ACR Appropriateness Criteria® Hydronephrosis on Prior Imaging-Unknown Cause.

Initial imaging evaluation of hydronephrosis of unknown etiology is a complex subject and is dependent on clinical context. In asymptomatic patients, it is often best conducted via CT urography (CTU) without and with contrast, MR urography (MRU) without and with contrast, or scintigraphic evaluation with mercaptoacetyltriglycine (MAG3) imaging. For symptomatic patients, CTU without and with contrast, MRU without and with contrast, MAG3 scintigraphy, or ultrasound of the kidneys and bladder with Doppler imaging are all viable initial imaging studies. In asymptomatic pregnant patients, nonionizing imaging with US of the kidneys and bladder with Doppler imaging is preferred. Similarly, in symptomatic pregnant patients, US of the kidneys and bladder with Doppler imaging or MRU without contrast is the imaging study of choice, as both ionizing radiation and gadolinium contrast are avoided in pregnancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The mean Hounsfield unit range acquired from different slices produces superior predictive accuracy for pyonephrosis in obstructive uropathy.

PURPOSE: To determine the non-contrast computer tomography imaging features of pyonephrosis and evaluate the predictive value of Hounsfield units (HUs) in different hydronephrotic region slices. MATERIALS AND METHODS: We retrospectively reviewed data from patients with hydronephrosis who had renal-ureteral calculi. All patients were categorized into pyonephrosis and simple hydronephrosis groups. Baseline characteristics, the mean HU values in the maximal hydronephrotic region (uHU) slice, and the range of uHU in different slices (ΔuHU) were compared between the two groups. Univariate and multivariate analyses were performed to identify risk factors for pyonephrosis. RESULTS: Among the 181 patients enrolled in the current study, 71 patients (39.2%) were diagnosed with pyonephrosis. The mean dilated pelvis surface areas were comparable between patients with pyonephrosis and simple hydronephrosis (822.61 mm² vs. 877.23 mm², p=0.722). Collecting system debris (p=0.022), a higher uHU (p=0.038), and a higher ΔuHU (p<0.001) were identified as independent risk factors for pyonephrosis based on multivariate analysis. The ΔuHU sensitivity and specificity were 88.7% and 86.4%, respectively, at a cutoff value of 6.56 (p<0.001), whereas the sensitivity and specificity for detecting pyonephrosis at a uHU cutoff value of 7.96 was 50.7% and 70.9%, respectively (p=0.003). CONCLUSIONS: Non-contrast computer tomography was shown to accurately distinguish simple hydronephrosis from pyonephrosis in patients with obstructive uropathy. Evaluation of the ΔuHU in different slices may be more reliable than the uHU acquired from a single slice in predicting pyonephrosis.

Utility of ultrasound-based scoring system in post-pyeloplasty recovery.

BACKGROUND/OBJECTIVE: Differentiation of uretero-pelvic junction obstruction (UPJO) from non-obstructive dilatation (NOD) is a major challenge. The aim of this retrospective study is to determine whether pyeloplasty prediction score (PPS) could predict the need for surgery and resolution after surgery. METHODS: Among patients with antenatally diagnosed hydronephrosis, those who were stable during post-natal follow-up were considered NOD. The UPJO group were the ones who worsened and underwent pyeloplasty based on conventional indications. All patients with UPJO underwent laparoscopic dismembered pyeloplasty. PPS was determined based on three ultrasound parameters obtained retrospectively: Society of Fetal Urology (SFU) grade of hydronephrosis, transverse anteroposterior (APD), and the absolute percentage difference of ipsilateral and contralateral renal lengths. RESULTS: Among 137 patients included (R:L = 59:73; M:F 102:35), 96 were conservatively managed (NOD), while 41 patients (29%) needed pyeloplasty (UPJO). Mean PPS was 4.2 (1.2) in the NOD group and it was significantly higher at 10.8 (1.63) in the UPJO group (p = 0.001). All patients with PPS > 8 needed a pyeloplasty, while two patients with PPS of 7 needed pyeloplasty due to drop in renal function. PPS cutoff value of >8 had a sensitivity 95%, specificity 100% and a likelihood ratio of 20. Post-pyeloplasty PPS resolution was proportional to the duration of follow-up. CONCLUSIONS: A PPS cutoff value of 8 or above is associated with the presence of significant UPJO. PPS is also useful in the assessment of hydronephrosis recovery post-pyeloplasty. The limitation of PPS: it can only be applied in the presence of contralateral normal kidney.

