Quantitative Assessment Of Left Ventricular Function Research Articles

Feasibility of single-shot compressed sensing cine imaging for analysis of left ventricular function and strain in cardiac MRI

To compare single-shot compressed sensing (CS) cine imaging with conventional segmented cine imaging for reliable quantification of left ventricular (LV) volume and strain assessment during cardiac magnetic resonance imaging (CMRI). Thirty-seven participants underwent both single-shot CS and conventional segmented cines that covered the entire LV. LV volumetric and strain values were obtained. LV volumes, global strain, the standard deviation of time to peak strain (SD-TPS) in the radial, longitudinal, and circumferential directions were compared using the Student's t-test and intraclass correlation coefficient (ICC). Interobserver and intra-observer variabilities of the LV strain values for the two cines method were determined using ICC. Single-shot CS cine-derived LV volumes and myocardial mass measurements correlated strongly with segmented cines (ICC >0.798) and minor systematic end-systolic volume overestimations resulting in ejection fraction underestimations. Single-shot CS cine-derived global strain and SD-TPS were poorly to moderately correlated with segmented cines (ICC from 0.045-0.706). All global strain values derived from single-shot CS cines were underestimated compared with segmented cine-derived values; however, no significant differences in radial and longitudinal SD-TPS between the two cines were found. Among the patient-related factors, heart rate was a strong predictive factor of global longitudinal strain underestimations (p=0.039) in the CS cines. Inter- and intra-observer LV strain variabilities derived from CS and segmented cines were good to excellent. Single-shot CS cine CMRI is feasible for the quantitative assessment of LV function. Currently, strain values derived from the two techniques are not interchangeable.

Motion-Corrected Real-Time Cine Magnetic Resonance Imaging of the Heart: Initial Clinical Experience.

Free-breathing real-time (RT) imaging can be used in patients with difficulty in breath-holding; however, RT cine imaging typically experiences poor image quality compared with segmented cine imaging because of low resolution. Here, we validate a novel unsupervised motion-corrected (MOCO) reconstruction technique for free-breathing RT cardiac images, called MOCO-RT. Motion-corrected RT uses elastic image registration to generate a single heartbeat of high-quality data from a free-breathing RT acquisition. Segmented balanced steady-state free precession (bSSFP) cine images and free-breathing RT images (Cartesian, TGRAPPA factor 4) were acquired with the same spatial/temporal resolution in 40 patients using clinical 1.5 T magnetic resonance scanners. The respiratory cycle was estimated using the reconstructed RT images, and nonrigid unsupervised motion correction was applied to eliminate breathing motion. Conventional segmented RT and MOCO-RT single-heartbeat cine images were analyzed to evaluate left ventricular (LV) function and volume measurements. Two radiologists scored images for overall image quality, artifact, noise, and wall motion abnormalities. Intraclass correlation coefficient was used to assess the reliability of MOCO-RT measurement. Intraclass correlation coefficient showed excellent reliability (intraclass correlation coefficient ≥ 0.95) of MOCO-RT with segmented cine in measuring LV function, mass, and volume. Comparison of the qualitative ratings indicated comparable image quality for MOCO-RT (4.80 ± 0.35) with segmented cine (4.45 ± 0.88, P = 0.215) and significantly higher than conventional RT techniques (3.51 ± 0.41, P < 0.001). Artifact and noise ratings for MOCO-RT (1.11 ± 0.26 and 1.08 ± 0.19) and segmented cine (1.51 ± 0.90, P = 0.088 and 1.23 ± 0.45, P = 0.182) were not different. Wall motion abnormality ratings were comparable among different techniques (P = 0.96). The MOCO-RT technique can be used to process conventional free-breathing RT cine images and provides comparable quantitative assessment of LV function and volume measurements to conventional segmented cine imaging while providing improved image quality and less artifact and noise. The free-breathing MOCO-RT reconstruction method may have considerable clinical utility in cardiac magnetic resonance imaging for patients with difficulty breath-holding.

Prediction of stroke volume by global left ventricular longitudinal strain in patients undergoing assessment for cardiac transplantation

PurposeSpeckle-tracking echocardiography (STE) is a novel technique that can be used for assessment of left ventricular (LV) longitudinal deformation dynamics. Using cardiac catheterization as the reference standard, the aim of this study was to evaluate the relation between LV global longitudinal strain (GLS) assessed by STE and LV stroke volume in patients undergoing assessment for cardiac transplantation. MethodsConventional echocardiography and STE were performed during right-sided cardiac catheterization in 51 patients referred for cardiac transplant assessment. Thermodilution LV stroke volume indexed (LVSVI) was used as the reference standard. Univariate regression analyses and receiver operating characteristics curves were used to test correlations between LVSVI and GLS by STE. ResultsGlobal longitudinal strain was obtained successfully in 95.5% of patients. Among all variables analyzed, GLS best predicted the LVSVI (r = 0.79; P < .0001). Minor correlations with the LVSVI were observed for tissue Doppler–derived systolic mitral annular velocity (r = 0.51; P < .005) and for LV ejection fraction (r = 0.32; P < .05). ConclusionsIn a group of patients referred for cardiac transplant assessment, LV longitudinal deformation analysis by STE closely correlates with LVSVI, suggesting that, in this particular clinical setting, this new parameter may help provide an accurate, noninvasive, and quantitative assessment of LV function.

Three-dimensional echocardiographic assessments of exercise-induced changes in left ventricular shape and dyssynchrony in patients with dynamic functional mitral regurgitation

Left ventricular (LV) shape and LV dyssynchrony are two cofactors associated with functional mitral regurgitation (MR) in patients with heart failure. Both can be accurately examined by real-time three-dimensional echocardiography (3DE). We examined the relationship between dynamic MR and exercise-induced changes in LV shape and synchronicity using 3DE. Fifty patients with systolic LV dysfunction underwent 2D and 3D quantitative assessment of LV function, shape, and synchronicity at rest and during symptom-limited exercise test. According to the magnitude of change in MR, patients were divided into EMR group (15 patients, 30%), if the degree of MR increased during test, and NEMR group. During exercise, the changes in LV volumes and ejection fraction were similar in both groups, whereas changes in mitral valvular deformation parameters, in LV sphericity index, and in the extent of LV dyssynchrony were more pronounced in the EMR group. At rest, only the 3D sphericity index could distinguish the two groups. By stepwise multiple regression model, dynamic changes in the systolic dyssynchrony index, sphericity index, and coaptation distance were associated with dynamic MR (r(2) = 0.45, P = 0.012). Dynamic MR during exercise is related to the 3D changes in LV shape and in LV synchronicity.