Frederica Papadopoulou

Safety of contrast-enhanced ultrasound in children for non-cardiac applications: a review by the Society for Pediatric Radiology (SPR) and the International Contrast Ultrasound Society (ICUS)

The practice of contrast-enhanced ultrasound in children is in the setting of off-label use or research. The widespread practice of pediatric contrast-enhanced US is primarily in Europe. There is ongoing effort by the Society for Pediatric Radiology (SPR) and International Contrast Ultrasound Society (ICUS) to push for pediatric contrast-enhanced US in the United States. With this in mind, the main objective of this review is to describe the status of US contrast agent safety in non-cardiac applications in children. The five published studies using pediatric intravenous contrast-enhanced US comprise 110 children. There is no mention of adverse events in these studies. From a European survey 948 children can be added. In that survey six minor adverse events were reported in five children. The intravesical administration of US contrast agents for diagnosis of vesicoureteric reflux entails the use of a bladder catheter. Fifteen studies encompassing 2,951 children have evaluated the safety of intravesical US contrast agents in children. A European survey adds 4,131 children to this group. No adverse events could be attributed to the contrast agent. They were most likely related to the bladder catheterization. The existing data on US contrast agent safety in children are encouraging in promoting the widespread use of contrast-enhanced US.

Duplex Collecting System Diagnosed During the First 6 Years of Life After a First Urinary Tract Infection: A Study of 63 Children

PURPOSE We determined the prevalence, anatomical variants and coexisting complications of duplex collecting systems in children with a history of UTI. Additionally, we compared the prevalence and severity of the coexisting anomalies with those found in single systems. MATERIALS AND METHODS We reviewed the records of children younger than 6 years who were evaluated following a first UTI during a 9-year period to identify those with duplex systems. Children without duplication anomalies comprised the control group. RESULTS Of 774 evaluated children 63 (8%), more commonly females than males, had duplex systems. CDS were as common as IDS. VUR was the most commonly associated anomaly, with a higher prevalence in CDS (66%) and IDS (47%) compared to single systems (26%, p <0.0001 and p = 0.007, respectively). Ectopic ureterocele, which was the second most common associated anomaly, was found in 20% of the CDS but in none of the IDS or single systems. The occurrence of renal scarring was similar among CDS, IDS (13%) and single systems (10%). Poorly functioning pole moieties occurred more often in CDS (40%) compared to IDS (4%, p = 0.003), and were observed in none of the single systems. The resolution rate of reflux tended to be higher in IDS compared to CDS. CONCLUSIONS CDS were a common finding among children with UTI who had duplication anomalies. Although CDS and IDS were accompanied by VUR more often than were single systems, CDS were associated more often with severe VUR, other serious complications and poor renal function.

Revascularization Process of the Bone–Patellar Tendon–Bone Autograft Evaluated by Contrast-Enhanced Magnetic Resonance Imaging 6 and 12 Months After Anterior Cruciate Ligament Reconstruction

Background: Contrast-enhanced magnetic resonance imaging (MRI) studies conducted on animal models have shown that the observed signal intensity changes are related to the degree of graft vascularity and its biomechanical properties. Purpose: To evaluate by contrast-enhanced MRI the revascularization process at 3 distinct sites discerned in relation to the surrounding microenvironment along the course of bone–patellar tendon–bone (BPTB) autograft in uncomplicated human anterior cruciate ligament (ACL)–reconstructed knees. Study Design: Case series; Level of evidence, 4. Methods: Thirty-two male patients were assessed with a 3-dimensional fast field echo/short tau inversion recovery (FFE/STIR) MRI sequence at the third postoperative day and at time intervals of 6 and 12 months after surgery. Signal-to-noise quotient (SNQ) was calculated for 3 specific graft sites (intra-articular site, intraosseous tibial tunnel site, and intraosseous juxta screw site) before and after gadolinium administration. Comparisons of the enhancement index (EI: SNQafter/SNQbefore gadolinium) were performed independently for each graft site and time interval. Results: Three days postoperatively, insufficient vascularization was noticed at the 3 sites. Six and 12 months after surgery, the enhancement index was significantly increased in all 3 sites (P < .001). The intra-articular site, 6 months postoperatively, achieved satisfactory contrast medium uptake (enhancement index >1), with significantly higher enhancement index values compared with the other 2 sites (P < .001). Twelve months after surgery, only the intraosseously enclosed sites displayed an increase of the enhancement index, although nonsignificant (P = .09 and P = .07, respectively). Conclusion: Revascularization of the graft occurs gradually along its length, with the intra-articular site being the first and the faster part to complete this phase, while both the intraosseous sites are still in progress throughout the first postoperative year. Revascularization is an important link at the intrinsic healing chain of the ACL graft. The surrounding microenvironment does seem to play a significant role in this process, and the differences in its composition along the graft course are reflected at the revascularization progress of the corresponding sites.

