[(Uro)genital developmental disorders]. / (Uro)genitale Entwicklungsstörungen.

CLINICAL ISSUE: Congenital anomalies of the urogenital tract are common, whereas isolated developmental disorders of the genital organs are rare and varied. The type and timing of imaging to characterize these developmental disorders and the planning of any treatment are the subject of discussion. The aim of this article is to provide a brief overview of embryology, diagnostic procedures, and examples of findings. STANDARD RADIOLOGICAL METHODS: The primary procedure for imaging the genitals is sonography, which must be performed with appropriate empathy. In addition to the genitals, the general situation of the kidneys and urinary tract should be examined, as urogenital malformations are often combined. Dedicated magnetic resonance imaging (MRI) is indicated as advanced imaging in interdisciplinary consultations. Invasive procedures, such as genitography combined with micturition cystourethrography (MCU) using X­rays or contrast-enhanced sonography, are rarely required. Computed tomography (CT) or excretory urography play no role. CONCLUSION: Imaging plays an important role in the assessment of genital anomalies. Knowledge of embryology facilitates anatomical understanding and the assessment of pathologies.

Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography.

Voiding cystourethrography (VCUG) is a fluoroscopic technique that allows the assessment of the urinary tract, including the urethra, bladder, and-if vesicoureteral reflux (VUR) is present-the ureters and the pelvicalyceal systems. The technique also allows for the assessment of bladder filling and emptying, providing information on anatomical and functional aspects. VCUG is, together with contrast-enhanced voiding urosonography (VUS), still the gold standard test to diagnose VUR and it is one of the most performed fluoroscopic examinations in pediatric radiology departments. VCUG is also considered a follow-up examination after urinary tract surgery, and one of the most sensitive techniques for studying anatomy of the lower genitourinary tract in suspected anatomical malformations. The international reflux study in 1985 published the first reflux-protocol and graded VUR into five classes; over the following years, other papers have been published on this topic. In 2008, the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force published the first proposed VCUG Guidelines with internal scientific society agreement. The purpose of our work is to create a detailed overview of VCUG indications, procedural recommendations, and to provide a structured final report, with the aim of updating the 2008 VCUG paper proposed by the European Society of Paediatric Radiology (ESPR). We have also compared VCUG with contrast-enhanced VUS as an emergent alternative. As a result of this work, the ESPR Urogenital Task Force strongly recommends the use of contrast-enhanced VUS as a non-radiating imaging technique whenever indicated and possible.

[CF Lung Disease - a German S3 Guideline: Pseudomonas aeruginosa]. / S3-Leitlinie: Lungenerkrankung bei Mukoviszidose ­ Pseudomonas aeruginosa.

Cystic Fibrosis (CF) is the most common autosomal recessive genetic multisystemic disease. In Germany, it affects at least 8000 people. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the airway epithelial lining fluid which leads to reduction of the mucociliary clearance.Even if highly effective, CFTR modulator therapy has been available for some years and people with CF are getting much older than before, recurrent and chronic infections of the airways as well as pulmonary exacerbations still occur. In adult CF life, Pseudomonas aeruginosa (PA) is the most relevant pathogen in colonisation and chronic infection of the lung, leading to further loss of lung function. There are many possibilities to treat PA-infection.This is a S3-clinical guideline which implements a definition for chronic PA-infection and demonstrates evidence-based diagnostic methods and medical treatment in order to give guidance for individual treatment options.

[Imaging after kidney transplantation in childhood and adolescence]. / Bildgebung nach Nierentransplantation im Kindes- und Jugendalter.

