing pediatric hospital (FSPH), a pediatric "hospital within a hospital" (PHWH), a non-pediatric hospital (NPH), or an outpatient radiology facility (ORF). Multivariate linear regression was used to analyze factors associated with the completeness of the VCUG reports (percent of items reported from the 23-item checklist).

RESULTS

Six-hundred and two VCUGs were performed at 90 institutions. Of those, 76% were read by a pediatric radiologist, and 49% were performed at a FSPH (Table). On average, less than half of the 23 items in our standardized assessment tool were included in VCUG reports (mean 48%, SD 12). The completeness of reports varied by facility type: 51% complete at FSPH (SD 11), 50% at PHWH (SD 10), 36% at NPH (SD 11), and 43% at ORF (SD 8) (p < 0.0001). In multivariate analysis, VCUG reports generated at NPH or ORF had 8% fewer items included (95% CI 3.0-12.8, p < 0.01), and those generated at PHWH did not differ from those generated at FSPH. Reports read by a non-pediatric radiologist had 6% fewer items included (95% CI 3-9.7; p < 0.01) compared with those read by a pediatric radiologist.

DISCUSSION

There is substantial underreporting of findings in VCUG reports when assessing a widely represented sample of routine, community-generated reports using an idealized standard. Although VUR was often reported, other crucial anatomic and functional findings of the VCUG were consistently underreported across all facility types.

CONCLUSION

Although pediatric radiologist and pediatric hospitals generated more complete VCUG reports compared with those having non-pediatric origins, the differences are small when considering the substantial underreporting of VCUG findings in general. This underscores the opportunities for improvement in reporting of VCUG findings.

Imaging in the diagnosis of pediatric urolithiasis

Pediatric urolithiasis is an important and increasingly prevalent cause of pediatric morbidity and hospital admission. Ultrasound (US) is the recommended primary imaging modality for suspected urolithiasis in children. There is, however, widespread use of CT as a first-line study for abdominal pain in many institutions involved in pediatric care. The objective of this review is to outline state-of-the-art imaging modalities and methods for diagnosing urolithiasis in children. The pediatric radiologist plays a key role in ensuring that the appropriate imaging modality is performed in the setting of suspected pediatric urolithiasis. Our proposed imaging algorithm starts with US, and describes the optimal technique and indications for the use of CT. We emphasize the importance of improved communication with a greater collaborative approach between pediatric and general radiology departments so children undergo the appropriate imaging evaluation.

MRI-based reference range for the renal pelvis anterior-posterior diameter in children ages 0-19 years

OBJECTIVE

To determine the mean and normal range of anteroposterior diameter (APD) of the renal pelves in children.

METHODS

Patients aged 0-19 years with normal spinal MRIs were identified after institutional review board approval. Those with dilating uropathy or abdominal surgery/radiation were excluded. The maximum APD was measured. A mixed linear model was fit to determine the relationship between APD and age, adjusted for bladder distention. The left and right kidneys were treated independently.

RESULTS

283 left and 285 right renal units were included. For the left, a 3.5% increase in APD per year was predicted (p < 0.0001), with the average APD for infants and 18-year olds with non-distended bladders being 2.5 mm (95th percentile: 7.2 mm) and 4.6 mm (13.4 mm), respectively. For the right, a 3.9% increase in APD per year was predicted (p < 0.0001), with the average APD for infants and 18-year olds with non-distended bladders being 2.8 mm (8.4 mm) and 5.5 mm (16.6 mm), respectively. Compared with a non-distended bladder, a distended bladder increased the predicted APD between 23% (right) and 38% (left) (p = 0.01 and p < 0.0001, respectively).

CONCLUSION

The mean and normal ranges of APD measured by MRI in children are provided. APD increases with age and bladder distension and is greater on the left. Advances in knowledge: This article establishes normative ranges for APD, a critical component of genitourinary tract evaluation, and does so using the most precise imaging modality for this condition.

