Abstract Background Phase-resolved functional lung magnetic resonance imaging (PREFUL-MRI) enables simultaneous, free-breathing, radiation-free assessment of regional lung perfusion and ventilation. This study aimed to provide preliminary reference data for lung perfusion and ventilation using PREFUL-MRI in healthy adults, and to characterize the physiological dependencies of these metrics on two breathing patterns, sex, and age. Methods In this prospective observational study, 87 healthy adults underwent PREFUL-MRI at 1.5 T during both normal and deep-slow breathing. Perfusion- and ventilation-related metrics were quantified via an automated pipeline. Paired comparisons between breathing states were performed using Wilcoxon signed-rank tests; unpaired comparisons between sexes and age groups (< 45 vs. ≥45 years) used Mann–Whitney U tests, with Holm–Bonferroni and Benjamini–Hochberg false-discovery-rate corrections applied to control for multiple comparisons. Results Mean perfusion (7.7% vs. 6.0%, Holm-Bonferroni adjusted p < 0.001) and ventilation defects (8.6% vs. 5.1%, Holm-Bonferroni adjusted p = 0.010) were decreased, and mean ventilation (15.8% vs. 48.3%, Holm-Bonferroni adjusted p < 0.001) and perfusion defects (1.9% vs. 7.9%, Holm-Bonferroni adjusted p = 0.005) increased during deep breathing compared with normal breathing. Twenty-eight participants had increased lung perfusion while 59 had reduced perfusion during deep breathing relative to normal breathing. During normal breathing, men exhibited higher mean ventilation than women (20.2% vs. 14.2%, Holm-Bonferroni adjusted p = 0.018). During deep breathing, men demonstrated higher total perfusion defect percentage and matched ventilation-perfusion defects than women (FDR adjusted q < 0.05). Total perfusion defect percentage was lower in participants aged ≥ 45 years than in those aged < 45 years (1.8% vs. 2.7%, FDR adjusted q = 0.036). Mean flow-volume loop correlations were similar between breathing patterns, sexes, and age groups after multiple comparison correction ( p > 0.05). Conclusions PREFUL-MRI can captures physiological variations related to breathing pattern, sex, and age in healthy adults. These findings provide a framework for distinguishing normal physiological heterogeneity from pathological change in clinical PREFUL-MRI interpretation. Clinical trial number Not applicable.

PURPOSE:To evaluate the quantitative performance of Phase-Resolved Functional Lung Magnetic Resonance Imaging (PREFUL-MRI) versus ventilation/perfusion (V/Q) single photon emission computed tomography (SPECT) and compare their correlations with invasive hemodynamics in pulmonary vascular diseases (PVDs). METHODS:This study retrospectively included adult PVD patients who underwent PREFUL-MRI on a 1.5 Tesla MRI and V/Q SPECT within three days from a prospective PVD cohort. Quantitative perfusion parameters including PREFUL-derived perfusion defect percentage (QDPexclusive) and SPECT-derived quantitative pulmonary perfusion defect percentage scores (QPPDs) were compared between groups (with and without pulmonary hypertension [PH]), assessed for inter-method agreement, and correlated with hemodynamic parameters from right heart catheterization. RESULTS:A total of 76 adult patients (41 female; median age, 53 years) were included (52 with PH and 24 without PH). Both modalities differentiated PH from non-PH patients significantly (QPPDs: 30.6% vs. 18.2%, p = 0.001; QDPexclusive: 38.4% vs. 14.1%, p < 0.001). QDPexclusive showed moderate correlation with QPPDs (r = 0.430, p < 0.001) and negligible mean bias (-2.97%). Notably, QDPexclusive exhibited stronger correlations with mean pulmonary arterial pressure (r = 0.553) and pulmonary vascular resistance (r = 0.595; both p < 0.01) than QPPDs (r = 0.298 and 0.301, both p < 0.05). CONCLUSION:PREFUL-MRI is a valid, radiation-free functional imaging method for assessing perfusion defects in PVDs. The stronger correlation with hemodynamics indicates that PREFUL-MRI provides enhanced physiological insight and may be more suitable for monitoring disease severity in patients with PVDs.

