BACKGROUND: Liver Imaging Reporting and Data System M (LR-M) lesions may appear targetoid or nontargetoid, but their clinicopathologic and prognostic differences remain unclear. PURPOSE: To compare clinical, pathological...BACKGROUND: Liver Imaging Reporting and Data System M (LR-M) lesions may appear targetoid or nontargetoid, but their clinicopathologic and prognostic differences remain unclear. PURPOSE: To compare clinical, pathological, and prognostic features of targetoid and nontargetoid LR-M lesions on dynamic contrast enhanced-MRI (DCE-MRI). STUDY TYPE: Retrospective. SUBJECTS: 119 consecutive patients (82 male, mean age = 62.9 ± 10.3 years) with 119 LR-M observations (75 targetoid, 44 nontargetoid) and at least 2 years of follow-up. FIELD STRENGTH/SEQUENCE: 1.5T and 3.0T; T2-weighted fast spin echo sequence, diffusion-weighted image, and dynamic T1-weighted-gradient-echo sequence using an extracellular contrast agent. ASSESSMENT: Three radiologists categorized lesions as targetoid or nontargetoid. Clinical, laboratory, imaging, and histopathologic data were collected. STATISTICAL TESTS: Group differences were evaluated using t-tests and chi-square/Fisher's exact tests. Survival outcomes were assessed using Kaplan-Meier method with log-rank test and Cox proportional hazards regression. Inverse probability of treatment weighting (IPTW) was applied before survival analysis. A p-value < 0.05 was considered significant. RESULTS: The nontargetoid group had significantly higher serum AFP (6684.7 ± 15,988 vs. 194.9 ± 898.4 ng/mL), larger lesion size (9.10 ± 5.55 cm vs. 3.55 ± 2.96 cm), cirrhosis (95% vs. 76%), extrahepatic disease (50% vs. 19%), and malignancy (95% vs. 82%). Nontargetoid group showed significantly higher mortality (75% vs. 41%), progression (77% vs. 45%), shorter overall survival (477 ± 629 vs. 1226 ± 1147 days), and time-to-progression (333 vs. 1003 days). On multivariable analysis with Cox proportional hazards regression, targetoid morphology was significantly associated with improved overall survival (HR = 0.28) and progression-free survival (HR = 0.36), whereas histology was not significant (HCC vs. non-HCC). DATA CONCLUSION: Targetoid morphology is significantly associated with improved survival and delayed progression, supporting its role as a prognostic imaging biomarker. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 5.
BACKGROUND: Non-contrast coronary MR angiography (CMRA) is a validated, non-invasive, radiation-free technique for coronary stenosis assessment. However, its application to myocardial bridging (MB) is limited, with large...BACKGROUND: Non-contrast coronary MR angiography (CMRA) is a validated, non-invasive, radiation-free technique for coronary stenosis assessment. However, its application to myocardial bridging (MB) is limited, with large-scale evidence for its diagnostic performance lacking. PURPOSE: To evaluate the diagnostic accuracy and morphological consistency of non-contrast CMRA for detecting MB, using photon-counting coronary CT angiography (CCTA) as the reference standard. STUDY TYPE: Retrospective. SUBJECTS: One hundred and ninety-six patients with suspected or confirmed coronary artery disease (men: 141; mean age: 62.9 ± 10.6 years) who underwent both photon-counting CCTA and CMRA. FIELD STRENGTH/SEQUENCES: 3.0T; 3D nonselective pulse non-enhanced whole-heart balanced steady-state free precession sequence. ASSESSMENT: The presence and morphology (location, length, depth, stenosis severity) of MB were assessed using both CMRA and CCTA and compared. Diagnostic performance for diagnosing MB using CMRA was calculated. STATISTICAL TESTS: Diagnostic performance was assessed using sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV); morphological characteristics of MB were compared using Bland-Altman analysis and intraclass correlation coefficients (ICC). A two-sided p < 0.05 indicated statistical significance. RESULTS: CCTA identified 92 MBs in 87 patients (44.4%; 82 single- and 5 multi-segment), and CMRA detected 89 MBs in 84 patients (42.9%; 79 single- and 5 multi-segment). CMRA had a diagnostic accuracy of 98.5%, sensitivity of 96.6%, specificity of 100%, NPV of 97.3%, and PPV of 100%. CMRA and CCTA demonstrated excellent agreement in the assessment of morphological characteristics for location (ICC = 0.98), length (ICC = 0.98), and depth (ICC = 0.98), with moderate agreement for stenosis severity (ICC = 0.71). DATA CONCLUSION: Non-contrast CMRA showed excellent diagnostic performance for MB assessment and has potential to be a feasible, non-invasive, radiation-free, and contrast-free alternative to CCTA. TECHNICAL EFFICACY: Stage 2.