Intrarenal Reflux: Diagnosis at Contrast-Enhanced Voiding Urosonography

Vesicoureteral reflux (VUR) is a childhood condition that is usually diagnosed by fluoroscopic voiding cystourethrography (VCUG). Intrarenal reflux (IRR) of infected urine is believed to play an important role in the pathogenesis of reflux-associated pyelonephritis and subsequent parenchymal scarring and is traditionally depicted by fluoroscopic VCUG. This case series describes the phenomenon of IRR occurring in association with VUR in 4 children as depicted by contrast-enhanced voiding urosonography. The ability of contrast-enhanced voiding urosonography to show IRR when it occurs in conjunction with VUR compares favorably to that of fluoroscopic VCUG.

Sperm Retrieval in Adolescents and Young Adults with Klinefelter Syndrome: A Prospective, Pilot Study

OBJECTIVE

To assess sperm retrieval rates in adolescents and young adults with Klinefelter syndrome, with the ultimate goal of improving fertility in this population. Secondary aims were to evaluate other clinical characteristics of the cohort and identify predictors of sperm retrieval.

STUDY DESIGN

Patients 12-25 years of age with Klinefelter syndrome (47,XXY) were recruited at the Boston Children's Hospital. Physical examination, biochemical evaluation, scrotal ultrasonography, and semen analysis were performed. Neurocognitive data were collected. Microdissection sperm extraction (unilateral micro-testicular sperm extraction) was offered to individuals with no sperm in their ejaculates. Given the small sample size, analysis was primarily descriptive.

RESULTS

Fifteen patients were enrolled. None had sperm in their ejaculates. Ten patients underwent unilateral micro-testicular sperm extraction. Sperm retrieval rate was 50%. From a neurocognitive standpoint, subjects reported problems with peers, conduct, and overall difficulties. Incidentally, one-third of the patients were found to have testicular microlithiasis and 17% of subjects with renal ultrasound imaging had bilateral renal medullary nephrocalcinosis.

CONCLUSIONS

This pilot study suggests that sperm retrieval rates in adolescents and young adults with Klinefelter syndrome are comparable with those reported in older men. However, larger studies are needed to confirm our findings. The clinical significance of the scrotal and renal ultrasound findings merits further investigation.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01817296.

The role of imaging in pediatric bladder augmentation

Bladder augmentation (also called augmentation cystoplasty) refers to a number of surgical methods that increase the capacity and compliance of the urinary bladder. Imaging has an important role in the postoperative evaluation of bladder augmentation. The most common augmentation procedures utilize enteric segments to augment the bladder. The various types of bladder augmentation have characteristic appearances on different imaging modalities. Spontaneous bladder perforation is a complication that is seen in both early and late post-operative periods and it is one of the most important complications for radiologists to be aware of as it is life-threatening. We review the indications for bladder augmentation in children, the surgical techniques employed, the normal postoperative appearances on imaging studies and the role of imaging complications of bladder augmentation including delayed spontaneous bladder rupture, which is life-threatening.

Predictive value of specific ultrasound findings when used as a screening test for abnormalities on VCUG

BACKGROUND

Renal and bladder ultrasound (RBUS) is often used as an initial screening test for children after urinary tract infection (UTI), and the 2011 AAP guidelines specifically recommend RBUS be performed first, with voiding cystourethrogram (VCUG) to be performed only if the ultrasound is abnormal. It is uncertain whether specific RBUS findings, alone or in combination, might make RBUS more useful as a predictor of VCUG abnormalities.

AIMS

To evaluate the association of specific RBUS with VCUG findings, and determine whether predictive models that accurately predict patients at high risk of VCUG abnormalities, based on RBUS findings, can be constructed.

METHODS

and study sample: A total of 3995 patients were identified with VCUG and RBUS performed on the same day. The RBUS and VCUG reports were reviewed and the findings were classified. Analysis was limited to patients aged 0-60 months with no prior postnatal genitourinary imaging and no history of prenatal hydronephrosis.

