Radiology. Cardiothoracic imaging最新文献

Purpose To assess the predictive value of left atrial (LA) fast long-axis strain derived from cardiac MRI for thrombotic events (TEs) in individuals with hypertrophic cardiomyopathy (HCM). Materials and Methods This secondary analysis of an ongoing prospective trial (Chinese Clinical Trial Registry: ChiCTR1900024094) included consecutive participants with HCM without atrial fibrillation (AF) who underwent cardiac MRI from January 2012 to December 2020. The LA fast long-axis strain was obtained by semiautomatically tracking the distance between the atrioventricular junction and the midposterior LA wall. The primary end point was the occurrence of TEs, including ischemic stroke, transient ischemic attack, and systemic thromboembolism. The predictive value of LA strain was determined with Cox analysis. Results Overall, 714 participants with HCM (mean age ± SD, 50.1 years ± 14.3; 441 men, 273 women; obstructive HCM, n = 289; apical HCM, n = 144) were included (median follow-up: 51 months). Twenty-eight (3.9%) participants with HCM experienced TEs, 60% (17 of 28) of whom had no new-onset AF. Those who experienced TEs had lower LA reservoir and conduit strains (16.2% ± 7.3 vs 21.8% ± 8.3, P = .001; 5.9% ± 3.5 vs 9.7% ± 5.5, P = .01, respectively), with no evidence of a difference in LA booster strain between groups. LA reservoir and conduit strain were independent predictors of TEs in different multivariable models, even after adjusting for age, diabetes, and left ventricular ejection fraction (adjusted hazard ratios: reservoir strain [per 5% decrease], 1.29-1.34 [95% CI: 1.05, 1.50]; conduit strain [per 5% decrease], 1.42-1.47 [95% CI: 1.04, 1.67]). Conclusion Cardiac MRI-derived LA reservoir and conduit strain were independent predictors for the occurrence of TEs in individuals with HCM without AF. Keywords: MR-Imaging, Left Atrium, Cardiomyopathies, Hypertrophic Cardiomyopathy, Thromboembolism, Cardiac Magnetic Resonance Chinese Clinical Trial Registry no. ChiCTR1900024094 Supplemental material is available for this article. © RSNA, 2025.

Purpose To assess the repeatability of real-time cine pulmonary MRI measures of metronome-paced tachypnea (MPT)-induced dynamic hyperinflation and its relationship with chronic obstructive pulmonary disease (COPD) severity. Materials and Methods SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS) (ClinicalTrials.gov identifier no. NCT01969344) is a multicenter prospective cohort study that recruited individuals with COPD with 20 or more pack-years smoking history and controls aged 40-80 years. SPIROMICS-HF is a cross-sectional study evaluating cardiopulmonary interactions in COPD from December 2019 to April 2024. Two-dimensional coronal real-time cine pulmonary MRI (3.2 frames/sec) was performed during MPT twice. Lung masks and lung MR images from an independent study were used for transfer learning to segment real-time cine pulmonary MR images. Dynamic hyperinflation was evaluated as the increase in end-expiratory lung volume (EELV) during tidal breathing to the end of MPT. Repeatability was assessed with intraclass correlation coefficients, and multivariable associations with COPD severity were examined. Results Of the 70 participants (mean age, 67 years ± 10 [SD]; 37 male, 33 female) included in the study, 59% had COPD. The transfer learning model achieved high accuracy in lung segmentation (Dice similarity coefficient, 0.94 ± 0.03). There was good scan-rescan agreement for EELV and dynamic hyperinflation (intraclass correlation coefficient, 0.99 and 0.87, respectively). Dynamic hyperinflation was associated with COPD severity (P trend = .01, with a mean difference between severe COPD and controls of 0.24 L). Conclusion A transfer learning model yielded reproducible quantification of MPT-induced dynamic hyperinflation at real-time cine pulmonary MRI, with greater dynamic hyperinflation in participants with more severe COPD. Keywords: Chronic Obstructive Pulmonary Disease, MR Imaging, Pulmonary, Lung, Technology Assessment Supplemental material is available for this article. ClinicalTrials.gov identifier: NCT01969344 © RSNA, 2025.

Purpose To investigate the prognostic value of T1 mapping, extracellular volume fraction (ECV), and T2 mapping in a large cohort of patients with acute myocarditis. Materials and Methods This retrospective study included patients with acute myocarditis who underwent cardiac MRI (3.0 T) between March 2016 and October 2022. Diagnosis was confirmed by diagnostic cardiac MRI criteria or endomyocardial biopsy. The primary end point was major adverse cardiovascular events (MACEs), defined as the composite of cardiac death, heart failure hospitalization, heart transplantation, sustained ventricular arrhythmia, and recurrent myocarditis. Univariable and multivariable Cox regression analyses were performed to assess the association of clinical and cardiac MRI variables with the primary end point. The prognostic value of each model was assessed using the Harrell C index. Results A total of 235 patients (mean age, 32 years ± 13 [SD]; 150 [63.8%] men) were included. During a mean follow-up of 1637 days (IQR: 1441-1833 days), MACEs occurred in 45 (19%) patients. Patients with MACEs had higher global native T1, ECV, and T2 values (1342 msec ± 64 vs 1263 msec ± 48; P < .001; 39.1% ± 8.7 vs 32.7% ± 5.7; P < .001; 61.1 msec ± 10.0 vs 55.3 msec ± 9.4; P = .03, respectively). In a series of multivariable Cox regression models, native T1 (per 10-msec increase: hazard ratio, 1.61; 95% CI: 1.31, 1.98; P < .001) and ECV (per 5% increase: hazard ratio, 1.70; 95% CI: 1.38, 2.08; P < .001) independently predicted MACE occurrence, and the addition of native T1 (Harrell C index = 0.76) or ECV (Harrell C index = 0.79) to the model including only clinical variables, left ventricular ejection fraction, and septal late gadolinium enhancement (Harrell C index = 0.72) improved discrimination for the primary end point. Conclusion Cardiac MRI-derived native T1 and ECV were independent predictors of MACEs in patients with acute myocarditis and provided incremental prognostic value when combined with conventional parameters. Keywords: MRI, Cardiac, Heart, Inflammation Supplemental material is available for this article. © RSNA, 2025.

