[Comparison of functional magnetic resonance urography and dynamic renal scintigraphy in the functional assessment of ureteropelvic junction obstruction in children].

PURPOSE: In order to determine the role and significance of functional magnetic resonance urography (fMRU) in the diagnosis of ureteropelvic junction obstruction (UPJO), a comparative analysis of the results of fMRU and dynamic renal scintigraphy (DRS) was carried out. MATERIALS AND METHODS: From January 2017 to December 2019, fMRU and diuretic DRS were performed in 36 patients (mean age 89+/-63 months). Boys - 26 (72.2%), girls - 10 (27.8%). Left-sided hydronephrosis was detected in 23 (63.9%) children, right-sided in 12 (33.3%) patients, and bilateral lesions in 1 (2.8%) patient (2 renal units (RU)). Antenatal hydronephrosis was detected in 9 (25%) patients, and postnatally in 27 (75%) patients. According to ultrasound data, grade II hydronephrosis occurred in 11 (29.8%) RU, grade III - in 21 RU (56.7%), and grade IV - in 5 RU (13.5%) according to the SFU classification. A diuretic test was performed in 26 patients. RESULTS: Median and quartiles of differential renal function (DRF) according to fMRU data on the affected side were 37% [29; 43], and according to DRS - 46% [40;49]. When performing fMRU, a positive diuretic test was detected in 20 patients, 5 patients - negative and 1 patient - doubtful, and according to the DRS data, 12 patients had a positive test, 10 patients - negative and 4 patients - doubtful. Differences in DRF between fMRU and DRS varied between 0.7-33%. The average value of differences in DRF on the affected side was 11.3+/-8.5%. When comparing the results of DRF on the affected side, a moderate correlation was found on the Cheddock scale (r=0.59, p<0.05) between fMRU and DRS data. In comparison of the DRF using the Wilcoxon test, statistically significant differences were revealed (p<0,05). SUMMARY: Our experience demonstrates the high potential of fMRU in terms of replacing the classical methods of diagnosis of UPJO in children, taking into account the high correlation coefficients between the results of fMRU and DRS. Standardization of the fMRU protocol will increase the diagnostic relevance of information and in the future will make fMRU the only necessary study to determine management tactics for patients with UPJO.

Point-of-care ultrasound is an accurate, time-saving, and cost-effective modality for post-operative imaging after pyeloplasty.

BACKGROUND: Dismembered pyeloplasty is considered the gold standard treatment for ureteropelvic junction obstruction (UPJO). Although the frequency and timing of follow up imaging after pyeloplasty is variable, renal ultrasound (RUS) is commonly utilized. With minimal training, point-of-care ultrasound (POCUS) can be easily performed by a urologist during a post-operative visit. OBJECTIVE: Our hypothesis is that POCUS is an accurate, time-saving, and cost-effective alternative to a complete retroperitoneal ultrasound (CRUS) performed by the Radiology Department after pyeloplasty. STUDY DESIGN: The clinical records of all children who underwent pyeloplasty (by any method) over a 12 month period at our institution were retrospectively reviewed. The exact timing and method (POCUS vs. CRUS) of follow up imaging was surgeon-dependent. Statistical analysis was performed to compare the time and cost of POCUS vs. CRUS. The clinical course of each patient who had each type of imaging was assessed. RESULTS: A total 45 patients were included in this analysis. Over a mean follow up period of 29 months, a total of 73 CRUS and 67 POCUS were performed. Each CRUS on average added 2 h to each patient's healthcare encounter. Had the 73 CRUS been performed as POCUS instead, this would have corresponded to $83,751 less charges to payers. There was no difference in the rate of the detection of worsening, stable, or improved hydronephrosis (HN) between either modality (p > 0.05). The recommended follow up time for observed HN was no different between CRUS and POCUS (p > 0.05). Children with worsening HN on POCUS underwent functional studies without confirmatory CRUS. Interestingly, two patients had metachronous, contralateral UPJO discovered during post-operative imaging. These were both discovered by POCUS. Nineteen (42%) patients who had attended at least one post-operative visit were eventually loss to follow-up. This occurred exclusively in those who did not have worsening ultrasound (p < 0.01). There was no difference in the loss to follow-up after POCUS (8) or CRUS (12) (p > 0.05). CONCLUSIONS: POCUS performed by a urologist is an accurate assessment of HN after pyeloplasty with time and cost savings to compared to a CRUS performed by a radiologist. POCUS is not associated with any difference in rate of detection of worsening HN or rate of loss to follow up.