Purpose To evaluate the feasibility, efficiency, and diagnostic concordance of a full comprehensive free-breathing cardiac MRI protocol. Materials and Methods In this prospective study conducted between June 2024 and August 2024, free-breathing and breath-holding MRI acquisitions were compared across all sequences using a 3.0-T scanner. Outcomes included scanning time, image quality, left ventricular (LV) functional parameters, and tissue characterization. Paired comparisons between free-breathing and breath-holding acquisitions were performed using matched-pairs Wilcoxon tests or t tests as appropriate. Results In this analysis of 605 participants (mean age ± SD, 48 years ± 17; 422 male), the full free-breathing cardiac MRI protocol reduced scanning duration compared with breath-holding techniques (20.9 minutes ± 3.1 vs 34.4 minutes ± 7.5; P < .001); free-breathing cine, T1 mapping, and late gadolinium enhancement (LGE) acquisitions achieved 54%, 28%, and 33% time reductions, respectively. Free-breathing cardiac MRI consistently achieved diagnostic image quality: Cine had a slightly lower score (4 [IQR, 4-4] vs 5 [IQR, 4-5]; P < .001), whereas T1/T2 mapping and flow showed similar scores of 5 (P > .05). LGE scores were higher with free-breathing (5 [IQR, 5-5] vs 5 [IQR, 4-5]; P < .001). Interobserver agreement was strong (κ = 0.80-0.93). Compared with the breath-holding measurement, free-breathing LV end-diastolic volume and LV end-systolic volume were higher (189.94 mL ± 84.74 vs 192.92 mL ± 86.32, P < .001; 104.99 mL ± 83.14 vs 108.52 mL ± 84.45, P < .001, respectively), whereas LV ejection fraction was lower (50.01% ± 17.93 vs 48.92% ± 17.66, P < .001), with excellent agreement between methods (intraclass correlation coefficient, 0.98-0.99). Native T1 values and LGE mass were slightly higher with free-breathing (P ≤ .001) but remained in excellent agreement with breath-holding methods. Conclusion Full free-breathing cardiac MRI reduced scanning duration while maintaining diagnostic image quality and strong agreement with breath-holding techniques across all sequences. Keywords: Cardiac MRI, Free-breathing, Breath-holding, Cardiac Imaging Supplemental material is available for this article. © RSNA, 2026.

The pathophysiological changes of lung perfusion and ventilation in fibrosing interstitial lung diseases (F-ILD) remain inadequately characterized. This study aimed to analyze lung perfusion and ventilation characteristics in F-ILD patients using phase-resolved functional lung magnetic resonance imaging (PREFUL MRI) as well as their correlation with the severity of F-ILD. This cross-sectional study prospectively included 30 patients diagnosed with F-ILD (19 males, 64.6 ± 9.5 years) and 30 age- and sex-matched normal controls. All participants underwent PREFUL MRI as well as pulmonary function tests. High-resolution CT (HRCT) was performed for the patient cohort. Ventilation and perfusion-related parameters obtained from PREFUL MRI were analyzed and correlated with PFTs and fibrotic lesions identified on HRCT. Compared with normal controls, F-ILD patients showed significant differences in mean perfusion (7.55

To assess whether phase-resolved functional lung MRI (PREFUL-MRI) can differentiate pulmonary arterial hypertension (PAH) from chronic thromboembolic pulmonary hypertension (CTEPH) and to compare PREFUL-derived perfusion and ventilation characteristics between the two entities. In this single-center study (January 2024–March 2025), patients with pulmonary hypertension (PH) who underwent PREFUL-MRI, ventilation/perfusion single-photon emission CT/CT (V/Q SPECT/CT), and right-heart catheterization within 1 week were retrospectively enrolled. PREFUL-MRI was acquired with a free-breathing fast spoiled gradient echo sequence to generate perfusion and ventilation maps. PREFUL maps and V/Q SPECT/CT were assessed by four blinded readers. Quantitative PREFUL parameters were compared between PAH and CTEPH, and correlations with hemodynamics were analyzed. Fifty-three PH patients were included (PAH 26, CTEPH 27). All manifested multiple perfusion defects on PREFUL maps. Visual assessment with PREFUL yielded 70

