These findings provide quantitative baseline data for normal renal vasculature and support further clinical validation of NC-MRA protocols in patients with renal artery disease or contraindications to gadolinium-based contrast agents.
Abstract
This within-subject study compared non-contrast renal MRA (NC-MRA) at 1.5 T, 3 T and 5 T via comprehensive quantitative and subjective imaging assessments, and further explored imaging disparities between standard and high-resolution 5 T sequences.
Thirty-nine healthy volunteers underwent standardized same-day non-contrast MRA scans across the three magnetic field strengths; both standard and high-resolution protocols were implemented on the 5 T scanner. Quantitative parameters including apparent signal-to-noise ratio (aSNR), apparent contrast-to-noise ratio (aCNR) and vessel sharpness were calculated using the erector spinae muscle as the local noise reference, an approach intended to reduce g-factor related noise bias between different scanners. Two senior radiologists performed subjective image scoring independently as blinded readers. All images were fully anonymized by removing scanner and sequence identifiers, and the presentation order of image datasets was randomly rearranged for each reviewer to minimize potential reading bias.
Statistically significant inter-group differences were detected for all quantitative indicators (all
p
< 0.05). The 5 T standard protocol yielded the highest median aSNR and aCNR values, while the 5 T high-resolution sequence achieved optimal vessel sharpness and clearer visualization of distal subsegmental renal branches. Both 5 T protocols were superior to 1.5 T and 3 T sequences in terms of artifact suppression, vascular contour delineation and subjective diagnostic confidence.
The two tested 5 T NC-MRA protocols were associated with improved image-quality metrics and artifact scores in healthy volunteers. These findings provide quantitative baseline data for normal renal vasculature and support further clinical validation of NC-MRA protocols in patients with renal artery disease or contraindications to gadolinium-based contrast agents.
BACKGROUND
Detection of the small coronary branches using 5T Dixon (5TDixon) sequence, analysis of visualization and performance comparison with 3T Dixon (3TDixon) sequence.
MATERIALS AND METHODS
A prospective study was conducted involving 22 healthy adult volunteers (mean age, 25 years ± 3 [SD]; twelve male participants) who underwent navigator-gated three-dimensional MR angiography at both 5TDixon and 3TDixon. The visualization rates, image quality scores and visualized lengths of the small coronary branches were quantitatively compared between 5TDixon and 3TDixon sequences.
RESULTS
The 5TDixon sequence demonstrated superior performance to the 3TDixon sequence, yielding a significantly shorter scan time (10.01 ± 3.17 min vs. 13.71 ± 3.36 min, P = 0.002), a significantly higher SNRRCA-pro (76.08 ± 13.68 vs. 29.08 ± 6.63, P < 0.001) and a significantly higher CNRRCA-pro (72.25 ± 14.48 vs. 24.72 ± 5.72, P < 0.001).The visualization rates of the right anterior ventricular branch, acute marginal branch, and atrioventricular nodal artery were significant higher at 5TDixon compared with 3TDixon, whereas no statistically significant differences were observed for the conus branch, sinoatrial nodal artery and the anterior septal artery. Score of image quality of small coronary branches was higher for 5TDixon compared with 3TDixon (all P < 0.05). Among paired visible branches, 5TDixon generally demonstrated longer visualized vessel segments than 3TDixon, while length result for atrioventricular nodal artery was reported descriptively because of very small paired sample sizes.
CONCLUSION
5T Non-contrast Dixon Whole-Heart Coronary MR Angiography provides an effective tool for visualizing small coronary branches and demonstrates superior performance compared with 3T.
Runzhi Zhang, Chuangwei Wei, Yan Xu et al.· BMC Medical Imaging· 0 citations
To demonstrate the diagnostic value of CE-T2 FLAIR sequence in addition to CE-T1WI in MR imaging of intracranial pathologies. The CE-T2 FLAIR sequence is not widely utilised, but if included in standard MR acquisition protocols, it might enhance patient care by increasing diagnostic sensitivity and facilitating early diagnosis before an invasive CSF sample is obtained. A total of 64 patients underwent Gadolinium contrast-enhanced MRI of the brain on uMR Omega 3.0 T. A hospital-based diagnostic validity study was conducted for one year, from 2024 to 2025, at a tertiary care teaching hospital. Intravenous contrast was given in the form of Gadolinium dimeglumine (0.5 mmol/ml). All patients who were referred for a contrast-enhanced brain MRI to rule out meningeal or parenchymal pathology were included in the study. A mean age of 43.14 years with a standard deviation of 20.84 years, reflecting a broad age distribution, was considered in the study. On T1WI, hypointense (60.9%) and isointense (20.3%) findings were the most frequent. On T2WI, heterogeneous (29.7%) and hyperintense (65.6%) findings were the most frequent. 73.4% of lesions had post-contrast enhancement on T1WI. 90.6% of the lesions showed enhancement on the post-contrast T2 FLAIR sequence, with superior background-lesion contrast and distinctive perilesional oedema in the latter sequence. Post-contrast T2 FLAIR, as a more sensitive imaging sequence, was supported by its superior ability to detect modest enhancement and define lesion borders. CE T2 FLAIR might improve diagnostic accuracy and facilitate prompt clinical decision-making if included in standard neuroimaging protocols.
Hemlata Sarkar, Sibani Patro, Neekita Meher et al.· The Egyptian Journal of Radi...· 0 citations
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.
Xin Miao, N. Lee, HaiThuy N. Nguyen et al.· Radiology Advances· 0 citations
Accelerated 2D DL, 3D Cube, and 3D qDESS protocols demonstrated diagnostic agreement and diagnostic image quality comparable to the conventional knee MRI protocol while reducing scan time to ~ 6 min.
Ananya Goyal, J. MacKay, M. Petterson et al.· Skeletal Radiology· 0 citations
This prospective study aimed to evaluate the feasibility of magnetic resonance (MR) sialography in dogs, compare image quality between 1.5 and 3 T scanners, and assess the effect of fat suppression (FS). Five healthy beagle dogs underwent MR imaging (MRI) at both field strengths using three-dimensional (3D) fast spin-echo (FSE) and 3D FSE-FS sequences. Qualitative (four-point scoring of visibility and delineation) and quantitative (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) assessments were performed for each salivary duct. Interobserver agreement was near-perfect (κ = 0.861; 95% confidence interval, 0.833-0.890). Qualitatively, the mandibular salivary duct was well visualized at both field strengths, whereas the sublingual salivary duct was reliably visualized only at 3 T (p = 0.031). The parotid salivary duct showed improved delineation at 3 T (p = 0.031), and the zygomatic salivary duct tended to improve visibility and delineation at 3 T. Quantitatively, the mandibular salivary duct showed increased SNR and significantly higher CNR at 3 T (p = 0.031). FS had no significant qualitative effect but increased CNR at 3 T for the mandibular, sublingual, and parotid ducts (p = 0.031). MR sialography is a feasible method for evaluating salivary ducts in dogs, with 3 T MRI providing superior visualization of small ducts such as the sublingual salivary duct. These findings indicate that MR sialography may be valuable for assessing the mandibular-sublingual salivary duct complex, a common site of salivary diseases in dogs, and may provide a normal reference for future studies on salivary gland diseases in dogs.
Seul-Bit Shin, Nohwon Park, Y. Jung et al.· Veterinary Radiology & Ultra...· 0 citations
