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.

Evaluation of the post-processing algorithms SimGrid and S-Enhance for paediatric intensive care patients and neonates.

BACKGROUND: Post-processing software can be used in digital radiography to achieve higher image quality, especially in cases of scattered radiation. SimGrid is a grid-like software based on a Convolutional Neuronal Network that estimates the distribution and degree of scattered radiation in radiographs and thus improves image quality by simulating an anti-scatter grid. S-Enhance is an algorithm programmed to improve contrast visibility of foreign material. OBJECTIVE: The objective of this study was to evaluate the SimGrid and S-Enhance digital radiography post-processing methods for neonatology and paediatric intensive care. MATERIALS AND METHODS: Two hundred and ten radiographs from the neonatal (n = 101, 0 to 6 months of age) and paediatric (n = 109, 6 months to 18 years of age) intensive care units performed in daily clinical routine using a mobile digital radiography system were post-processed with one of the algorithms, anonymized and then evaluated comparatively by two experienced paediatric radiologists. For every radiograph, patient data and exposure data were collected and analysed. RESULTS: Analysis of different radiographs showed that SimGrid significantly improves image quality for patients with a weight above 10 kg (range: 10-30 kg: odds ratio [OR] = 6.683, P < 0.0001), especially regarding the tracheobronchial system, intestinal gas, and bones. Utilizing S-Enhance significantly advances the assessment of foreign material (OR = 136.111, P < 0.0001) and bones (OR = 34.917, P < 0.0001) for children of all ages and weight, whereas overall image quality decreases. CONCLUSION: SimGrid offers a differentiated spectrum in image improvement for children beyond the neonatal period whereas S-Enhance especially improves visibility of foreign material and bones for all patients.

[Top ten pediatric radiological emergencies]. / Top Ten der kinderradiologischen Notfälle.

Pediatric emergencies encompass a wide range of different findings. These include injuries to the child's body due to high-energy trauma or abuse, unclear limitations of consciousness and primarily unspecific abdominal or thoracic pain as well as swallowing or inhalation of foreign bodies. Detailed knowledge of the various imaging methods and the correct application are important. This article gives an overview of the significance of imaging techniques for emergency diagnostics in childhood and adolescence.

Safety of gadobutrol in more than 1,000 pediatric patients: subanalysis of the GARDIAN study, a global multicenter prospective non-interventional study.

BACKGROUND: Gadobutrol is a gadolinium-based contrast agent, uniquely formulated at 1.0 mmol/ml. Although there is extensive safety evidence on the use of gadobutrol in adults, few studies have addressed the safety and tolerability of gadobutrol in pediatric patients. OBJECTIVE: This subanalysis of data from the GARDIAN study evaluated the safety and use of gadobutrol in pediatric patients (age <18 years). MATERIALS AND METHODS: The GARDIAN study was a large phase IV non-interventional prospective multicenter post-authorization safety study performed in Europe, Asia, North America and Africa. A total of 23,708 patients were included who were scheduled to undergo cranial or spinal MRI, liver or kidney MRI, or MR angiography with gadobutrol enhancement. The primary study endpoint was the overall incidence of adverse drug reactions (ADRs) and serious adverse events (SAEs) following gadobutrol administration. RESULTS: The GARDIAN study included 1,142 children (age <18 years) who received gadobutrol at a mean dose of 0.13 (range 0.04-0.50) mmol/kg body weight. Gadobutrol was well tolerated in these children, with low rates of ADRs (0.5%) and no SAEs, consistent with results in adults enrolled in the GARDIAN study. Rates of adverse events and ADRs were unrelated to pediatric age or gadobutrol weight-adjusted dose. There were no symptoms suggestive of nephrogenic systemic fibrosis. Investigators rated the contrast quality of gadobutrol-enhanced images as good or excellent in 97.8% of pediatric patients, similar to the main study population. CONCLUSION: Gadobutrol is very well tolerated and provides excellent contrast quality at the recommended weight-adjusted dose in children (age <18 years), similar to the profile in adults.

Lung ultrasound in children and adolescents with long-term effects of COVID-19: Initial results.

