RPS 712 - Paediatric abdominal radiology, new developments in ultrasound, MRI and CT

Author Block: D. Pelaez Sanchez, L. Vara de Andres, A. M. Lancharro Zapata, C. Marin Rodriguez, M. Sánchez Pérez, A. Aguado Del Hoyo, M. d. M. Tolin Hernandi, C. Miranda Cid, C. Sanchez Sanchez; Madrid/ES
Purpose: Contrast-enhanced intestinal ultrasound (CEUS) is a less invasive and more cost-effective imaging modality compared to magnetic resonance enterography (MRE) and colonoscopy for assessing the lower gastrointestinal tract and related complications in Crohn’s disease. Its use in paediatric settings is gaining interest due to its safety profile and real-time functional imaging capabilities.
Methods or Background: This study included 48 CEUS measurements performed in paediatric patients during the acute phase of inflammatory bowel disease. Quantitative CEUS parameters - including area under the curve (AUC), time to peak (TTP), and peak intensity (PI) - were correlated with findings from MRE and colonoscopy, as well as with faecal calprotectin levels, to evaluate their diagnostic utility against parameters in subacute and chronic phases - with no active inflamation - in order to establish a clincally useful threshold.
Results or Findings: The CEUS parameters showed a strong correlation with faecal calprotectin levels and with imaging and endoscopic findings consistent with active inflammation. Increases in AUC, TTP, and PI were directly proportional to the degree of inflammatory activity identified through MRE and colonoscopy.
Conclusion: Quantitative parameters obtained from CEUS appear to reliably reflect the presence and severity of active inflammation in paediatric Crohn’s disease. These findings support the potential role of CEUS as a non-invasive, reproducible, and effective tool for diagnosis and follow-up in this patient population.
Limitations: The limitations of the study are the small sample size which may limit the statistical power and generalisability of the findings, the retrospective and observational analysis, which may introduce potential biases and limit causal inferences and the single-hospital focus, which may restrict the applicability of the results to broader or more diverse paediatric populations..
Funding for this study: No.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: Y. Dong, Y. Huang, Y. Qiu, Y. Wang, J. Chen, L. Wei, R. Cheng; Shanghai/CN
Purpose: To evaluate the diagnostic performance of ultrasound-derived fat fraction (UDFF) in diagnosing hepatic steatosis in pediatric patients with metabolic dysfunction-associated steatotic liver disease (MASLD).
Methods or Background: In this prospective study, pediatric patients diagnosed with MASLD were enrolled. All patients underwent UDFF measurements (six acquisitions) in V/VIII hepatic segments, using the Acuson Sequoia ultrasound system (Siemens Healthineers, USA) with a DAX probe (1.0 – 3.5 MHz) before magnetic resonance imaging proton density fat fraction (MRI-PDFF) measurement within one week. Bland-Altman analysis and Spearman correlation coefficient were performed. Area under the receiver operating characteristic curves (AUCs) was performed to assess the diagnostic performance of UDFF measurements in hepatic steatosis. Intraclass correlation coefficients (ICCs) were calculated to estimate the consistency of UDFF measurements.
Results or Findings: From May 2024 to December 2024, 27 patients (median age, 12 years; median body mass index, 28.4 kg/m2) were included. The median UDFF value was 13.0 % (IQR: 6.0 – 21.5). UDFF and MRI-PDFF had a mean bias of 3.4 %, with a 95 % LOA ranging from -17.3 % to 24.0 %. UDFF values showed a positive correlation with MRI-PDFF (r = 0.69). Taking MRI-PDFF ≥ 5 %, ≥ 15 %, and ≥ 25 % as the reference standard for diagnosing hepatic steatosis grade ≥ S1, ≥ S2, and S3, the AUCs of UDFF were 0.80, 0.84, and 0.82, with the cutoff values of 9.5 %, 10.5 %, and 12.8 %, respectively. The ICC of UDFF measurements was 0.92 (95 % CI: 0.86 – 0.96).
Conclusion: UDFF measurement demonstrates good diagnostic performance in diagnosing and grading hepatic steatosis in pediatric MASLD patients.
Limitations: The sample size is limited because it includes pediatric patients with metabolic dysfunction-associated steatotic liver disease from one center.
Funding for this study: This project was supported by the Sino-German Mobility Program of NSFC and DFG (Grant No. M-0504) and the National Natural Science Foundation of China (Grant No. 82071942).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics Committee of Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Approval Number: XHEC-C-2022-121-2)