Focused abdominal ultrasound.

A focused point-of-care abdominal ultrasound is an examination performed at the patient's location and interpreted within the clinical context. This review gives an overview of this examination modality. The objective is to rapidly address predefined dichotomised questions about the presence of an abdominal aortic aneurysm, gallstones, cholecystitis, hydronephrosis, urinary retention, free intraperitoneal fluid, and small bowel obstruction. FAUS is a valuable tool for emergency physicians to promptly confirm various conditions upon the patients' arrival, thus reducing the time to diagnosis and in some cases eliminating the need for other imaging.

Ultrasound accuracy in evaluating renal calculi in Maysan province.

Renal calculi are a common clinical presentation. While ultrasound (US) is a widely used imaging modality for kidney stone diagnosis due to its accessibility and lower cost, its accuracy compared to computerized tomography (CT), the gold standard, remains understudied. This cross-sectional study evaluated the diagnostic accuracy of ultrasound for detecting and characterizing kidney stones compared to computed tomography (CT). Fifty-six patients with suspected kidney stones based on flank pain underwent abdominal ultrasound to assess stone presence, size, location, and the severity of any hydronephrosis (kidney swelling). These findings were then confirmed with a subsequent non-contrast CT scan. There was a fair agreement between US and CT (Kappa = 0.368) for detecting the stone location. The US could not detect 7 (12.5%) stones, being less sensitive in the middle and upper calyx compared to CT. There was a fair agreement between the US and CT (Kappa = 0.394) for detecting the severity of hydronephrosis. The US was less sensitive to moderate and severe hydronephrosis compared to CT. The abdominal ultrasound demonstrated excellent reliability for stone size measurement (intraclass correlation = 0.924), with CT measurements only slightly larger on average (mean difference 0.9 mm). Although abdominal ultrasound provides reliable stone size assessment, its capacity to accurately localize stones and assess hydronephrosis severity is limited.

Role of urinary N-acetyl-beta-D-glucosaminidase in predicting the prognosis of antenatal hydronephrosis.

PURPOSE: Urinary biomarkers are known to be able to diagnose renal damage caused by obstruction at an early stage. We evaluated the usefulness of urine N-acetyl-beta-D-glucosaminidase (NAG) to determine the prognosis of antenatal hydronephrosis. MATERIALS AND METHODS: From January 2019 to December 2021, a retrospective study was performed on patients with grade 3 or 4 hydronephrosis. We analyzed the ultrasonographic findings and the urinary NAG/Cr ratio between the laparoscopic pyeloplasty (LP) group and active surveillance (AS) group. RESULTS: A total of 21 children underwent LP for ureteropelvic junction (UPJ) obstruction and 14 children underwent AS. The mean age at the time of examination was 3.7 months (1.7-7.5 months) in the LP and 5.2 months (0.5-21.5 months) in the AS (p=0.564). The mean anteroposterior pelvic diameter was 30.0 mm (15.0-49.0 mm) in the LP and 16.7 mm (9.0-31.3 mm) in the AS (p=0.003). The mean renal parenchymal thickness was 2.6 mm (1.2-3.7 mm) in the LP and 3.8 mm (2.9-5.5 mm) in the AS (p=0.017). The urinary NAG/Cr ratio was 26.1 IU/g (9.8-47.4 IU/g) in the LP and 11.1 IU/g (2.6-18.1 IU/g) in the AS (p=0.003). After LP, the urinary NAG/Cr ratio was significantly reduced to 10.4 IU/g (3.4-14.2 IU/g) (p=0.023). CONCLUSIONS: The urinary NAG/Cr ratio, one of the biomarkers of acute renal injury, is closely related to the degree of hydronephrosis. Therefore, it may be useful to determine whether to perform surgery on the UPJ obstruction and to predict the prognosis.

