Pediatric Radiology最新文献

Background

Increased positron emission tomography (PET) scanner z-axis coverage provides an opportunity in pediatrics to reduce dose, anesthesia, or repeat scans due to motion.

Objective

Recently, our digital PET scanner was upgraded from a 25-cm to a 30-cm z-axis coverage. We compare the two systems through National Electrical Manufacturing Association (NEMA) testing and evaluation of paired images from patients scanned on both systems.

Materials and methods

NEMA testing and a retrospective review of pediatric patients who underwent clinically indicated 18F-fluorodeoxyglucose (FDG) PET computed tomography (PET/CT) on both systems with unchanged acquisition parameters were performed. Image quality was assessed with liver signal to noise ratio (SNR-liver) and contrast to noise ratio (CNR) in the thigh muscle and liver with results compared with an unpaired t-test. Three readers independently reviewed paired (25 cm and 30 cm) images from the same patient, blinded to scanner configuration.

Results

Expansion to 30 cm increased system sensitivity to 29.8% (23.4 cps/kBq to 30.4 cps/kBq). Seventeen patients (6 male/11 female, median age 12.5 (IQR 8.3–15.0) years, median weight 53.7 (IQR 34.2–68.7) kg) were included. SNR-liver and CNR increased by 35.1% (IQR 19.0–48.4%) and 43.1% (IQR 6.2–50.2%) (P-value <0.001), respectively. All readers preferred images from the 30-cm configuration. A median of 1 (IQR 1–1) for fewer bed positions was required with the 30-cm configuration allowing a median of 91 (IQR 47–136) s for shorter scans.

Conclusion

Increasing z-axis coverage from 25 to 30 cm on a current-generation digital PET scanner significantly improved PET system performance and patient image quality, and reduced scan duration.

Background

The process of vascular development is essential for shaping complex craniofacial structures. Investigating the interplay between vascular development and orofacial morphogenesis holds critical importance in clinical practice and contributes to advancing our comprehension of (vascular) developmental biology. New insights into specific vascular developmental pathways will have far-reaching implications across various medical disciplines, enhancing clinical understanding, refining surgical techniques, and elucidating the origins of congenital abnormalities. Embryonic development of the craniofacial vasculature remains, however, under-exposed in the current literature. We imaged and created 3-dimensional (D) reconstructed images of the craniofacial arterial system from two early-stage human embryonic samples.

Objective

The aim of this study was to investigate the vascular development of the craniofacial region in early-stage human embryos, with a focus on understanding the interplay between vascular development and orofacial morphogenesis.

Materials and methods

Reconstructions (3-D) were generated from high-resolution diffusible iodine-based contrast-enhanced computed tomography (diceCT) images, enabling visualization of the orofacial arterial system in human embryonic samples of Carnegie stages (CS) 14 and 18 from the Dutch Fetal Biobank, corresponding to weeks 7 and 8.5 of gestation.

Results

From two human embryonic samples (ages CS 14 and 18), the vascular development of the orofacial region at two different stages of development was successfully stained with B-Lugol and imaged using a micro-computed tomography (micro-CT) scanner with resolutions of 2.5-μm and 9-μm voxel sizes, respectively. Additionally, educational 3-D reconstructions of the orofacial vascular system were generated using AMIRA 2021.2 software.

Conclusion

Micro-CT imaging is an effective strategy for high-resolution visualization of vascular development of the orofacial region in human embryonic samples. The generated interactive 3-D educational models facilitate better understanding of the development of orofacial structures.

Graphical abstract

The spectrum of acquired pediatric demyelinating syndromes has been expanding over the past few years, to include myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), as a distinct neuroimmune entity, in addition to pediatric-onset multiple sclerosis (POMS) and aquaporin 4-IgG-seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD). The 2023 MOGAD diagnostic criteria require supporting clinical or magnetic resonance imaging (MRI) features in patients with low positive myelin oligodendrocyte glycoprotein IgG titers or when the titers are not available, highlighting the diagnostic role of imaging in MOGAD. In this review, we summarize the key diagnostic features in MOGAD, in comparison to POMS and AQP4+NMOSD. We describe the lesion dynamics both during attack and over time. Finally, we propose a guideline on timing of imaging in clinical practice.

Over the last decades, magnetic resonance imaging (MRI) has emerged as a valuable adjunct to prenatal ultrasound for evaluating fetal malformations. Several radiological societies advocate for standardised and structured reporting practices to enhance the uniformity of imaging language. Compared to narrative formats, standardised and structured reports offer enhanced content quality, minimise reader variability, have the potential to save reporting time, and streamline the communication between specialists by employing a shared lexicon. Structured reporting holds promise for mitigating medico-legal liability, while also facilitating rigorous scientific data analyses and the development of standardised databases. While structured reporting templates for fetal MRI are already in use in some centres, specific recommendations and/or guidelines from international societies are scarce in the literature. The purpose of this paper is to propose a standardised and structured reporting template for fetal MRI to assist radiologists, particularly those with less experience, in delivering systematic reports. Additionally, the paper aims to offer an overview of the anatomical structures that necessitate reporting and the prevalent normative values for fetal biometrics found in current literature.