BACKGROUND:Automation in cardiovascular magnetic resonance (CMR) scans holds the potential to improve examination efficiency and workflow consistency. Prospective clinical evidence validating automated scan workflows in routine CMR practice remains limited. METHODS:In this prospective randomized study, consecutive patients referred for non-stress CMR were assigned to either an automated or a manual free-breathing scanning workflow. The fully automated workflow integrated automated plane prescription of multiple steps required for successful image acquisition. The primary endpoint was total examination time; secondary endpoints included plane prescription accuracy, image quality scores, scanner idle time, and technologist workload. RESULTS:Of 255 screened patients, 221 were included (automated, n = 109; manual, n = 112). All examinations were diagnostically adequate. The automated and manual workflows showed a similarly low incidence of plane prescription misalignment, corresponding to 19.3% (21/109) and 17.9% (20/112) misalignment events per examination, respectively, with no significant difference between groups (0.19 vs. 0.18 events per examination, P = 0.780). No significant differences were observed across imaging planes or technologist experience levels, and image quality scores were comparable between workflows (2.74 ± 0.67 vs. 2.69 ± 0.70, P = 0.547). However, the automated scanning workflow significantly reduced total examination time (19.16 ± 2.32 vs. 21.25 ± 2.25 min, P < 0.001) and scanner idle time (7.80 ± 1.80 vs. 10.12 ± 2.03 min, P < 0.001), with consistent savings across all experience levels. Operator workload was also substantially lower with automated scanning, evidenced by fewer mouse clicks and keystrokes (both P < 0.01). CONCLUSIONS:An automated CMR scanning workflow improves examination efficiency and reduces operator workload without compromising image quality or plane prescription accuracy, supporting its integration in routine clinical CMR practice.

ObjectiveTo analyze the clinical and genetic features of oculopharyngodistal myopathy (OPDM) patients and compare the phenotypic differences among various causative genes.MethodsA total of 65 genetically confirmed OPDM patients from 43 unrelated families, who were admitted to the Department of Neurology, Peking University First Hospital between January 2008 and December 2025, were retrospectively included.The general demographic data, clinical manifestations, laboratory/auxiliary examinations, muscle pathology, and genetic test results were systematically collected and analyzed. The clinical and pathological characteristics among different OPDM subtypes were compared.ResultsAmong the 65 patients(39 male and 26 female), the mean age of onset was (31.20±10.43) years (range: 14 to 63 years). The initial symptom was predominantly distal limb weakness (67.44%), which gradually progressed to involve the extraocular muscles, pharyngeal muscles, facial muscles and proximal limb muscles. Serum creatine kinase levels were mildly to moderately elevated. Muscle pathological examinations revealed rimmed vacuoles and intranuclear inclusions (within muscle fibers). The mean duration from onset to diagnosis was (12.33±7.88) years (range: 1 to 32 years). All probands had negative results on conventional next-generation whole-exome sequencing; pathogenic variants were identified through third-generation long-read sequencing or OPDM-targeted repeat-primed polymerase chain reaction(RP-PCR). Among the 43 families, OPDM2 subtype was the most common genetic subtype (n=25), followed by OPDM4 subtype (n=8), OPDM3 subtype (n=6), OPDM1 subtype (n=3), and OPDM5 subtype (n=1). All OPDM probands subtypes were highly similar in age at onset and muscle pathological changes. However, OPDM3 subtype may be complicated by cerebral white matter lesions and other extra-muscular organ involvement. The proportion of OPDM4 patients who developed distal limb weakness only after 10 years of disease onset(40.0%) was significantly higher than that of other subtypes (all 0.0%, P=0.0122).ConclusionsOPDM2 was the predominant subtype in this study. All subtypes share similar age of onset and muscular pathological changes, yet exhibit distinct disease progression patterns. Future multicenter prospective cohort studies are warranted to further elucidate the clinical characteristics, pathogenetic mechanisms, and prognostic differences among OPDM subtypes.