The ultrasound (US) examination is the most important imaging procedure in the clinical care of children with chronic kidney disease, the assessment before kidney transplantation and in the acute and chronic phase after successful kidney transplantation. In trained hands, particularly with experience in Doppler sonography, US ensures that vascular complications, such as occlusions, thrombosis, stenosis as well as non-vascular complications, e.g., urinary tract dilatation, abscesses, hematomas, urine leaks or lymphoceles, are cost-effectively and rapidly diagnosed at any time. For the diagnosis of acute rejection, the US signs in the intraindividual course are only suggestive, but not specific. The gold standard for the diagnosis of acute rejection is a kidney biopsy. In these cases, US serves to exclude other causes. The use of multimodal techniques, various Doppler techniques and microvascular procedures, such as superb microvascular imaging (SMI) or B­flow and contrast-enhanced ultrasonography (CEUS), optimizes the imaging in the context of transplantations in children. Magnetic resonance imaging with diffusion-weighed imaging (DWI), magnetic resonance angiography (MRA) and magnetic resonance urography (MRU) as well as functional MRU (fMRU) performed with the administration of gadolinium-containing contrast agents, are part of the extended diagnostics and possibly necessary for surgical planning in the early phase after kidney transplantation and for long-term assessment after transplantation. Excretory urography is associated with ionizing radiation and intravenous administration of iodine-containing contrast medium and is obsolete in children. Computed tomography (CT) using age-adapted and weight-adapted dose protocols is an alternative in emergencies if MRI is not available.

[Congenital anomalies of the kidneys and urinary tract (CAKUT) : Embryology in radiology and fetal magnetic resonance imaging]. / Angeborene Anomalien der Nieren und ableitenden Harnwege (CAKUT) : Embryologie in der Radiologie und fetale Magnetresonanztomographie.

CLINICAL PROBLEM: Congenital anomalies of the kidney and urinary tract (CAKUT) are very common findings in fetal diagnostics. Their effects range from variants without pathological significance to pronounced functional impairment with the need for renal replacement therapy in childhood. Sometimes the genital organs are also affected. The aim of the article is to provide an overview of embryology and examples of key findings. IMAGING PROCEDURES: In the fetal period, magnetic resonance imaging (MRI) is used, while postnatally, sonography with the option of contrast-enhanced micturition urosonography (MUS, ceVUS) dominates imaging in pediatric radiology, supplemented in individual cases by fluoroscopy (micturition cysturethrography) and MRI. Quantitative methods for assessing kidney function and excretion (MAG3 scintigraphy, functional MR urography) are essential when planning further therapeutic procedures, especially in obstructive uropathies. CONCLUSION: Imaging plays an essential role in the assessment of abnormalities of the kidneys and urinary tract both pre- and postnatally. Knowledge of embryology facilitates anatomical understanding and assessment of pathologies.

[Hip dysplasia]. / Hüftdysplasie.

BACKGROUND: Hip dysplasia is one of the most common malformations in childhood and has a significant impact on the further life of those affected. A distinction must be made between congenital and the much rarer acquired dysplasia. Early diagnosis and therapy are pivotal for further development of patients. OBJECTIVES: The paper gives an overview of current radiological possibilities of diagnosis with focus on congenital hip dysplasia supplemented by insights into therapeutic options. MATERIALS AND METHODS: Basic and review papers were analyzed. RESULTS: Clinical examination of the newborn has low sensitivity and specificity in the diagnosis of hip dysplasia. The introduction of Graf ultrasound screening has significantly improved the early detection of dysplastic hips. With the help of sonography, but also magnetic resonance imaging (MRI), the shape of the acetabulum and the position of the femoral head in the socket can be precisely and quickly determined, while X­ray examinations have their place especially in the context of follow-up examinations after treatment from the age of 1 year and in the diagnosis of secondary dysplasia. Therapeutic options range from spreading treatment to open reduction with fixation in the newborn as well as conversion osteotomy in older children. CONCLUSION: Early detection of hip dysplasia is critical to the course of treatment. The right choice of examination method and correct performance are essential for further treatment.

Radiation Exposure and Frequency of Dental, Bitewing and Occlusal Radiographs in Children and Adolescents.