BACKGROUND: In oral tongue squamous cell carcinoma (OTSCC), cervical lymph node metastasis (CLNM) reduces predicted survival by 50%. However, MRI sensitivity for occult nodal disease is only 35.7%, reflecting limited mic...BACKGROUND: In oral tongue squamous cell carcinoma (OTSCC), cervical lymph node metastasis (CLNM) reduces predicted survival by 50%. However, MRI sensitivity for occult nodal disease is only 35.7%, reflecting limited microstructural specificity. PURPOSE: To investigate whether diffusion-relaxation correlated spectroscopic imaging (DR-CSI) metrics with peritumoral extensions contribute toward the prediction of CLNM in OTSCC. STUDY TYPE: Prospective. POPULATION: 99 patients (33 female and 66 male) with pathologically confirmed OTSCC. FIELD STRENGTH/SEQUENCE: 3T; a spin-echo echo-planar DR-CSI with 35 contrasts. ASSESSMENT: Tumor-stroma ratio (TSR), density of tumor-infiltrating lymphocytes (TILs), perineural invasion (PNI) and differentiation status were determined from histology. Tumor greatest diameter and depth of invasion (DOI) were evaluated from MRI. Apparent diffusion coefficient (ADC) maps and T maps were derived from DR-CSI data. Five DR-CSI compartmental metrics in intratumoral and peritumoral regions, V-V, were calculated. STATISTICAL TESTS: Mann-Whitney U-test, Chi-square test, or Spearman correlation analysis. Multivariable logistic regression and receiver operating characteristic (ROC) analysis for diagnostic performance. Significance criteria: p < 0.05. RESULTS: 51 patients were CLNM negative. Intratumoral V in the CLNM-positive group (34.80% ± 18.51%) was significantly lower than that in the CLNM-negative group (47.86% ± 23.37%), while V (25.07% ± 12.49%) and V (22.12% ± 11.46%) in the CLNM-positive group were significantly higher than those in the CLNM-negative group. ADC and T showed no significant separation (p = 0.084, 0.493, respectively). A multivariable logistic model comprising the significant intratumoral and peritumoral DR-CSI metrics (V, V, and V) together with the morphologic variables (tumor greatest diameter and DOI) achieved an area under curve (AUC) value of 0.792 for CLNM classification, representing a non-significant improvement over the morphologic variables model alone (AUC 0.709, p = 0.069). DATA CONCLUSION: The intratumoral and peritumoral DR-CSI metrics, combined with morphologic variables, improved preoperative discrimination of nodal status in OTSCC in this single center cohort, though external validation is warranted. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 2.