Evaluation of upper tract urothelial carcinomas by contrast-enhanced ultrasound. / Valoración del carcinoma urotelial de vías superiores mediante ecografía con contraste.

AIM: To describe the findings and behaviour of contrast-enhanced ultrasound in the study of upper tract urothelial tumours and to assess its usefulness for diagnosis. MATERIAL AND METHODS: We reviewed our hospital's database over a period of 45 months to identify patients diagnosed with upper tract urothelial carcinomas. We reviewed the findings on mode B-ultrasound, contrast-enhanced ultrasound (location and qualitative assessment of intensity and washout of enhancement), and made a comparison with other techniques (computed tomography or magnetic resonance), and with the surgical specimen. RESULTS: We found 42 patients with a diagnosis of upper tract urothelial carcinoma confirmed with surgery over the period reviewed. Twenty-eight (67%) patients underwent contrast-enhanced ultrasound. Baseline ultrasound showed hydronephrosis with or without ureteral dilatation with echogenic content occupying the renal calyx (6), pelvis (10) or ureter (12). After injection of contrast, enhancement was noticed in 100% of the lesions, with similar intensity to the cortex in 23, and less in 5. Twenty-four lesions showed early washout, before the cortex, between 40 and 55seconds after the injection. The diagnosis was correct in 27 cases. Localisation coincided with the histological specimen in 28 cases, and 3 patients had additional distal carcinoma foci. CONCLUSION: Contrast-enhanced ultrasound is a useful technique for diagnosing upper tract urothelial tumours that increases confidence in the diagnosis.

Radiological noninvasive assessment of ureteral stone impaction into the ureteric wall: A critical evaluation with objective radiological parameters.

PURPOSE: To determine the predictive value of certain radiological parameters for an objective asssessment of the presence of ureteral stone impaction. MATERIALS AND METHODS: Seventy-nine patients with a single proximal ureteral stones were retrieved from the departmental database. Both clinical and particularly radiological data of all cases were well evaluated on this aspect. In addition to the time period between the first colic attack and definitive management; diameter of proximal ureter and renal pelvis, longitudinal and transverse stone size, Hounsfied unit (HU) of the stone and lastly ureteral wall thickness at the impacted stone site were all carefully evaluated and noted. RESULTS: Patients had a single proximal ureteral stone. While mean age of the cases was ranged 20 to 78 years; mean stone size was 15.62±4.26 mm. Evaluation of our data demonstrated that although there was a statistically significant correlation between ureteral wall thickness and patients age, transverse diameter of the stone, ureteral diameter just proximal to the stone, renal pelvic diameter and the duration of renal colic attacks; no correlation could be demonstrated between patients sex and the HU of the stone. CONCLUSIONS: Prediction of the presence and degree of proximal ureteral stone impaction is a challenging issue and our data indicated a highly significant correlation between ureteral wall thickness and the some certain radiological as well as clinical parameters evaluated which will give an objective information about the presence of impaction which may in turn be helpful in the follow-up and also management plans of such calculi.

Epidemiology, diagnosis, preoperative evaluation and prognostic assessment of upper-tract urothelial carcinoma (UTUC).

PURPOSE: Upper-tract urothelial carcinoma (UTUC) is a relatively uncommon disease with limited available evidence on specific topics. The purpose of this article was to review the previous literature to summarize the current knowledge about UTUC epidemiology, diagnosis, preoperative evaluation and prognostic assessment. METHODS: Using MEDLINE, a non-systematic review was performed including articles between January 2000 and February 2016. English language original articles, reviews and editorials were selected based on their clinical relevance. RESULTS: UTUC accounts for 5-10 % of all urothelial cancers, with an increasing incidence. UTUC and bladder cancer share some common risk factors, even if they are two different entities regarding practical, biological and clinical characteristics. Aristolochic acid plays an important role in UTUC pathogenesis in certain regions. It is further estimated that approximately 10 % of UTUC are part of the hereditary non-polyposis colorectal cancer spectrum disease. UTUC diagnosis remains mainly based on imaging and endoscopy, but development of new technologies is rapidly changing the diagnosis algorithm. To help the decision-making process regarding surgical treatment, extent of lymphadenectomy and selection of neoadjuvant systemic therapies, predictive tools based on preoperative patient and tumor characteristics have been developed. CONCLUSIONS: Awareness regarding epidemiology, diagnosis, preoperative evaluation and prognostic assessment changes is essential to correctly diagnose and manage UTUC patients, thereby potentially improving their outcomes.