Author Block: M. Zellner, M. S. Schmidt, F. Huber, C. Paverd, A. Martin, S. Micic, V. Spyropoulou, C. J. J. Kellenberger; Zürich/CH
Purpose: The burden of liver disorders in children, including metabolic dysfunction-associated steatotic liver disease, underscores the need for non-invasive diagnostic tools. Ultrasound modalities namely Shear wave elastography (SWE), shear wave dispersion (SWD), and attenuation imaging (ATI) are potential alternatives to invasive methods. However, robust paediatric reference data for these techniques remain scarce.
Methods or Background: This retrospective study aimed to define normative values for SWE, SWD, and ATI in a healthy paediatric population and explore how these parameters are influenced by age, sex, body mass index (BMI), and fasting state. From a larger cohort of 734 children, 264 (135 girls; median age 11.5 years) with no evidence of liver pathology were included. All participants underwent liver ultrasound with a standardized protocol, acquiring five ATI and ten SWE/SWD measurements per child. Only high-quality acquisitions were analyzed.
Results or Findings: Median values were: ATI 0.54 dB/cm/MHz (IQR: 0.50–0.58), SWE 1.24 m/s (IQR: 1.14–1.33), and SWD 11.70 (m/s)/kHz (IQR: 10.84–12.13). ATI and SWD were inversely associated with age (p = 0.0003 and p = 0.0048), and SWD showed a significant negative correlation with BMI z-score (p < 0.0001) and was lower in females (p = 0.0013). SWE demonstrated a weak positive relationship with depth of measurement (p = 0.0261). Fasting duration did not significantly affect any parameter.
Conclusion: These findings establish paediatric reference ranges for SWE, SWD, and ATI, highlighting the influence of age and sex—especially on SWD and ATI and emphasizing the importance of contextual interpretation in clinical practice.
Limitations: This study has several limitations. Its retrospective design introduces potential for selection and information bias. Despite careful screening, undetected minor illnesses may have subtly affected liver viscoelasticity. Finally, the predominantly white study population may limit generalizability to more diverse ethnic groups.
Funding for this study: The authors disclose that the retrospective data analysis was supported by funding from Canon Medical Systems, received by the first author
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Documentation of written informed consent from parents or legal guardians was reviewed retrospectively prior to data analysis. Clinical data and laboratory data were extracted from digital patient records. The study was approved by the local ethics committee

Author Block: I. C. Simcock¹, A. Lamouroux², S. C. Shelmerdine¹, C. Hutchinson¹, N. Sebire¹, O. Arthurs¹; ¹London/UK, ²Montpellier/FR
Purpose: To demonstrate the yield of abdominal and pelvic diagnoses at less-invasive autopsy following a post-mortem fetal micro-CT investigation for early gestation pregnancy loss.
Methods or Background: Micro-CT provides high-resolution imaging for early gestation fetuses (usually below 20 weeks, or <300 g bodyweight), typically following a miscarriage or termination of pregnancy, allowing parents a less invasive autopsy investigation.
We retrospectively analysed micro-CT diagnoses made on an unselected population of over 1200 early gestation fetuses between 2017 and 2024.
Results or Findings: We made 277 individual abdominal/pelvic diagnoses on Micro-CT, in 196/1200 patients (16.3%). 100/277 (36.1%) were solely abdominal, 61/277 (22.0%) solely pelvic, 27/277 (9.7%) were both, and 96/277 (34.7%) were external anomalies.
We demonstrate the spectrum of disorders detected using Micro-CT: the commonest were abdominal-pelvic wall defects 84/277 (30.3%) and renal anomalies 77/277 (27.8%). The commonest renal anomalies were horseshoe kidneys 16/77 (20.8%), and cystic kidneys 13/77 (16.9%).
Imaging was diagnostic in almost all cases except for 17/1200 (1.4%) non-diagnostic scans due to severe maceration.
Conclusion: We present the spectrum of abdominal/pelvic anomalies identified using post-mortem fetal Micro-CT. This information provides less-invasive autopsy for parents and clinical audit. The findings may be used to inform the likelihood of fetal abnormalities in subsequent pregnancies.
Limitations: Single centre data from a large specialist centre. Not all parents consented to invasive autopsy, so not all diagnoses could be histologically confirmed.
Funding for this study: Funding for this work was received from the the National Institute for Health and Care Research - UK (ICS, SCS, OJA) and the Mobility funding grant - Montpellier and Nimes University Hospital, France (AL). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics approval (17/WS/0089).

