Journal of Magnetic Resonance Imaging最新文献

Background: Pancreatic damage is a common digestive system disease with no specific drugs. Static magnetic field (SMF), the key component of magnetic resonance imaging (MRI), has demonstrated prominent effects in various disease models.

Purpose: To study the effects of 0.1-9.4 T SMFs on pancreatic injury induced by alcohol, and acute pancreatitis (AP) induced by L-arginine (L-Arg).

Study type: Prospective, animal model.

Animal model: Twelve healthy C57BL/6J male mice, 30 AP model male mice, and 30 alcohol-associated liver disease (AALD) model male mice.

Field strength/sequence: 1.5-9.4 T SMFs for 12 hours and 0.1 T SMF for 72 hours. No imaging sequence was used.

Assessment: Histological analysis on AALD mice pancreas was conducted. For L-Arg-induced AP mice, their body weight, food/water consumption, open field behavior, blood analysis, as well as histological analysis, inflammatory, oxidative stress of the pancreas were measured. In vitro cellular experiments were also conducted.

Statistical tests: Data are presented as means ± SD and analyzed using the two-tailed Student's t-test or one-way analysis of variance (ANOVA) test. P values <0.05 were considered statistically significant.

Results: 1.5-7 T SMFs significantly reduced alcohol-induced pancreatic damage, increasing the structurally intact acinar area from 51.5% to 78.3%, whereas the effect of 9.4 T SMF is not obvious. 0.1 T SMF can reduce the AP mice lethality, increase the structurally intact acinar area from 31.0% to 59.7%, associated with the reduced pancreatic inflammatory responses (78.1% reduction of F4/80 and 80.0% reduction of MPO), 20.0% decreased oxidative stress and 53.2% reduced pancreatic cell apoptosis.

Data conclusion: High-field MRI may be safe for pancreatic-related diseases at the animal level. SMFs have a future potential to be developed as non-invasive and highly penetrating physical modalities for the treatment of pancreatic injury including AP.

Plain language summary: This study aims to evaluate the safety and potential therapeutic effects of moderate- to high-intensity static magnetic fields (SMFs) on mice with pancreatic injury. Their findings revealed that SMFs between 1.5 and 7 Tesla (T) helped reduce alcohol-induced pancreatic damage, while a stronger 9.4 T showed no effect. Interestingly, for mice with L-arginine-induced acute pancreatitis, a weaker 0.1 T significantly increased the area of healthy acinar cells from 31.0% to 59.7%. These results not only suggest that MRI-related SMFs are safe for pancreatic diseases in animals, but also unravel the potential of SMFs as a future treatment option for pancreatic disorders.

Evidence level: N/A TECHNICAL EFFICACY: Stage 1.

INTRAVOXEL INCOHERENT MOTION (IVIM) MRI-BASED PERFUSION FRACTION AND WATER DIFFUSION MAPS FROM THE UPPER LEG OF A YOUNG (27 YEARS) AND AN OLD (90 YEAR) SUBJECT AT REST AND AFTER DYNAMIC KNEE EXTENSION EXERCISE AT 3.25-MINUTE INTERVALS. REGIONS OF INTEREST FOR THE ACTIVE RECTUS FEMORIS MUSCLE (RED) AND FOR A PART OF THE INACTIVE ADDUCTOR MAGNUS MUSCLE (WHITE) ARE INDICATED. NOTE THE PRONOUNCED DIFFERENCE IN PERFUSION FRACTION BETWEEN THE YOUNG AND OLD SUBJECTS AFTER EXERCISE. REPRODUCED FROM ADELNIA ET AL. WITH PERMISSION FROM JOHN WILEY & SONS, INC. BY HOOIJMANS ET AL. (535-560)

Background: In arrhythmogenic cardiomyopathy (ACM), left ventricle-dominant presentation has poorer outcomes than right-dominant presentation, suggesting that interventricular functional disparity might play a role in patients' prognosis. However, the prognostic impact of ventricular functional discordance in ACM patients remains unknown.

Purpose: To assess whether ventricular functional disparity measured as ventricular discordance index, defined as the ratio of right-ventricular ejection fraction (RVEF) to left-ventricular ejection fraction (LVEF), might reveal prognostic disparities between phenotypes and offer added risk stratification value.

Study type: Retrospective.

Subjects: A total of 222 patients with ACM (mean age 44 ± 16 years, 144 males) from three centers were included.

Field strength/sequence: 3-T, cine imaging.

Assessment: Ventricular discordance index was calculated using cine-derived RVEF and LVEF, for which a threshold was determined using Youden J index. Clinically ventricular discordance was defined as ventricular discordance index above the threshold. The major adverse cardiac events (MACE), was defined as sudden cardiac death, appropriate implantable cardioverter-defibrillator intervention, and aborted cardiac arrest. International task diagnostic force criteria and the 5-year risk score were evaluated.

Statistical tests: The prognostic implications of ventricular discordance index and clinically ventricular discordance were evaluated using multivariable Cox analysis. P < 0.05 indicated the statistical significance.

Results: During a median follow-up of 50 months, 81 (37%) patients experienced MACE. The ventricular discordance index was independently associated with MACE (hazard ratio [HR]: 1.49; 95% confidence interval [CI]: 1.23-1.82). Patients classified under clinically ventricular discordance experienced higher MACE rates and were less likely to meet the task force structural criteria. clinically ventricular discordance was independently associated with MACE (adjusted HR: 2.2; 95% CI: 1.36-3.55). Clinically ventricular discordance, LV involvement and the 5-year risk score in combined reclassified 20.3% of patients compared to 2015 task force classification.

Data conclusion: Ventricular discordance was associated with MACE in ACM, potentially providing prognostic value beyond the 5-year risk score.

Level of evidence: 3 TECHNICAL EFFICACY: 5.