Contemporary assessment of renal stone complexity using cross-sectional imaging.

Recently, several scoring systems have been proposed to predict outcomes of percutaneous nephrolithotomy, objectively and quantitatively assessing kidney calculi complexity using cross-sectional imaging. These scoring systems are promising new tools that can guide surgical decision making, predict surgical outcomes, counsel patients undergoing stone surgery, and improve standardized academic reporting in percutaneous kidney stone surgery. In this article, we review features of each of these systems, their similarities and differences, and their applicability in clinical practice and relevance in academic reporting.

Irreversible electroporation of the pig kidney with involvement of the renal pelvis: technical aspects, clinical outcome, and three-dimensional CT rendering for assessment of the treatment zone.

PURPOSE: To analyze irreversible electroporation (IRE) of the pig kidney with involvement of the renal pelvis. MATERIALS AND METHODS: IRE of renal tissue including the pelvis was performed in 10 kidneys in five pigs. Three study groups were defined: group I (two applicators with parallel configuration; n = 11), group II (three applicators with triangular configuration; n = 2), and group III (six applicators with complex configuration; n = 3). After IRE and before euthanasia, pigs underwent contrast-enhanced computed tomography (CT). Technical aspects (radial distance of applicators, resulting mean current), clinical outcome (complications, blood samples), and three-dimensional CT rendering for assessment of the treatment zone (short axis, circularity) were assessed. RESULTS: Radial distances of applicators were 14.3 mm ± 2.8 in group I, 12.3 mm ± 1.9 in group II, and 16.4 mm ± 3.5 in group III. Resulting mean currents were 25.7 A ± 6.5 in group I, 27.0 A ± 7.1 in group II, and 39.4 A ± 8.9 in group III. In group III, two perirenal hematomas were identified. There was no damage to the renal pelvis. During IRE, clinical blood parameters and cardiovascular markers did not change significantly. Short axis measurements were 20.6 mm ± 3.6 in group I, 31.9 mm ± 8.2 in group II, and 39.3 mm ± 2.4 in group III (P < .01 between groups). Circularity scores were 0.8 ± 0.2 in group I, 0.7 ± 0.1 in group II, and 0.7 ± 0.1 in group III, with a score of 1 indicating perfect roundness (P value not significant). CONCLUSIONS: IRE of the pig kidney with involvement of the renal pelvis is feasible and safe. Size but not shape of the treatment zone is significantly affected by applicator configuration.

Hydronephrosis index: a better physiological reference in antenatal ultrasound for assessment of fetal hydronephrosis.

OBJECTIVE: To establish a nomogram of fetal hydronephrosis index (HI) (anteroposterior diameter of renal pelvis divided by urinary bladder volume) at different gestational ages, to serve as a new reference for antenatal ultrasound examination, and to avoid overestimation of fetal hydronephrosis due to transient effect of a distended fetal bladder. STUDY DESIGN: 504 uncomplicated singleton pregnancies from 20 to 38 weeks' gestation were included. In each fetus, the maximum anteroposterior diameters of both renal pelves were measured on transverse view of fetal kidneys. Urinary bladder volume was calculated using the ovoid volume formula. HI was derived accordingly. RESULTS: Values of HI vary significantly at different trimesters of pregnancy. HI was much higher (mean = 0.1543) from 20 to 27 weeks' gestation, and its value decreased significantly (mean = 0.0253) from 28 to 38 weeks' gestation (P < .05, independent-sample t test). As gestational age increased, HI decreased (R(2) = 0.5921). CONCLUSIONS: HI is easy to be measured and can be used as a new physiological reference for assessment of fetal hydronephrosis by eliminating the confounding effect of a full fetal bladder. The change in values of HI throughout gestation supports the clinical importance of a nomogram for this new index.

Management of mild fetal pyelectasis: a comparative analysis.

