[A Rare Cause of Perinatal Postrenal Failure with Megalourethra]. / Seltene Ursache eines Perinatalen Postrenalen Nierenversagens mit Megalourethra.

We present a case of a premature infant with a presumed obstructive uropathy found to be a megalourethra leading to a perinatal postrenal failure. A megalourethra - an uncommon cause of urethral dilatation - is a congenital, non-obstructive anomaly of the penile erectile tissue. We think that a distal stenosis resulted in dysplasia of the penile tissue and an aspect of a megalourethra. Further diagnostic workup included urinary tract sonograms, a voiding cystourethrogram and MAG3 scintigrafy. Initially the patient was managed with supportive care such as a suprapubic urinary catheter, followed by surgical intervention (Bengt Johanson).

Exercise-Induced Hypoxemia in Juvenile Thyroid Carcinoma With Lung Metastases.

PURPOSE: Exercise-induced arterial hypoxemia (EIAH) has been reported in patients with juvenile thyroid cancer treated with radioiodine for lung metastases. This retrospective study tested the hypothesis that EIAH is due to ventilation-perfusion-mismatch in this rare pulmonary condition. METHOD: 50 patients (age 13-23 years) treated for juvenile thyroid carcinoma and lung metastasis with 131I and 24 controls with thyroid cancer but without lung metastases and prior 131I-treatment were assessed in a state of acute hypothyroidism by com-puted tomography of the lungs, pulmonary function testing, cardiopulmonary exercise test with measurements of gas exchange, oxygen saturation, alveolar-arterial difference in pO2 (p(A-a)O2) and pCO2 (p(ET-a)CO2). RESULTS: 10 of the 50 patients with lung metastases showed EIAH. They had more pronounced pulmonary fibrosis on computed tomography, a widened p(A-a)O2, and p(ET-a)CO2, a lower DVE/DVCO2-slope, a lower respiratory rate and no increased dead space ventilation. A more pronounced EIAH was associated with male gender, younger age, lower diffusion capacity, higher p(ET-a)CO2 during exercise and a higher peak exercise tidal volume over vital capacity ratio. CONCLUSION: EIAH in patients with thyroid carcinoma and pulmonary metastases is not related to ventilation-perfusion mismatch but to alveolar hypoventilation, possibly related to an increased work of breathing with pulmonary fibrosis.

Off-label-use of sulfur-hexafluoride in voiding urosonography for diagnosis of vesicoureteral reflux in children: A survey on adverse events.

AIM: To evaluate the risk profile of sulfur hexafluoride in voiding urosonography (VUS) based on a large cohort of children. METHODS: Since 2011 sulfur hexafluoride (SH, SonoVue®, Bracco, Italy) is the only ultrasound contrast available in the European Union and its use in children has not been approved. Within a 4-year-period, 531 children with suspected or proven vesicoureteral reflux (f/m = 478/53; mean age 4.9 years; 1 mo-25.2 years) following parental informed consent underwent VUS with administration of 2.6 ± 1.2 mL SH in a two-center study. A standardized telephone survey on adverse events was conducted three days later. RESULTS: No acute adverse reactions were observed. The survey revealed subacute, mostly self-limited adverse events in 4.1% (22/531). The majority of observed adverse events (17/22) was not suspected to be caused by an allergic reaction: Five were related to catheter placement, three to reactivated urinary tract infections, five were associated with perineal disinfection before voiding urosonography or perineal dermatitis and four with a common cold. In five patients (0.9%) hints to a potential allergic cause were noted: Perineal urticaria was reported in three interviews and isolated, mild fever in two. These were minor self-limited adverse events with a subacute onset and no hospital admittance was necessary. Ninety-six point two percent of the parents would prefer future VUS examinations with use of SH. CONCLUSION: No severe adverse events were observed and indications of self-limited minor allergic reactions related to intravesical administration of SH were reported in less than 1%.

Prospective Biomarker Screening for Diagnosis of Invasive Aspergillosis in High-Risk Pediatric Patients.