BACKGROUND: Ankle cartilage is prone to degeneration due to overuse. Developing a non-invasive MRI technique to detect early running-induced lesions enables timely intervention. PURPOSE: To evaluate the value of the ultr...BACKGROUND: Ankle cartilage is prone to degeneration due to overuse. Developing a non-invasive MRI technique to detect early running-induced lesions enables timely intervention. PURPOSE: To evaluate the value of the ultrashort echo time magnetization transfer (UTE-MT) sequence in monitoring tibiotalar cartilage changes in amateur marathon runners before and after a marathon. STUDY TYPE: Prospective. SUBJECTS: Thirty amateur marathon runners (25 males, 5 females; range: 24-50 years). SEQUENCE: 3D UTE-MT (gradient-echo), 3D UTE-T2* (gradient-echo). ASSESSMENT: MRI scans at three time points: 1 week pre-marathon, 2 days post-marathon, and 4 weeks post-marathon. Medial and lateral tibiotalar cartilage was subdivided into 12 subregions, consisting of anterior, middle, and posterior segments for the tibial and talus parts on each side. The UTE-MTR and UTE-T2* values were measured per subregion at each time point. STATISTICAL TESTS: Repeated measures one-way ANOVA and the Tukey test. p < 0.05 was considered statistically significant. RESULTS: Most cartilage subregions showed decreased UTE-MTR values 2 days post-marathon and increased after 4 weeks. Significant differences in UTE-MTR over time were observed in 9 subregions, including the medial and lateral anterior, middle, and posterior tibial cartilage (MTiA, MTiM, MTiP, LTiA, LTiM, LTiP), the medial and lateral posterior talus regions (MTaP, LTaP), and the medial middle talus cartilage (MTaM). Post hoc tests revealed significant UTE-MTR decreases 2 days post-marathon in all 9 regions (Rate: MTiA: -3.9%; MTiM: -2.8%; MTiP: -3.0%; MTaP: -4.5%; MTaM: -4.2%; LTiA: -3.5%; LTiM: -4.7%; LTiP: -5.8%; LTaP: -6.8%), with significant increases in MTiA (3.7%) and MTaM (4.4%) at 4 weeks. UTE-T2* values rose in most cartilage regions at 2 days post-marathon and continued increasing at 4 weeks. Only MTiP, LTiM, and LTaM showed significant changes. DATA CONCLUSION: This study demonstrates that the UTE-MT sequence enables the quantitative assessment of dynamic changes in tibiotalar joint cartilage after a marathon. TECHNICAL EFFICACY: Stage 1.
Alsharif W, Gareeballah A, Alahmadi G
… +11 more, Iskander B, Alahmadi R, Alrehaily E, Alhazmi FH, Qurashi AA, Aldahery S, Alshamrani KM, Alahmadi A, Alshoabi S, Alsaedi A, Elkady R
BACKGROUND: Contrast administration may contribute to patient anxiety and safety concerns during magnetic resonance imaging (MRI), yet patient experiences specific to contrast-enhanced MRI (CE-MRI) examination remain und...BACKGROUND: Contrast administration may contribute to patient anxiety and safety concerns during magnetic resonance imaging (MRI), yet patient experiences specific to contrast-enhanced MRI (CE-MRI) examination remain underexplored. PURPOSE: To explore patients' experiences during CE-MRI examination, focusing on anxiety levels and safety perceptions. STUDY TYPE: Questionnaire-based study with follow-up patient interviews. SUBJECTS: Two hundred and three adult patients undergoing CE-MRI in public hospitals; 28 participated in follow up interviews. FIELD STRENGTH/SEQUENCE: 1.5 Tesla/standardized MRI scanning protocols across multiple body regions comprised 6-17 sequences per examination, with total table times ranging from 30 to 50 min, depending on the anatomical region examined. ASSESSMENT: A structured questionnaire consisted of 31 items covering demographic characteristics, scan related information, experience with the CE-MRI examination, including information received, and anxiety assessment before, during, and after the CE-MRI examination using a four-point Likert scale. Following the CE-MRI examination, 28 patients from this original cohort participated in semi-structured interviews to explore their anxiety levels and perceptions of safety during the examination. STATISTICAL TEST: Quantitative data were analyzed using SPSS, and a p value < 0.05 was considered significant. While qualitative data were analyzed thematically using NVivo software. RESULTS: Forty-six percent of patients reported increased anxiety during contrast administration, and 26.1% rated the information provided about the examination unclear. It was found that 35% felt the examination did not meet their expectations based on the information given. Anxiety was more prevalent among females (Mean = 1.71), younger patients (Mean = 2.04), and those with higher education levels (Mean = 1.96). Qualitative findings identified key anxiety triggers, including sensory discomfort, fear of unknown outcomes, and poor timing or poor clarity of information. Empathetic communication and clarity were perceived as essential anxiety-reducing factors. Notably, anxiety levels significantly decreased after the examination (χ = 24.955). DATA CONCLUSION: Anxiety levels were influenced by sex, age, education level, the provided information, and the quality of communication. EVIDENCE LEVEL: 4. STAGE OF TECHNOLOGY EFFICACY: Stage 3 (Diagnostic Thinking).
BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic autoimmune disease involving inflammation in the liver and biliary system, manifesting as biliary strictures and cholestasis, and leading to hepatic fibrosis....BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic autoimmune disease involving inflammation in the liver and biliary system, manifesting as biliary strictures and cholestasis, and leading to hepatic fibrosis. Due to variable patterns of fibrosis, precise criteria for risk stratification of these patients have yet to be determined. Elasticity-based methods are widely used to estimate the stage of liver fibrosis in PSC. PURPOSE: To review the role of different modalities of quantitative elastography in relation to the clinical and fibrosis biomarkers of PSC for the diagnosis and prognosis of this disease. STUDY TYPE:SYSTEMATIC REVIEW: Population or subjects or phantom or specimen or animal model: We conducted a systematic review, adhering to the PRISMA guidelines, and searched PubMed and found 24 articles on the performance of elastography techniques in PSC. ASSESSMENT: We qualitatively evaluated methodological limitations including patient selection, reference standard, elasticity acquisition protocols, and outcome definitions. STATISTICAL TESTS: N/A. RESULTS: Based on our review, magnetic resonance elastography (MRE) performs better than vibration controlled transient elastography (VCTE), point shear-wave elastography (p-SWE), and acoustic radiation force impulse (ARFI) in prediction of poor clinical outcomes in patients with PSC. MRE, an operator-independent technique, estimates liver stiffness by averaging nearly the total liver volume. Compared with ultrasound-based elastography, MRE has a lower technical failure rate in assessment of liver fibrosis. Liver stiffness determined by MRE is also correlated with clinical scores such as Primary Sclerosing Cholangitis Risk Estimate Tool (PREsTo) and Mayo Risk Score (MRS) in patients with PSC. DATA CONCLUSION: Of the elastography methods reviewed, MRE appears to be a preferred modality for staging liver fibrosis and risk stratification of patients with PSC, whereas ultrasound-based techniques like VCTE are more accessible but might be less accurate. Further studies are warranted to assess the diagnostic and prognostic performance of the various elastography techniques in patients with PSC. TECHNICAL EFFICACY STAGE: 5.
BACKGROUND: One manifestation of multiple sclerosis (MS) is abnormal iron-related susceptibility changes in deep gray matter (DGM), contributing to oxidative stress and neurodegeneration. Intermittent fasting (IF) is a m...BACKGROUND: One manifestation of multiple sclerosis (MS) is abnormal iron-related susceptibility changes in deep gray matter (DGM), contributing to oxidative stress and neurodegeneration. Intermittent fasting (IF) is a metabolic intervention that may influence inflammatory and iron-related pathways. PURPOSE: To compare susceptibility-derived phase values in DGM between fasting and non-fasting periods in patients with MS. STUDY TYPE: Retrospective observational cohort study. POPULATION: 36 patients with MS were studied: a fasting group (n = 20; mean age 33.1 ± 9.6 years; 14 males), a non-fasting control group (n = 14; mean age 34.9 ± 10.8 years; 10 males), and two cases with additional measurements. FIELD STRENGTH/SEQUENCE: 1.5 T; Echo Planar Susceptibility-Weighted Imaging (EPI-SWI). ASSESSMENT: Paramagnetic mean phase values (pMPVs) were measured in nine bilateral DGM regions at 2 time points separated by a 1-year interval. STATISTICAL TESTS: Paired and independent t-tests were used to analyze phase value changes; a p-value of less than 0.05 was considered statistically significant. RESULTS: Inter-rater reliability was high (ICC = 0.91). The fasting group had lower pMPVs at the second time compared to the first (48.91 ± 10.45 vs. 38.38 ± 11.23; mean difference -10.53; 95% CI: -13.28 to -7.78), with consistent reductions across all subregions. The non-fasting group showed the opposite pattern (45.42 ± 19.98 vs. 52.99 ± 21.05; 95% CI: 4.71 to 10.43), while bilateral thalamic values remained stable (left p = 0.104; right p = 0.938). Serial case studies are associated with temporal patterns in pMPVs during fasting and non-fasting intervals. DATA CONCLUSION: Measurements during fasting periods were associated with lower pMPVs in DGM in multiple sclerosis compared to non-fasting periods. TECHNICAL EFFICACY: Stage 3.