Dental radiographs are valuable diagnostic aids for oral healthcare, but exposure to ionizing radiation carries health risks, especially in children due to their high radio-sensitivity. Valid reference values for intraoral radiographs in children and adolescents are still missing. This study aimed to investigate the radiation dose values and underlying justifications of dental, bitewing and occlusal X-rays in children and adolescents. Data from routinely executed intraoral radiographs between 2002 and 2020 with conventional and digital tube-heads were extracted from the Radiology Information System. The effective exposure was calculated from technical parameters and statistical tests performed. A total number of 4455 intraoral (3128 dental, 903 bitewing and 424 occlusal) radiographs were investigated. For dental and bitewing radiographs, the dose area product (DAP) was 2.57 cGy × cm2 and the effective dose (ED) 0.77 µSv. For occlusal radiographs, the DAP was 7.43 cGy × cm2 and the ED 2.22 µSv. Overall, 70.2% of all intraoral radiographs were dental, 20.3% bitewing and 9.5% occlusal radiographs. The most frequent indication for intraoral radiographs was trauma (28.7%), followed by caries (22.7%) and apical diagnostics (22.7%). Moreover, 59.7% of all intraoral radiographs were taken in boys, especially for trauma (66.5%) and endodontics (67.2%) (p ≤ 0.00). Girls were significantly more frequently X-rayed for caries diagnostics than boys (28.1% vs. 19.1%, p ≤ 0.00). The average ED of 0.77 µSv for intraoral dental and bitewing radiographs in this study was within the range of other reported values. The technical parameters of the X-ray devices were found at the lowest recommended levels to best limit the radiation exposure and to assure acceptable diagnostic efficacy. Intraoral radiographs were performed predominantly for trauma, caries and apical diagnostics-reflecting general recommendations for the use of X-rays in children. For improved quality assurance and radiation protection, further studies are necessary to determine the meaningful dose reference level (DRL) for children.

Pediatric computed tomography doses in Germany from 2016 to 2018 based on large-scale data collection.

PURPOSE: Accumulating evidence from epidemiological studies that pediatric computed tomography (CT) examinations can be associated with a small but non-zero excess risk for developing leukemia or brain tumor highlights the need to optimize doses of pediatric CT procedures. Mandatory dose reference levels (DRL) can support reduction of collective dose from CT imaging. Regular surveys of applied dose-related parameters are instrumental to decide when technological advances and optimized protocol design allow lower doses without sacrificing image quality. Our aim was to collect dosimetric data to support adapting current DRL to changing clinical practice. METHOD: Dosimetric data and technical scan parameters from common pediatric CT examinations were retrospectively collected directly from Picture Archiving and Communication Systems (PACS), Dose Management Systems (DMS), and Radiological Information Systems (RIS). RESULTS: We collected data from 17 institutions on 7746 CT series from the years 2016 to 2018 from examinations of the head, thorax, abdomen, cervical spine, temporal bone, paranasal sinuses and knee in patients below 18 years of age. Most of the age-stratified parameter distributions were lower than distributions from previously-analyzed data from before 2010. Most of the third quartiles were lower than German DRL at the time of the survey. CONCLUSIONS: Directly interfacing PACS, DMS, and RIS installations allows large-scale data collection but relies on high data-quality at the documentation stage. Data should be validated by expert knowledge or guided questionnaires. Observed clinical practice in pediatric CT imaging suggests lowering some DRL in Germany is reasonable.

Whole-body diffusion magnetic resonance imaging with simultaneous multi-slice excitation in children and adolescents.

BACKGROUND: Whole-body magnetic resonance imaging (WB-MRI) is an increasingly used guideline-based imaging modality for oncological and non-oncological pathologies during childhood and adolescence. While diffusion-weighted imaging (DWI), a part of WB-MRI, enhances image interpretation and improves sensitivity, it also requires the longest acquisition time during a typical WB-MRI scan protocol. Interleaved short tau inversion recovery (STIR) DWI with simultaneous multi-slice (SMS) acquisition is an effective way to speed up examinations. OBJECTIVE: In this study of children and adolescents, we compared the acquisition time, image quality, signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC) values of an interleaved STIR SMS-DWI sequence with a standard non-accelerated DWI sequence for WB-MRI. MATERIALS AND METHODS: Twenty children and adolescents (mean age: 13.9 years) who received two WB-MRI scans at a maximum interval of 18 months, consisting of either standard DWI or SMS-DWI MRI, respectively, were included. For quantitative evaluation, the signal-to-noise ratio (SNR) was determined for b800 images and ADC maps of seven anatomical regions. Image quality evaluation was independently performed by two experienced paediatric radiologists using a 5-point Likert scale. The measurement time per slice stack, pause between measurements including shim and total measurement time of DWI for standard DWI and SMS-DWI were extracted directly from the scan data. RESULTS: When including the shim duration, the acquisition time for SMS-DWI was 43% faster than for standard DWI. Qualitatively, the scores of SMS-DWI were higher in six locations in the b800 images and four locations in the ADC maps. There was substantial agreement between both readers, with a Cohen's kappa of 0.75. Quantitatively, the SNR in the b800 images and the ADC maps did not differ significantly from one another. CONCLUSION: Whole body-MRI with SMS-DWI provided equivalent image quality and reduced the acquisition time almost by half compared to the standard WB-DWI protocol.

