Reproducibility of Volumetric Analysis using Ultra-Low-Field Portable Magnetic Resonance Imaging

Ultra-Low-Field Brain MRI for Point-of-Care Applications: A Technology Review.

The recent developments in ultra-low-field brain MRI are reviewed, which enable imaging in open environments and demonstrate initial clinical applicability in point-of-care settings, and future developments are envisioned to address the current limitations of image quality and contrast in ultra-low-field brain MRI systems.

Validation of Compressed Sensing Accelerated Magnetization Prepared Rapid Acquisition Gradient Echo for Fast and Reliable Brain Volume Measurement

Objectives: To assess the clinical viability of compressed sensing magnetization, we prepared a rapid acquisition gradient echo (CS-MPRAGE) for brain volume measurement by comparing its scan time and image quality with standard MPRAGE. Methods: In this retrospective study, we analyzed a total of 40 morphologically normal MRIs from relatively young subjects (mean age 27.03 ± 5.02, range 19~40, F:M = 33:7) who underwent both CS-MPRAGE and standard MPRAGE. MRI was performed with a 3T MR scanner using a 64-channel head coil. Volumetric data analysis was conducted using commercial AI-powered quantification software. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNRgray matter/white matter) were measured and compared. Qualitative analysis based on overall image quality, deep gray matter delineation, artifacts, and gray–white matter differentiation was rated on a five-point visual scoring system. Statistical analyses included paired t-tests, intraclass correlation coefficients (ICCs) and Pearson correlation. Results: CS-MPRAGE had a significantly shorter scan time than standard MPRAGE (1:46 vs. 5:20 min; p < 0.001). Whole-brain volume was similar (standard-MPRAGE, 1176.89 ± 105.36; CS-MPRAGE, 1181.14 ± 105.62 mL; r = 0.988; ICC, 0.9754–0.9931). Gray matter and regional lobe volumes were comparable, while the white matter volume was slightly larger with CS-MPRAGE. CNR of the gray–white matter was significantly higher with CS-MPRAGE (left, 30.45 ± 11.21 vs. 49.53 ± 32.71; right, 30.73 ± 11.97 vs. 46.89 ± 30.40; p = 0.0001) while SNR were similar across key brain regions. Conclusions: CS-MPRAGE provides high-quality 3D images and reliable volume data with significantly reduced acquisition time and comparable image quality.

Current Medical Imaging

Systematic comparison of MPRAGE and BRAVO T1-weighted MRI pulse sequences and brain morphometry in high-risk young adults.

Structural MRI is widely used in psychiatric research to investigate brain morphometry, but variability in acquisition methods may influence the reproducibility of findings. In particular, differences between commonly used T1-weighted sequences such as Magnetization Prepared Rapid Acquisition Gradient Echo (MPRAGE) and Brain Volume (BRAVO) have not been thoroughly evaluated. This study examined the comparability of these sequences using a within-subject design in a sample of 115 young adults (59.13% female; mean age 20.58 ± 1.13) reporting high-risk substance use, primarily cannabis misuse. Participants underwent 3 T MRI scanning with both MPRAGE and BRAVO protocols. Scan quality was assessed according to Human Connectome Project standards, and brain morphometry was quantified using the Desikan atlas, including measures of cortical thickness, surface area, and cortical and subcortical volumes. Associations between morphometric measures and cannabis use indicators were evaluated using partial correlations. Results indicated that MPRAGE scans were rated as slightly higher in quality compared to BRAVO. Reliability of morphometric measures across sequences was very good to excellent (intraclass correlation coefficients ranging from 0.85 to 0.99), demonstrating strong overall agreement. However, systematic differences were observed in absolute estimates: BRAVO yielded higher cortical thickness values, whereas MPRAGE produced larger estimates of surface area and brain volume. Additionally, discrepancies emerged in the detection of significant associations between brain measures and cannabis use. These findings suggest that while MPRAGE and BRAVO provide broadly consistent morphometric data, sequence-dependent differences may meaningfully impact study outcomes and interpretations in neuroimaging research.

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.

Testing the reliability of novel Voxel Placement approaches for Magnetic Resonance Spectroscopy