Standardization of pediatric uroradiological terms: A multidisciplinary European glossary

Surgical validation of functional magnetic resonance urography in the study of ureteral anomalies distal to the uretero-pelvic junction in a pediatric cohort

BACKGROUND

Ureteral anomalies distal to the uretero-pelvic junction (UPJ) belong to the wide spectrum of congenital anomalies of the kidney and urinary tract (CAKUT). They can cause severe obstruction requiring a detailed anatomical depiction to define the surgical approach. Up to date, ultrasonography, voiding cystourethrography and scintigraphy are considered the gold-standard diagnostic tools to study obstructive anomalies of the urinary tract; however, they do not provide accurate ureteral anatomical details. The aim of our study was to evaluate the concordance between functional magnetic resonance urography (fMRU) and intraoperative findings to define ureteral anomalies distal to UPJ.

METHODS

Pediatric patients with ureteral anomalies distal to the UPJ who underwent surgery after performing fMRU were retrospectively collected. Surgical data were compared with radiological results. The concordance was assessed considering both pathological and non-pathological urinary tracts and was calculated by means of the Cohen's kappa coefficient. fMRU diagnostic accuracy was defined by sensitivity, specificity, and binomial exact confidence intervals.

RESULTS

We included 46 patients. The sensitivity and specificity of fMRU were 98.0% and 83.3%; positive predictive value 90.4%, negative predictive value 96.2%. The concordance between surgical findings and fMRU was 92.3%, with a Cohen's k coefficient of 0.83 (excellent).

CONCLUSIONS

Our study demonstrates the excellent agreement between fMRU and surgical findings in the definition of ureteral anomalies distal to the UPJ in children. Thus, it could be considered a valid imaging technique in the preoperative planning as it provides the surgeon with important information regarding the etiology and site of the obstruction.

Influence of constipation on enuresis

INTRODUCTION

Constipation has classically been considered as a risk factor of enuresis, although there are increasingly more publications that report a similar prevalence of constipation in both enuretics and non-enuretics.

OBJECTIVE

To determine the influence of constipation in monosymptomatic and non-monosymptomatic enuresis, and to find out the prevalence of the three disorders, as well as the lower urinary tract dysfunction and bladder-bowel dysfunction in the population.

MATERIAL AND METHOD

A cross-sectional observational prevalence study on a representative population sample of 5-9 year-old school boys and girls of Galicia, Spain. A questionnaire was completed in the schools on urinary and bowel habits, which included questions from the Paediatric Lower Urinary Tract Scoring System (PLUTSS) diagnostic questionnaire and grading of the lower urinary tract dysfunctions. The enuresis was diagnosed using the International Children's Continence Society (ICSS), and if it was also associated with diurnal symptoms, it was also classified as non-monosymptomatic enuresis. The constipation was evaluated using the Rome III criteria and the adapted Bristol stool scale.

RESULTS

A total of 772 questionnaires were included in the study. The prevalence of constipation was 20% and that of enuresis was 9.1% (62.9% monosymptomatic enuresis and 37.1% non-monosymptomatic), with the prevalence of bladder-bowel dysfunction being 5.2%. It was observed that constipation had no influence on the presence of monosymptomatic enuresis, but it did have an influence on non-monosymptomatic enuresis and lower urinary tract dysfunctions, where it was a significant risk factor.

CONCLUSIONS

The differential diagnosis between monosymptomatic and non-monosymptomatic enuresis is essential in the initial evaluation of the patient with enuresis, since the therapeutic management and the characteristics of both disorders are different, with constipation only being a risk factor in cases of non-monosymptomatic enuresis.

Comparative Study Between Functional MR Urography and Renal Scintigraphy to Evaluate Drainage Curves and Split Renal Function in Children With Congenital Anomalies of Kidney and Urinary Tract (CAKUT)

Background: Obstructive congenital anomalies of the kidney and urinary tract have a high risk of kidney failure if not surgically corrected. Dynamic renal scintigraphy is the gold standard technique to evaluate drainage curves and split renal function (SRF). Objectives: To compare functional magnetic resonance (MR) urography with dynamic renal scintigraphy in measuring volumetric SRF and in the classification of drainage curves in patients with congenital anomalies of the kidney and urinary tract. Materials and Methods: We retrospectively collected patients with hydroureteronephrosis or pelvicalyceal dilatation at renal ultrasound, who underwent both functional MR urography and dynamic renal scintigraphy (DRS) within 6 months. DRS studies were evaluated by a single nuclear medicine physician with a double reading. Functional MR urography renograms were blind evaluated twice by two radiologists. The functional MR urographyintra- and inter-reading agreements as well as the agreement between the two imaging techniques were calculated. SRF was evaluated by Area Under the Curve and Rutland-Patlak methods. Drainage curves were classified as normal, borderline or accumulation patterns by both the techniques. Results: Fifty-two children were studied, 14 with bilateral involvement. A total of 104 kidney-urinary tracts were considered: 38 normal and 66 dilated. Considering Area Under the Curve and Rutland-Patlak for SRF, the intra- and inter-reader agreements of functional MR urography had excellent and good results, respectively, and the two techniques demonstrated a good concordance (r2: 67% for Area Under the Curve and 72% for Rutland-Patlak). Considering drainage curves, the inter-readers agreement for functional MR urography and the concordance between the two techniques were moderate (Cohen's k, respectively, 55.7 and 56.3%). Conclusions: According to our results, there are no significant differences between functional MR urography and DRS in measuring volumetric SRF and in the classification of drainage curves in patients with congenital anomalies of the kidney and urinary tract.