Frequency of Dental X-ray Diagnostics in Children and Adolescents: What Is the Radiation Exposure?

Children are exposed to ionizing radiation through radiographs during their development for various reasons. At present, there are no officially valid reference values for dental X-rays in children and adolescents for dental X-ray diagnostics. This study retrospectively examined 9680 extraoral dental radiographs in pediatric patients between 2002 and 2020. The aim was to analyze the radiation doses in pediatric patients, which indications were used, and whether there were specific age and gender differences. The evaluation showed that radiation doses were considered low, with dose area products of 2.2 cGy × cm2 for a lateral cephalogram, 14 cGy × cm2 for an orthopantomogram (OPG), and 45 cGy × cm2 for cone beam computer tomography (CBCT). This corresponds to an effective dose of 1.5 µSv for a lateral cephalogram, 7 µSv for an OPG, and 33.8 µSv for CBCT. Of the 9680 images, 78% were orthopantomograms, and only 0.4% were CBCT images. OPG has become more important over the years, as reflected in the indication. Approximately one-third of all extraoral exposures are orthodontic indications. Overall, the indications were similar for both genders. According to the dental indications, boys were X-rayed slightly more frequently than girls (54.5-45.5%). A future publication of dose guide values and corresponding guidelines is of high priority.

Ultrasound findings of the thyroid gland in children and adolescents.

Ultrasonography (US) is an important diagnostic tool in evaluating thyroid diseases in pediatric patients. This pictorial essay reviews the application of various ultrasound techniques such as B-Mode ultrasound and color Doppler, elastography and contrast enhanced ultrasound (CEUS) in children and adolescents in various thyroid pathologies including congenital thyroid abnormalities, diffuse thyroid diseases (DTD), focal thyroid lesions and thyroid malignancy.

A novel free-breathing abdominal RAVE T2/T1 hybrid MRI sequence in patients with cystic fibrosis: Preliminary results.

OBJECTIVES: Patients with cystic fibrosis (CF) increasingly require imaging for the diagnosis of abdominal complications. We prospectively evaluated the image quality and signal-to-noise ratio (SNR) of a modern radial volumetric encoding (RAVE) T2/T1 hybrid sequence for abdominal magnetic resonance imaging (MRI). RAVET2/T1 is a three-dimensional radial sequence with fat saturation and blood flow suppression that acquires T2- and T1-weighted contrasts in one scan in an identical slice position during free-breathing. METHODS: Sixteen CF patients underwent axial T2 HASTE (1000 ms/93 ms TR/TE), T1 DIXON (6.8 ms/2.4 ms/4.8 ms TR/TE1/TE2), and RAVE T2/T1 hybrid sequence (1200 ms/1.7 ms/3.3 ms/4.9 ms/102 ms TR/TE1/TE2/TE3/TE4) of the upper abdomen at 1.5 Tesla. The SNR values in six different regions were assessed and compared using the Wilcoxon signed-rank test. The image quality criteria were rated on a 5-point Likert scale. RESULTS: In all regions, the SNR was significantly higher in the T2 weighted aspect of the RAVE T2/T1 hybrid sequence compared to T2 HASTE (p < 0.05) and significantly lower in the T1 weighted in-phase aspect of the RAVE T2/T1 hybrid sequence compared to the T1 DIXON sequence (p < 0.05). Qualitatively the T2 weighted aspect of the RAVE T2/T1 hybrid sequence was rated significantly higher than the T2 HASTE in 6 of 7 categories (p < 0.05) and the T1 weighted in-phase aspect of the RAVE T2/T1 hybrid sequence was rated significantly higher than the T1 DIXON in 2 of 6 categories (p < 0.05). CONCLUSIONS: The abdominal radial RAVE T2/T1 hybrid sequence provided higher image quality and SNR than the T2HASTEsequence. Together with increased robustness against motion artifacts, the RAVE T2/T1 hybrid sequence appears to be a good tool for abdominal imaging in CF patients.