BACKGROUND:Artificial intelligence (AI)-assisted assessment of left ventricular ejection fraction (LVEF) has been increasingly adopted in clinical practice. In this study we aimed to assess the reliability and reproducibility of AI-assisted LVEF assessment in a diverse, real-world, multicentre setting. METHODS:We conducted a retrospective multicentre study involving 354 cardiac magnetic resonance examinations. A standardized LVEF reassessment (M-LVEF) was performed using QMass 8.1 (Medis Medical Imaging, Leiden, Netherlands) and systematically compared with original report-derived LVEF values (R-LVEF) generated using vendor-specific AI tools. For interobserver reproducibility assessment, 3 operators independently analyzed 30 randomly selected cases using fully manual and AI-assisted modes, the latter also performed with QMass 8.1 software. Operator A performed 2 measurements in both modes for intraobserver analysis. RESULTS:In overall and single-centre analyses, the consistency between R-LVEF and M-LVEF was good or excellent (intraclass correlation coefficient ≥ 0.86), but the 95% limits of agreement all exceeded ± 5%. In 44.3% of cases > 5% differences between R-LVEF and M-LVEF were observed, and 17.5% showed > 10% differences. The AI-assisted method not only significantly reduced LVEF assessment time compared with manual analysis, but also showed superior reproducibility. This was evidenced by greater interobserver agreement among 3 operators (intraclass correlation coefficients, 0.968, 0.974, 0.984 for AI vs 0.913, 0.924, 0.971 for manual, respectively) and greater intraobserver reproducibility, all with significantly lower coefficients of variation (5.6%, 8.8%, 9.3% vs 2.5%, 3.8%, 4.4%, respectively; 3.5% vs 1.0% [P < 0.05). CONCLUSIONS:There are individual differences in AI-assisted LVEF assessment, but it has significant advantages in efficiency and reproducibility, making AI a worthwhile tool to facilitate cardiac magnetic resonance quantification.

To assess the consistency of left ventricular (LV) characteristics on cine cardiac magnetic resonance (CMR) images acquired from compressed-sensing (CS) accelerated cine versus standard segmented cine (Std-cine) sequences, both utilizing a balanced steady-state free precession (bSSFP) readout. We conducted a systematic review and meta-analysis. Electronic databases were searched for studies where both CS-cine and Std-cine sequences were performed for individual participants and LV characteristic data from the two sequences were reported separately. Two investigators independently assessed the eligibility of the retrieved studies and extracted data. Key outcomes included LV ejection fraction (LVEF), volume, mass, and image quality. We performed subgroup analyses for children, breath control, arrhythmia, and MRI field intensity. Thirty-five studies were included. The LVEF (

This study aimed to assess differences in left ventricular ejection fraction (LVEF) measurements between cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE) and identify determinants influencing clinical classification discordance. We retrospectively enrolled patients who underwent both CMR and TTE imaging within a 1-week interval. The study endpoint was a comparative analysis of LVEF measurements between 2 modalities. We also assessed the impact of these measurements on clinical decisions, referencing the European Society of Cardiology's heart failure and specific threshold (50%, 35%) classification. Logistic regression was used to explore the association of imaging characteristics with LVEF classification differences. 1,213 patients were included. The median LVEF values were 58% for TTE and 49% for CMR. The modalities demonstrated moderately strong agreement in LVEF measurements (intraclass correlation coefficient = 0.64). Using the heart failure classification, LVEF categories were determined by both modalities in 65.0% of patients, whereas 33.5% of patients were downward reclassified by CMR. Analysis using thresholds of 50% and 35% indicated inconsistent LVEF classification in 2.7%, 73.4%, and 63.4% of patients, respectively. Multivariate regression analysis showed that septal (odds ratio = 2.02; 95% confidence interval: 1.55 to 2.62) and lateral (odds ratio = 1.82; 95% confidence interval: 1.40 to 2.37) motion abnormalities were associated with LVEF classification differences. In conclusion, septal and lateral wall motion abnormalities detected on TTE are strong predictors of reclassification. CMR should be prioritized in such cases to guide clinical management and mitigate TTE-related misclassification risks.

To validate the use of full free-breathing (FB) motion-corrected (MoCo) cardiac MRI examinations in assessing biventricular systolic function and tissue characterization compared with the reference standard breath-hold (BH) examination. In this prospective study, 216 patients underwent 3-T cardiac MRI. Of these patients, 113 underwent FB motion-corrected cardiac cine imaging in addition to standard BH cine imaging; the remaining 103 patients underwent FB motion-corrected late gadolinium enhancement (LGE) imaging in addition to standard BH LGE imaging. Image quality was assessed with a five-point scale (1 = nondiagnostic, 5 = very good). Left ventricular (LV) and right ventricular (RV) functional parameters and LGE mass in BH and FB examinations were analyzed using Wilcoxon signed-rank test, Bland-Altman plots, and linear regression. Subjective image quality between the FB and BH groups was comparable for cine imaging (4.02 ± 0.81 vs. 4.14 ± 0.79, P = 0.220) but was significantly better in the FB group for LGE (4.79 ± 0.46 vs. 4.16 ± 0.79, P < 0.001). Scan times for both cine (149.46 ± 32.29 s vs. 392.61 ± 47.02 s, P < 0.001) and LGE (198.12 ± 41.90 s vs. 361.69 ± 46.17 s, P < 0.001) were consistently shorter in the FB group than in the BH group. No significant differences were found in biventricular volumetric parameters or LGE mass measurements between FB and BH groups. Bland-Altman plots and linear regression analysis showed good agreement for LV and RV functional parameters and LGE mass in BH and FB sequences. Full FB cardiac MRI produces high-quality images and could be a suitable alternative for patients who cannot tolerate multiple BHs or long examination times.