Author Block: Y. Wang, Y. Dong, H. Feng, L. Wei, R. Cheng, Y. Huang, Y. Wang; Shanghai/CN
Purpose: To investigate the value of Ultra Micro Angiography (UMA) imaging in evaluating the inflammation activity of pediatric Crohn's disease (CD) patients.
Methods or Background: The Pediatric Crohn’s Disease Activity Index (PCDAI) was regarded as the reference standard to evaluate the activity of CD. Before treatment, pediatric CD patients underwent B mode ultrasound (BMUS) and recorded the parameters. Color Doppler Flow Imaging (CDFI) and UMA were used to evaluate the blood flow in the most thickened diseased bowel wall using Limberg scores. The diagnostic performance of UMA and CDFI in assessing the inflammatory activity of pediatric CD was compared.
Results or Findings: A total of 54 pediatric CD patients were included and divided into three groups: inactive, mild and moderate-to-severe CD. When assessing bowel wall blood flow using CDFI, there was no statistically significant difference in bowel wall blood flow signals between the mild CD and the inactive CD (P > 0.05). There was statistically significant difference in blood flow signals between the mild and moderate-to-severe CD groups (P < 0.05). When assessing bowel wall blood flow using UMA, there were statistically significant differences in blood flow signals among all three groups (all P < 0.05). ROC analysis revealed that diagnostic performance of the UMA-BMUS model was significantly better than that of the CDFI-BMUS model (AUC 0.911 vs. 0.819; sensitivity 86.9 % vs. 72.2 %; specificity 94.5 % vs. 91.7 %; P < 0.05).
Conclusion: By sensitively depicting the low-velocity and tiny blood flow signals of the inflamed bowel wall, UMA is an effective noninvasive imaging method to make semi-quantitative evaluation of the activity of pediatric CD.
Limitations: The assessment of pediatric CD activity was based on semi-quantitative evaluation. Further multi-center studies are still necessary to verify our results.
Funding for this study: National Natural Science Foundation of China (Grant No. 82071942)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The university hospital’s ethics committee : ID No. XHEC-C-2024-038-2

Author Block: S. Song, J. Kim, M-J. Lee, K. H. Han, Y. Kwon, H. Koh, Y. W. Kim, E. J. Lee, H. Yoon; Seoul/KR
Purpose: To evaluate correlation between MR-proton density fat fraction (PDFF) and ultrasound-based parameters (attenuation coefficient [AC] and backscatter coefficient [BSC]) in pediatric patients, assess respiratory influence, and derive the optimal predictive model under various breathing conditions.
Methods or Background: This prospective study included consecutive pediatric patients with suspected fatty liver disease who underwent abdominal ultrasound and MRI with PDFF at baseline. AC and BSC were each acquired ten times during free breathing (FB) and breath holding (BH). Pearson correlation and linear regression assessed associations of AC and BSC with MR-PDFF. Multiple regression incorporating AC and BSC evaluated respiratory interactions. Additionally, 12 novel predictive models were constructed under FB and BH, with performance compared using adjusted R² and root mean square error (RMSE).
Results or Findings: Finally 44 patients (mean age 14.1 years) were included. AC and BSC showed significant correlations with MR-PDFF regardless of breathing condition (all p < 0.001). Multiple regression models during BH demonstrated better performance compared with FB (adjusted R², 0.64 vs 0.58; RMSE, 7.5 vs 8.0). There was no significant interaction effects of AC and BSC on MR-PDFF with breathing condition. Among 12 predictive models, the ordinary least squares (OLS) model performed best under BH (RMSE 7.14), while the support vector machine (SVM) model performed best under FB (RMSE 7.66).
Conclusion: In conclusion, AC and BSC are significantly correlated with MR-PDFF in pediatric patients under both breathing conditions. Predictive performance is slightly higher with BH, but the difference is minimal. The SVM model under FB still provided clinically acceptable accuracy, may be helpful for children with limited respiratory cooperation.
Limitations: Limitations in our study include small sample size, single-center design, relatively older cohort, and lack of external validation.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by our hospital’s institutional review board. Written informed consent was obtained from all participants.

