Purpose To determine whether cardiac MRI strain parameters independently predict PET/CT-defined myocardial inflammation in patients with cardiac sarcoidosis (CS). Materials and Methods This retrospective study included patients with definite or probable CS who underwent cardiac MRI and fluorine 18 fluorodeoxyglucose (FDG) PET/CT between January 2010 and October 2022 within 90 days per the Japanese Circulation Society criteria. Strain parameters, including the peak circumferential strain (PCS), peak longitudinal strain (PLS), and diastolic strain rates, were calculated using feature tracking on cine steady-state free precession images. Inflammation was defined by focal FDG uptake using the 17-segment American Heart Association model. T2-weighted and late gadolinium enhancement (LGE) images were qualitatively assessed. Segment-level comparisons were performed between inflamed and noninflamed segments. Multivariable logistic regression clustered at the patient level was adjusted for LGE, T2 signal abnormality, age, sex, and left ventricular end-diastolic volume index. Receiver operating characteristic (ROC) curve analysis was used to evaluate the added value of strain metrics over the left ventricular ejection fraction (LVEF) for inflammation. Results Among 125 included patients (mean age, 59.5 years ± 12.7 [SD]), 60% (n = 75) had at least one segment with inflammation on FDG PET/CT images. Of these 75 patients, 61% (n = 46) were male. Segment-level analysis revealed inflammation in 18.1% (385 of 2125) of the segments. The PCS and PLS were lower in inflamed segments than in noninflamed segments (-14.1% vs -18.4% and -10.3% vs -13.0%, respectively; P < .001 for both) and independently predicted inflammation in multivariable analysis (odds ratio, 1.79 and 1.62, respectively; P < .01 for both). Adding PCS to LVEF improved inflammation detection (area under the ROC curve, 0.72 vs 0.63; P = .04). Conclusion Circumferential and longitudinal strain from cardiac MRI independently predicted PET-defined myocardial inflammation. Keywords: MRI, PET/CT, Heart, Cardiomyopathy, Cardiac Strain, Cardiac Sarcoidosis, Myocardial Inflammation © RSNA, 2026.
Purpose To investigate the association between biventricular imbalance, as reflected by the left ventricular (LV) and right ventricular (RV) global longitudinal strain (GLS) ratio derived from cardiac MRI feature tracking, and all-cause death in isolated left ventricular myocardial infarction. Materials and Methods In this multicenter retrospective study, the primary end point was all-cause mortality. The GLS ratio was defined as the ratio of LVGLS and RVGLS. Long-axis (two, three, and four chambers) and short-axis cine sequences were used for strain analysis. Kaplan-Meier curves, Cox proportional hazards regression, and the C statistic were used for statistical analysis. Results In the internal testing set (919 patients; median age, 59 years [IQR, 51-66 years]; 769 [83.7%] male), 90 (9.8%) patients died over a median follow-up period of 60.9 months (IQR, 47.7-83.6 months). The GLS ratio was the strongest independent predictor for all-cause death (adjusted hazard ratio [HR], 1.69; 95% CI: 1.45, 1.97; P < .001). The model, along with clinical conventional imaging, RVGLS, and GLS ratio, demonstrated improved discrimination (C statistic, 0.82; 95% CI: 0.76, 0.87) and calibration (χ2, 71.88). A GLS ratio of more than 0.95 was responsible for a fourfold death risk after multivariable adjustment. In those with normal RVGLS (HR, 2.43; 95% CI: 1.15, 5.10; P = .02), reserved LVGLS (HR, 5.38; 95% CI: 2.46, 11.79; P < .001), and both (HR, 7.76; 95% CI: 2.16, 11.90; P = .002), a high GLS ratio (>0.95) still predicted all-cause death. Conclusion In isolated LV myocardial infarction, an elevated GLS ratio may provide additional prognostic information for all-cause death.
Purpose To evaluate the predictive value of cardiac MRI-derived left atrial strain (LAS) for new-onset atrial fibrillation (AF) in apical hypertrophic cardiomyopathy (AHCM). Materials and Methods This retrospective study included patients with AHCM with no prior history of AF who underwent 3.0-T cardiac MRI between May 2016 and December 2023. LAS parameters-reservoir strain (εs), conduit strain (εe), and booster pump strain (εa)-and minimum left atrial volume index (LAVImin) were measured. The clinical end point was new-onset AF as confirmed with electrocardiography, Holter monitoring, or implantable cardiac devices. Cox proportional hazards models and time-dependent receiver operating characteristic (ROC) analyses were performed to evaluate associations and discriminatory performance for new-onset AF. Results A total of 156 patients (mean age, 51.0 years ± 11.5 [SD]; 113 male) were included. During a median follow-up of 33 months, AF occurred in 21 patients. In multivariable Cox models adjusted for age, body mass index, and LAVImin, LAS parameters were independently associated with incident AF (εs: hazard ratio [HR], 0.79 [95% CI: 0.69, 0.90], P < .001; εa: HR, 0.65 [95% CI: 0.50, 0.83], P < .001; and εe: HR, 0.79 [95% CI: 0.65, 0.95], P = .01). In the nested Cox models, adding LAS to a baseline clinical-volumetric model improved model fit and discrimination, with the χ2 value improving from 36.22 to 54.90 and the concordance index value improving from 0.846 to 0.930 (P < .001 for both). The LAVImin provided complementary prognostic information, with its contribution varying across strain-specific models. Time-dependent ROC analyses demonstrated that LAS identified the development of AF well across prespecified time horizons. Conclusion Cardiac MRI-derived LAS was independently associated with new-onset AF in AHCM and provided incremental prognostic value beyond routine clinical and left atrial volumetric measures. Keywords: Apical Hypertrophic Cardiomyopathy, Atrial Fibrillation, Cardiac MRI, Left Atrial Strain, Heart, Cardiomyopathies, MR Imaging Supplemental material is available for this article. © RSNA, 2026.
