(1) This study evaluates the impact of an AI denoising algorithm on image quality, diagnostic accuracy, and radiological workflows in pediatric chest ultra-low-dose CT (ULDCT). (2) Methods: 100 consecutive pediatric thorax ULDCT were included and reconstructed using weighted filtered back projection (wFBP), iterative reconstruction (ADMIRE 2), and AI denoising (PixelShine). Place-consistent noise measurements were used to compare objective image quality. Eight blinded readers independently rated the subjective image quality on a Likert scale (1 = worst to 5 = best). Each reader wrote a semiquantitative report to evaluate disease severity using a severity score with six common pathologies. The time to diagnosis was measured for each reader to compare the possible workflow benefits. Properly corrected mixed-effects analysis with post-hoc subgroup tests were used. Spearman’s correlation coefficient measured inter-reader agreement for the subjective image quality analysis and the severity score sheets. (3) Results: The highest noise was measured for wFBP, followed by ADMIRE 2, and PixelShine (76.9 ± 9.62 vs. 43.4 ± 4.45 vs. 34.8 ± 3.27 HU; each p < 0.001). The highest subjective image quality was measured for PixelShine, followed by ADMIRE 2, and wFBP (4 (4–5) vs. 3 (4–5) vs. 3 (2–4), each p < 0.001) with good inter-rater agreement (r ≥ 0.790; p ≤ 0.001). In diagnostic accuracy analysis, there was a good inter-rater agreement between the severity scores (r ≥ 0.764; p < 0.001) without significant differences between severity score items per reconstruction mode (F (5.71; 566) = 0.792; p = 0.570). The shortest time to diagnosis was measured for the PixelShine datasets, followed by ADMIRE 2, and wFBP (2.28 ± 1.56 vs. 2.45 ± 1.90 vs. 2.66 ± 2.31 min; F (1.000; 99.00) = 268.1; p < 0.001). (4) Conclusions: AI denoising significantly improves image quality in pediatric thorax ULDCT without compromising the diagnostic confidence and reduces the time to diagnosis substantially.

Background: Treatment of unstable forearm fractures in the metaphyseal-diaphyseal junction (MDJ) zone is still a matter of debate. Major drawbacks of all types of fixations include either invasiveness, technical impracticality, or lack of acceptance by patients. This study reports results after antegrade ESIN (a-ESIN) compared to transepiphyseal intramedullary K-wire (TIK) for unstable MDJ forearm fractures. Methods: The MDJ of the forearm was defined as the square over the joints of both forearm bones subtracted with the square over the metaphysis of the radius alone. The data of 40 consecutive patients < 16 years of age who were treated either by a-ESIN (later treatment period) or TIK (early treatment period) for an unstable MDJ forearm fracture at a single high-volume pediatric trauma center were retrospectively analyzed. Results: The average age was slightly lower in the first group (TIK = 7.42 years; a-ESIN = 10.5 years). An additional ulna fracture was found in 50% of cases and was treated with a classic antegrade ESIN in 10/20 (TIK) and 6/20 cases (a-ESIN). Additional plaster cast immobilization was performed in all cases with TIK and in three cases with a-ESIN. After TIK, no complication, malalignment, or functional limitation occurred. After a-ESIN, 19/20 patients had an event-free course with stable retention and healing without axial malalignment. In one case, a temporary sensor dysfunction occurred. The same patient suffered a refracture two months after the original trauma, which required a closed reduction. Metal removal was performed after 84 days (TIK) and 150 days (a-ESIN). The outcome in all patients was good. Conclusion: Both a-ESIN and TIK are minimally invasive procedures that are technically easy to perform. Both methods are safe and lead to a complete restoration of the forearm’s range of motion. The decisive advantage of a-ESIN is the possibility of postoperative immobilization-free rehabilitation.

Background: Functional magnetic resonance urography (MRU) is well established in the diagnostic workup of urinary tract anomalies in children, providing comprehensive morphological and functional information. However, dynamic contrast-enhanced images acquired in the standard Cartesian k-space manner are prone to motion artifacts. A newly introduced 4D high spatiotemporal resolution dynamic contrast-enhanced magnetic resonance imaging based on variable density elliptical centric radial stack-of-stars sharing technique has shown improved image quality regarding motions under free breathing. Objective: The aims of this study were to implement this 4D free-breathing sequence for functional MRU and to compare its image quality and analyzability with standard breath-hold Cartesian MRU. Materials and Methods: We retrospectively evaluated all functional 4D MRU performed without general anesthesia between September 2021 and December 2022 and compared them with matched pairs (age, affected kidney, diagnosis) of standard Cartesian MRU between 2016 and 2022. Image analysis was performed by 2 radiologists independently regarding the following criteria using a 4-point Likert scale, with 4 being the best: overall image quality, diagnostic confidence, respiratory motion artifacts, as well as sharpness and contrast of aorta, kidneys, and ureters. We also measured vertical kidney motion due to respiratory motion and compared the variance for each kidney using F test. Finally, both radiologists calculated the volume, split renal volume (vDRF), split renal Patlak function (pDRF), and split renal function considering the volume and Patlak function (vpDRF) for each kidney. Values were compared using Bland-Altman plots and F test. Results: Forty children (20 for 4D free-breathing and standard breath-hold, respectively) were enrolled. Ten children of each group were examined using feed-and-sleep technique (median age: 4D, 3.3 months; standard, 4.2 months), 10 were awake (median age: 4D, 8.9 years; standard, 8.6 years). Overall image quality, diagnostic confidence, respiratory motion artifacts, as well as sharpness and contrast of the aorta, kidneys, and ureters were rated significantly better for 4D free-breathing compared with standard breath-hold by both readers (P ranging from <0.0001 to 0.005). Vertical kidney motion was significantly reduced in 4D free-breathing for the right and the left kidney (both P < 0.001). There was a significantly smaller variance concerning the differences between the 2 readers for vpDRF in 4D MRU (P = 0.0003). In contrast, no significant difference could be demonstrated for volume (P = 0.05), vDRF (P = 0.93), and pDRF (P = 0.14). Conclusions: We demonstrated the feasibility of applying a 4D free-breathing variable density stack-of-stars imaging for functional MRU in young pediatric patients with improved image quality, fewer motion artifacts, and improved functional analyzability.