Hydronephrotic lower moiety of duplex systems: Observations using diuresis renography.

PURPOSE: The purpose of this study is to characterize the prevalence and behavior of hydronephrosis of non-refluxing lower moiety of duplex kidneys using MAG-3 diuresis renography. We compare our data to previous case series and ureteropelvic junction obstruction of single systems. MATERIALS AND METHODS: An IRB-approved database of over 5000 diuresis renograms performed in 2025 patients was queried to identify cases of hydronephrosis of lower moiety of duplex kidneys suspicious for ureteropelvic obstruction, excluding those with hydroureter or reflux. Kidney function and post-furosemide drainage parameters on initial and follow-up diuresis renograms were recorded. Medical records and patient outcomes were reviewed. RESULTS: In total, 19 renal units were identified in 18 patients (11 male, 7 female), age range 0.5 months to 17.8 years, including one patient with bilateral lower moiety hydronephrosis. Initial diuresis renograms in 12 asymptomatic patients (13 renal units) with antenatal hydronephrosis demonstrated varying drainage patterns from normal to obstructed. Follow-up studies showed worsening drainage in 3 patients, who all underwent surgery. Drainage improved in 4 patients and remained unchanged in 5 patients (6 renal units). Of the 6 patients presenting with Dietl's crisis, 5 showed obstructive drainage on initial diuresis renogram, 2/5 with decreased function. All 5 obstructed patients underwent surgery. CONCLUSION: Hydronephrosis of the lower moiety of a duplex system is rare and behaves similarly to single systems. The majority are diagnosed antenatally, display a dynamic nature, and may present with acute obstruction. Diuresis renography is a valuable tool in its evaluation and management.

Efficacy of laparoscopic pyeloplasty for pediatric hydronephrosis caused by symptomatic versus asymptomatic endogenous ureteropelvic junction obstruction: a retrospective analysis.

OBJECTIVE: To retrospectively compare the differences in the surgical efficacy and prognosis of laparoscopic pyeloplasty for hydronephrosis caused by symptomatic versus asymptomatic ureteropelvic junction obstruction (UPJO) in children and determine whether clinical symptoms affect the surgical outcome and prognosis. METHODS: Children who underwent laparoscopic pyeloplasty in our hospital from January 2018 to December 2022 were retrospectively analyzed. The children were divided into symptomatic and asymptomatic groups according to their main symptoms. The primary outcomes were the surgical success rate, change in renal parenchymal thickness, and change in renal pelvis anteroposterior diameter. The secondary outcomes were postoperative complications, reoperation rate, operative duration, intraoperative blood loss, and drainage tube indwelling time. RESULTS: In total, 224 children with UPJO were enrolled; 148 (66.1%) were symptomatic and 76 (33.9%) were asymptomatic. The symptomatic group showed a significantly greater mean change in renal parenchymal thickness, significantly higher surgical success rate, and significantly lower postoperative complication rate. CONCLUSIONS: In the present study, asymptomatic children had a lower surgical success rate, less postoperative imaging improvement, and more postoperative complications than symptomatic children. The presence or absence of clinical symptoms may affect the surgical outcome and prognosis.

Ureteral stricture formation after endoscopic removal of obstructing stones: could it be predicted with well-assessed radiological parameters?