BACKGROUND:Late gadolinium enhancement (LGE) imaging is considered the imaging reference standard for the diagnosis of myocardial infarction and scarring. The aim of this study is to evaluate a free-breathing high-resolution three-dimensional (3D) Dixon LGE imaging prototype with image navigation (iNAV) in chronic myocardial infarction on a 3T system. METHODS:Consecutive myocardial infarction patients were enrolled to undergo CMR examination between February 2024 and January 2025. LGE protocols included breath-hold two-dimensional (2D) phase-sensitive inversion recovery (PSIR) and free-breathing iNAV 3D Dixon acquisitions. Radiologist image quality scoring, contrast ratio (CR), quantitative LGE assessment, and scan time were obtained and reported. Paired t-tests, Wilcoxon signed-rank tests, and repeated-measures ANOVA were used for the comparison. RESULTS:A total of 32 participants (50 years ± 11; 31 male, 1 female) were included. 3D LGE reduced scan time by 2m9s (3D: 4m34s [3m50s, 5m17s], 2D: 6m43s [5m17s, 7m41s], P<0.001). Overall image quality showed no difference (3D: 4 [3, 4], 2D: 4 [3, 5], P = 0.474). 3D LGE showed a trend toward higher image quality scores (3D: 4 [3, 4], 2D: 3 [2, 4], P = 0.053) in patients with respiratory motion artifacts on 2D images. LGE-to-blood CR was significantly higher in the 3D LGE than the 2D LGE images (P<0.001). LGE mass (P = 0.11) and LGE extent (P = 0.02) showed no significant difference between the 3D and 2D LGE datasets. CONCLUSION:Free-breathing iNAV 3D Dixon LGE is feasible at 3T, achieving comparable image quality and scar quantification to 2D PSIR within shorter scan times. It improves CR and enables simultaneous assessment of myocardial fibrosis and fat infiltration.

Background:Percutaneous coronary intervention (PCI) can quickly restore epicardial coronary blood flow in patients with acute ST-segment elevation myocardial infarction (STEMI) to rescue the ischemic myocardium but it also frequently results in microvascular damage and further myocyte necrosis. The changes in left ventricular (LV) hemodynamics in these patients after PCI are not clearly understood. The main objective of this study was to characterize the parameters of LV blood flow kinetic energy (KE) and to explore the predictive value of these parameters on 4D flow cardiac magnetic resonance (CMR) imaging for poor prognosis in patients with STEMI after PCI. Methods:This prospective study included 32 acute STEMI patients who underwent PCI and 21 healthy controls without heart or lung diseases. All participants underwent CMR examinations and were grouped based on the presence of anterior wall myocardial infarction, microvascular obstruction (MVO), and intra-myocardial hemorrhage (IMH) as well as the LV ejection fraction (EF). KE values were normalized to the LV end-diastolic volume (EDV) to obtain KEiEDV parameters for comparison between subgroups and the healthy control group. Correlation analysis was performed between KEiEDV parameters and multiple cardiac function parameters. Results:The delayed ejection flow component was significantly higher in the anterior group (F=3.847, P=0.028), MVO (F=6.035, P=0.004), IMH (F=4.164, P=0.021), and EF <50% groups (F=5.488, P=0.007) than in the control group and other subgroups. The direct flow component was lower in the anterior, MVO, and EF <50% groups than in the control group (P=0.024, 0.016, 0.049, respectively) and lower in the IMH group than in the non-IMH and control groups (F=5.285, P=0.008). The ratio of peak systolic KEiEDV of direct flow to the delayed ejection flow (Pd/Pde) was significantly lower in the MVO and IMH groups (P=0.006 and 0.006). Statistical differences were observed in the KEiEDV parameters related to diastolic function among the subgroups, especially in the non-MVO group. Some KEiEDV parameters were strongly or moderately correlated with parameters reflecting LV structure and function. Conclusions:LV KEiEDV parameters can quantitatively reflect hemodynamic and energetics abnormalities in acute STEMI patients after PCI. The changes in the delayed ejection flow component, direct flow component, and Pd/Pde reflect the decrease of LV work efficiency and may explain based on hemodynamic insights, especially energetics, the key pathophysiology in these patients who are prone to a poor prognosis.