[Tuberous sclerosis complex]. / Tuberöse-Sklerose-Komplex.

CLINICAL BACKGROUND: Tuberous sclerosis complex (TSC) is a phakomatosis and is a tumor predisposition syndrome. As a genetic multisystem disease, patients present with a broad range of changes in the brain, heart, skin, kidneys, and lungs. OBJECTIVES: Which imaging modalities are required to monitor TSC patients according to current international recommendations? MATERIALS AND METHODS: Common findings in TSC are cortical tubers, subependymal nodules, and giant cell astrocytomas in the central nervous system (CNS), rhabdomyomas in the heart, and cysts and angiomyolipomas in the kidneys. Magnetic resonance imaging (MRI) of the brain and kidneys and abdominal ultrasound are the imaging modalities of choice, due to the very good soft tissue contrast and lack of X­ray radiation. RESULTS: Using standard and functional MRI sequences in a multimodal approach, the type, malignancy, size, and morphology of changes in TSC can be reliably determined. Abdominal ultrasound using high-resolution transducers can be used to rapidly and reliably detect even the smallest changes in the kidneys. CONCLUSION: Regular follow-up of patients with TSC using MRI and ultrasound is necessary for early detection of complications, for planning individualized therapy, and for optimal lifelong care.

Preliminary results of abdominal simultaneous multi-slice accelerated diffusion-weighted imaging with motion-correction in patients with cystic fibrosis and impaired compliance.

OBJECTIVES: The aim of this prospective study was to compare scan time, image quality, signal-to-noise Ratio (SNR), and apparent diffusion coefficient (ADC) values of simultaneous multi-slice accelerated diffusion-weighted imaging with motion-correction (DWI SMS Moco) to standard diffusion-weighted imaging (sDWI) in free-breathing abdominal magnetic resonance imaging (MRI) in pediatric and young adult patients with cystic fibrosis (CF). MATERIAL AND METHODS: 16 patients (7 male and 9 female, 12-41 years old) with CF were examined prospectively in a single-center from November 2020 to March 2021 on a 1.5 Tesla clinical MR scanner. The characteristics of overall image quality and delimitability of mesenteric lymph nodes were evaluated using a 5-point Likert scale by two experienced pediatric radiologists independently from each other. Quantitative parameters with SNR and ADC values were assessed in 8 different locations and compared using a Wilcoxon signed-rank test. RESULTS: The acquisition time for DWI SMS Moco was 32% shorter than for sDWI. Regarding quality comparison, overall image quality and delimitability of mesenteric lymph nodes were significant higher in DWI SMS Moco (p ≤ 0.05 for both readers). The readers preferred DWI SMS Moco to sDWI in all cases (16/16). Mean SNR values from DWI SMS Moco and sDWI were similar in 7 from 8 locations. The ADC values showed no significant difference between DWI SMS Moco and sDWI in any of the evaluated locations (p > 0.05). CONCLUSIONS: The DWI SMS Moco improves overall image quality and delimitability of mesenteric lymph nodes compared to sDWI with similar SNR and ADC values and a distinguished reduction of scan time in free-breathing by one third. We conclude that MRI with DWI SMS Moco could be helpful in monitoring the effect of the high-efficiency modulator (HEM) therapy in cystic fibrosis (CF) patients homozygous or heterozygous for F508del in the abdomen.

In vitro measurements of radiation exposure with different modalities (computed tomography, cone beam computed tomography) for imaging the petrous bone with a pediatric anthropomorphic phantom.