Combined biomarker screening is increasingly used to diagnose invasive aspergillosis (IA) in high-risk patients. In adults, the combination of galactomannan (GM) and fungal DNA detection has proven to be beneficial in the diagnosis of IA. Data in purely pediatric cohorts are scarce. Here, we monitored 39 children shortly before and after allogeneic stem cell transplantation twice weekly by use of a commercial GM enzyme-linked immunosorbent assay (ELISA) and a PCR assay based on amplification of the pan-Aspergillus ITS1/5.8S ribosomal operon. In addition, clinical data were recorded and classification of IA was performed according to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria. Among the 39 high-risk children, we identified 4 patients (10.3%) with probable and 2 (5.1%) with possible IA. All patients with probable IA were repeatedly positive for both tests (means of 9.5 and 6.8 positive GM and PCR samples, respectively), whereas both possible IA cases were detected by PCR. The sensitivity and specificity were, respectively, 67% and 89% for GM and 100% and 63% for PCR. Positive and negative predictive values were, respectively, 50% and 100% for GM and 27% and 100% for PCR. For the combined testing approach, both values were 100%. The number of positive samples seemed to be lower in patients undergoing antifungal therapy. Sporadically positive tests occurred in 12% (GM) and 42% (PCR) of unclassified patients. In summary, our data show that combined monitoring for GM and fungal DNA also results in a high diagnostic accuracy in pediatric patients. Future studies have to determine whether combined testing is suitable for early detection of subclinical disease and how antifungal prophylaxis impacts assay performance.

Self-gated Non-Contrast-enhanced Functional Lung MR Imaging for Quantitative Ventilation Assessment in Patients with Cystic Fibrosis.

Purpose To assess the clinical feasibility of self-gated non-contrast-enhanced functional lung (SENCEFUL) magnetic resonance (MR) imaging for quantitative ventilation (QV) imaging in patients with cystic fibrosis (CF). Materials and Methods Twenty patients with CF and 20 matched healthy volunteers underwent functional 1.5-T lung MR imaging with the SENCEFUL imaging approach, in which a two-dimensional fast low-angle shot sequence is used with quasi-random sampling. The lungs were manually segmented on the ventilation-weighted images to obtain QV measurements, which were compared between groups. QV values of the patients were correlated with results of pulmonary function testing. Three radiologists rated the images for presence of ventilation deficits by means of visual inspection. Mann-Whitney U tests, receiver operating characteristic analyses, Spearman correlations, and Gwet agreement coefficient analyses were used for statistical analysis. Results QV of the entire lungs was lower for patients with CF than for control subjects (mean ± standard deviation, 0.09 mL/mL ± 0.03 vs 0.11 mL/mL ± 0.03, respectively; P = .007). QV ratios of upper to lower lung halves were lower in patients with CF than in control subjects (right, 0.84 ± 0.2 vs 1.16 ± 0.2, respectively [P < .001]; left, 0.88 ± 0.3 vs 1.11 ± 0.1, respectively [P = .017]). Accordingly, ventilation differences between the groups were larger in the upper halves (Δ = 0.04 mL/mL, P ≤ .001-.002). QV values of patients with CF correlated with forced vital capacity (r = 0.7; 95% confidence interval [CI]: 0.21, 0.91), residual volume (static hyperinflation, r = -0.8; 95% CI: -0.94, 0.42), and forced expiratory volume in 1 second (airway obstruction, r = 0.7; 95% CI: 0.21, 0.91). Disseminated small ventilation deficits were the most frequent involvement pattern, present in 40% of the functional maps in CF versus 8% in the control subjects (P < .001). Conclusion SENCEFUL MR imaging is feasible for QV assessment. Less QV, especially in upper lung parts, and correlation to vital capacity and to markers for hyperinflation and airway obstruction were found in patients with CF. © RSNA, 2016.

Diagnostic features of prematurely fused cranial sutures on plain skull X-rays.

PURPOSE: The characteristic features of prematurely fused craniosynostosis in plain radiographs have already been described in literature, but there is no clinical trial investigating the individual features of every single form of craniosynostosis. We described suture-specific characteristics as well as its frequency of appearance in plain radiographs in every different form of craniosynostosis. Intraoperative findings served as control to confirm the diagnosis. METHODS: One hundred twenty-seven children with prematurely fused cranial sutures who underwent a skull X-ray from 2008 to 2012 were investigated in the present study. In detail, 34 children with frontal, 60 with sagittal, 13 with unilateral and 14 with bilateral coronal synostosis and 3 with unilateral lambdoid craniosynostosis as well as 3 children with a bilateral lambdoid synostosis were included. RESULTS: Typical radiological characteristics in craniosynostosis exist. These features as well as its frequency in craniosynostosis in plain skull radiographs are presented. In all cases, these typical features enabled a correct diagnosis, which was confirmed by intraoperative findings. CONCLUSION: The frequency of the appearance of typical features is listed and may serve as a "mental internal check list" in the radiological approach to craniosynostosis. The study points out the value of plain skull X-rays as it enabled proper diagnosis in all investigated 127 cases.

Co-Occurence of Reciprocal Translocation and COL2A1 Mutation in a Fetus with Severe Skeletal Dysplasia: Implications for Genetic Counseling.