True fast imaging with steady-state precession and motion-corrected phase-sensitive inversion recovery sequences showed comparable performance to turbo fast low-angle shot phase-sensitive inversion recovery in cardiac MRI, although with shorter scan times.

Background:Segmented phase-sensitive inversion recovery (PSIR) turbo fast low-angle shot (FLASH) has become the reference standard sequence for late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. However, it has a long scanning time, requires multiple breath holds, and is prone to motion artifacts. This study aimed to compare the accuracy of two fast LGE sequences with FLASH PSIR in acute myocardial infarction (AMI) detection and quantification of LGE. Methods:We prospectively recruited consecutive AMI patients who underwent clinical contrast-enhanced CMR with three different LGE sequences at Beijing Friendship Hospital. The overall image quality (IQ) score and contrast-to-noise ratio (CNR) were used to comprehensively evaluate IQ. LGE and microvascular obstruction (MVO) were qualitatively and quantitatively assessed. Results:A total of 110 AMI patients (90 males, 58.61±10.9 years) were included in our analyses. Of these, 100 patients (84 males, 58.6±10.9 years) presented LGE (+), and 60 patients developed MVO. Participants were divided into three groups according to the LGE results, namely LGE (-), LGE (+) without MVO, and LGE (+) with MVO. The overall IQ score and CNR for the two fast sequences [single-shot true fast imaging with steady-state precession (TrueFISP PSIR), PSIR motion-corrected, free-breathing single-shot balanced steady-state free precession (moco bSSFP)] were significantly higher than those for the FLASH PSIR (P<0.001). On visual assessment, the number of layers (P=0.20 and 0.22, respectively) and segments (P=0.09 and 0.32, respectively) for LGE displayed no difference and showed excellent matching with those of FLASH PSIR. There were no significant differences in LGE mass (P=0.61 and 0.83, respectively) and MVO mass (P=0.15 and 0.55, respectively) between the FLASH PSIR and the two fast sequences. Conclusions:In clinical practice, these two rapid sequences can achieve good IQ, as well as accurate localization and quantification of LGE when acquired during a single breath hold or in a free-breathing state. We recommend them as the preferred LGE CMR sequence for AMI patients.

PURPOSE:To propose a new method for characterizing sequences with higher resolution or readout length than allowed by standard field monitoring approaches. METHODS:Our proposed method was devised to characterize entire readout gradients by stitching multiple segment-specific dynamic field measurements obtained across a matched number of consecutive TRs corresponding to a certain segmentation of the readout gradient. The utility of our proposed stitching method for high-order dynamic field measurements was illustrated using 2D spiral sequences. It was first demonstrated at 10.5 T and then at 7 T using both simulated and experimental MRI data. At 10.5 T, two extreme spiral readout scenarios were considered where standard field monitoring did not work. Our method was then validated in humans at 7 T, where spiral sequences were employed for brain imaging. At 7 T, our method was further compared against gradient impulse response function (GIRF)-based trajectory prediction. RESULTS:At 10.5 T, our stitching method outperformed the standard approach, producing plausible dynamic field measurements throughout entire readouts. At 7 T, it produced nearly identical measurements for one readout where standard field monitoring also worked; for another readout when standard field monitoring did not work, it still produced sensible field measurements, improving image reconstruction for both simulated and experimental MRI data. CONCLUSION:Our proposed stitching method provides an effective means to characterize challenging imaging gradients using commercially available hardware and without assuming a linear gradient system, thereby having utility for many applications especially those aiming for ultrahigh-resolution MRI at ultrahigh field.