Introduction: Chronic health effects following acute COVID-19 are increasingly observed as the pandemic continues and are grouped under long COVID. Although the acute course of the COVID disease is often milder, long COVID also affects children and adolescents. As the symptoms present in Long-COVID often seem to be non-specific and not limited to organ systems, clarification of the causes and the creation of a meaningful, efficient and targeted diagnostic algorithm is urgently needed. Methods: Therefore, in this prospective observational study, we examined 30 children with long COVID using lung ultrasound and compared the results with those of 15 lung-healthy children. Results: In our study, no significant difference was found between the two groups in the morphological criteria of lung ultrasound of the pleura or pleural lung structures. There was no significant correlation between the lung ultrasound findings and clinical Data. Discussion: Our findings are congruent with the current, albeit sparse, data. It is possible that the causes of persistent thoracic symptoms in long COVID might be more likely to be present in functional examinations, but not morphologically imageable. Nonspecific symptoms do not appear to be due to changes in the lung parenchyma. In conclusion, lung ultrasound alone and without baseline in acute disease is not suitable as a standard in the follow-up of long COVID patients. Further investigations on the morphological and functional changes in patient with long COVID is needed.

Bridging bronchus--a rare cause of recurrent wheezy bronchitis.

BACKGROUND: Wheezing is a common symptom in infants and toddlers. Usually it occurs due to viral infection of the lower airways and no further diagnostic procedures are necessary. However in rare cases, other reasons such as anatomical malformation have to be considered. CASE PRESENTATION: We report about an infant with recurrent episodes of wheezy bronchitis, which persisted despite adequate therapy. Bronchoscopy and computed tomography of the lung with three-dimensional reconstruction revealed a rare bronchial branching anomaly - the so called "bridging bronchus". In contrast to previous case reports, this infant showed no additional malformations, which seems to be important for the prognosis. CONCLUSION: To the best of our knowledge this is the first report about a patient with a bridging bronchus in its "original form" without associated anomalies of the trachea-bronchial system or other organs.

[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.

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.

Ultrasound elastography in children - nice to have for scientific studies or arrived in clinical routine?

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

Differences in Cerebellar Volume as a Diagnostic and Prognostic Biomarker in Children and Adolescents With Epilepsy of Unknown Etiology.

INTRODUCTION AND OBJECTIVE: Epilepsy is one of the most common brain diseases during childhood and adolescence. Atrophy in different brain areas is possible during epilepsy. This study aimed to verify whether cerebellar volume differences could be detected by volume analysis using magnetic resonance imaging (MRI) in children with epilepsy. METHOD: In this retrospective study, 41 children (3.1-18.8 years) with epilepsy of unknown etiology were included (duration of epilepsy 1.9 ± 3 years). A cranial MRI with a volumetric 3-dimensional, T1-weighted sequence was used for volume analysis. The MRIs of 26 patients with headache (5.3-17.1 years) were analyzed for comparison. A volume analysis of the cerebellum was performed using region-based morphometry. Total cerebellar volume, total white and gray matter volume, and 48 regional lobules (L), separated into white and gray matter, were calculated. Cerebellar volumes are presented in relative ratios as the volume fraction of cerebellar volume to total intracranial volume: CV/TIV. RESULTS: The ratio of overall white matter volume was significantly lower in the case group (23.93 × 10-3, P = .039). A significantly lower ratio of regional white matter volume was detected in LV right (P = .031) and left (P = .014), in LVIIIB right (P = .011) and left (P = .019), and in LVIIIA left (P = .009). CONCLUSION: Our results emphasize that volume analysis of the total cerebellar volume alone is insufficient to characterize cerebellar differences in children with epilepsy. Rather, in specific cerebellar region volume analysis using region-based morphometry, children with epilepsy showed significantly lower regional volumes of lobules, which are important for sensorimotor function (LV, LVIII) and higher cognitive function (crus I).

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.

Case Report: Report of 2 Different Cases of Ovarian Teratoma Evaluated by Dynamic Contrast-Enhanced Ultrasound.

Ovarian masses are not easily differentiated on transabdominal ultrasound in children. A useful supplement in various pediatric applications is dynamic contrast-enhanced ultrasound (dynCEUS). It can be performed quickly and easily. However, the literature for dynCEUS on pediatric ovarian masses is limited. We compared two cases with ovarian teratoma in which dynCEUS was a helpful additional tool.