Author Block: E. Höhne, S. Fischer, T. Vogl, V. Koch, S. Mahmoudi, I. Yel, K. Eichler, L. D. Grünewald; Frankfurt/DE
Purpose: Accurate assessment of liver, spleen, and kidney size is essential in pediatric diagnostics, where ultrasound provides a safe, accessible, and non-invasive tool. This study aimed to establish contemporary, population-based reference values for abdominal organ dimensions in children and adolescents in order to reflect current growth patterns and support reliable clinical decision-making.
Methods or Background: A total of 27,696 abdominal ultrasound examinations performed in children and adolescents (0–18 years) between 2000 and 2025 at a large tertiary referral center in Germany were retrospectively evaluated. Organ dimensions were measured by experienced pediatric radiologists using standardized protocols. Age-related percentile curves (P3–P97) were established with Generalized Additive Models for Location, Scale, and Shape (GAMLSS) to account for non-linear growth dynamics.
Results or Findings: Organ-specific datasets included 12,254 livers, 12,703 spleens, 16,254 right kidneys, and 16,516 left kidneys. All organs exhibited characteristic non-linear growth trajectories. No significant sex-related differences were identified for spleen (p = 0.195), liver (p = 0.517), right kidney (p = 0.712), or left kidney (p = 0.797), supporting the use of unified reference values. The left kidney consistently exceeded the right in size (p < 0.0001), with a mean difference of 2–5 mm.
Conclusion: This study provides updated, population-specific percentile curves for liver, spleen, and kidney dimensions, derived from one of the largest pediatric ultrasound datasets in Central Europe. These normative values offer a robust reference framework to support the differentiation between physiological growth variation and pathological organ enlargement in children and adolescents.
Limitations: The retrospective, single-center design and the absence of anthropometric parameters such as height or weight may limit the generalizability of the presented age-based reference values.
Funding for this study: No funding was obtained for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This retrospective cohort study was approved by the institutional review board (approval #2024-1854_1) with waiver of informed consent.

Author Block: A. Martin-Champetier, B. Binselim, E. Dammann, B. Roquelaure, A. Fabre, O. Boillot, A. Dabadie, P. Petit; Marseille/FR
Purpose: Portal vein stenosis is a common complication after paediatric liver transplantation. The value of ultrasound compared with portal angiography in detecting stenosis and its recurrence after balloon angioplasty has been little studied.
Methods or Background: Children who underwent liver transplantation and subsequently received portal angioplasty in our centre were retrospectively included. Demographic, clinical, biological, and ultrasound data were collected and correlated with the presence of angiographic portal vein stenosis. In cases of recurrence after balloon dilatation, the previously collected data as well as angiographic findings were analysed.
Results or Findings: Twenty-one children (median age 42 months) underwent 43 portographies. Angiographic stenosis was confirmed in 37 procedures (86.0%), and recurrence occurred after 22 procedures (56.4%). In multivariate analysis, no criterion was associated with the presence of stenosis or recurrence. ROC curves suggested thresholds associated with angiographically proven stenosis (AUC > 0.5) for the following criteria: “B-mode measurement of stenosis”, “increase in trans-anastomotic velocity compared with postoperative ultrasound”, and “trans-anastomotic pressure gradient”. The ROC curve also suggested that the criterion “balloon size” was associated with recurrence (AUC > 0.5).
Conclusion: Our study did not identify predictive criteria for stenosis or recurrence in multivariate analysis. Further studies are required to reduce the number of portal angiographies and improve the management of these stenoses.
Limitations: This retrospective design resulted in missing data for certain variables, such as splenic elastography. Although this represents the largest cohort reported in the paediatric literature, the relatively small sample size may have limited the statistical power of the analysis.
Funding for this study: No external funding was received for the conduct of this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study received approval from our institution’s health data commission and is registered under file number ZJCRST.