Achondrogenesis type II is an autosomal-dominant disease leading to severe micromelic dwarfism. Here, we report on the postmortem identification of a de novo heterozygous mutation in the COL2A1 gene (c.1529G>A, p.Gly510Asp) in a fetus who presented with generalized hydrops fetalis and severe micromelia during prenatal sonographic examinations. Initially, a reciprocal translocation t(4;17)(q31;p13) was detected in this fetus by chorionic villus sampling. Subsequent chromosomal analysis of maternal and paternal blood showed that the patient's mother was carrier of the same reciprocal translocation. SNP array analysis of the fetus did not provide evidence for chromosomal imbalances or CNVs that could be associated with the fetal phenotype. The coexistence of a cytogenetic (reciprocal translocation) and a molecular genetic (COL2A1 mutation) abnormality in the fetus carries important implications for genetic counseling.

Contrast-enhanced voiding urosonography phantom study: intravenous iodinated and gadolinium-based contrast agents may cause false-negative results in assessment of vesicoureteral reflux in children.

BACKGROUND: Contrast-enhanced voiding urosonography (ce-VUS) is commonly requested simultaneously to other diagnostic imaging necessitating intravenous contrast agents. To date there is limited knowldedge about intravesical interactions between different types of contrast agents. OBJECTIVE: To assess the effect of excreted intravenous iodinated and gadolinium-based contrast agents on the intravesical distribution of ultrasound contrast within contrast-enhanced voiding urosonography. MATERIALS AND METHODS: Iodinated (iomeprol, iopamidol) and gadolinium-based (gadoterate meglumine) contrast agents were diluted to bladder concentration and injected into balloons filled with saline solution. CT scans were performed to assess the contrast distribution in these phantoms. Regions of interest were placed at the top and bottom side of each balloon and Hounsfield units (HU) were measured. Three other balloons were filled with saline solution and contrast media likewise. The ultrasound contrast agent sulphur hexafluoride was added and its distribution was assessed using sonography. RESULTS: MDCT scans showed a separation of two liquid layers in all bladder phantoms with the contrast layers located at the bottom and the saline solution at the top. Significant differences of the HU measurements at the top and bottom side were observed (P < 0.001-0.007). Following injection of ultrasound contrast agent, US showed its distribution exclusively among the saline solution. CONCLUSIONS: False-negative results of contrast-enhanced voiding urosonography may occur if it is performed shortly after imaging procedures requiring intravenous contrast.

Thrombosis as a complication of central venous access in pediatric patients with malignancies: a 5-year single-center experience.

BACKGROUND: Reliable central venous access (CVC) is essential for hematology-oncology patients since frequent puncture of peripheral veins-e.g., for chemotherapy, antibiotic administration, repeated blood sampling, and monitoring-can cause unacceptable pain and psychological trauma, as well as severe side effects in cases of extravasation of chemotherapy drugs. However, CVC lines still carry major risk factors, including thrombosis, infection (e.g., entry site, tunnel, and luminal infections), and catheter dislocation, leakage, or breakage. METHODS: Here we performed a retrospective database analysis to determine the incidence of CVC-associated thrombosis in a single-center cohort of 448 pediatric oncologic patients, and to analyze whether any subgroup of patients was at increased risk and thus might benefit from prophylactic anticoagulation. RESULTS: Of the 448 patients, 269 consecutive patients received a CVC, and 55 of these 269 patients (20%) also had a thrombosis. Of these 55 patients, 43 had at least one CVC-associated thrombosis (total number of CVC-associated thrombosis: n = 52). Among all patients, the median duration of CVC exposure was 464 days. Regarding exposure time, no significant difference was found between patients with and without CVC-associated thrombosis. Subclavia catheters and advanced tumor stages seem to be the main risk factors for the development of CVC-associated thrombosis, whereas pharmacologic prophylaxis did not seem to have a relevant impact on the rate of thrombosis. CONCLUSIONS: We conclude that pediatric surgeons and oncologists should pay close attention to ensuring optimal and accurate CVC placement, as this appears the most effective tool to minimize CVC-associated complications.

SElf-gated Non-Contrast-Enhanced FUnctional Lung imaging (SENCEFUL) using a quasi-random fast low-angle shot (FLASH) sequence and proton MRI.