Aalbregt E, Stehling W, Schrauben EM
… +7 more, van Schuppen J, Meijboom LJ, Takx RAP, Nederveen AJ, van Ooij P, Jongkind V, Yeung KK
J Magn Reson Imaging
· 2026 May · PMID 41670165
·
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BACKGROUND: 4D flow MRI-derived parameters such as wall shear stress (WSS) may improve abdominal aortic aneurysm (AAA) progression prediction. Validation of this biomarker is needed, but longitudinal data are lacking. PU...BACKGROUND: 4D flow MRI-derived parameters such as wall shear stress (WSS) may improve abdominal aortic aneurysm (AAA) progression prediction. Validation of this biomarker is needed, but longitudinal data are lacking. PURPOSE: Investigate longitudinal WSS changes and associations with AAA morphology. STUDY TYPE: Prospective. SUBJECTS: Fifteen patients (mean age 68.7 ± 8.9 years; 1 female) with AAA > 30 mm in diameter. FIELD STRENGTH/SEQUENCE: 3.0 T, 4D flow MRI, 3D cine balanced steady state free precession, and Dixon. ASSESSMENT: Patients had baseline and follow-up MRI studies, separated by 6 months. A previously developed automated post-processing 4D flow MRI software was utilized to assess WSS, total lumen, and thrombus volumes. Maximum diameter in the anteroposterior (AP) and left-right (LR) directions was measured by three radiologists (with 13, 12, and 3 years of experience) based on the Dixon MRI at both time-points. Statistically significant growth was defined as an increase exceeding twice the standard error of the measurement. Baseline and follow-up 3D WSS maps were visually compared to identify potential temporal differences. STATISTICAL TESTS: The Wilcoxon signed-rank test was applied to evaluate differences in diameter, volume, and WSS measurements between baseline and follow-up. Spearman's rank correlation coefficients were calculated to assess correlations between (half-year change in) WSS values and AAA diameter and volumes. RESULTS: Maximum AAA diameter increased significantly from baseline to follow-up. Also, a significant difference was observed in maximum peak WSS between baseline and follow-up. A significant inverse correlation was observed between the change in minimum peak WSS and AAA lumen volume over follow-up. Visual assessment of WSS maps may improve 4D flow-based AAA surveillance by identifying localized changes. DATA CONCLUSION: Maximum AAA diameter increased over the study period. Changes in WSS were inversely associated with changes in AAA lumen volume over follow-up but not with maximum AAA diameter. Longer follow-up is needed to assess the potential of WSS as a biomarker for AAA progression. EVIDENCE LEVEL: Level 2. TECHNICAL EFFICACY: Level 3.
BACKGROUND: Intratumoral fibrosis influences treatment efficacy and prognosis of rectal cancer (RC). The roles of MR elastography (MRE) and Virtual MRE (VMRE) remain unclear in assessing it in RC. PURPOSE: To evaluate MR...BACKGROUND: Intratumoral fibrosis influences treatment efficacy and prognosis of rectal cancer (RC). The roles of MR elastography (MRE) and Virtual MRE (VMRE) remain unclear in assessing it in RC. PURPOSE: To evaluate MRE for assessing intratumoral fibrosis in RC, identify optimal b-values for VMRE, and compare their diagnostic performance. STUDY TYPE: Prospective cohort. POPULATION: A total of 71 participants with pathologically confirmed RC (47 men; mean age, 62 ± 10 years). FIELD STRENGTH/SEQUENCES: 3T, T2-weighted turbo-spin echo, contrast-enhanced T1-weighted gradient-recalled echo, Intravoxel incoherent motion (IVIM) (b = 0, 100, 200, 1000, 1500 s/mm), and spin-echo MRE. ASSESSMENT: All participants were divided at a 7:3 ratio: subgroup 1 (N = 49) determined the optimal b-value combination and established the empirical relationship between shifted apparent diffusion coefficient (sADC) and VMRE (Vc, Vφ) based on IVIM, with MRE (c, φ) as reference; subgroup 2 (N = 22) validated this relationship. MRE and VMRE evaluated intratumoral fibrosis in 43 surgically diagnosed participants. STATISTICAL TESTS: Receiver operating characteristic (ROC), Pearson correlation, DeLong test. Bonferroni-adjusted p < 0.05 indicated statistical significance. RESULTS: The optimal combination of b-values was 0 and 1500 s/mm (r = -0.808, r = -0.644) for VMRE in subgroup 1. In 43 surgically diagnosed participants, area under curves (AUCs) of c and φ for assessing intratumoral fibrosis were 0.779 and 0.684, respectively (Adjusted p = 0.828). AUCs of Vc and Vφ converted from sADC values were 0.792 and 0.784, respectively (Adjusted p > 0.999). No significant differences in AUCs were observed among all parameters (Adjusted p: 0.384 to > 0.999). Sensitivity and specificity ranges of MRE and VMRE were 85.7%-90.5% and 54.5%-68.2%, respectively. DATA CONCLUSIONS: MRE was used to evaluate intratumoral fibrosis in RC. The optimal b-values combination for VMRE in RC was 0 s/mm and 1500 s/mm. No significant difference was observed for assessing intratumoral fibrosis between MRE and VMRE. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 2.