The possible role of well-assessed radiological parameters in the prediction of ureteral stricture formation in cases with impacted obstructive ureteral calculi has been evaluated. 46 adult patients with or without ureteral stricture formation after ureteroscopic stone management were included. In addition to stone size and some certain radiological parameters including ureteral wall thickness (UWT) of the involved ureter at the impacted stone site was also measured and noted on computed tomography (CT) images. Parameters were evaluated in two subgroups of cases, namely: Group 1: patients in whom a ureteral stricture formed after endoscopic stone removal and Group 2: patients normal ureteral anatomy without any stricture formation. The possible relationship between the UWT values and degree of hydronephrosis (HN) with subsequent stricture formation was comparatively evaluated. All of the stones were proximal ureteral calculi in both groups. Both the degree of HN and proximal ureteral diameter (PUD) parenchymal was higher in cases with stricture formation. In addition, mean parenchymal thickness was lower and mean values of UWT measurements at the stone site were 3.70 ± 0.97 mm and 2.17 ± 0.26 mm in Groups 1 and 2, respectively. A cutoff value 2.49 mm for UWT was found to be highly predictive for stricture formation. UWT value calculated at the obstructing stone site was found to be predictive enough for the likelihood of ureteral stricture formation with high sensitivity and specificity . This evaluation along with some other radiological parameters may enable the urologists to follow such cases on this aspect with necessary measures taken.

Renal point-of-care ultrasound performed by ED staff with limited training and 30-day outcomes in patients with renal colic.

BACKGROUND AND AIM: Emergency Department (ED) renal point-of-care ultrasound (PoCUS) in renal colic by accredited specialists has good prognostic value. This may not be generalizable to under-resourced EDs. We investigated PoCUS in renal colic in our ED with lesser training. METHODS: We performed a single-centre health records review of adult ED patients with renal colic and PoCUS. Patients were managed by a non-ED specialist/resident doctor with no POCUS accreditation in consultation with an attending. These doctors attended a 3.5-h training session conducted by accredited attendings to examine hydronephrosis. They needed to verify their PoCUS findings with an attending during the first two weeks of their six-month posting before performing it independently. The primary outcome was 30-day urological procedures in hydronephrotic vs. non-hydronephrotic groups. Secondary outcomes were the distribution of primary outcome with grades of hydronephrosis, 30-day ED nephrolithiasis-related reattendances in hydronephrotic vs. non-hydronephrotic groups and its distribution with grades of hydronephrosis. We compared outcomes using Fisher's exact test. We also reported crude odds ratio (COR) and 95% CI of primary outcome between hydronephrotic vs. non-hydronephrotic groups. p values ≤ 0.05 were significant. RESULTS: We recruited 651 patients; 160 (24.6%) without and 491 (75.4%) with hydronephrosis. Rates of grades of hydronephrosis were: mild (76.6%), moderate (13.8%), severe (1.2%) and undifferentiated (8.4%). There was a difference in 30-day urological procedures (rates [95% CI]) in hydronephrotic vs. non-hydronephrotic groups, 11.2 [8.7-14.0]% vs. 2.5 [1.0-6.3]%; p < 0.001; COR (95% CI) 4.9 (1.8-13.8); p = 0.002. Increasing 30-day urological procedural rates were associated with increasing grade of hydronephrosis [no: 2.5%, mild: 7.7%, moderate: 23.5%, severe: 67.0% and undifferentiated: 14.6%; p < 0.001]. No differences occurred in other secondary outcomes. CONCLUSIONS: Renal PoCUS could be performed by non-ED specialist/resident doctors to identify patients without hydronephrosis who rarely required urological intervention. Hydronephrotic patients could benefit from further risk stratification.

