Evaluation of a novel flexible, lightweight blanket-like torso coil in pediatric MRI at 1.5-T - initial experience.

Improved SNR and Image Quality of Pediatric MRI with a Shape Conforming High-Density Posterior Cushion Coil

A high-density posterior cushion coil (HDPCC) can improve the SNR in pediatric MRI by conforming to the body and minimizing distance to the imaged volume when compared to a conventional rigid built-in table coil array. Posterior coil arrays built into MRI tables are mainstays but provide suboptimal performance in pediatric imaging due to their distance from the imaged volume and lower coil density. Our goal is to improve pediatric MRI by constructing a prototype 30-channel high-density posterior cushion coil (HDPCC) incorporated into a padded cushion. Twenty-five pediatric patients were scanned with the HDPCC, and twenty-five pediatric controls served as the comparison group using standard coils. Two radiologists graded image quality on a 5-point scale. SNR was measured in the right paraspinal musculature and the liver. All images obtained with the HDPCC were diagnostic (mean score 4.13/5). SNR in the superficial tissues of the paraspinal musculature was 34% higher with the HDPCC than with standard coils, while SNR in the deeper tissues of the liver was statistically similar between the two coils. HDPCC yields improved the signal-to-noise ratio in phantoms and pediatric study participants by conforming to the body.

Simultaneous 3D structural-functional assessment of pediatric lung using 0.55-T MRI: A feasibility study

Pediatric pulmonary diseases are commonly evaluated with imaging that either involves ionizing radiation or lacks regional functional information. To evaluate the feasibility of simultaneous structural and functional lung assessment in pediatric participants without radiation, contrast administration, or breath-holding. This retrospective study analyzed pediatric patients with pulmonary disease and healthy participants, who were recruited from August 2023 to December 2025 via convenience sampling and underwent awake lung MRI on wide-bore 0.55-T scanners. A prototype balanced steady-state free-precession sequence with a half-radial dual-echo readout (bSTAR) was acquired with free breathing. Respiratory-resolved 3D images were reconstructed for structural evaluation and quantitative ventilation mapping. Two pediatric radiologists independently scored image quality (robustness to motion and streak artifacts, and parenchymal signal) and the anatomic visibility of the airways and vessels using 4-point Likert scales. Inter-reader agreement of structural findings was evaluated using Cohen’s κ. Ventilation defect percentage measured by bSTAR was compared with 2D phase-resolved functional lung (PREFUL) MRI using Pearson correlation and Bland–Altman analysis. Fourteen participants (median [range] age, 11 [6—16] years; eight female) were scanned. Image quality scores ranged from 3.0 to 3.8 on Likert scales. All cases were diagnostically acceptable (artifact robustness scores ≥2), with consistent visualization of segmental airway walls and subsegmental vasculature. Structural findings, including consolidation, mucus plugging, ground-glass opacity, air trapping, bronchiectasis, and mosaic hypointensity, showed substantial inter-reader agreement (κ = 0.6–0.8). Ventilation defects measured by bSTAR correlated strongly with PREFUL (r = 0.81, p < 0.001), with 95% limits of agreement of − 18% to 23%. Simultaneous structural-functional lung imaging in a single free-breathing acquisition was feasible in this cohort of older awake pediatric participants using 0.55-T MRI, with structural images suitable for evaluating major pulmonary findings and quantitative ventilation metrics correlating strongly with PREFUL.

Development of a CT/MRI-compatible anthropomorphic multimodal deformable male pelvic phantom for end-to-end quality assurance testing in MR-guided online adaptive radiotherapy.

Fast ungated five-dimensional cardiac MRI on a 1.5 T MR-linac for MRI-guided radiotherapy

Background: Stereotactic arrhythmia radio-ablation (STAR) for patients with ventricular tachycardia is currently limited by complex cardiorespiratory motion. Current 5D-MRI motion models require long acquisition and reconstruction times, limiting clinical viability. Objective: To develop a fast, ungated 5D-MRI reconstruction method for personalized motion characterization to support MRI-guided STAR treatments. Methods: We propose a fast, ungated 5D-MRI reconstruction method based on the CMR-MOTUS framework. The method uses a 3D Cartesian acquisition with a joint optimization framework to reconstruct a motion-corrected reference image and low-rank deformation vector fields (DVFs). By exploiting the low rank structure, we explicitly disentangle respiratory and cardiac motion during optimization. Then, the DVFs are used for 5D-MRI reconstruction with a retrospectively adjustable number of motion states. Validation was performed using digital and physical cardiorespiratory phantoms. Furthermore, the approach was evaluated using 10 healthy volunteers, comparing motion consistency with 2D cine MRI. Results: Validation of 5D CMR-MOTUS using digital and physical phantoms demonstrated accurate 5D-MRI reconstruction. In the physical phantom, 5D CMR-MOTUS achieved a left-ventricle DICE of 0.96 +/- 0.01. In the volunteer cohort, the 5D-MRI scans showed strong motion to 2D cine MRI, with a cardiac motion error of 0.1 +/- 0.9 mm and a respiratory motion error of 0.2 +/- 2.9 mm. Crucially, 5D-MRI data were acquired in 1 minute and reconstructed in 6 minutes. Conclusions: The proposed 5D-MRI method enables rapid, high-quality, and personalized motion characterization, demonstrating potential for integration into MRI-guided STAR treatments. Data Availability: The 3D k-space data and 5D reconstructions for the ten volunteers are publicly available at https://doi.org/10.5281/zenodo.21278894

Canine brain imaging with a new low-field portable (0.05 T) MRI scanner: a pilot in vivo comparison to conventional 1.5 T

This pilot study successfully translated a previously developed LF MRI canine cadaver brain protocol for in vivo application and compared the acquired images with paired 1.5 T MRI images from 21 different canine patients, representing the first in vivo usage and evaluation of a 0.05 T MRI in a clinical veterinary context.

Evaluation of a modular flexible coil for thoracic outlet syndrome MRI at 3 T.