Real-Time 3D Interventional Echocardiography

XV, 205 p. 255 illus., 251 illus. in color.onlin

Feasibility of regional left ventricular endocardial curvature analysis from cardiac magnetic resonance images

Introduction Left ventricular (LV) remodeling is usually assessed using changes in LV volume. Because this methodology describes only global effects of remodeling while disregarding changes in ventricular shape that may occur independently of volume, the importance of shape analysis is increasingly recognized. While most previous studies focused on global LV shape, we hypothesized that 3D analysis of regional endocardial curvature could provide clinically useful information on localized remodeling

Normal reference values of left ventricular strain using three-dimensional speckle tracking echocardiography: results from a multicentre study

AIMS: Three-dimensional (3D) speckle tracking echocardiography (3DSTE) has been shown to be an accurate and reliable clinical tool for the evaluation of global and regional left ventricular (LV) function through strain analysis, but the absence of normal values has precluded its widespread use in clinical practice. The aim of this prospective multicentre study was to establish normal reference values of LV strain parameters using 3DSTE in a large healthy population. METHODS AND RESULTS: A total of 303 healthy subjects (156 males [51%], between 18 and 82 years of age, ejection fraction [EF] 61 +/- 3%), stratified to provide approximately equal proportions of healthy subjects of 18-30, 31-40, 41-50, 51-60, and >60 years of age, underwent 3DSTE. Data were analysed for LV volumes, EF, mass, and global and regional circumferential, longitudinal, radial, and area strain. Significant but small differences between men and women were found for longitudinal and area strains, as well as between different age groups for all LV strain parameters. However, large differences in normal values were observed between different segments, walls, and levels of the LV for radial and longitudinal strains, whereas circumferential and area strains demonstrated generally consistent normal ranges across the LV. CONCLUSIONS: Normal ranges of global and regional LV strain using 3DSTE have been established for clinical use. Differences in the magnitude of LV strain are present between men and women as well as different age groups. Moreover, there are differences between different segments, walls, and levels as part of the functional non-uniformity of the normal LV that necessitates the use of segment-specific normal ranges for radial and longitudinal strains. Circumferential and area strains demonstrate the most consistent normal ranges overall

Volumetric analysis of regional left ventricular function with real‐time three‐dimensional echocardiography: validation by magnetic resonance and clinical utility testing

Background: Quantitative information on regional left ventricular volumes from real-time three-dimensional echocardiography (RT3DE) images has significant clinical potential but needs validation. Aim: To validate these measurements against cardiac magnetic resonance (CMR) and test the feasibility of automated detection of regional wall motion (RWM) abnormalities from RT3DE data. Methods: RT3DE (Philips) and CMR (Siemens) images were obtained from 31 patients and analysed by using prototype software to semiautomatically calculate indices of regional left ventricular function, which were compared between RT3DE and CMR (linear regression, Bland-Altman). Additionally, CMR images were reviewed by an expert, whose RWM grades were used as a reference for automated classification of segments as normal or abnormal from RT3DE and from CMR images. For each modality, normal regional ejection fraction (REF) values were obtained from 15 patients with normal wall motion. In the remaining 16 patients, REFs were compared with thresholds that were derived from patients with normal wall motion and optimised using receiver operating characteristic analysis. Results: RT3DE measurements resulted in good agreement with CMR. Regional indices calculated in patients with normal wall motion varied between segments, but overall were similar between modalities. In patients with abnormal wall motion, RWM was graded as abnormal in 74% segments. CMR and RT3DE thresholds were similar (16-segment average 55 (10)% and 56 (7)%, respectively). Automated interpretation resulted in good agreement with expert interpretation, similar for CMR and RT3DE (sensitivity 0.85, 0.84; specificity 0.81, 0.78; accuracy 0.84, 0.84, respectively). Conclusion: Analysis of RT3DE data provides accurate quantification of regional left ventricular function and allows semiautomated detection of RWM abnormalities, which is as accurate as the same algorithm applied to CMR images

Real-time 3-dimensional echocardiographic quantification of left ventricular volumes

Objectives: We sought to study: 1) the accuracy and reproducibility of real-time 3-dimensional echocardiographic (RT3DE) analysis of left ventricular (LV) volumes in a multicenter setting, 2) interinstitutional differences in relationship with the investigators' specific experience, and 3) potential sources of volume underestimation. Background: Reproducibility and accuracy of RT3DE evaluation of LV volumes has not been validated in multicenter studies, and LV volumes have been reported to be underestimated compared to cardiac magnetic resonance (CMR) standard. Methods: A total of 92 patients with a wide range of ejection fractions underwent CMR and RT3DE imaging at 4 different institutions. Images were analyzed to obtain LV end-systolic volume (ESV) and end-diastolic volume (EDV). Reproducibility was assessed using repeated analyses. The investigation of potential sources of error included: phantom imaging, intermodality analysis-related differences, and differences in LV boundary identification, such as inclusion of endocardial trabeculae and mitral valve plane in the LV volume. Results: The RT3DE-derived LV volumes correlated highly with CMR values (EDV: r = 0.91; ESV: r = 0.93), but were 26% and 29% lower consistently across institutions, with the magnitude of the bias being inversely related to the level of experience. The RT3DE measurements were less reproducible (4% to 13%) than CMR measurements (4% to 7%). Minimal changes in endocardial surface position (1 mm) resulted in significant differences in measured volumes (11%). Exclusion of trabeculae and mitral valve plane from the CMR reference eliminated the intermodality bias. Conclusions: The RT3DE-derived LV volumes are underestimated in most patients because RT3DE imaging cannot differentiate between the myocardium and trabeculae. To minimize this difference, tracing the endocardium to include trabeculae in the LV cavity is recommended. With the understanding of these intermodality differences, RT3DE quantification of LV volume is a reliable tool that provides clinically useful information