ABSTRAIT: CONTEXTE ET OBJECTIF: L'échographie rénale au point de soin (PoCUS) dans les coliques rénales par des spécialistes agréés a une bonne valeur pronostique. Cela peut ne pas être généralisable aux SU sous-financés. Nous avons étudié PoCUS dans les coliques rénales dans notre DE avec une formation moindre. MéTHODES: Nous avons effectué un examen des dossiers médicaux d'un seul centre des patients adultes atteints de coliques rénales et de PoCUS. Les patients étaient pris en charge par un médecin résident/spécialiste non-membre de la DG sans accréditation POCUS en consultation avec un médecin traitant. Ces médecins ont assisté à une séance de formation de 3,5 heures menée par des titulaires accrédités pour examiner l'hydronéphrose. Ils devaient vérifier leurs résultats PoCUS auprès d'un assistant pendant les deux premières semaines de leur affectation de six mois avant de l'effectuer de manière indépendante. Le critère de jugement principal était des procédures urologiques de 30 jours dans les groupes hydronéphrotiques vs non-hydronephrotiques. Les critères de jugement secondaires étaient la distribution du critère de jugement primaire avec les grades d'hydronéphrose, les reattendances liées à la néphrose ED de 30 jours dans les groupes hydronéphrotiques vs non hydronéphrotiques et sa distribution avec les grades d'hydronéphrose. Nous avons comparé les résultats en utilisant le test exact de Fisher. Nous avons également signalé un rapport de cotes brut (RC) et un IC à 95 % du critère de jugement principal entre les groupes hydronéphrotiques et non hydronéphrotiques. Les valeurs de P 0,05 étaient significatives. RéSULTATS: Nous avons recruté 651 patients; 160 (24,6%) sans et 491 (75,4%) avec hydronéphrose. Les taux d'hydronéphrose étaient les suivants : légère (76,6 %), modérée (13,8 %), sévère (1,2 %) et indifférenciée (8,4 %). Il y avait une différence dans les interventions urologiques de 30 jours (taux [IC à 95 %]) dans les groupes hydronéphrotiques par rapport aux groupes non-hydronephrotiques, 11,2 [8,7-14,0] % contre 2,5 [1,0-6,3]%; p < 0,001; RCC (IC à 95 %) 4,9 (1,8-13,8); p = 0,002. L'augmentation des taux de procédures urologiques de 30 jours était associée à l'augmentation du grade d'hydronéphrose [non : 2,5%, léger : 7,7%, modéré : 23,5%, sévère : 67,0% et indifférencié : 14,6%; p < 0,001]. Aucune différence n'est survenue dans les autres critères de jugement secondaires. CONCLUSIONS: La PoCUS rénale pourrait être réalisée par des médecins non spécialistes/résidents de la D pour identifier les patients sans hydronéphrose qui ont rarement nécessité une intervention urologique. Les patients hydronéphrotiques pourraient bénéficier d'une meilleure stratification des risques.

Predicting obstruction risk using common ultrasonography parameters in paediatric hydronephrosis with machine learning.

OBJECTIVE: To sensitively predict the risk of renal obstruction on diuretic renography using routine reported ultrasonography (US) findings, coupled with machine learning approaches, and determine safe criteria for deferral of diuretic renography. PATIENTS AND METHODS: Patients from two institutions with isolated hydronephrosis who underwent a diuretic renogram within 3 months following renal US were included. Age, sex, and routinely reported US findings (laterality, kidney length, anteroposterior diameter, Society for Fetal Urology [SFU] grade) were abstracted. The drainage half-times were collected from renography and stratified as low risk (<20 min, primary outcome), intermediate risk (20-60 min), and high risk of obstruction (>60 min). A random Forest model was trained to classify obstruction risk, here named the 'Artificial intelligence Evaluation of Renogram Obstruction' (AERO). Model performance was determined by measuring area under the receiver-operating-characteristic curve (AUROC) and decision curve analysis. RESULTS: A total of 304 patients met the inclusion criteria, with a median (interquartile range) age of diuretic renogram at 4 (2-7) months. Of all patients, 48 (16%) were low risk, 102 (33%) were intermediate risk, 156 (51%) were high risk of obstruction based on diuretic renogram. The AERO achieved a binary AUROC of 0.84, multi-class AUROC of 0.74 that was superior to the SFU grade, and external validation (n = 64) binary AUROC of 0.76. The most important features for prediction included age, anteroposterior diameter, and SFU grade. We deployed our application in an easy-to-use application (https://sickkidsurology.shinyapps.io/AERO/). At a threshold probability of 30%, the AERO would allow 66 more patients per 1000 to safely avoid a renogram without missing significant obstruction compared to a strategy in which a renogram is routinely performed for SFU Grade ≥3. CONCLUSIONS: Coupled with machine learning, routine US findings can improve the criteria to determine in which children with isolated hydronephrosis a diuretic renogram can be safely avoided. Further optimisation and validation are required prior to implementation into clinical practice.