The purpose of this study was to evaluate whether changes in repeated lung ultrasound (LUS) or chest X-ray (CXR) of coronavirus disease 2019 (COVID-19) patients can predict the development of severe disease and the need for treatment in the intensive care unit (ICU). In this prospective monocentric study, COVID-19 patients received standardized LUS and CXR at day 1, 3 and 5. Scores for changes in LUS (LUS score) and CXR (RALE and M-RALE) were calculated and compared. Intra-class correlation was calculated for two readers of CXR and ROC analysis to evaluate the best discriminator for the need for ICU treatment. A total of 30 patients were analyzed, 26 patients with follow-up LUS and CXR. Increase in M-RALE between baseline and follow-up 1 was significantly higher in patients with need for ICU treatment in the further hospital stay (p = 0.008). Both RALE and M-RALE significantly correlated with LUS score (r = 0.5, p < 0.0001). ROC curves with need for ICU treatment as separator were not significantly different for changes in M-RALE (AUC: 0.87) and LUS score (AUC: 0.79), both being good discriminators. ICC was moderate for RALE (0.56) and substantial for M-RALE (0.74). The present study demonstrates that both follow-up LUS and CXR are powerful tools to track the evolution of COVID-19, and can be used equally as predictors for the need for ICU treatment.

Background: Fluoroscopically guided jejunal tube placement via percutaneous endoscopic gastrostomy (PEG-J) provides minimally invasive post-pyloric access in children. Limited data exist regarding routine application and procedural risks. Objective: To evaluate the safety and technical success of PEG-J in pediatric patients, performed without general anesthesia or sedation. Materials and methods: All pediatric cases of fluoroscopically guided PEG-J procedures performed between 2011 and 2025 were included. Fluoroscopic images were reviewed to determine the final position of the tube tip. Technical success, complications, anatomical variants, and tube patency were assessed. Fluoroscopy time and dose area product (DAP) were documented. Results: A total of 126 PEG-J procedures in 60 children (36 males) were analyzed. The technical success rate was 85% (107/126) with final tube tip placement in the jejunum in 88 cases (82%) and in the duodenum in 19 cases (18%). Nineteen procedures (15%) were unsuccessful, including six with documented anatomical causes (steep vertical duodenal entry, n =2; malrotation, hiatus hernia, hooked stomach in superior mesenteric artery syndrome, steep take-off of the jejunum with kinking of the tube at the ligament of Treitz, n =1 each) and 13 without documented reasons. The median fluoroscopy time was 5 min 24 s (range, 2 s–37 min), at a frame rate of 0.5 frames per second. The median DAP was 6.1 cGy·cm ² (range, 0.08–343 cGy·cm ² ). Conclusion: Fluoroscopically guided PEG-J placement is a safe and effective procedure in pediatric patients, with high technical success and low radiation exposure. Graphical

Megacalycosis is a rare non-obstructive congenital anomaly of the kidneys. The underlying pathogenesis has not yet been understood. Theories include the coexistence of distinct calyceal developmental stages, malformation of the calyceal structure, and transient, self-limiting obstruction. The management of this condition consists of close sonographic and functional follow-up. It is of the utmost importance to differentiate between an obstructive cause of hydronephrosis, although this can be challenging. Avoiding unnecessary surgical intervention is a crucial objective in this regard. The number of case series is limited, and the follow-up periods are often brief. The study included pediatric patients with megacalycosis who had been treated at the institution between 2009 and 2024. The extracted data comprised demographics, prior treatments, and follow-up data concerning sonographic and functional tests. The two-sample Student's t-test or the Mann-Whitney-U test were employed, depending on the normality of the distribution of the variables. The statistical analysis was conducted using Microsoft Excel 365. A total of 19 affected kidneys in 18 patients were identified. The median follow-up period was 5 years (range 1.2-13). All patients exhibited stable renal function at Tc-99m MAG3 scintigraphy. While a plateau phase was evident in the majority of patients following furosemide injection, delayed tracer clearance 40-60 min later was adequate. In cases where the diagnosis was uncertain or where prior surgery had been performed, retrograde pyelography was a valuable additional tool for ruling out obstruction. This is the largest series with the longest follow-up period of patients affected by megacalycosis to date. The diagnostic process can be challenging. The only appropriate management is non-operative, which preserves renal function. Retrograde pyelography can be a useful additional tool in cases where the diagnosis is uncertain.