ANALYSIS

The associations between large numbers of specific RBUS findings with abnormalities seen on VCUG were investigated. Both multivariate logistic models and a neural network machine learning algorithms were constructed to evaluate the predictive power of RBUS for VCUG abnormalities (including VUR or bladder/urethral findings). Sensitivity, specificity, predictive values and area under receiving operating curves (AUROC) of RBUS for VCUG abnormalities were determined.

RESULTS

A total of 2259 patients with UTI as the indication for imaging were identified. The RBUS was reported as "normal" in 75.0%. On VCUG, any VUR was identified in 41.7%, VUR grade > II in 20.9%, and VUR grade > III in 2.8%. Many individual RBUS findings were significantly associated with VUR on VCUG. Despite these strong univariate associations, multivariate modeling didn't result in a predictive model that was highly accurate. Multivariate logistic regression built via stepwise selection had: AUROC = 0.57, sensitivity = 86% and specificity = 25% for any VUR; AUROC = 0.60, sensitivity = 5% and specificity = 99% for VUR grade > II; and AUROC = 0.67, sensitivity = 6% and specificity = 99% for VUR grade > III. The best predictive model constructed via neural networks had: AUROC = 0.69, sensitivity = 64% and specificity = 60% for any VUR; AUROC = 0.67, sensitivity = 18% and specificity = 98% for VUR grade > II; and AUROC = 0.79, sensitivity = 32% and specificity = 100% for VUR grade > III.

CONCLUSIONS

Even with the state-of-the-art predictive models, abnormal findings on RBUS provide a poor screening test for genitourinary abnormalities. Renal bladder ultrasound and VCUG should be considered complementary, as they provide important, but different, information.

Variation in the documentation of findings in pediatric voiding cystourethrogram

BACKGROUND

Few standards exist for reporting results of voiding cystourethrogram (VCUG).

OBJECTIVE

To assess the variation in reporting of VCUG findings from different facilities using a standardized assessment tool.

MATERIALS AND METHODS

VCUG reports were evaluated for demographic, technical, anatomical and functional information. Reports were categorized by age, gender, indication and vesicouretal reflux (VUR) status. Institutions were classified as a free-standing pediatric hospital (n = 3), pediatric hospital within a hospital (n = 11), or non-pediatric facility (n = 24) and reports were classified as having been read by a pediatric radiologist or not. Each category of outside reports (n = 152) was randomly matched with a twice-larger group of Hospital A reports from the same category (n = 304). Multivariate linear regression was used to analyze the association between the primary outcome (percentage of items described in dictated VCUG report) and the type of radiologist and institution.

RESULTS

Of the 456 studies, 66% were in girls, 56% were in those <12 months old, and the indication was urinary tract infection (UTI) in 81%. The mean percentage of items reported was 67 ± 14% (74 ± 7% at free-standing pediatric hospitals, 61 ± 10% at pediatric hospitals within a hospital, and 48 ± 11% at non-pediatric facilities). In multivariate analysis, VCUG reports generated at non-pediatric facilities had 17% fewer items included (95% CI: 14.5-19.7%, P < 0.0001), and pediatric hospitals within a hospital had 9% fewer items included (5.9-12.5%, P < 0.0001) when compared to free-standing pediatric hospitals. Reports read by a pediatric radiologist had 12% more items included (9.1-15.3%, P < 0.0001) compared to those read by a non-pediatric radiologist.

CONCLUSION

More complete VCUG reports were observed when generated at free-standing pediatric hospitals and when interpreted by a pediatric radiologist.

Bladder exstrophy: current management and postoperative imaging

Bladder exstrophy is a rare malformation characterized by an infra-umbilical abdominal wall defect, incomplete closure of the bladder with mucosa continuous with the abdominal wall, epispadias, and alterations in the pelvic bones and muscles. It is part of the exstrophy-epispadias complex, with cloacal exstrophy on the severe and epispadias on the mild ends of the spectrum. Bladder exstrophy is the most common of these entities and is more common in boys. The goal of this paper is to describe common methods of repair and to provide an imaging review of the postoperative appearances.