ESPR Uroradiology Task Force and ESUR Paediatric Working Group—Imaging recommendations in paediatric uroradiology, Part V: childhood cystic kidney disease, childhood renal transplantation and contrast-enhanced ultrasonography in children

The ESPR Uroradiology Task Force and the ESUR Paediatric Working Group present two new recommendations on imaging in childhood cystic kidney disease and in childhood renal transplantation, and address the presently restricted availability of contrast-enhanced (ce) US in children. New insights into the genetics require an updated classification of paediatric cystic kidney disease along with a new concept of diagnostic imaging. Characteristic imaging features are key to the new classification. Available recommendations for imaging renal transplantation in children are not satisfactory. The following consensus-based algorithm proposes a more effective and more uniform imaging concept, reducing invasiveness, enhancing diagnostic accuracy, and facilitating future multicentre studies and meta-analysis. At present, ce-US in children can only be performed off-license, since the only approved US contrast agent (CA) for children has been taken off the market. Nevertheless, paediatric ce-US is practiced at multiple places using Sonovue® (Bracco, Milan, Italy), a generally available agent in Europe. From a medical and scientific perspective, paediatric ce-US should be promoted, and efforts are undertaken to collect data on paediatric US-CA applications. Routine paediatric imaging depends on local expertise and availability of equipment. The imaging recommendations and supportive data are intended to ease the physicians’ difficult task of dealing with the specific diagnostic demands of paediatric paediatric cystic kidney disease and transplantation.

Loss of FEV1 in cystic fibrosis: correlation with HRCT features

Abstract. The purpose of this study was to determine which high-resolution computed tomography (HRCT) features in patients with cystic fibrosis are most strongly associated with functional impairment as expressed by forced expiratory volume in one second (FEV1). Forty-seven patients with cystic fibrosis underwent chest HRCT and had pulmonary function tests. The HRCT examinations were evaluated for 11 features scored using a modification of Bhalla system and FEV1 was recorded as percentage of the predicted value. Univariate and multivariate correlations between HRCT scores and FEV1 were performed. The most common HRCT feature was bronchiectasis (98%) followed by atelectasis–consolidation (81%), bronchial wall thickening (77%), tree-in-bud sign (74%), mucous plugging (72%) and mosaic perfusion pattern (47%). On univariate analysis the following features correlated strongly with FEV1: bronchial wall thickening (p<0.0000001), tree-in-bud sign (p<0.0000001), mucous plugging (p<0.0000001), atelectasis–consolidation (p<0.0000001), thickening of interlobular septa (p<0.0002), severity (p<0.0002) and extent of bronchiectasis (p<0.0002). On multivariate analysis bronchial wall thickening and atelectasis–consolidation were the strongest independent determinants of the FEV1. We found a regression equation between FEV1 and the two HRCT features: FEV1=constant variable+a multiplied by bronchial wall thickening+b multiplied by atelectasis–consolidation (a and b=regression coefficients, R2=0.48). The major morphological determinants of functional abnormality in cystic fibrosis, as expressed by the loss of FEV1, are bronchial wall thickening and atelectasis–consolidation.

Implications of 99mTc-DMSA Scintigraphy Performed During Urinary Tract Infection in Neonates

OBJECTIVE: To evaluate prospectively whether normal scintigraphic results during urinary tract infections (UTIs) in neonates were predictive of the absence of dilating vesicoureteral reflux (VUR) (grade ≥III) and permanent renal damage (PRD). METHODS: Term neonates with a first symptomatic, community-acquired UTI participated in the study. Urinary tract ultrasonography and technetium-99m-labeled dimercaptosuccinic acid (99mTc-DMSA) scintigraphy were performed within 72 hours after diagnosis and voiding cystourethrography within 1 to 2 months. DMSA scintigraphy, to determine the development of PRD, was repeated 6 months after UTI. RESULTS: Seventy-two neonates (144 renal units) were enrolled. Acute pyelonephritis was diagnosed through early DMSA scintigraphy in 19% of renal units, VUR in 22%, and grade ≥III VUR in 13%. The majority (71%) of renal units with grade ≥III VUR had normal early DMSA scintigraphic results. The sensitivity and specificity of abnormal early DMSA scintigraphic results to predict grade ≥III VUR were 29% (95% confidence interval: 11%–55%) and 82% (95% confidence interval: 74%–88%), respectively. PRD was found in 7% of renal units, all of which had abnormal early DMSA scintigraphic results. PRD was significantly more frequent among renal units with grade ≥III VUR than among nonrefluxing renal units (P < .05). CONCLUSIONS: Normal early DMSA scintigraphic results for neonates with symptomatic UTIs were helpful in ruling out later development of PRD but were not predictive of the absence of dilating VUR. To rule out dilating VUR, voiding cystourethrography may be required.