BACKGROUND: Various imaging modalities, such as multi-detector computed tomography (CT) and cone beam CT are commonly used in infants for the diagnosis of hearing loss and surgical planning of implantation hearing aid devices, with differing results. OBJECTIVE: We compared three different imaging modalities available in our institution, including a high-class CT scanner, a mid-class CT scanner and an angiography system with a cone beam CT option, for image quality and radiation exposure in a phantom study. MATERIALS AND METHODS: While scanning an anthropomorphic phantom imitating a 1-year-old child with vendor-provided routine protocols, organ doses, surface doses and effective doses were determined for these three modalities with thermoluminescent dosimeters. The image quality was evaluated using the signal difference to noise ratio (SDNR) and the spatial resolution of a line-pair insert in the phantom head. The dose efficiency, defined as the ratio of SDNR and effective dose, was also compared. RESULTS: The organ and surface doses were lowest with the high-class CT protocol, but the image quality was the worst. Image quality was best with the cone beam CT protocol, which, however, had the highest radiation exposure in this study, whereas the mid-class CT was in between. CONCLUSION: Based on our results, high-end CT should be used for surgical planning because it has the lowest dose, while the image quality is still sufficient for this purpose. However, if highest image quality is needed and required, e.g., by ENT surgeons, the other modalities should be considered.

Two Cases of Veno-occlusive Disease/Sinusoidal Obstruction Syndrome After Thioguanine Treatment for Acute Lymphoblastic Leukemia.

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation conditioning or high-dose chemotherapy. The underlying pathogenesis involves toxic injury to hepatocytes and sinusoidal endothelial cells. Presenting symptoms include ascites, weight gain, hepatomegaly, and hyperbilirubinemia. Severe VOD/SOS with multiorgan failure has a mortality rate of >80% if left untreated. Thioguanine, a chemotherapy drug used to treat acute lymphoblastic leukemia, has been shown to cause VOD/SOS. Here, we describe cases of 2 patients who developed very severe VOD/SOS after starting thioguanine for acute lymphoblastic leukemia; both achieved complete remission with defibrotide and experienced no defibrotide-related adverse events.

Ultrashort echo time MRI of the lung in children and adolescents: comparison with non-enhanced computed tomography and standard post-contrast T1w MRI sequences.

OBJECTIVES: To compare the diagnostic value of ultrashort echo time (UTE) magnetic resonance imaging (MRI) for the lung versus the gold standard computed tomography (CT) and two T1-weighted MRI sequences in children. METHODS: Twenty-three patients with proven oncologic disease (14 male, 9 female; mean age 9.0 + / - 5.4 years) received 35 low-dose CT and MRI examinations of the lung. The MRI protocol (1.5-T) included the following post-contrast sequences: two-dimensional (2D) incoherent gradient echo (GRE; acquisition with breath-hold), 3D volume interpolated GRE (breath-hold), and 3D high-resolution radial UTE sequences (performed during free-breathing). Images were evaluated by considering image quality as well as distinct diagnosis of pulmonary nodules and parenchymal areal opacities with consideration of sizes and characterisations. RESULTS: The UTE technique showed significantly higher overall image quality, better sharpness, and fewer artefacts than both other sequences. On CT, 110 pulmonary nodules with a mean diameter of 4.9 + / - 2.9 mm were detected. UTE imaging resulted in a significantly higher detection rate compared to both other sequences (p < 0.01): 76.4% (84 of 110 nodules) for UTE versus 60.9% (67 of 110) for incoherent GRE and 62.7% (69 of 110) for volume interpolated GRE sequences. The detection of parenchymal areal opacities by the UTE technique was also significantly higher with a rate of 93.3% (42 of 45 opacities) versus 77.8% (35 of 45) for 2D GRE and 80.0% (36 of 45) for 3D GRE sequences (p < 0.05). CONCLUSION: The UTE technique for lung MRI is favourable in children with generally high diagnostic performance compared to standard T1-weighted sequences as well as CT. Key Points • Due to the possible acquisition during free-breathing of the patients, the UTE MRI sequence for the lung is favourable in children. • The UTE technique reaches higher overall image quality, better sharpness, and lower artefacts, but not higher contrast compared to standard post-contrast T1-weighted sequences. • In comparison to the gold standard chest CT, the detection rate of small pulmonary nodules small nodules ≤ 4 mm and subtle parenchymal areal opacities is higher with the UTE imaging than standard T1-weighted sequences.

MRI Characteristics of Pediatric Renal Tumors: A SIOP-RTSG Radiology Panel Delphi Study.