Inner border--a specific and significant colposcopic sign for moderate or severe dysplasia (cervical intraepithelial neoplasia 2 or 3).

OBJECTIVE: Investigation of the correlation between the colposcopic sign inner border and cervical intraepithelial neoplasia (CIN) 2 or 3 and its association with specific human papillomavirus (HPV) types and the age of the patient. STUDY DESIGN: Colpophotographs or cervicograms were taken from 947 women referred due to an abnormal cervical finding. Occurrence of the colposcopic sign inner border was evaluated retrospectively by 2 independent colposcopists. Histologic evaluation was based on punch or cone biopsies. Human papillomavirus testing was done using Hybrid Capture I or a polymerase chain reaction-based HPV test. RESULTS: The prevalence of the colposcopic phenomenon inner border in women with an atypical transformation zone was 7.6% (53/695). In 70% of women with inner border, CIN 2 or 3 was confirmed histologically. The sensitivity of the colposcopic sign inner border for detection of CIN 2 or 3 was 20%, and the specificity was 97%. In patients with inner border, the odds ratio for CIN 2 or 3 was 7.7 (95% CI=4.2-14.3). There was no significant association between inner border and any high-risk HPV type. Cervical intraepithelial neoplasia 2 or 3 associated with inner border was significantly more frequent in patients younger than 35 years. CONCLUSION: Inner border is a rare colposcopic phenomenon but highly specific for CIN 2 or 3 in young women.

Pharmacokinetics and safety of gadobutrol-enhanced magnetic resonance imaging in pediatric patients.

OBJECTIVES: This clinical study investigated the pharmacokinetics and safety of gadobutrol, a magnetic resonance (MR) imaging extracellular contrast agent, in pediatric patients aged 2 to 17 years. MATERIALS AND METHODS: In this open-label, multicenter study, patients scheduled for routine contrast-enhanced MR imaging of the brain, spine, liver or kidney, or MR angiography received a single intravenous injection of gadobutrol (0.1 mmol/kg/0.1 mL/kg). Patients were stratified by age groups (2-6, 7-11, and 12-17 years). Blood and urine samples were collected at prespecified time points and analyzed for gadolinium concentrations. Plasma data were evaluated by means of a nonlinear mixed effects model, and urine data were analyzed using descriptive statistics. In addition, the safety of gadobutrol was evaluated. RESULTS: A total of 130 patients (2-6 years, n = 45; 7-11 years, n = 39; 12-17 years, n = 46) were included in the final population pharmacokinetic analysis. Gadobutrol pharmacokinetics in children aged 2 to 17 years were adequately described by an open 2-compartment model with elimination from the central compartment. The median estimates (2.5th percentile, 97.5th percentile) of body weight-normalized total body clearance (L/h/kg) per age group were 0.10 (0.05, 0.17) for all ages, 0.13 (0.09, 0.17) in the 2 to 6 year age group, 0.10 (0.05, 0.17) in the 7 to 11 year age group and 0.09 (0.05, 0.10) in the 12 to 17 year age group. The body weight-normalized median estimates of total volume of distribution (L/kg) were 0.20 (0.12, 0.28) for all ages, 0.24 (0.20, 0.28) in the 2 to 6 year age group, 0.19 (0.14, 0.23) in the 7 to 11 year age group and 0.18 (0.092, 0.23) in the 12 to 17 year age group. Median gadolinium plasma concentrations at 20 minutes postinjection were simulated using the population pharmacokinetic model and ranged from 414 (13 kg subject) to 518 micromol/L (65 kg subject). Body weight was identified as the major covariate influencing the pharmacokinetic parameters of total body clearance and central volume of distribution. Age was not found to be an additional independent parameter. The median amount of renally excreted gadolinium was 77.0% of the administered dose within 6 hours postinjection, indicating that gadobutrol was renally excreted in this pediatric population aged 2 to 17 years. Gadobutrol was well tolerated, with drug-related adverse events of mild intensity reported for 8 (5.8%) of 138 patients. CONCLUSIONS: Observed differences in pharmacokinetics were attributed to body weight, with no additional independent effect of age. Thus, no dose adjustment from the standard dose of gadobutrol in adults based on body weight (0.1 mmol/kg) is necessary in pediatric patients aged 2 to 17 years. Gadobutrol was safe and well tolerated in the pediatric population in this study.