BACKGROUND: Noninvasive detection of chronic pancreatitis (CP) is important for proper treatment and prevention of severe pain and pancreatic insufficiency. PURPOSE: To evaluate if Tρ MRF is significantly different in he...BACKGROUND: Noninvasive detection of chronic pancreatitis (CP) is important for proper treatment and prevention of severe pain and pancreatic insufficiency. PURPOSE: To evaluate if Tρ MRF is significantly different in healthy volunteers and patients with CP. STUDY TYPE: Prospective. POPULATION: Seventeen healthy volunteers (9 male, mean age: 38.0 ± 6.7 years) and 20 patients (12 male, mean age: 53.6 ± 6.4 years) who were clinically diagnosed with CP. FIELD STRENGTH/SEQUENCE: 3 T, Tρ MRF acquired during breath-hold (BH-MRF) and free breathing (FB-MRF), conventional T/T mapping sequences. ASSESSMENT: Mean T/T/Tρ values in the whole pancreas were compared between diagnosed CP patients and controls. The Cambridge classification (CC) score was used to divide patients into mild-moderate (CC = 1-3) and severe (CC = 4) CP subgroups. T, T, and Tρ relaxation maps were generated from both breath-hold (BH) and free-breathing (FB) MRF data. STATISTICAL TESTS: Mixed effects models were calculated for healthy control versus CP, and between mild-moderate and severe CP. Receiver operator characteristic (ROC) curves were analyzed and areas under the curves (AUCs) were calculated. A p-value < 0.05 was considered significant and multiple comparison corrections were applied. RESULTS: BH-MRF T/T/Tρ values were significantly higher in the CP group (1327.3, 48.6, 49.1 ms) compared to healthy controls (821.6, 41.6, 39.5 ms) with AUCs of 0.994, 0.873, and 0.862, respectively. The MRF BH T/T/Tρ values of mild-moderate CP (N = 7) and severe CP (N = 13) patients were also significantly higher compared to healthy controls. T was significantly higher in severe CP compared to mild-moderate CP (1497 and 1012.1 ms, respectively) with AUC = 0.945. FB MRF T relaxation times demonstrated good correlation with BH values (0.981), while T and Tρ had moderate correlations (0.507 and 0.697, respectively). DATA CONCLUSIONS: T, T, and Tρ relaxation times have potential for noninvasively assessing CP. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 2.