Ultrasound as a screening test for genitourinary anomalies in children with UTI

BACKGROUND

The 2011 American Academy of Pediatrics guidelines state that renal and bladder ultrasound (RBUS) should be performed after initial febrile urinary tract infection (UTI) in a young child, with voiding cystourethrogram (VCUG) performed only if RBUS shows abnormalities. We sought to determine test characteristics and predictive values of RBUS for VCUG findings in this setting.

METHODS

We analyzed 3995 clinical encounters from January 1, 2006 to December 31, 2010 during which VCUG and RBUS were performed for history of UTI. Patients who had previous postnatal genitourinary imaging or history of prenatal hydronephrosis were excluded. Sensitivity, specificity, and predictive values of RBUS for VCUG abnormalities were determined.

RESULTS

We identified 2259 patients age <60 months who had UTI as the indication for imaging. RBUS was reported as "normal" in 75%. On VCUG, any vesicoureteral reflux (VUR) was identified in 41.7%, VUR grade >II in 20.9%, and VUR grade >III in 2.8%. Sensitivity of RBUS for any abnormal findings on VCUG ranged from 5% (specificity: 97%) to 28% (specificity: 77%). Sensitivity for VUR grade >III ranged from 18% (specificity: 97%) to 55% (specificity: 77%). Among the 1203 children aged 2 to 24 months imaged after a first febrile UTI, positive predictive value of RBUS was 37% to 47% for VUR grade >II (13% to 24% for VUR grade >III); negative predictive value was 72% to 74% for VUR grade >II (95% to 96% for VUR grade >III).

CONCLUSIONS

RBUS is a poor screening test for genitourinary abnormalities. RBUS and VCUG should be considered complementary as they provide important, but different, information.

Nationwide emergency department imaging practices for pediatric urolithiasis: room for improvement

PURPOSE

Children are particularly vulnerable to the harmful effects of medical radiation, and children with urolithiasis comprise a group that may undergo repeated radiation intensive imaging tests. We sought to characterize imaging practices for children presenting to the emergency department with suspected urolithiasis and to determine factors associated with the choice of imaging study.

MATERIALS AND METHODS

Using the 2006 to 2010 Nationwide Emergency Department Sample, we conducted a retrospective cohort study of patients younger than 18 years presenting with suspected urolithiasis. We determined imaging practices for visits to emergency departments where billing codes for computerized tomography and ultrasound were reliably reported. Logistic regression was used to delineate patient and hospital level factors associated with the use of computerized tomography vs ultrasound.

RESULTS

We identified 18,096 pediatric visits for suspected urolithiasis in the 1,191 Nationwide Emergency Department Sample emergency departments with reliable imaging codes. A total of 11,215 patients underwent computerized tomography alone, ultrasound alone or both. Of the patients 9,773 (87%) underwent computerized tomography alone. Computerized tomography use peaked in 2007 and declined thereafter. On multivariate analysis several factors were associated with the use of computerized tomography alone, including smaller proportion of pediatric patients treated at the emergency department, older age, location in the Midwest or South, evaluation at a nonteaching hospital and visit on a weekend.

CONCLUSIONS

Computerized tomography use is highly prevalent for children presenting with suspected urolithiasis. The lowest computerized tomography use is in emergency departments that care for more children. Ultrasound is used infrequently regardless of site. Awareness regarding risks of computerized tomography and consideration of alternatives including ultrasound are warranted in caring for these patients.

Prospective systematic intervention to reduce patient exposure to radiation during pediatric ureteroscopy

PURPOSE

After prospective measurement of radiation exposure during pediatric ureteroscopy for urolithiasis, we identified targets for intervention. We sought to systematically reduce radiation exposure during pediatric ureteroscopy.