Voiding Cystourethrogram Before Pyeloplasty: To Do or Not To Do?

OBJECTIVE: To assess the incidence of concomitant vesicoureteral reflux (VUR) in unilateral cases of ureteropelvic junction obstruction (UPJO) and to identify factors that predict VUR. METHODS: Files of 381 pediatric patients who underwent unilateral pyeloplasty between 2000 and 2017 were retrospectively reviewed. A total of 270 patients with available data and ≥5 years of follow-up were eligible for this study. Demographic parameters, preoperative hydronephrosis grade, renal pelvis anteroposterior diameter (APD), renal parenchymal thickness (PT), split renal functions on MAG-3 scan and VUR status were noted. The patients were divided into two groups: those with concomitant VUR (group I, n: 24, 8.9%) and those without VUR (group II, n: 246, 91.1%). RESULTS: Among 270 patients (205 boys, 75.9%) with a median age of 4 months (2-98), 197 (72.9%) had antenatal hydronephrosis. Median follow-up was 11 years (5-22). Among 24 patients with concurrent VUR, 6 (25%) had grade II VUR, whereas grade III-V VUR was detected in 18 (75%). Of these, 12 (50%) had ipsilateral VUR, 3 (12.5%) had contralateral, and 9 (37.5%) had bilateral VUR. In a median 137-month follow-up, spontaneous VUR resolution was observed in 6 (25%) patients, whereas 15 (62.5%) patients underwent endoscopic subureteral injection and 3 (12.5%) patients ureteroneocystostomy, respectively. Preoperative APD [35.5, (Inter Quantile Range) IQR (27.6-36.0) vs 26.5 IQR (25.0-35.0), P = .004] were significantly higher in group I, whereas group I had significantly lower PT [3.7, IQR (3.4-6.4) vs 5.8 IQR (4.4-6.1), P = .026]. Predictive factors for concomitant VUR were presentation with febrile UTI (odds ratio (OR): 2.769, P = .048), PT <3.95 mm (OR: 1.367, P = .043), and APD >28.8 mm (OR: 1.035, P = .001). CONCLUSION: Our results indicated that concomitant VUR and UPJO might be detected in 1 out of every 11 patients undergoing pyeloplasty, while some type of surgical intervention for VUR was required in 75% of these patients. Thus, voiding cystourethrogram prior to pyeloplasty may be limited in those presenting with febrile urinary tract infection, having higher APD and lower PT on preoperative urinary ultrasonography.

Application of ultrasound-guided percutaneous nephrostomy in the treatment of a solitary kidney with hydronephrosis due to renal tuberculosis.