OBJECTIVE: The purpose of this study was to compare 2 protocols for the antenatal management of isolated mild fetal pyelectasis and perform a cost analysis. METHODS: A retrospective analysis of unilateral and bilateral mild fetal pyelectasis followed at our institution from 2003 to 2006 was conducted. Fetuses with additional congenital anomalies or aneuploidy were excluded. Chi(2) analysis was used, and P < .05 was considered significant. RESULTS: Two hundred forty-four cases were identified, of which the majority were male (75.4% versus 24.6%). Eighty-eight patients were reevaluated every 4 weeks (protocol 1). The remaining 156 patients were reevaluated once in the third trimester (protocol 2). The mean number of ultrasound examinations in protocol 1 was 3.24, at a cost of $1187, compared with protocol 2, at $798. Resolution occurred in 59%, stabilization in 29%, and progression in 12%. There were no cases of progression to severe pyelectasis or a need for in utero intervention in either group. CONCLUSIONS: Mild fetal pyelectasis can be managed with 1 additional third-trimester ultrasound examination without a compromise in patient care. Average cost savings were $389 per patient for protocol 2, suggesting a benefit from this protocol over protocol 1.

Multidetector computed tomography arteriography in the preoperative assessment of patients with ureteropelvic junction obstruction.

BACKGROUND: Nowadays, endoscopic management of ureteropelvic junction (UPJ) obstruction is the treatment of choice. However, in the presence of crossing vessels, the success rate of endoscopic management decreases and the risk of hemorrhagic and vascular complications rises. The purpose of this study is to evaluate patients with UPJ obstruction using contrast enhanced multidetector computed tomography (CT) angiography to aid in surgical planning and management. PATIENTS AND METHODS: Between 2001 and 2005, 27 patients (mean age: 43 years; age range: 17-75 years) with UPJ obstruction were studied with multidetector CT angiography. Identification and characterization of crossing vessels was performed with multidirectional images and three-directional reconstructions. RESULTS: 12 patients (44%) were found to have 16 crossing vessels (vessels in contact with the UPJ or within a vicinity of less than 2 mm). Nine of these vessels were arteries and seven were veins. Nine vessels crossed anteriorly, two posteriorly, and one anteromedially. Endopyelotomy was contraindicated in these 12 patients due to the presence of crossing vessels. Eleven out of the 12 patients underwent a pyeloplasty by open surgery or laparoscopy, where the presence of crossing vessels was confirmed. One of the 12 patients did not undergo surgery. CONCLUSION: Multidetector CT angiography permits an adequate preoperative assessment of patients with UPJ obstruction as it is able to identify the presence and location of crossing vessels. Furthermore, it allows to study in detail the anatomy of the renal area and its vascular variants.

Late second trimester assessment of pyelectasis (SERP) to predict pediatric urological outcome is improved by checking additional features.

OBJECTIVE: Counseling for pyelectasis in the late 2nd trimester is usually based only upon assessing the antero-posterior (AP) width of the renal pelvis. We hypothesized that checking additional features would better predict postnatal outcome. STUDY DESIGN: Ultrasound (<24 weeks gestational age (GA)) and newborn outcome data collected prospectively since 1986 were analyzed retrospectively. We determined if outcome predictions in kidneys with a sonographically evident renal pelvis (SERP), which had evaluation of additional features (e.g., renal and bladder lengths, presence of a dilated ureter or dilated calyces) are more accurate than those that did not have these features. RESULTS: There were 286 fetuses studied with pediatric follow-up of an average of 6.5 years. There were 338 exams providing 459 ultrasound images with SERP. Additional features were not assessed in 183 fetuses; however 103 fetuses did have evaluation of additional features. These features were categorized as abnormal (92) or as normal (11). Fetuses with SERP and abnormal additional features required extensive urological care or died 6.1 times more often than fetuses in which additional features were not examined (p < 0.001) and 12.9 times more often when additional features were normal (p < 0.001). CONCLUSION: Fetal kidneys with SERP (<24 weeks GA) and an abnormal additional ultrasound feature had extensive pediatric care significantly more often than when such features were not evaluated or were normal.

Is newer always better? A comparative study of 3 lithotriptor generations.