BACKGROUND: The SIOP-Renal Tumor Study Group (RTSG) does not advocate invasive procedures to determine histology before the start of therapy. This may induce misdiagnosis-based treatment initiation, but only for a relatively small percentage of approximately 10% of non-Wilms tumors (non-WTs). MRI could be useful for reducing misdiagnosis, but there is no global consensus on differentiating characteristics. PURPOSE: To identify MRI characteristics that may be used for discrimination of newly diagnosed pediatric renal tumors. STUDY TYPE: Consensus process using a Delphi method. POPULATION: Not applicable. FIELD STRENGTH/SEQUENCE: Abdominal MRI including T1- and T2-weighted imaging, contrast-enhanced MRI, and diffusion-weighted imaging at 1.5 or 3 T. ASSESSMENT: Twenty-three radiologists from the SIOP-RTSG radiology panel with ≥5 years of experience in MRI of pediatric renal tumors and/or who had assessed ≥50 MRI scans of pediatric renal tumors in the past 5 years identified potentially discriminatory characteristics in the first questionnaire. These characteristics were scored in the subsequent second round, consisting of 5-point Likert scales, ranking- and multiple choice questions. STATISTICAL TESTS: The cut-off value for consensus and agreement among the majority was ≥75% and ≥60%, respectively, with a median of ≥4 on the Likert scale. RESULTS: Consensus on specific characteristics mainly concerned the discrimination between WTs and non-WTs, and WTs and nephrogenic rest(s) (NR)/nephroblastomatosis. The presence of bilateral lesions (75.0%) and NR/nephroblastomatosis (65.0%) were MRI characteristics indicated as specific for the diagnosis of a WT, and 91.3% of the participants agreed that MRI is useful to distinguish NR/nephroblastomatosis from WT. Furthermore, all participants agreed that age influenced their prediction in the discrimination of pediatric renal tumors. DATA CONCLUSION: Although the discrimination of pediatric renal tumors based on MRI remains challenging, this study identified some specific characteristics for tumor subtypes, based on the shared opinion of experts. These results may guide future validation studies and innovative efforts. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 3.

Safety and parents´ acceptance of ultrasound contrast agents in children and adolescents - contrast enhanced voiding urosonography and contrast enhanced ultrasound.

AIMS: To evaluate the safety of the contrast enhanced voiding urosonography (ceVUS) and contrast enhanced ultrasound (CEUS) in children and adolescence and to receive data about parents' acceptance of intravesical and intravenous application of sulfur hexafluoride. MATERIAL AND METHODS: In this prospective, single centre study conducted over a 1 year study period, parents of 56 children (f/m=32/24; mean age 3.1 years; range 3 weeks - 15.9 years) with ceVUS and of 30 children (f/m=15/15; mean age 10.5 years; range 2 months - 17.7 years) with CEUS agreed to be included. A standardized telephone survey about the acceptance of the parents during and after the procedure as well as the adverse events (AE) were conducted within three days of the examination. RESULTS: The parents would agree with the use of both ceVUS and CEUS as a diagnostic tool again in 96% (54/56) or 100% (30/30) of the cases, respectively and 92.9% (52/56) would prefer ceVUS to voiding cystourethrography (VCUG). In addition, 83.3% (25/30) would prefer CEUS to CT and 73.3% (22/30) would prefer CEUS to MRI. AE were reported in 3.6% after ceVUS (2/56; skin rash, mild fever) and in 3.3% after CEUS (1/30; vomiting). AE were subacute and self­limited. CONCLUSIONS: The vast majority of parents prefer ceVUS and CEUS to VCUG, CT or MRI because of the safety profile of the contrast agent and diagnostic accuracy.

Diagnosis and Therapy of Female Genital Malformations (Part 2). Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/052, May 2019).

Objectives Female genital malformations may be present in the form of individual entities, they may involve neighboring organs or they may occur in the context of complex syndromes. Given the anatomical structures of the vulva, vagina, uterus and uterine appendages, the clinical picture of malformations varies greatly. Methods This S2k-guideline was developed by representative members from different medical specialties and professions as part of the guidelines program of the DGGG, SGGG and OEGGG. The recommendations and statements were developed and voted on using a structured consensus process with neutral moderation. Recommendations This guideline is the first comprehensive summary of female genital malformations from infancy to adulthood which covers clinical examinations, diagnostic workups and treatment options. Additional chapters have been included on complex urogenital malformations, vascular malformations, psychosomatic care, and tumor risk.