Purpose To compare the acquisition time, image quality, and late gadolinium enhancement (LGE) visualization and quantification on phase-sensitive inversion recovery (PSIR) images using 5.0-T versus 3.0-T cardiac MRI. Materials and Methods In this prospective crossover study, 49 participants (mean ± SD age, 43.7 years ± 13.1; 39 men) suspected or diagnosed with nonischemic cardiomyopathy were enrolled from April 2023 to March 2024 and randomly assigned to group 1 (5.0-T followed by 3.0-T LGE cardiac MRI) or group 2 (3.0-T followed by 5.0-T LGE cardiac MRI). PSIR images were acquired at spatial resolutions of 1.2, 0.9, and 1.6 mm. Image quality and LGE were qualitatively evaluated using a five-point Likert scale by two readers, and signal-to-noise ratio, contrast-to-noise ratio, and LGE mass were quantitatively assessed. Bland-Altman plots were used to evaluate interreader agreement. Results There was no evidence of a difference in the acquisition time for obtaining a single-layer PSIR image at 5.0 T compared with 3.0 T (P > .05 for all), irrespective of resolutions at 1.2, 0.9, and 1.6 mm. The 5.0-T PSIR images demonstrated better image quality and LGE visualization compared with 3.0-T images, particularly at 1.2 mm (image quality: median 5 [IQR, 5-5] vs median 5 [IQR, 4-5]; P = .004; LGE score: median 5 [IQR, 5-5] vs median 4.25 [IQR, 4-5]; P < .001). No evidence of differences in image quality or LGE scores was found between 5.0-T and 3.0-T cardiac MRI at 1.6-mm resolution. Signal-to-noise ratio and contrast-to-noise ratio were higher on 5.0-T PSIR images across all resolutions compared with 3.0-T images (P < .001 for all), but no evidence of a difference was found in LGE mass measurements. Conclusion The study demonstrates that 5.0-T PSIR imaging offers better image quality and LGE visualization than 3.0-T PSIR, particularly at a 1.2-mm resolution, in individuals with nonischemic cardiomyopathy. Keywords: MRI, Cardiac, Heart, Comparative Studies, Nonischemic Cardiomyopathy, Late Gadolinium Enhancement, Phase-Sensitive Inversion Recovery Supplemental material is available for this article. ©RSNA, 2024.

Purpose To provide reference values for four-dimensional (4D) flow MRI in healthy fetuses and evaluate reliability of fetal 4D flow MRI hemodynamics in third trimester fetuses with normal cardiovascular development or suspected coarctation of the aorta (CoA). Materials and Methods Pregnant patients with healthy fetuses or fetuses with echocardiographic concern for CoA were prospectively recruited between May 2021 and October 2023. Doppler US-gated fetal 4D flow MRI was performed at 3 T. Repeated 4D flow (time permitting) and two-dimensional (2D) phase contrast (PC) MRI data were acquired. Net flow was quantified, and the reliability of 4D flow measurement was evaluated by using precision across adjacent measurement planes, internal consistency based on conservation of mass, comparison of net flow from 4D flow MRI versus 2D PC MRI, and repeatability of 4D flow from separate acquisitions. Results Data were obtained in 34 pregnant participants (mean maternal age, 33 years ± 5 [SD]; mean gestational age, 35 weeks ± 2; n = 22 healthy fetuses and 12 fetuses with suspected CoA). Precision was high across all vascular segments (mean within-subject coefficient of variation = 7%). For mass conservation, there was an average difference of 19% ± 12 between ductus arteriosus plus isthmus flow versus descending aorta flow (r = 0.76). Net flow measured with 4D flow MRI correlated with that measured with 2D PC MRI (r = 0.51) but was underestimated relative to 2D PC MRI by approximately 34%. Hemodynamic parameters quantified from repeated 4D flow acquisitions had good agreement, with an intraclass correlation coefficient of 0.94 between test and retest data. Conclusion Hemodynamic measurements derived from fetal 4D flow MRI were reliable, showing good internal consistency, precision, and repeatability; however, as expected, 4D flow MRI underestimated absolute blood flow relative to 2D PC MRI. Keywords: Fetal MRI, Cardiac, Aorta, Hemodynamics/Flow Dynamics, Pulmonary Arteries Supplemental material is available for this article. © RSNA, 2024.