The effects of gestational age and growth restriction on compensatory kidney growth

BACKGROUND Low birth weight is associated with altered renal development, adult onset hypertension and renal disease. The aim of this prospective longitudinal study was to estimate the renal growth during the first 2 years of life in small-for-gestational age (SGA) infants of varied gestational age (GA) and with differing degrees of growth retardation (GR) at birth. Material and methods. The study included 466 children: SGA, n = 243, and appropriate-for-gestational age (AGA), n = 223, classified according to GA into three groups (28-34, 34-36 and >36 weeks, respectively). The SGA children were also classified according to the degree of GR: birth weight <3rd percentile, and birth weight 3-10th percentiles. Serial renal ultrasonography (US) for kidney length (KL) measurement was performed at the ages of 36 and 40 weeks corrected age and 3, 6, 12 and 24 months of chronological age. The ratios of KL(3) to crown to heel length (CHL), body weight (BW) and body surface area (BSA) were used as estimators of relative kidney length (RKL). RESULTS A total of 1898 measurements were performed. In the full-term and near-term SGA infants (GA >36 weeks), RKL was similar to or even higher than that in AGA controls (P < 0.05 at 12 and 24 months). In two groups of preterm infants (GA 34-36, 28-34 weeks), RKL was lower than in AGA controls either after the first 6 months (GA 34-36 group, P < 0.05) or throughout the study period (GA 28-34 group, P < 0.05). The absolute KL was more severely affected in the preterm babies (GA <36 weeks) with BW <3rd percentile than in those of GA 3rd-10th percentile. CONCLUSION While in full-term and near-term SGA infants RKL is similar to or even higher than that of AGA infants, in smaller preterm babies (<36 weeks of GA) the RKL is impaired up to the second year of life.

Renal venous thrombosis in an infant with predisposing thrombotic factors: color Doppler ultrasound and MR evaluation.

Abstract.We report a case of a neonate with hereditary thrombophilia presenting with renal venous thrombosis (RVT). Early color Doppler findings of RVT were lacking venous flow, and the arterial diastolic flow was reversed. This very high-resistance arterial flow is for the first time described in neonatal RVT. Magnetic resonance imaging showed low signal intensity of the renal pyramids on T1- and T2-weighted images, suggesting acute hemorrhage. After intravenous contrast injection, persistent cortical enhancement was observed along with lack of medullary enhancement. Despite the progressive reestablishment of some venous drainage, the kidney showed atrophy and loss of function.

European Society of Paediatric Radiology abdominal imaging task force recommendations in paediatric uroradiology, part IX: Imaging in anorectal and cloacal malformation, imaging in childhood ovarian torsion, and efforts in standardising paediatric uroradiology terminology

At the occasion of the European Society of Paediatric Radiology (ESPR) annual meeting 2015 in Graz, Austria, the newly termed ESPR abdominal (gastrointestinal and genitourinary) imaging task force set out to complete the suggestions for paediatric urogenital imaging and procedural recommendations. Some of the last missing topics were addressed and proposals on imaging of children with anorectal and cloacal malformations and suspected ovarian torsion were issued after intense discussions and a consensus finding process that considered all evidence. Additionally, the terminology was adapted to fit new developments introducing the term pelvicalyceal dilatation/distension (PCD) instead of the sometimes misunderstood hydronephrosis. The present state of paediatric urogenital radiology was discussed in a dedicated minisymposium, including an attempt to adapt terminology to create a standardised glossary.

Angiotensin II type 2 receptor gene polymorphism in caucasian children with a wide spectrum of congenital anomalies of the kidney and urinary tract

The A-1332G transition of the angiotensin II type 2 receptor (AT2R) gene was found to occur more often in males with ureteropelvic (UPJO) or ureterovesical junction obstruction (UVJO). However, other studies have shown controversial results. Τhe frequency of this polymorphism was investigated in 275 Caucasian children (153 boys, 122 girls) with a wide spectrum of congenital anomalies both of upper (165) and lower (110) urinary tract system and in 200 controls (100 boys, 100 girls). Among the included malformations, renal agenesis and duplex collecting system (DCS) were studied for the first time. The frequency of the G allele did not differ among patients (193 of 397 total alleles, 48.6%) and controls (146 of 300, 48.7%). No significant difference was also found in the frequency of the G allele in subgroups of congenital uropathies compared with controls. When analysis was performed in males and females separately, no significant difference was found in the frequency of the G allele in male (45.1%) or female (50.8%) patients compared with male (57.0%) or female (44.5%) controls. Our data indicate that the AT2R gene A-1332G transition is not associated with the development of human congenital uropathies and further investigations should be carried out to unravel their etiology.