The Interfield Strength Agreement of Left Ventricular Strain Measurements at 1.5 T and 3 T Using Cardiac MRI Feature Tracking

Abstract

Background: Left ventricular (LV) strain measurements can be derived using cardiac MRI from routinely acquired balanced steady-state free precession (bSSFP) cine images. Purpose: To compare the interfield strength agreement of global systolic strain, peak strain rates and artificial intelligence (AI) landmark-based global longitudinal shortening at 1.5 T and 3 T. Study Type: Prospective. Subjects: A total of 22 healthy individuals (mean age 36 AE 12 years; 45% male) completed two cardiac MRI scans at 1.5 T and 3 T in a randomized order within 30 minutes. Field Strength/Sequence: bSSFP cine images at 1.5 T and 3 T. Assessment: Two software packages, Tissue Tracking (cvi42, Circle Cardiovascular Imaging) and QStrain (Medis Suite, Medis Medical Imaging Systems), were used to derive LV global systolic strain in the longitudinal, circumferential and radial directions and peak (systolic, early diastolic, and late diastolic) strain rates. Global longitudinal shortening and mitral annular plane systolic excursion (MAPSE) were measured using an AI deep neural network model. Statistical Tests: Comparisons between field strengths were performed using Wilcoxon signed-rank test (P value < 0.05 considered statistically significant). Agreement was determined using intraclass correlation coefficients (ICCs) and Bland-Altman plots. Results: Minimal bias was seen in all strain and strain rate measurements between field strengths. Using Tissue Tracking, strain and strain rate values derived from long-axis images showed poor to fair agreement (ICC range 0.39-0.71), whereas global longitudinal shortening and MAPSE showed good agreement (ICC = 0.81 and 0.80, respectively). Measures derived from short-axis images showed good to excellent agreement (ICC range 0.78-0.91). Similar results for the agreement of strain and strain rate measurements were observed with QStrain. Conclusion:The interfield strength agreement of short-axis derived LV strain and strain rate measurements at 1.5 T and 3 T was better than those derived from long-axis images; however, the agreement of global longitudinal shortening and MAPSE was good.

Is atrial fibrillation in HFpEF a distinct phenotype? Insights from multiparametric MRI and circulating biomarkers

“…Although the AF group in this study did have a marginally lower LV EF compared to the SR group, it remained within normal limits (63 ± 8%). Despite this, we found a lower GLS and GCS in the AF group with values much below those of healthy volunteers [ 30 – 32 ], with average GLS and GCS measuring 16 and 19% respectively in healthy volunteer data from our group using similar methodology [ 33 ]. This may suggest a pathological role of impairment of systolic function both in the subendocardial and circumferential myofibres in the development of HFpEF in patients with AF.…”

Ethnic differences in cardiac structure and function assessed by MRI in healthy South Asian and White European people: A UK Biobank Study

“…RA EF was derived as per the formula above but for right atrial values. LV systolic strain and diastolic strain rates were calculated by CMR feature tracking using the cvi42 Tissue Tracking module, to derive longitudinal and circumferential peak early diastolic strain rates (PEDSR), global longitudinal strain (GLS) and global circumferential strain (GCS), as previously described [11] , [12] . Manual examination of strain rate curves was undertaken to identify PEDSR, defined as the first peak of the strain rate curve.…”