Pediatric Radiology最新文献

Background: Hepatocyte cytokeratin 7 (CK7) is a reliable marker for evaluating the severity of cholestasis in chronic cholestatic cholangiopathies. However, there is currently no noninvasive test available to assess the status of hepatocyte CK7 in pancreaticobiliary maljunction patients.

Objective: We aimed to develop a deep learning radiomics nomogram using magnetic resonance images (MRIs) to preoperatively identify the hepatocyte CK7 status and assess cholestasis progression in patients with pancreaticobiliary maljunction.

Materials and methods: In total, 180 pancreaticobiliary maljunction patients were retrospectively enrolled and were randomly divided into a training cohort (n = 144) and a validation cohort (n = 36). CK7 status was determined through immunohistochemical analysis. Pyradiomics and pretrained ResNet50 were used to extract radiomics and deep learning features, respectively. To construct the radiomics and deep learning signature, feature selection methods including the minimum redundancy-maximum relevance and least absolute shrinkage and selection operator were employed. The integrated deep learning radiomics nomogram model was constructed by combining the imaging signatures and valuable clinical feature.

Results: The deep learning signature exhibited superior predictive performance compared with the radiomics signature, as evidenced by the higher area under the curve (AUC) values in validation cohort (0.92 vs. 0.81). Further, the deep learning radiomics nomogram, which incorporated the radiomics signature, deep learning signature, and Komi classification, demonstrated excellent predictive ability for CK7 expression, with AUC value of 0.95 in the validation cohort.

Conclusion: The proposed deep learning radiomics nomogram exhibits promising performance in accurately identifying hepatic CK7 expression, thus facilitating prediction of cholestasis progression and perhaps earlier initiation of treatment in pancreaticobiliary maljunction children.

Olfactory schwannoma is a very rare tumor, whose origin is still under investigation. We report the case of a 16-year-old adolescent who presented with worsening headaches, hyposmia, and a convulsive crisis. Brain imaging showed a frontobasal lesion, attached to the cribriform plate, with solid and multiseptated cystic components. The patient underwent complete resection of the lesion. A comprehensive molecular study confirmed a methylation pattern consistent with schwannoma. Although rare, olfactory schwannomas should be considered in the differential diagnosis of anterior cranial fossa tumors. Given its benign nature, a complete resection leads to favorable long-term outcomes.

Background: Radial k-space sampling is widely employed in paediatric magnetic resonance imaging (MRI) to mitigate motion and aliasing artefacts. Artificial intelligence (AI)-based image reconstruction has been developed to enhance image quality and accelerate acquisition time.

Objective: To assess image quality of deep learning (DL)-based denoising image reconstruction of body MRI in children.

Materials and methods: Children who underwent thoraco-abdominal MRI employing radial k-space filling technique (PROPELLER) with conventional and DL-based image reconstruction between April 2022 and January 2023 were eligible for this retrospective study. Only cases with previous MRI including comparable PROPELLER sequences with conventional image reconstruction were selected. Image quality was compared between DL-reconstructed axial T1-weighted and T2-weighted images and conventionally reconstructed images from the same PROPELLER acquisition. Quantitative image quality was assessed by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the liver and spleen. Qualitative image quality was evaluated by three observers using a 4-point Likert scale and included presence of noise, motion artefact, depiction of peripheral lung vessels and subsegmental bronchi at the lung bases, sharpness of abdominal organ borders, and visibility of liver and spleen vessels. Image quality was compared with the Wilcoxon signed-rank test. Scan time length was compared to prior MRI obtained with conventional image reconstruction.

Results: In 21 children (median age 7 years, range 1.5 years to 15.8 years) included, the SNR and CNR of the liver and spleen on T1-weighted and T2-weighted images were significantly higher with DL-reconstruction (P<0.001) than with conventional reconstruction. The DL-reconstructed images showed higher overall image quality, with improved delineation of the peripheral vessels and the subsegmental bronchi in the lung bases, sharper abdominal organ margins and increased visibility of the peripheral vessels in the liver and spleen. Not respiratory-gated DL-reconstructed T1-weighted images demonstrated more pronounced respiratory motion artefacts in comparison to conventional reconstruction (P=0.015), while there was no difference for the respiratory-gated T2-weighted images. The median scan time per slice was reduced from 6.3 s (interquartile range, 4.2 - 7.0 s) to 4.8 s (interquartile range, 4.4 - 4.9 s) for the T1-weighted images and from 5.6 s (interquartile range, 5.4 - 5.9 s) to 4.2 s (interquartile range, 3.9 - 4.8 s) for the T2-weighted images.

Conclusion: DL-based denoising image reconstruction of paediatric body MRI sequences employing radial k-space sampling allowed for improved overall image quality at shorter scan times. Respiratory motion artefacts were more pronounced on ungated T1-weighted images.

Background: Conventional four-dimensional (4D) flow magnetic resonance imaging (MRI) is limited by long scan times, particularly in pediatric congenital heart disease (CHD) patients.

Objective: This study evaluates accelerated 4D flow MRI incorporating respiratory compensation and cardiac view sharing in healthy adults and pediatric CHD patients.

Materials and methods: Subjects underwent 5-min free-breathing protocol with a three-dimensional (3D) radial trajectory and compressed sensing reconstruction. The 4D flow MRI reconstruction pipeline was improved by respiratory soft-gating and cardiac view sharing. Flow in major thoracic vessels was compared with two-dimensional (2D) phase contrast MRI, the reference standard.