PURPOSE: To investigate the value of ultrasound-guided percutaneous nephrostomy and nephrostomy tube replacement for treating a solitary kidney with hydronephrosis due to renal tuberculosis. METHODS: Clinical data of patients with a solitary kidney with hydronephrosis caused by renal tuberculosis who underwent ultrasound-guided percutaneous nephrostomy in our hospital from January 2011 to December 2022 were retrospectively analyzed. The associated success rate and complications were statistically analyzed, pre- and post-catheterization changes in serum creatinine and blood urea nitrogen levels were compared, success rate and complications of nephrostomy tube replacement in patients with long-term catheterization were statistically analyzed, and the impact of long-term catheterization on patient life was investigated. RESULTS: Overall, 32 patients aged 17-75 years (average age: 44.1 ± 16.9 years) underwent ultrasound-guided percutaneous nephrostomy. Sixty-three punctures were performed; the puncture success rate was 100%. The levels of serum creatinine and blood urea nitrogen of patients decreased after catheterization, and the differences between the pre-catheterization and post-catheterization were significant (P < 0.05). There were 1, 3, and 12 cases of serious, minor, and fistula-related complications, respectively. The mean duration of the indwelling catheter was 56.7 ± 36.2 (range, 13-120) months. The number of nephrostomy tube replacements was 344 times, and the success rate was 100%. All patients could take care of the puncture point by themselves. CONCLUSION: Ultrasound-guided percutaneous nephrostomy and nephrostomy tube replacement have a high success rate and few complications, which can improve the renal function of patients. It is of great value for treating a solitary kidney with hydronephrosis caused by renal tuberculosis.

Clearance While Upright on Initial Diuretic Renography Predicts the Need for Surgery in Children With Congenital Hydronephrosis.

OBJECTIVE: To improve the predictive ability of diuretic renography (DR) for surgical intervention in children with congenital hydronephrosis (CH) and concern for ureteropelvic junction obstruction. METHODS: Children with CH born between 2007 and 2021 who underwent initial DR prior to 6months of life, had both clearance while upright (CUP) and T ½ reported, and did not have immediate surgical intervention after the first DR were retrospectively evaluated for surgical intervention during the period of clinical observation. Once the optimal cut-points were identified for CUP and T ½, they were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: In total 65 patients were included in the final analysis with 33 (50.8%) undergoing surgical intervention (pyeloplasty) and 32 (49.2%) still on observation at last follow-up. The optimal cut-points for predicting surgical intervention were 28.1 minutes for T ½ and 22.4% for CUP. Applying the CUP cut-point of 22.4% we achieved a sensitivity of 60.6% (95% CI: 43.9-77.3), specificity of 96.9% (95% CI: 90.1-100.0), positive predictive value of 95.2% (95% CI: 86.1-100.0), and negative predictive value of 70.5% (95% CI: 57.0-83.9). CONCLUSION: A low CUP accurately predicts surgical intervention in children with CH who are initially observed. Although there is no singular measure on DR that can with absolute certainty predict future clinical course, our data do suggest there is utility in incorporating CUP (if <22.4%) into the decision process. Further research is necessary to help guide the management of children with intermediate CUP values.

Non-contrast-enhanced magnetic resonance urography for measuring split kidney function in pediatric patients with hydronephrosis: comparison with renal scintigraphy.

BACKGROUND: Split kidney function (SKF) is critical for treatment decision in pediatric patients with hydronephrosis and is commonly measured using renal scintigraphy (RS). Non-contrast-enhanced magnetic resonance urography (NCE-MRU) is increasingly used in clinical practice. This study aimed to investigate the feasibility of using NCE-MRU as an alternative to estimate SKF in pediatric patients with hydronephrosis, compared to RS. METHODS: Seventy-five pediatric patients with hydronephrosis were included in this retrospective study. All patients underwent NCE-MRU and RS within 2 weeks. Kidney parenchyma volume (KPV) and texture analysis parameters were obtained from T2-weighted (T2WI) in NCE-MRU. The calculated split KPV (SKPV) percent and texture analysis parameters percent of left kidney were compared with the RS-determined SKF. RESULTS: SKPV showed a significant positive correlation with SKF (r = 0.88, p < 0.001), while inhomogeneity was negatively correlated with SKF (r = - 0.68, p < 0.001). The uncorrected and corrected prediction models of SKF were established using simple and multiple linear regression. Bland-Altman plots demonstrated good agreement of both predictive models. The residual sum of squares of the corrected prediction model was lower than that of the uncorrected model (0.283 vs. 0.314) but not statistically significant (p = 0.662). Subgroup analysis based on different MR machines showed correlation coefficients of 0.85, 0.95, and 0.94 between SKF and SKPV for three different scanners, respectively (p < 0.05 for all). CONCLUSIONS: NCE-MRU can be used as an alternative method for estimating SKF in pediatric patients with hydronephrosis when comparing with RS. Specifically, SKPV proves to be a simple and universally applicable indicator for predicting SKF.