Obtaining functional information on the human lung is of tremendous interest in the characterization of lung defects and pathologies. However, pulmonary ventilation and perfusion maps usually require contrast agents and the application of electrocardiogram (ECG) triggering and breath holds to generate datasets free of motion artifacts. This work demonstrates the possibility of obtaining highly resolved perfusion-weighted and ventilation-weighted images of the human lung using proton MRI and the SElf-gated Non-Contrast-Enhanced FUnctional Lung imaging (SENCEFUL) technique. The SENCEFUL technique utilizes a two-dimensional fast low-angle shot (FLASH) sequence with quasi-random sampling of phase-encoding (PE) steps for data acquisition. After every readout, a short additional acquisition of the non-phase-encoded direct current (DC) signal necessary for self-gating was added. By sorting the quasi-randomly acquired data according to respiratory and cardiac phase derived from the DC signal, datasets of representative respiratory and cardiac cycles could be accurately reconstructed. By application of the Fourier transform along the temporal dimension, functional maps (perfusion and ventilation) were obtained. These maps were compared with dynamic contrast-enhanced (DCE, perfusion) as well as standard Fourier decomposition (FD, ventilation) reference datasets. All datasets were additionally scored by two experienced radiologists to quantify image quality. In addition, one initial patient examination using SENCEFUL was performed. Functional images of healthy volunteers and a patient diagnosed with hypoplasia of the left pulmonary artery and left-sided pulmonary fibrosis were successfully obtained. Perfusion-weighted images corresponded well to DCE-MRI data; ventilation-weighted images offered a significantly better depiction of the lung periphery compared with standard FD. Furthermore, the SENCEFUL technique hints at a potential clinical relevance by successfully detecting a perfusion defect in the patient scan. It can be concluded that SENCEFUL enables highly resolved ventilation- and perfusion-weighted maps of the human lung to be obtained using proton MRI, and might be interesting for further clinical evaluation.

Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI.

BACKGROUND: Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease. OBJECTIVE: To evaluate free-breathing DWI, as compared to contrast-enhanced MRI, in children, adolescents and young adults with Crohn disease. MATERIALS AND METHODS: This retrospective study included 33 children and young adults with Crohn disease ages 17 ± 3 years (mean ± standard deviation) and 27 matched controls who underwent small-bowel MRI with contrast-enhanced T1-weighted sequences and DWI at 1.5 T. The detectability of Crohn manifestations was determined. Concurrent colonoscopy as reference was available in two-thirds of the children with Crohn disease. RESULTS: DWI and contrast-enhanced MRI correctly identified 32 and 31 patients, respectively. All 22 small-bowel lesions and all Crohn complications were detected. False-positive findings (two on DWI, one on contrast-enhanced MRI), compared to colonoscopy, were a result of large-bowel lumen collapse. Inflammatory wall thickening was comparable on DWI and contrast-enhanced MRI. DWI was superior to contrast-enhanced MRI for detection of lesions in 27% of the assessed bowel segments and equal to contrast-enhanced MRI in 71% of segments. CONCLUSION: DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition.

Acute Muscle Trauma due to Overexercise in an Otherwise Healthy Patient with Cystic Fibrosis.

Cystic fibrosis (CF) is one of the most common inherited diseases and is caused by mutations in the CFTR gene. Although the pulmonary and gastrointestinal manifestations of the disease remain in the focus of treatment, recent studies have shown expression of the CFTR gene product in skeletal muscle cells and observed altered intramuscular Ca(2+) release dynamics in CFTR-deficient animal models. Physical exercise is beneficial for maintaining fitness and well-being in CF patients and constitutes one aspect of modern multimodal treatment, which has considerably increased life span and reduced morbidity. We report on a case of acute muscle trauma resulting from excessive dumbbell exercise in a young adult with cystic fibrosis and describe clinical, laboratory and imaging characteristics of acute exercise-induced muscle injury.

Popliteal cysts in paediatric patients: clinical characteristics and imaging features on ultrasound and MRI.

Popliteal cysts, or Baker cysts, are considered rare in children and may exhibit particular features, as compared with adults. We studied data from 80 paediatric patients with 55 Baker cysts, examined over a period of 7 years, and correlated clinical presentation with findings on ultrasonography and MRI. Prevalence of popliteal cysts was 57% in arthritic knees, 58% with hypermobility syndrome, and 28% without risk factors. Only one patient had a trauma history and showed an ipsilateral cyst. Mean cyst volume was 3.4 mL; cysts were larger in boys. Patients with arthritis had echogenic cysts in 53%. Cyst communication with the joint space was seen in 64% on ultrasonography and 86% on MRI. In conclusion, Baker cysts are a common finding in a clinically preselected paediatric population. Children with Baker cysts should be assessed for underlying arthritis and inherited joint hypermobility, while sporadic Baker cysts appear to be common, as well.