MATERIALS AND METHODS

We designed and implemented a pre-fluoroscopy quality checklist for patients undergoing ureteroscopy at our institution as part of a quality improvement initiative. Preoperative patient characteristics, operative factors, fluoroscopy settings and radiation exposure were recorded. Primary outcomes were the entrance skin dose in mGy and midline dose in mGy before and after checklist implementation.

RESULTS

We directly observed 32 consecutive ureteroscopy procedures using the safety checklist, of which 27 were done in pediatric patients who met study inclusion criteria. Outcomes were compared to those in 37 patients from the pre-checklist phase. Pre-checklist and postchecklist groups were similar in patient age, total operative time or patient thickness. The mean entrance skin dose and midline dose were decreased by 88% and 87%, respectively (p <0.01). Significant improvements were noted among the major radiation dose determinants, total fluoroscopy time (reduced by 67%), dose rate setting (appropriately reduced dose setting in 93% vs 51%) and excess skin-to-intensifier distance (reduced by 78%, each p <0.01).

CONCLUSIONS

After systematic evaluation of our practices and implementation of a fluoroscopy quality checklist, there were dramatic decreases in radiation doses to children during ureteroscopy.

Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern

OBJECTIVES

Clinical significance and management of prenatal hydronephrosis (PNH) are sources of debate. Existing studies are flawed with biased cohorts or inconsistent follow-up. We aimed to evaluate the incidence of pathology in a large cohort of PNH and assess the biases and outcomes of this population.

METHODS

We reviewed 1034 charts of fetuses with PNH. Records of delivered offspring were reviewed at a pediatric center and analyzed with respect to prenatal and postnatal pathology and management.

RESULTS

Prenatal resolution of hydronephrosis occurred in 24.7% of pregnancies. On first postnatal ultrasound, some degree of dilatation was present in 80%, 88% and 95% of mild, moderate and severe PNH cases, respectively. At the end of follow-up, hydronephrosis persisted in 10%, 25% and 72% of children, respectively. Incidence of vesicoureteral reflux did not correlate with severity of PNH. Children with postnatal workup had more severe PNH than those without.

CONCLUSIONS

Despite prenatal resolution totalizing 25%, pelvic dilatation persisted on first postnatal imaging in most cases, thus justifying postnatal ultrasound evaluation. Whereas most mild cases resolved spontaneously, a quarter of moderate and more than half of severe cases required surgery. Patients with postnatal imaging and referral had more severe PNH, which could result in overestimation of pathology.

A novel method of evaluating ureteropelvic junction obstruction: dynamic near infrared fluorescence imaging compared to standard modalities to assess urinary obstruction in a swine model

PURPOSE

Dynamic near infrared fluorescence imaging of the urinary tract provides a promising way to diagnose ureteropelvic junction obstruction. Initial studies demonstrated the ability to visualize urine flow and peristalsis in great detail. We analyzed the efficacy of near infrared imaging in evaluating ureteropelvic junction obstruction, renal involvement and the anatomical detail provided compared to conventional imaging modalities.

MATERIALS AND METHODS

Ten swine underwent partial or complete unilateral ureteral obstruction. Groups were survived for the short or the long term. Imaging was performed with mercaptoacetyltriglycine diuretic renogram, magnetic resonance urogram, excretory urogram, ultrasound and near infrared imaging. Scoring systems for ureteropelvic junction obstruction were developed for magnetic resonance urogram and near infrared imaging. Physicians and medical students graded ureteropelvic junction obstruction based on magnetic resonance urogram and near infrared imaging results.

RESULTS

Markers of vascular and urinary dynamics were quantitatively consistent among control renal units. The same markers were abnormal in obstructed renal units with significantly different times of renal phase peak, start of pelvic phase and start of renal uptake. Such parameters were consistent with those obtained with mercaptoacetyltriglycine diuretic renography. Near infrared imaging provided live imaging of urinary flow, which was helpful in identifying the area of obstruction for surgical planning. Physicians and medical students categorized the degree of obstruction appropriately for fluorescence imaging and magnetic resonance urogram.

