Free‐Breathing Compressed Sensing Cine Cardiac MRI for Assessment of Left Ventricular Strain by Feature Tracking in Children

Abstract

BackgroundCardiac MRI feature‐tracking (FT) with breath‐holding (BH) cine balanced steady state free precession (bSSFP) imaging is well established. It is unclear whether FT‐strain measurements can be reliably derived from free‐breathing (FB) compressed sensing (CS) bSSFP imaging.PurposeTo compare left ventricular (LV) strain analysis and image quality of an FB CS bSSFP cine sequence with that of a conventional BH bSSFP sequence in children.Study TypeProspective.Subjects40 children able to perform BHs (cohort 1 [12.1 ± 2.2 years]) and 17 children unable to perform BHs (cohort 2 [5.2 ± 1.8 years]).Field Strength/Sequence3T, bSSFP sequence with and without CS.AssessmentAcquisition times and image quality were assessed. LV myocardial deformation parameters were compared between BH cine and FB CS cine studies in cohort 1. Strain indices and image quality of FB CS cine studies were also assessed in cohort 2. Intraobserver and interobserver variability of strain parameters was determined.Statistical TestsPaired t‐test, Wilcoxon signed‐rank test, intraclass correlation coefficient (ICC), and Bland–Altman analysis. A P‐value <0.05 was considered statistically significant.ResultsIn cohort 1, the mean acquisition time of the FB CS cine study was significantly lower than for conventional BH cine study (15.6 s vs. 209.4 s). No significant difference were found in global circumferential strain rate (P = 0.089), global longitudinal strain rate (P = 0.366) and EuroCMR image quality scores (P = 0.128) between BH and FB sequences in cohort 1. The overall image quality score of FB CS cine in cohort 2 was 3.5 ± 0.5 with acquisition time of 14.7 ± 2.1 s. Interobserver and intraobserver variabilities were good to excellent (ICC = 0.810 to 0.943).Data ConclusionFB CS cine imaging may be a promising alternative technique for strain assessment in pediatric patients with poor BH ability.Level of Evidence1Technical EfficacyStage 1

The effects of flip angle and gadolinium contrast agent on single breath-hold compressed sensing cardiac magnetic resonance cine for biventricular global strain assessment

“…This observation suggests that the CS cine, used in our study as a single breath-hold high-speed technique, may not furnish equivalent strain values for patients with various cardiovascular conditions even with almost the same acquisition parameters (see Table 1 ). This discovery fails to replicate the strain value comparison results observed in other studies between CS-based cine and conventional cine, which demonstrate only minor differences ( 23 – 25 ). The accurate functioning of the FT algorithm is heavily reliant on achieving a high contrast between the blood and myocardium ( 26 ).…”