PURPOSE: At a single center we compared the efficacy of 3 generations of lithotriptors using identical protocol inclusion and followup criteria but with different modes of anesthesia. MATERIALS AND METHODS: We compared stone disintegration and dilatation of the pyelocaliceal system achieved in a prospective, randomized trial comparing the original HM3 (Dornier Medtech, Kennesaw, Georgia) and Lithostar Plus (LSP) lithotriptors, and a matched, consecutive series of 107 treatments with the Modulith SLX. Stone disintegration and dilatation of the pyelocaliceal system were evaluated by abdominal plain x-ray and renal ultrasonography 1 day and 3 months after treatment. RESULTS: A total of 82 treatments with the HM3, 75 with the LSP and 107 with the SLX were analyzed, matched for stone burden and location within the pyelocaliceal system. On postoperative day 1, 91%, 65% and 48% patients treated with the HM3, LSP and SLX, respectively, were stone-free or had fragments that were 2 mm or less (HM3 vs LSP p <0.001, HM3 vs SLX p <0.001 and LSP vs SLX p = 0.015). Three to 5 mm fragments were found in 7%, 21% and 35% of patients (p = 0.006, <0.001 and 0.06), and fragments 6 mm or greater were found in 1%, 14% and 15% (p = 0.002, <0.001 and 0.1, respectively). The re-treatment rate was 4% in the HM3 group, 13% in the LSP group and 38% in the SLX group (HM3 vs LSP p = 0.05, HM3 vs SLX p <0.001 and LSP vs SLX p <0.001). Obstructive pyelonephritis occurred in 1% of the HM3 group, 8% of the LSP group and 5% of the SLX group (HM3 vs LSP p = 0.02, HM3 vs SLX p = 0.12 and LSP vs SLX p = 0.4). All re-treatments except those in 5 patients were performed with the HM3. Therefore, the 3-month stone-free rate was comparable in all 3 groups (HM3 87%, LSP 80% and SLX 81%). CONCLUSIONS: This study indicates that the HM3 lithotriptor disintegrates caliceal and renal pelvic stones better than the LSP and SLX machines, resulting in fewer complications and re-treatments. Disintegration with the LSP machine was also superior to that of the SLX with a need for fewer re-treatments.

Assessment of agreement of a quantitative variable: a new graphical approach.

In clinical or epidemiologic research, the measurement of variables always implies some degree of error. Because it is impossible to control the various sources of variation, the assessment of the reliability of a measurement is essential. Otherwise, concordance analysis must take into account the "clinical" interpretation of the measurement under study, because its practical usefulness is of central importance. In this article, we propose a new approach to assess the reliability of a quantitative measurement. We use a graphical approach familiar to statisticians and data analysts of the biomedical area, associating to it the useful feature of interpretation based on the proportion of concordant cases. We believe that the proposed graphical approach can serve as a complement, or as a alternative, to the Altman-Bland method for agreement analysis. It allows a simple interpretation of agreement that takes into account the "clinical" importance of the differences between observers or methods. In addition, it allows the analysis of reliability or agreement, by means of survival analysis techniques.

Congenital stenosis of ureteropelvic junction: assessment with multislice CT.

PURPOSE: To assess the feasibility of Multislice spiral CT (MSCT) with volume rendering (VR) and maximum intensity projection (MIP) reconstructions in recognizing ureteropelvic junction obstruction (UPJO). MATERIALS AND METHODS: Twenty-seven patients with UPJO underwent MSCT. To visualise the excretory system, 50 ml of uroangiografic contrast medium was administered by drip infusion via the cubital vein 180 minutes before the CT scan. MSCT was performed after the injection of 120 ml of contrast medium at a flow rate of 3.5 ml/sec. Dual-phase scanning was performed 25s and 55s after contrast medium administration. MIP and VR reconstructions were obtained on a dedicated workstation. RESULTS: In 11/27 (41%) patients, UPJO was due to an anomalous ureteropelvic junction (UPJ). In 9/27 (33%), the stenosis was caused by anomalous vessels. In 3/27 (11%), stenosis was due to an anomalous UPJ position even though anomalous accessory vessels could be seen. In 4/27 (15%), anomalous vessels were also identified but the presence of a pyeloureteral stent did not allow us to establish whether these vessels were the cause of UPJO. CONCLUSIONS: MSCT and MIP and VR reconstructions allow identification of the causes of congenital UPJO and provide useful information for appropriate treatment planning.

Ureteropelvic junction obstruction: use of helical CT for preoperative assessment--comparison with intraarterial angiography.