CONCLUSIONS

Near infrared imaging offers a feasible way to obtain live, dynamic images of urine flow and ureteral peristalsis. Qualitative and quantitative parameters were comparable to those of conventional imaging. Findings support fluorescence imaging as an accurate, easy to use method of diagnosing ureteropelvic junction obstruction.

Patient and family impact of pediatric genitourinary diagnostic imaging tests

PURPOSE

The impact of diagnostic genitourinary imaging on patients and families is poorly understood. We measured patient and family reaction to commonly performed genitourinary imaging studies using a standardized measurement tool.

MATERIALS AND METHODS

We surveyed families undergoing genitourinary imaging (renal ultrasound, voiding cystourethrography, radionuclide cystogram, static renal scintigraphy and diuretic renal scintigraphy) using a Likert scaled 11-item survey to assess impact across 4 domains (pain, anxiety, time, satisfaction). Survey scores were analyzed using ANOVA and linear regression.

RESULTS

A total of 263 families were surveyed (61 renal ultrasound, 52 voiding cystourethrogram, 55 radionuclide cystogram, 47 mercaptoacetyltriglycine dynamic renal scintigraphy, 48 dimercaptosuccinic acid static renal scintigraphy). Mean patient age was 2.1 years old. Of the patients 45% were male and 77% were white. Patient age, gender and prior genitourinary imaging experience varied by study type. Study type was significantly associated with total and weighted scores on the genitourinary imaging survey (both p <0.0001). Renal ultrasound was scored as better and mercaptoacetyltriglycine dynamic renal scintigraphy was worse than voiding cystourethrogram, radionuclide cystogram and dimercaptosuccinic acid static renal scintigraphy, which did not differ from each other. Other factors associated with worse total scores included patient age 1 to 3 years (p <0.001) and nonwhite race (p = 0.04). Gender, prior testing history, wait time and parent education were not associated with total scores. In the multivariate model renal ultrasound remained the best and mercaptoacetyltriglycine dynamic renal scintigraphy the worst (p <0.0001). In a direct comparison dimercaptosuccinic acid static renal scintigraphy and voiding cystourethrogram total scores did not differ (p = 0.59).

CONCLUSIONS

There were significant differences among genitourinary imaging studies regarding the patient/family experience, but there was no overall difference between dimercaptosuccinic acid static renal scintigraphy and voiding cystourethrogram. These findings may be useful to aid decision making when considering genitourinary imaging for children.

Prospective measurement of patient exposure to radiation during pediatric ureteroscopy

PURPOSE

Few data have been reported regarding radiation exposure during pediatric endourological procedures, including ureteroscopy. We measured radiation exposure during pediatric ureteroscopy and identify opportunities for exposure reduction.

MATERIALS AND METHODS

We prospectively observed ureteroscopy procedures as part of a quality improvement initiative. Preoperative patient characteristics, operative factors, fluoroscopy settings and radiation exposure were recorded. Our outcomes were entrance skin dose and midline dose (both mGy). Specific modifiable factors were identified as targets for potential quality improvement.

RESULTS

Direct observation was performed in 54 consecutive ureteroscopy procedures. Mean±SD patient age was 14.8±3.8 years (range 7.4 to 19.2), with 9 children being younger than 12 years. Mean±SD entrance skin dose was 46.4±48 mGy. Mean±SD midline dose was 6.2±5.0 mGy. The most important major determinant of radiation dose was total fluoroscopy time (mean±SD 2.68±1.8 minutes) followed by dose rate setting, child anteroposterior diameter and source to skin distance (all p<0.01). Analysis of factors affecting exposure levels revealed that use of ureteral access sheaths (p=0.01) and retrograde pyelography (p=0.04) were significantly associated with fluoroscopy time. We also found that dose rate settings were higher than recommended in up to 43% of cases and ideal C-arm positioning could have reduced exposure by 14% (up to 49% in some cases).

