Keywords: Body, Body, Pediatrics, abdominal adipose tissue, subcutaneous and visceral fat, insulin resistance

Motivation: Unravel the links between childhood abdominal fat distribution patterns and subsequent cardiometabolic risks aiming to provide effective strategies for preventing childhood obesity.

Goal(s): To investigate the presence of distinct abdominal fat accumulation patterns during infancy and childhood in a multi-ethnic cohort, and their associations with cardiometabolic risk.

Approach: Latent class growth mixture modeling was used to identify three trajectories (stable, slow acceleration, rapid acceleration) for deep subcutaneous (DSAT), superficial subcutaneous (SSAT), and visceral adipose tissues (VAT).

Results: Compared to Chinese children, Indian children had higher odds of being in the rapid acceleration trajectory. All accelerated trajectories were associated with inflammatory marker, hsCRP.

Impact: This research has the potential to impact public health by providing evidence-based insights into the relationships between abdominal fat distribution patterns and cardiometabolic health. Our findings may aid development of targeted interventions and strategies to mitigate long-term adverse cardiometabolic consequences.

Keywords: Body, Liver, Fat and iron quantification

Motivation: Free-breathing liver fat and iron quantification is of growing interest in pediatric patients. However, motion compensation is necessary for quantification accuracy, resulting in prolonged acquisition times.

Goal(s): This study was to retrospectively evaluate a newly developed technique with XD-GRASP reconstruction in pediatric patients.

Approach: Data with oversampled k-space radial views were undersampled to fewer radial views. All data were reconstructed and compared between a self-gating method and the proposed XD-GRASP method.

Results: When applied to data with undersampled radial views, the proposed XD-GRASP method reduced image artifacts and improved PDFF and R₂^* results compared to the self-gating method.

Impact: The proposed multi-echo stack-of-radial MRI method using motion-resolved reconstruction and multi-dimensional regularization may allow accelerated free-breathing liver PDFF and R₂^* mapping in pediatric patients.

Keywords: Body, Pediatric, liver, pancreas, spleen

Motivation: Cystic fibrosis (CF) is a multi-system, life-limiting genetic disorder. There is a need for multiorgan assessment in children with CF and the response to modulator therapies.

Goal(s): To perform multiorgan MRI in children to quantify lung, liver, pancreas, spleen, and gut function.

Approach: 8 children with CF and 3 healthy volunteers (HV) performed the protocol including quantitative assessment (T₁, T₂, T₂*, fat fraction (FF), stiffness) of liver, pancreas and spleen.

Results: Increased pancreas FF, T₁ and T₂, spleen T₁ and hepatic arterial velocity in CF compared to HVs. Increased liver T₁, T₂ and stiffness in a CF child independently diagnosed with liver disease.

Impact: This protocol will be used to study the effect of the Cystic Fibrosis Transmembrane Regulator Modulator therapy in children on liver toxicity, pancreas and gut function, and lung health, by performing MRI before and 12 months after commencement of Kaftrio.

Keywords: Adolescents, Whole Body

Motivation: Our study is motivated by the need to assess abbreviated whole-body MR for evaluating treatment response in pediatric patients with lymphoma.

Goal(s): To evaluate the diagnostic efficacy and reproducibility of a novel abbreviated whole-body MRI (WB-MRI) for response assessment in pediatric patients with lymphoma.

Approach: We conducted a multicenter prospective study included pediatric patients underwent both PET/CT and abbreviated WB-MRI at baseline and during follow-up. 

Results: The image quality of abbreviated WB-MRI was rated good or excellent, with high sensitivity and accuracy.

Impact: Abbreviated WB-MRI has the advantage of being non-invasive and without radiation exposure, making it an alternative to PET/CT for response surveillance in pediatric patients.

Keywords: Body, Pediatric

Motivation: To evaluate diagnostic image quality of novel 24-channel screen-printed flexible coil array in pediatric body MR at 3T

Goal(s): Whether the diagnostic image quality of novel 24-channel screen-printed flexible coil array in pediatric body MR at 3T is comparable to commercially available coils

Approach: Retrospective case-control study with pediatric patients who underwent clinical body MR exams using either screen-printed coils or commercial coils. A single radiologist reviewed image quality using anonymized randomized image stacks.

Results: A flexible screen-printed pediatric MRI receive coil yielded similar diagnostic image quality to commercial coils on body MRI exams performed in the clinical setting.   

Impact: Screen-printed pediatric MRI receive coil yielded comparable diagnostic image quality to commercial coils on body MRI exams performed in the clinical setting on 3T scanners while offering the advantages of comfort, flexibility, and ease of use.

