OBJECTIVES: Our aim was to evaluate the inter-vendor reproducibility of cardiovascular MR feature tracking (CMR-FT) for the measurement of segmental strain (SS) of the left ventricle (LV) as well as to test the accuracy of CMR-FT to detect regional myocardial pathology.
METHODS: We selected 45 patients: 15 with normal CMR findings, 15 with dilated cardiomyopathy, and 15 with acute myocardial infarction. Segmental longitudinal, circumferential, and radial strains were assessed with 4 different software. The inter-vendor difference as well as intra- and inter-observer variability was investigated. Furthermore, the accuracy of CMR-FT for the detection of structural (infarcted segments) as well as functional pathology (septal vs. lateral wall strain in left bundle branch block) was tested.
RESULTS: Between vendors, there were significant differences in values for all strains (p < 0.001). The software using a non-rigid algorithm for image registration and segmentation demonstrated the best intra- as well as inter-observer variability with interclass correlation coefficient (ICC) > 0.962 and coefficient of variation (CV) < 24%. For infarct location, the same software yielded the highest area under the curve values for radial and circumferential SS (0.872 and 0.859, respectively). One of the other three software using optical flow technology performed best for longitudinal SS (0.799) and showed the largest differences in SS between septum and lateral wall in the dilated cardiomyopathy group.
CONCLUSION: SS values obtained by CMR-FT are not interchangeable between vendors, and intra- and inter-observer reproducibility shows substantial variability among vendors. Overall, the different packages score relatively well to depict focal structural or functional LV pathology.
KEY POINTS: • Segmental myocardial strain values obtained by CMR feature tracking are not interchangeable between different vendors. • Intra- and inter-observer reproducibility shows substantial variability among vendors. • Segmental myocardial strains measured by CMR feature tracking score relatively well to depict focal structural or functional LV pathology.