Results: Fourteen pediatric CHD patients (median age: 13 years (interquartile range (IQR): 5)) and four healthy adult volunteers (median age: 26 years (IQR: 3)) were recruited. Soft-gating improved diaphragm sharpness and reduced respiratory-induced blur (image quality scores: healthy: 46.1 soft-gated vs. 47.2 non-gated; CHD: 47.8 soft-gated vs. 48.2 non-gated). View sharing reduced undersampling artifacts and enhanced the signal-to-noise ratio (SNR, healthy: +9.9%; CHD: +3.8%). In healthy adults, correlations with 2D phase contrast MRI were strong for mean flow (R²=0.94, slope=0.94±0.12, root mean square error (RMSE)=6.4 ml/s; bias=1.1±6.4 ml/s, P=0.45) and peak flow (R²=0.9, slope=0.86±0.13, RMSE=40.9 ml/s; bias=21.3±44.7 ml/s, P=0.04). Similarly, CHD patients showed a strong correlation for mean flow (R²=0.88, slope=0.93±0.09, RMSE=8.3 ml/s) and peak flow (R²=0.97, slope=0.98±0.03, RMSE=25.9 ml/s). Internal consistency for 4D flow MRI in CHD cases showed mean percent differences of 6.1% Main pulmonary artery=Left pulmonary artery+Right pulmonary artery and 6.5% Ascending aorta=Descending aorta+Superior vena cava.

Conclusion: The accelerated 4D flow MRI method provides robust flow quantification and visualization in pediatric CHD patients, strongly correlating with 2D phase contrast MRI and completing scans in 5 min for clinical use.

Background: Splenic stiffness is a potential imaging marker of portal hypertension. Normative spleen stiffness values are needed to define diagnostic thresholds.

Objective: To report stiffness measurements of the spleen in healthy children undergoing liver magnetic resonance (MR) elastography across MRI vendors and field strengths.

Materials and methods: This was a post-hoc analysis of data collected under a prospective multicenter cross-sectional study. Volunteers aged 7-17.9 years without a known history of liver or spleen disease were recruited for a research MRI between February 2018 and October 2019. Gradient recalled echo (GRE) or spin-echo-echo-planar imaging (SE-EPI) MR elastography was performed on a total of three vendor platforms and at two field strengths (1.5 T (T) and 3 T) with standard right upper quadrant passive driver placement (frequency of 60 Hz). Two independent reviewers measured spleen stiffness, length, and volume. Descriptive statistics, independent sample t-tests or Mann-Whitney test, and Pearson's or Spearman's correlation were used.

Results: From 101 study volunteers, 72 (34 female) had measurable splenic stiffness. Median age was 12 years (interquartile range [IQR], 9.9-14.9 years). Mean (± SD) spleen stiffness was 4.7 ± 0.9 kPa (IQR, 3.8-5.4 kPa) with 6.1 kPa reflecting the 95th percentile. Strong correlation was observed between reviewers (ICC = 0.89 [95%CI, 0.71-0.93; P < 0.001]). Male volunteers had slightly higher splenic stiffness compared to females: 4.9 ± 0.9 vs. 4.3 ± 0.8 kPa (P = 0.014). There was significant correlation between spleen stiffness and body mass index (r = 0.33 [95%CI, 0.06-0.56; P = 0.024]) but no other measure of patient size (r = 0.15-0.29). No significant difference in spleen stiffness was observed across vendors (P = 0.089) or field strengths (P = 0.236).

Conclusion: MR elastography-based spleen stiffness, measured as part of a liver MR elastography acquisition, is < 6.1 kPa in a healthy pediatric population and does not vary with MRI vendor or field strength.

The bone marrow of immunocompromised patients may exhibit abnormalities due to the underlying disease, adverse treatment effects, and/or complications arising from either source. Such complexity poses a significant diagnostic challenge, particularly in children. Magnetic resonance imaging (MRI) is the modality of choice when evaluating bone marrow in these patients. The high soft tissue contrast of MRI studies allows for detailed evaluation of bone marrow composition, including fat content, cellularity, and vascularisation. During the early years of life, bone marrow undergoes physiological maturation manifesting as a wide range of MRI findings. Understanding the most common MRI features during this phase of development is essential. However, it is equally critical to recognise physiological variations that can mimic pathological changes, as distinguishing between variations and truly pathological abnormalities is crucial for accurate diagnosis and management. This article reviews normal bone marrow and its variations during childhood, as well as the most common alterations presenting in immunocompromised patients.

Musculoskeletal injuries in adolescents tend to occur in particular locations and have distinct characteristics, as they affect an immature skeleton. Increased engagement in sports, extended training and competition periods, and early specialization in specific sports, among other factors, have contributed significantly to the rise in musculoskeletal sports injuries in adolescents. Furthermore, females show a particularly pronounced increase in sports participation, where anatomical and hormonal factors play crucial roles in the development and increased frequency of sports-related injuries. Consequently, there is a growing demand for diagnostic imaging techniques. Musculoskeletal and pediatric radiologists require a comprehensive understanding of intrinsic and extrinsic risk factors and the successive stages of skeletal development that can influence the specific characteristics of sports injuries in adolescents. These aspects are crucial for the diagnostic, prognostic, and therapeutic management of these injuries and for mitigating chronic conditions that could compromise future sports participation. This review analyzes the primary musculoskeletal injuries in adolescent athletes and highlights the pivotal role of different imaging methods in their diagnosis and management.