PURPOSE: To evaluate helical computed tomography (CT) in the preoperative assessment of crossing arteries in kidneys with ureteropelvic junction (UPJ) obstruction and to compare the results with those obtained by means of angiography. MATERIALS AND METHODS: Forty-one consecutive patients with symptomatic UPJ obstruction in 42 obstructed kidneys underwent renal helical CT and renal intraarterial digital subtraction angiography (DSA; flush aortography and bilateral selective renal injections). The helical CT and DSA images were interpreted in a blinded manner by two readers, and the results were compared. RESULTS: DSA showed 126 renal arteries in the 41 patients; 56% of patients had supernumerary renal arteries. Helical CT depicted 121 (96%) of these 126 renal arteries prospectively. Retrospectively, 124 (98%) renal arteries were visible on CT images. Twelve (29%) of the 42 kidneys with UPJ obstruction had identifiable arteries crossing the UPJ on DSA images. If DSA is used as the standard of reference, CT angiography was 100% sensitive and 96.6% specific for depicting these crossing arteries. CONCLUSION: Renal helical CT seems suitable to replace intraarterial DSA in the preoperative assessment of crossing arteries in kidneys with UPJ obstruction.

Quantitative SPECT of 99mTc-DMSA uptake in kidneys of infants with unilateral ureteropelvic junction obstruction: assessment of structural and functional abnormalities.

UNLABELLED: We evaluated individual renal function using quantitative SPECT of dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA) in infants with unilateral ureteropelvic junction (UPJ) obstruction and compared our findings with infants without obstruction. METHODS: QDMSA was performed on 13 infants (mean age of 2.8 +/- 2.8 mo) with unilateral UPJ obstruction and on 15 age-matched controls without obstruction. RESULTS: Control kidneys (n = 30) had a volume of 43.5 +/- 8.8 mL, a percentage injected dose (%ID)/mL 0.62 +/- 0.12 and uptake of 26.1% +/- 3.9%. Kidneys with UPJ obstruction (n = 13) had a volume of 61.2 +/- 19.3 mL, a %ID/mL of 0.42 +/- 0.11 and uptake of 25.4% +/- 8.2%. Contralateral kidneys (n = 13) had a volume of 44.0 +/- 11.9 mL, a %ID/mL of 0.57 +/- 0.16 and uptake of 24.2% +/- 4.6%. The uptake in obstructed kidneys was similar to that observed in contralateral and control kidneys (t = -0.77, P = 0.45; t = -0.37, P = 0.71; respectively). UPJ kidneys had a statistically significant increased volume and decreased %ID/mL, compared with contralateral kidneys (t = 3.35, P < 0.006 and t = 3.75, P < 0.003, respectively) and control kidneys (t = -4.2, P < 0.001 and t = 4.7, P < 0.001, respectively). There was no significant difference between contralateral kidneys and control kidneys regarding volume (t = -0.16, P = 0.87), %ID/mL (t = 0.98, P = 0.33) and uptake (t = -1.41, P = 0.16). Of 13 infants, 11 (85%) showed large kidneys with thinning of the renal cortex. In 1 infant, there was no difference between the obstructed and contralateral kidneys regarding volume, %ID/mL and uptake, and 1 infant showed significant decreased uptake in the UPJ kidney compared with the contralateral kidney. CONCLUSION: Although the overall renal function of the obstructed kidneys remained unchanged, there was a statistically significant decrease in the %ID/mL of renal tissue in UPJ kidneys, which may represent renal dysfunction. Increased functional volume with a thin cortex may represent a compensatory mechanism of the obstructed kidney. Such changes may contribute to the understanding of pathophysiologic mechanisms and may be an early sign of obstruction in infants with hydronephrosis. Further longitudinal studies with an extended number of infants and serial measurements of kidney volumes and %ID/mL are warranted to assess the significance of QDMSA in the management of infants with asymptomatic unilateral renal pelvic dilatation.

Assessment of increase in renal pelvic size on post-void sonography as a predictor of vesicoureteral reflux.