Background:Phase-resolved functional lung (PREFUL) magnetic resonance imaging (MRI) is a reliable, noninvasive method for assessing pulmonary ventilation and perfusion. However, the differences in subgroups of patients with chronic pulmonary embolism (CPE) have not been thoroughly investigated, and there may be significant clinical value in examining noninvasive methods for evaluating hemodynamics and right heart function in patients with CPE. This study aimed to evaluate pulmonary perfusion and ventilation in patients with suspected chronic thromboembolic pulmonary hypertension (CTEPH) via PREFUL MRI and further determined the correlations of these findings with right heart catheterization (RHC), right heart function indicators, and pulmonary function test results. Methods:A retrospective analysis was performed on patients with suspected CTEPH who were referred to our center between June 2020 and September 2022. All patients underwent RHC or echocardiography, pulmonary angiography (PA), ventilation-perfusion (V/Q) lung scan, or CTPA, with PREFUL MRI being conducted within 2 weeks of these tests. The diagnoses of CTEPH and chronic thromboembolic pulmonary disease (CTED) were established through multidisciplinary team discussions. Mean parameter values from five PREFUL MRI slices were calculated, including normalized perfusion (QN), exclusive perfusion defect percentage (QDPexc), total perfusion defect percentage (QDPtot), regional ventilation (RV), exclusive ventilation defect percentage (VDPexc), total ventilation defect percentage (VDPtot), and ventilation/perfusion match defect percentage (VQMdef). Clinical correlations were assessed through the comparison of PREFUL MRI parameters with hemodynamic data, right heart function indicators, and pulmonary function parameters. Results:In total, 42 patients (26 men and 16 women; mean age 53.5±13.5 years) with suspected CTEPH were analyzed: 31 had CTEPH and 11 had CTED. Significant differences between the two groups were found in QN, QDPexc, QDPtot, RV, and VDPexc. VQMdef demonstrated the best diagnostic performance among all parameters, with a sensitivity of 87%, specificity of 91%, and accuracy of 88%. QN, QDPexc, and QDPtot were correlated with mean pulmonary arterial pressure (mPAP; r=-0.490, r=0.539, and r=0.534, respectively; all P values <0.01). QDPexc and QDPtot were correlated with pulmonary vascular resistance (r=0.369 and r=0.362, respectively; P<0.05). QN, QDPexc, and QDPtot also were significantly correlated with right heart function indicators (all P values <0.01). RV was negatively correlated with percent predicted single-breath diffusing capacity of the lung for carbon monoxide (DLCO SB %pred; r=-0.588; P<0.001), and VDPtot was negatively correlated with the ratio of forced expiratory volume in 1 s to forced vital capacity (parameter expressed as a percentage of the predicted value) (r=-0.379; P=0.027). Conclusions:Quantitative parameters obtained from PREFUL MRI were correlated with hemodynamic status and cardiopulmonary function in patients with CTEPH or CTED. PREFUL MRI perfusion parameters demonstrated strong diagnostic performance for CTEPH, indicating their clinical potential.

The pathological changes in deep medullary veins (DMVs) have been reported in various diseases. However, accurate modeling and quantification of DMVs remain challenging. We aim to propose and assess an automated approach for modeling and quantifying DMVs at 7 Tesla (7 T) MRI. A multi-echo-input Res-Net was developed for vascular segmentation, and a minimum path loss function was used for modeling and quantifying the geometric parameter of DMVs. Twenty-one patients diagnosed as subcortical vascular dementia (SVaD) and 20 condition matched controls were included in this study. The amplitude and phase images of gradient echo with five echoes were acquired at 7 T. Ten GRE images were manually labeled by two neurologists and compared with the results obtained by our proposed method. Independent samples t test and Pearson correlation were used for statistical analysis in our study, and p value < 0.05 was considered significant. No significant offset was found in centerlines obtained by human labeling and our algorithm (p = 0.734). The length difference between the proposed method and manual labeling was smaller than the error between different clinicians (p < 0.001). Patients with SVaD exhibited fewer DMVs (mean difference = -60.710 ± 21.810, p = 0.011) and higher curvature (mean difference = 0.12 ± 0.022, p < 0.0001), corresponding to their higher Vascular Dementia Assessment Scale-Cog (VaDAS-Cog) scores (mean difference = 4.332 ± 1.992, p = 0.036) and lower Mini-Mental State Examination (MMSE) (mean difference = -3.071 ± 1.443, p = 0.047). The MMSE scores were positively correlated with the numbers of DMVs (r = 0.437, p = 0.037) and were negatively correlated with the curvature (r = -0.426, p = 0.042). In summary, we proposed a novel framework for automated quantifying the morphologic parameters of DMVs. These characteristics of DMVs are expected to help the research and diagnosis of cerebral small vessel diseases with DMV lesions.