Keywords: Lung, Lung, Functional, Pulmonary, non-contrast-enhanced

Motivation: bSSFP-based non-contrast-enhanced imaging is a promising alternative for functional lung imaging in pediatric patients. However, bSSFP acquisitions suffer from magnetic field inhomogeneities. 

Goal(s): Our goal is to investigate phase-cycled bSSFP acquisitions as a robust alternative in pediatric functional lung imaging. 

Approach: We acquired dynamic images using conventional and phase-cycled bSSFP acquisitions at 1.5T, from five 2-year-old patients after congenital diaphragmatic hernia repair. The images were non-rigid registered to a reference frame and functional maps were obtained using dynamic mode decomposition technique. 

Results: We have successfully obtained functional maps in all patients and observed a trend toward improved ventilation map homogeneity using phase-cycled acquisitions.

Impact: Pulmonary functional maps obtained via non-contrast-enhanced bSSFP acquisitions may suffer from field inhomogeneity artifacts. Here, we investigate phase-cycled bSSFP imaging in 2-year-old congenital diaphragmatic hernia patients, and show improved robustness, which may be beneficial for lung function assessments.

Keywords: Hyperpolarized MR (Gas), MSK, Hyperpolarized MR (Gas), Dynamic Imaging, Pediatric, Signal Modeling, Skeletal, Preclinical, Lung, Flow, Analysis/Processing

Motivation: The pressing need to develop and evaluate novel treatments of thoracic insufficiency syndrome (TIS), a condition with significant implications for compromised pulmonary growth and function.

Goal(s): To gain deeper insights into the altered lung function associated with TIS, ultimately improving patient care and outcomes.

Approach: Dynamic hyperpolarized-xenon-129 MRI was used to assess ventilation and gas exchange dynamics in pre-clinical models of TIS.

Results: Significant ventilation and gas exchange delays were found in the TIS animals compared to the healthy ones.

Impact: Our findings hold the promise to improve TIS assessment and treatment monitoring by providing crucial insights into altered lung function. This study offers a valuable tool for clinicians/researchers, fostering improved patient care and stimulating further TIS management and intervention research.

Keywords: Lung, Lung, Registration, Ventilation, Free-Breathing

Motivation: A previous study showed that MR-signal-based (RVent) and deformation-based approaches (JVent) for ventilation are theoretically equivalent, but result in different defects in a digital lung model. A verification of this finding using real data is pending. 

Goal(s): Test if both ventilation parameters result in significant differences on a global and regional level.

Approach: A retrospective analysis of 32 patients with non-CF Bronchiectasis was performed, calculating RVent, JVent and corresponding ventilation defects for three registration variants.

Results: There were significant differences and patterns on a global and regional level, which are consistent with the findings in the lung model study.

Impact: Inferior-superior gradient in deformation-based ventilation measurements might lead to a biased defect detection. Therefore, use of such parameters might require further correction and/or diligent registration optimization. Thus, signal-based ventilation with more stable performance across different registration variants might be benefical. 

Keywords: Lung, Lung

Motivation: There is a scarcity of personalised computational physiology models of the paediatric lung because most models have previously been derived for the adult lung from CT images.

Goal(s): We aim to derive personalised computational models of the paediatric lung from novel structure-function lung MRI techniques.

Approach: In this feasibility study, lung ZTE MR images from healthy children were used to create finite element soft tissue deformation mechanics models. 

Results: Simulations of regional supine lung tissue densities were shown to be similar to lung ZTE MRI densities, demonstrating the strong potential for developing computational paediatric lung models from MR images.

Impact: A computational physiology model of soft tissue deformation was created from lung ZTE MR images of healthy children, demonstrating the potential of using novel regional lung structure-function information for personalised paediatric computational models.

Keywords: Rare Disease, Low-Field MRI, Acquisition Methods, Data Acquisition, Pulse Sequence Design, Lower Airway, Tracheomalacia, Lung

Motivation: Tracheomalacia involves intermittent collapse of the lower airway and is difficult to diagnose. Currently, this condition is evaluated with invasive procedures like bronchoscopy or dynamic computer tomography (CT) which utilizes ionizing radiation.

Goal(s): To develop and optimize a high spatial and temporal resolution pulse sequence for evaluating tracheomalacia at 0.55T.

Approach: We optimize contrast (sequence, flip angle) for dynamic imaging in the lower airway for both 2D and SMS real-time imaging.

Results: Spiral acquisition achieves sufficient temporal resolution and the TrueFISP sequence (flip angle=32°) offers optimal contrast for imaging lower airway collapse.

Impact: We demonstrate the feasibility of capturing lower airway collapse with 2D and SMS real-time imaging (at 0.55T) in a way that is informative to the diagnosis and longitudinal monitoring of tracheomalacia.