Defining the optimal temporal and spatial resolution for cardiovascular magnetic resonance imaging feature tracking

Abstract

Background Myocardial deformation analyses using cardiovascular magnetic resonance (CMR) feature tracking (CMR-FT) have incremental value in the assessment of cardiac function beyond volumetric analyses. Since guidelines do not recommend specific imaging parameters, we aimed to define optimal spatial and temporal resolutions for CMR cine images to enable reliable post-processing. Methods Intra- and inter-observer reproducibility was assessed in 12 healthy subjects and 9 heart failure (HF) patients. Cine images were acquired with different temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolutions (high in-plane 1.5 × 1.5 mm through-plane 5 mm, standard 1.8 × 1.8 x 8mm and low 3.0 × 3.0 x 10mm). CMR-FT comprised left ventricular (LV) global and segmental longitudinal/circumferential strain (GLS/GCS) and associated systolic strain rates (SR), and right ventricular (RV) GLS. Results Temporal but not spatial resolution did impact absolute strain and SR. Maximum absolute changes between lowest and highest temporal resolution were as follows: 1.8% and 0.3%/s for LV GLS and SR, 2.5% and 0.6%/s for GCS and SR as well as 1.4% for RV GLS. Changes of strain values occurred comparing 20 and 30 frames/cardiac cycle including LV and RV GLS and GCS (p < 0.001–0.046). In contrast, SR values (LV GLS/GCS SR) changed significantly comparing all successive temporal resolutions (p < 0.001–0.013). LV strain and SR reproducibility was not affected by either temporal or spatial resolution, whilst RV strain variability decreased with augmentation of temporal resolution. Conclusion Temporal but not spatial resolution significantly affects strain and SR in CMR-FT deformation analyses. Strain analyses require lower temporal resolution and 30 frames/cardiac cycle offer consistent strain assessments, whilst SR measurements gain from further increases in temporal resolution.

Left Ventricular Strain Measurements Derived from MR Feature Tracking: A Head‐to‐Head Comparison of a Higher Temporal Resolution Method With a Conventional Method

“…Higher temporal resolutions could increase the comparability of the local patterns and reduce the effect of image de‐correlation, achieving higher accuracy 15 . In our study, greater GCS and GRS and associated SRs were obtained with the higher temporal resolution acquisitions, which is consistent with data from a previous STE study 20 and other recent findings 1,22 . Since the regional magnitude of deformation is related to global function performance, as assessed by LVEF, and the frame rate is dependent on HR, 26,27 we also conducted analyses depending on LVEF and HR.…”

“…This temporal resolution averaging may result in lower strain values for MR‐FT in comparison to STE 2,15 . The impact of temporal and spatial resolution on MR‐FT derived myocardial deformation indices has been discussed in a recent study which showed that global longitudinal strain (GLS) and global circumferential strain (GCS) values increased at higher frames/cycle 22 . However, the results were limited to a small sample, mainly involving healthy subjects.…”

Anterior STEMI associated with decreased strain in remote cardiac myocardium

“…A low frame rate could potentially affect the strain values. In a study by Backhaus et al, GLS was lower when the temporal resolution was 20 time frames compared to 30, 40 and 50 times frames in 5 mm and 10 mm slices [ 43 ]. But they found no difference in GLS regarding temporal resolution when using 8 mm slice thickness, such as we did in our study.…”

Comparison between conventional and compressed sensing cine cardiovascular magnetic resonance for left atrial volume and strain assessment

“…Although our observers were well trained and experienced, LA strain values obtained by CS cine images were signi cantly underestimated in comparison with those of segmented cine. Lower temporal resolution was an important factor for underestimation of myocardial strain, but the temporal resolutions of 39ms and 46ms had no different in uence on the value of strain [31].One possible explanation for this underestimation of CS strain is that the CS cine images with pseudo-random undersampling and iterative reconstruction present reduced signal-to-noise ratio and reduced ability to demonstrate the ne structure; therefore, LA blood pool and pericardial fat might have been included in the LA strain assessment [32]. For this reason, LA strain analysis should be conducted at the same cine sequence to follow-up in the future.…”