Background: Two-dimensional (2-D) shear wave elastography is a commonly used sonographic elastography method for the noninvasive measurement of liver stiffness. There is little liver stiffness data available in the pediatric population and its association with the child's weight is scarce.

Objective: The principal aim of our study was to determine weight-specific reference liver stiffness values in a pediatric population free of liver disease.

Materials and methods: In this retrospective single-center study, 2-D shear wave elastography values were recorded in children with no history of liver disease and with a clinically indicated ultrasound examination, between April 2021 and July 2022. Examinations were performed using an Aplio i800 and two Aplio a450 (Canon Medical Systems), with a convex probe (i8CX1 or 8C1 transducers). This population was divided into ten weight groups. We evaluated the relation between weight and liver elasticity values and compared right and left lobe measurements.

Results: During the period of the study, 235 children were included. We then excluded 64 patients (weight not available = 13, interquartile range to median ratio (IQR/M) greater than 30% = 51). On the final sample (171 patients, median age 6.5 years [0-18], median weight 22.6 kg [2.5-80]), stiffness values showed a global significant trend to increase with weight. In each group, there was no significant difference between right and left liver stiffness values. The mean normal liver stiffness value including all children was 5.3 ± 1.1 kPa.

Conclusion: Liver stiffness in our pediatric sample with no history of liver disease increases with weight. These data may help to distinguish normal from pathological elastography values.

Background: Artificial intelligence has been increasingly used in medical imaging and has demonstrated expert level performance in image classification tasks.

Objective: To develop a fully automatic approach for determining the Risser stage using deep learning on abdominal radiographs.

Materials and methods: In this multicenter study, 1,681 supine abdominal radiographs (age range, 9-18 years, 50% female) obtained between January 2019 and April 2022 were collected retrospectively from three medical institutions and graded manually using the United States Risser staging system. A total of 1,577 images from Hospitals 1 and 2 were used for development, and 104 images from Hospital 3 for external validation. From each radiograph, right and left iliac crest patch images were extracted using the pelvic bone segmentation model DeepLabv3 + with the EfficientNet-B0 encoder trained with 90 digitally reconstructed radiographs from pelvic computed tomography scans with a pelvic bone mask. Using these patch images, ConvNeXt-B was trained to grade according to the Risser classification. The model's performance was evaluated using accuracy, area under the receiver operating characteristic curve (AUROC), and mean absolute error.

Results: The fully automatic Risser stage assessment model showed an accuracy of 0.87 and 0.75, mean absolute error of 0.13 and 0.26, and AUROC of 0.99 and 0.95 on internal and external test sets, respectively.

Conclusion: We developed a deep learning-based, fully automatic segmentation and classification model for Risser stage assessment using abdominal radiographs.

Rationale and objectives: Introduction of post-mortem imaging has helped improve sudden unexpected death in infancy (SUDI) management in Europe. French guidelines were issued in 2007 to homogenise SUDI investigations including imaging. The aim of this study was to evaluate current imaging management of SUDI in France.

Material and methods: Between January 2022 and July 2022, all 35 SUDI French referral centres were invited to answer an e-mailed online survey including 29 questions divided into four different sections covering imaging practices for SUDI including radiology department organisation, imaging modalities performed, methods of reading, and current training resources. Partial responses were secondarily completed by a personal call to the SUDI imaging consultant. The current implementation of the 2007 recommendations was compared with a previous evaluation from 2015 and with current North American practices.

Results: The participation rate of centres performing SUDI imaging was 100% (35/35). Imaging was systematically performed in 94.3% (33/35) of the centres: 74.3% (26/35) using radiography; 5.7% (2/35) using ultrasound; 94.3% (33/35) using computed tomography (CT), including 89% (31/35) whole-body CT and 5.7% (2/35) brain CT; and 20% (7/35) using magnetic resonance imaging (MRI). Two centres (5.7%, 2/35) did not systematically perform brain imaging. One (2.9%, 1/35) used ultrasound-guided biopsy. In comparison with 2015, rates of brain imaging increased by 25.4% (P=0.008). There was no significant difference in the number of forensic MRIs performed between France and North America (P=0.663).

Conclusion: Despite improvements since 2015, full compliance with French guidelines for SUDI investigations remains incomplete. The use of imaging, particularly CT and brain imaging, has increased. Further efforts are needed to standardise imaging practices for optimal SUDI investigations.