Sensitivity of Myocardial Radiomic Features to Imaging Parameters in Cardiac MR Imaging

Background: Cardiac magnetic resonance (MR) images are often collected with different imaging parameters, which may impact the calculated values of myocardial radiomic features.

Purpose: To investigate the sensitivity of myocardial radiomic features to changes in imaging parameters in cardiac MR images.

Study type: Prospective.

Population: A total of 11 healthy participants/five patients.

Field strength/ sequence: A 3 T/cine balanced steady-state free-precession, T₁ -weighted spoiled gradient-echo, T₂ -weighted turbo spin-echo, and quantitative T₁ and T₂ mapping. For each sequence, the flip angle, in-plane resolution, slice thickness, and parallel imaging technique were varied to study the sensitivity of radiomic features to alterations in imaging parameters.

Assessment: Myocardial contours were manually delineated by experienced readers, and a total of 1023 radiomic features were extracted using PyRadiomics with 11 image filters and six feature families.

Statistical tests: Sensitivity was defined as the standardized mean difference (D effect size), and the robust features were defined at sensitivity < 0.2. Sensitivity analysis was performed on predefined sets of reproducible features. The analysis was performed using the entire cohort of 16 subejcts.

Results: 64% of radiomic features were robust (sensitivity < 0.2) to changes in any imaging parameter. In qualitative sequences, radiomic features were most sensitive to changes in in-plane spatial resolution (spatial resolution: 0.6 vs. flip angle: 0.19, parallel imaging: 0.18, slice thickness: 0.07; P < 0.01 for all); in quantitative sequences, radiomic features were least sensitive to changes in spatial resolution (spatial resolution: 0.07 vs. slice thickness: 0.16, flip angle: 0.24; P < 0.01 for all). In an individual feature level, no singular feature family/image filter was identified as robust (sensitivity < 0.2) across sequences; however, highly sensitive features were predominantly associated with high-frequency wavelet filters across all sequences (32/50 features).

Data conclusion: In cardiac MR, a considerable number of radiomic features are sensitive to changes in sequence parameters.

Evidence level: 1 TECHNICAL EFFICACY: Stage 1.