CONCLUSIONS

Children receive biologically significant radiation doses during ureteroscopy procedures. Several modifiable factors contribute to dose and could be targeted in efforts to implement dose reduction strategies.

Sonourethrogram to manage adolescent anterior urethral stricture

PURPOSE

Accurate measurement of anterior urethral stricture length is critical to determine the appropriate surgical approach. Retrograde urethrogram is often used to determine stricture location and length. However, the adult literature shows that retrograde urethrogram may underestimate stricture length. We investigated the role of sonographic urethrogram in the preoperative evaluation of adolescent urethral stricture disease.

MATERIALS AND METHODS

Between June 2008 and February 2009 we retrospectively evaluated 12 pediatric patients with urethral stricture disease using retrograde and sonographic urethrogram. Stricture length was categorized by 2 radiologists as I-less than 1, II-1 to 3 and III-greater than 3 cm. On sonographic urethrogram stricture length was measured as the longest extent of the urethral abnormality.

RESULTS

Mean patient age was 16.9 years (range 9.5 to 20.8). Retrograde urethrogram classified 7 cases as category I, 4 as category II and none as category III stricture, and 1 with no evidence of stricture. Sonographic urethrogram revealed strictures greater than 1 cm in all 7 category I cases and 2 of the 4 category II cases had strictures longer than 3 cm. One patient in whom retrograde urethrogram showed a category II stricture was stricture-free on sonographic urethrogram. One patient with a negative retrograde urethrogram had a stricture on sonographic urethrogram. Sonographic urethrogram upgraded stricture length in 10 of the 12 patients and outperformed retrograde urethrogram in 11.

CONCLUSIONS

Sonographic urethrogram is effective for evaluating adolescent urethral stricture disease. It may provide more accurate measurement of stricture length and improve preoperative planning.

Sonographic findings of ovarian torsion in children

BACKGROUND

The clinical diagnosis of ovarian torsion is challenging and findings on pelvic sonography can be pivotal in making the correct diagnosis.

OBJECTIVE

To determine the sonographic characteristics in children of surgically and pathologically proven ovarian torsion.

MATERIAL AND METHODS

We performed a retrospective review of the sonograms and medical records of 41 patients with surgically and pathologically proven ovarian torsion at a pediatric hospital between 1994 and 2005. All sonograms were reviewed retrospectively by two pediatric radiologists with attention to the size, echotexture, location, presence of peripheral round cysts, and evidence of flow on Doppler sonography within the torsed ovary. The amount of free pelvic fluid was also recorded.

RESULTS

The most common sonographic finding of ovarian torsion was an enlarged ovary/adnexal mass. All torsed adnexa were larger than the normal contralateral ovary, with the median volume 12 times that of the normal contralateral side. The majority (61%, n = 25) of the torsions occurred on the right. Color flow, either venous or arterial, was present in 62% (n = 21/34) of the torsed ovaries for which flow on Doppler sonography was documented. In 63% of the torsed ovaries (n = 26), the torsed adnexa appeared heterogeneous. Ovarian or para-ovarian pathology that may have acted as a potential lead point was present in 55% (n = 24) of torsed ovaries. The volume ratio of the torsed to normal ovary can predict the presence of an ovarian mass within the torsed ovary. In 70% of torsed ovaries with a volume ratio greater than 20, an ovarian mass was present, and in approximately 90% of those with a volume ratio less than 20, an internal mass was absent.

CONCLUSION

An enlarged heterogeneous appearing ovary is the most common finding in ovarian torsion. The presence or absence of flow by Doppler sonography is not helpful in the diagnosis. The volume ratio of the torsed to the normal ovary can predict the presence of an internal mass within the torsed adnexa.