BACKGROUND: P magnetic resonance spectroscopy (P-MRS) allows non-invasive assessment of mitochondrial function by quantifying metabolites of energy and phospholipid metabolism, but the association between these metabolic...BACKGROUND: P magnetic resonance spectroscopy (P-MRS) allows non-invasive assessment of mitochondrial function by quantifying metabolites of energy and phospholipid metabolism, but the association between these metabolic alterations and motor laterality in Parkinson's disease (PD) remains unknown. PURPOSE: To investigate the association between mitochondrial dysfunction and motor symptom lateralization in PD using P-MRS. STUDY TYPE: Retrospective. POPULATION: 34 PD patients with left-sided predominance (LPD; 20 M/14 F), 35 PD patients with right-sided predominance (RPD; 16 M/19 F), and 43 healthy controls (HCs; 20 M/23 F). FIELDSTRENGTH/SEQUENCE: 3T; 3D T1-weighted gradient-echo and 2D FID-based chemical shift imaging sequences. ASSESSMENT: P-MRS spectra from bilateral putamen, frontal, and temporoparietal cortices were quantified for adenosine triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi), phosphomonoesters (PME), and phosphodiesters (PDE). Metabolite levels were corrected for cerebrospinal fluid (CSF) partial volume effects. Metabolic ratios and laterality indices (LIs) were calculated and correlated with motor symptom LIs. STATISTICAL TESTS: General linear models, spearman's rank correlation, and receiver operating characteristic (ROC) analysis. p < 0.05 was considered statistically significant. RESULTS: RPD patients exhibited significantly elevated ATP (0.181 ± 0.005) and reduced PCr/ATP (0.979 ± 0.033) in the left putamen compared to HCs (0.164 ± 0.004; 1.098 ± 0.030); they also showed a significantly lower frontal PDE LI (-0.069 ± 0.022), higher temporoparietal Pi LI (0.086 ± 0.039), and reduced PCr/Pi LI (-0.106 ± 0.041) relative to LPD patients (-0.019 ± 0.022; -0.075 ± 0.040; 0.047 ± 0.042). In the temporoparietal cortex, the LIs of PCr/Pi (r = 0.260), PME/PDE (r = 0.323), and Pi (r = -0.315) were significantly correlated with the LIs of UPDRS-III scores. The Pi LI in the temporoparietal cortex showed a promising ability to distinguish LPD from RPD patients (AUC = 0.709). DATA CONCLUSION: Asymmetrical mitochondrial dysfunction, detected by P-MRS, correlates with motor symptom laterality in PD. These metabolic asymmetries may serve as the underlying basis for symptom lateralization. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 1.
J Magn Reson Imaging
· 2026 May · PMID 41645687
·
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BACKGROUND: Current reference standards for measuring gastric emptying and motility are not considered optimal due to the time required, ionizing radiation, invasiveness, and spatial resolution. PURPOSE: To assess gastri...BACKGROUND: Current reference standards for measuring gastric emptying and motility are not considered optimal due to the time required, ionizing radiation, invasiveness, and spatial resolution. PURPOSE: To assess gastric motility using novel real-time dynamic magnetic resonance imaging in combination with static measurements for gastric emptying and training of an automated deep-learning-based segmentation pipeline. STUDY TYPE: Prospective. PARTICIPANTS: The study included 36 healthy volunteers (20 female, mean 24 ± 3 years) and three patients with diagnosed Crohn's disease. FIELD STRENGTH/SEQUENCES: Participants ingested water to assess fasting motility and pineapple juice for the postprandial state. 3 T, 3D spoiled gradient echo (GRE) sequence and real-time spoiled GRE. ASSESSMENT: Gastric emptying was measured by using the gastric volume, while motility was analyzed by tracking changes in the antrum's cross-sectional area and applying Fast Fourier Transformation. Segmentations were performed using a trained semantic segmentation model. STATISTICAL TESTS: Linear Mixed Model with continuous dependent variables and fixed effects. Models included a random intercept for participants. Statistical significance was defined as p = 0.05. RESULTS: The method enabled volumetric analysis of gastric content from 3D breath-hold static acquisition and time-resolved quantification of peristaltic parameters from real-time FLASH2 imaging at high temporal resolution (here 6.24 fps). Water emptied rapidly and exponentially (t = 14.77 ± 10.55 min), while juice showed slower emptying (t = 64.24 ± 11.87 min). Contraction frequencies (fasted: 2.76 ± 0.43 cpm, fed: 2.89 ± 0.43 cpm) and velocities (fasted: 1.67 ± 0.38 mm/s, fed: 1.72 ± 0.37 mm/s) were within physiological ranges, with fasting conditions characterized by stronger occlusion compared to the fed. Measurements taken from three patients proved that the workflow could be used in a clinical context. DATA CONCLUSION: Real-time MRI with AI-based analysis enabled quantitative assessment of gastric emptying and motility, revealing physiological peristaltic parameters and state-dependent differences in occlusion. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 1.