Risk factors for adverse outcomes after pediatric pyeloplasty: A retrospective cohort study.

PURPOSE: To identify the risk factors for adverse outcomes after pediatric pyeloplasty. METHODS: We conducted a retrospective review of all children under the age of 14 years who underwent primary pyeloplasty for unilateral ureteropelvic junction (UPJ) obstruction at a single teaching hospital in Tunisia between January 1, 2013, and December 31, 2022. RESULTS: A total of 103 patients were included. Median age of patients at surgery was 27 months (interquartile range [IQR], 13-44). On ultrasound, median renal pelvic anteroposterior diameter was 3.2 cm (IQR, 2.3-4), and the median renal cortex thickness (RCT) was 2.5 mm (IQR, 2-3.5). Median differential renal function (DRF) on preoperative radionuclide renal scan was 40% (IQR, 30-46). Postoperative adverse outcomes occurred in 28 patients (27.2%). These included 19 cases of urinary tract infections (UTIs), 11 cases of UPJ restenosis, four cases of UPJ leakage, two cases of urinoma, and two cases of diversion-related complications. Multivariate logistic regression analysis revealed two factors significantly and independently related to postoperative negative outcomes: RCT <3 mm and DRF > 50%. CONCLUSION: Our study demonstrated that preoperative RCT on ultrasound of less than 3 mm and preoperative DRF on radionuclide renal scan of more than 50% were independent risk factors for adverse outcomes following pediatric pyeloplasty. These factors could be of interest in identifying, early on, patients who will develop postoperative negative outcomes, giving them more attention and support, and explaining the prognosis to the patient and family.

Analysis of the Efficacy of Elastography in Comparison with Dynamic Renal Nuclear Scintigraphy in the Evaluation of Unilateral Pelvi-Ureteric Junction Obstruction.

INTRODUCTION: In hydronephrosis due to pelviureteric junction obstruction (PUJO), an obstruction to urine flow may lead to increased pelvic pressure, which may cause interstitial fibrosis and renal impairment. Recently, there have been reports on renal pelvic assessment using ultrasound elastography (USE). This study was conducted to see if USE can evaluate PUJO and if it can be correlated to the findings of the dynamic renal nuclear scan. MATERIAL AND METHODS: In this observational study, only patients with unilateral PUJO underwent acoustic radiation force impulse (ARFI) elastography. A rectangular region of interest (ROI) measuring 5 × 10 mm was positioned on the cortex region of the upper, mid, and lower poles of the affected kidney. Three valid measurements were obtained, from which a mean value was calculated. A dynamic renal nuclear scan using Technetium-99m ethylene dicysteine (EC or TC99 m EC) was obtained and split renal function (SRF) was used for comparison. RESULTS: In the group of 20 patients, the mean age was 3.37 years. The mean SRF of the affected kidney was 26.65 %, and the corresponding USE value was 0.45 kpa. The Spearman's rho correlation coefficient for SRF and USE was 1 and 0.672, respectively (p = 0.001). Elastography was not feasible if SRF was less than 20 %. CONCLUSION: USE may be able to comment on the renal functional status of hydronephrosis. If USE is reported as non-feasible, it may suggest that renal function is grossly compromised. It may serve as an alternative diagnostic modality for renal functional evaluation. LEVEL OF EVIDENCE: Level II, Prospective Cohort Study.