Author Block: E. Höhne, S. Fischer, T. Vogl, S. Mahmoudi, P. Reschke, J. Gotta, V. Koch, L. D. Grünewald; Frankfurt/DE
Purpose: Reference values for thyroid volume are essential for diagnosing goiter and interpreting pediatric thyroid imaging, yet comprehensive data across the full pediatric age range remain scarce. This study aimed to establish updated sonographic reference values and percentile curves in children and adolescents (0–18 years) from a large European cohort.
Methods or Background: This retrospective single-centre cohort study included pediatric thyroid ultrasound examinations performed between 2000 and 2025 at a tertiary referral hospital. Thyroid lobe volumes were calculated from standardized measurements using the formula length × width × depth × 0.5, excluding the isthmus. In total, 4,965 left and 4,948 right lobes fulfilled quality criteria and were included in the analysis. Age-dependent percentile curves (P3–P97) were modeled using GAMLSS.
Results or Findings: Thyroid volume (Tvol) increased steadily from birth to late adolescence in both sexes. In boys, mean Tvol rose from 0.71 ml at birth to 8.09 ml at 18 years, and in girls mean Tvol increased from 0.53 ml to 7.46 ml. Peak annual growth occurred earlier in girls (11–12 years, +0.99 ml) than in boys (13–14 years, +0.73 ml), but overall mean Tvol did not differ significantly between sexes (p = 0.28). Across all ages, the right lobe was consistently larger than the left (p < 0.0001).
Conclusion: This large single-centre study provides updated sonographic reference values and percentile curves for thyroid volume across the entire pediatric age range. The results confirm established growth patterns, demonstrate consistent right–left asymmetry, and highlight population-specific deviations from WHO standards, supporting accurate clinical assessment in children and adolescents.
Limitations: Limitations include the retrospective single-centre design; validation in independent cohorts is warranted.
Funding for this study: No external funding received.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This retrospective cohort study received approval from the institutional review board (approval number 2024-1854_1), with informed consent waived.

Author Block: X. Zhang¹, L. Ji¹, R. Tang², M. Zhao¹; ¹Nanjing/CN, ²Shanghai/CN
Purpose: To evaluate the feasibility of using arterial spin labeling (ASL) to quantitatively assess placental perfusion in twin pregnancies and compare the results with singleton pregnancies.
Methods or Background: ASL imaging was performed on twin and singleton pregnancies to measure placental blood flow (BF). Gaussian mixture modeling was applied to partition twin placentas into regions corresponding to each fetus. Asymmetry index (AI) and hypoperfusion fraction (HF) were calculated for each fetus and compared between groups.
Results or Findings: Singleton placentas exhibited a mean AI close to 0%, with HF around 10% and BF_mean ranging from 150–400 ml/100g/min. Twin pregnancies showed a wider AI distribution (median -30%, range -120% to +90%) and higher HF in Twin A (11%) compared to Twin B (7%). The automated partitioning algorithm demonstrated stability in identifying perfusion regions.
Conclusion: ASL provides a non-invasive method to quantitatively assess placental perfusion in twin pregnancies, revealing significant perfusion asymmetry. This technique offers potential for early identification of at-risk fetuses and may complement existing imaging modalities in clinical practice.
Limitations: This study is a small-sample exploratory attempt, which may limit the generalizability of the findings. ASL acquisition was restricted to a few thick slices, potentially missing parts of the placenta. In twin pregnancies, placental vascular anastomoses make perfusion partitioning challenging, and our clustering-based segmentation may not fully match anatomical territories.
Funding for this study: Maternal and Child Health Hospital High-level Construction Project(GZL2529)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: It was approved by the institutional ethics committee of The First Affiliated Hospital of Nanjing Medical University.