BACKGROUND: During the course of our routine renal ultrasound examinations, we noticed that some children who developed dilatation of a renal pelvis following voiding had reflux found on voiding cystourethrography (VCUG). PURPOSE: To determine if increase in renal pelvic size on post-void ultrasound is an accurate predictor of vesicoureteral reflux. MATERIALS AND METHODS: Fifty-seven children (113 kidneys) underwent renal ultrasound and VCUG on the same day. Anteroposterior dimensions of the renal pelves were prospectively measured on ultrasound prior to and following patient voiding and correlated with the results of the VCUG. RESULTS: The diameter of the renal pelvis increased in 12 and decreased in 38 kidneys on post-void ultrasound. Vesicoureteral reflux occurred in 19 kidneys and among these kidneys, renal pelvic diameter increased in 2, decreased in 7, and was unchanged in 10 following voiding. There was no significant correlation between post-void change in renal pelvic diameter and the presence of vesicoureteral reflux. CONCLUSION: Increase in renal pelvic size on post-void ultrasound is not a reliable indicator of vesicoureteral reflux.

Detection and assessment of pyelectasis in the fetus: relationship to postnatal renal function.

OBJECTIVE: To assess the relationship between fetal pyelectasis determined by ultrasonography and postnatal renal function. METHODS: We first established normal values for anteroposterior, transverse, and longitudinal diameters of the renal pelvis sonographically in 68 normal fetuses at 30-40 weeks' gestation. We also evaluated prospectively the relationship between the severity of pyelectasis (diameter at least two standard deviations above the normal mean) in 36 fetuses at 30-40 weeks' gestation and postnatal renal function. Fetal renal function also was evaluated through measurement of the hourly urine production rate, whereas postnatal renal function was assessed by technetium 99m-diethylenetriamine penta-acetic acid renography and excretory urography. RESULTS: Fetal pyelectasis was diagnosed when renal pelvic diameters were at least 8 mm (anteroposterior), 11 mm (transverse), and 14 mm (longitudinal), all upper limits of normal diameters of 68 normal fetuses as determined in the first part of the study. Pyelectasis was associated with a normal urine production rate in all fetuses, but in six fetuses it was associated with a normal urine production rate in all fetuses, but in six fetuses it was associated with a progressive deterioration of renal function within the 1st month of life, requiring neonatal surgery. In the other 30 fetuses with pyelectasis, who did not require neonatal surgery, pyelectasis decreased gradually or totally disappeared within 2 years. Renal pelvic anteroposterior, transverse, and longitudinal pelvic diameters were at least 20, 25, and 26 mm, respectively, during late fetal life in those neonates at the time of corrective surgery. The mean anteroposterior diameter in those fetuses who did not require surgery at infancy (11 +/- 6 mm) was significantly less than in those requiring surgery (33 +/- 14 mm, P < .01). Likewise, the transverse diameters were 17 +/- 10 mm and 38 +/- 16 mm (P < .01) and the longitudinal diameters were 20 +/- 10 mm and 48 +/- 22 mm (P < .01). CONCLUSION: Neonatal surgery is recommended when the anteroposterior, transverse, and longitudinal renal pelvic diameters during the prenatal period are at least 20, 25, and 26 mm, respectively. Surgery is not necessary when the diameters are less than 20 mm.

Assessment of drainage in PUJ dilatation: pelvic excretion efficiency as an index of renal function.

Renal function is important when assessing the response of a dilated renal pelvis to a diuretic stimulus. Yet there is little in the literature to suggest how this should be undertaken. Our aim was to develop a model which we have called pelvic excretion efficiency (PEE). The PEE, which may be used to assess drainage, is a mathematical model of the ratio of the total kidney excretion to the total amount of isotope extracted from the blood by the kidney. Thirty-three children with a prenatal diagnosis of unilateral renal pelvic dilatation (PUJ) were treated conservatively after birth. As a group, they underwent a total of 164 diuretic DTPA renograms up to the age of 72 months. Drainage was assessed as the response to frusemide (defined as the time for the corrected renal curve to fall to 75% of the maximum value in the frusemide part of the study; T75), response to bladder emptying, a change of posture after frusemide (PM), and PEE. The contralateral normal kidney showed a combination of both 'good' T75 and PM drainage in 51% of renograms while the PEE showed drainage in all. The affected kidney with renal pelvic dilatation showed a combination of both 'poor' T75 and PM drainage in 42% of renograms. The PEE was low in 99% of these 'poor drainage' renograms. The PEE, the ratio of the mathematical model of renal uptake to excretion, is readily calculated and may be a more accurate and specific technique to assess drainage on diuretic renography.