The EACVI/ASE/Industry Task Force to standardize deformation imaging prepared this consensus document to standardize definitions and techniques for using two-dimensional (2D) speckle tracking echocardiography (STE) to assess left atrial, right ventricular, and right atrial myocardial deformation. This document is intended for both the technical engineering community and the clinical community at large to provide guidance on selecting the functional parameters to measure and how to measure them using 2D STE.This document aims to represent a significant step forward in the collaboration between the scientific societies and the industry since technical specifications of the software packages designed to post-process echocardiographic datasets have been agreed and shared before their actual development. Hopefully, this will lead to more clinically oriented software packages which will be better tailored to clinical needs and will allow industry to save time and resources in their development.

OBJECTIVES The aims of this study were to: 1) assess the feasibility of left ventricular (LV) vortex flow analysis using contrast echocardiography (CE); and 2) characterize and quantify LV vortex flow in normal subjects and patients with LV systolic dysfunction. BACKGROUND Vortices that form during LV filling have specific geometry and anatomical locations that are critical determinants of directed blood flow during ejection. Therefore, it is clinically relevant to assess the vortex flow patterns to better understand the LV function. METHODS Twenty-five patients (10 normal and 15 patients with abnormal LV systolic function) underwent CE with intravenous contrast agent, Definity (Bristol-Myers Squibb Medical Imaging, Inc., North Billerica, Massachusetts). The velocity vector and vorticity were estimated by particle image velocimetry. Average vortex parameters including vortex depth, transverse position, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also estimated. RESULTS Vortex depth and vortex length were significantly lower in the abnormal LV function group (0.443 ± 0.04 vs. 0.482 ± 0.06, p < 0.05; 0.366 ± 0.06 vs. 0.467 ± 0.05, p < 0.01, respectively). Vortex width was greater (0.209 ± 0.05 vs. 0.128 ± 0.06, p < 0.01) and sphericity index was lower (1.86 ± 0.5 vs. 3.66 ± 0.6, p < 0.001) in the abnormal LV function group. Relative strength (1.13 ± 0.4 vs. 2.10 ± 0.8, p < 0.001), vortex relative strength (0.57 ± 0.2 vs. 1.19 ± 0.5, p < 0.001), and vortex pulsation correlation (0.63 ± 0.2 vs. 1.31 ± 0.5, p < 0.001) were significantly lower in the abnormal LV function group. CONCLUSIONS It was feasible to quantify LV vorticity arrangement by CE using particle image velocimetry in normal subjects and those with LV systolic dysfunction, and the vorticity imaging by CE may serve as a novel approach to depict vortex, the principal quantity to assess the flow structure.

Two-dimensional speckle tracking echocardiography (2D STE) is a novel technique of cardiac imaging for quantifying complex cardiac motion based on frame-to-frame tracking of ultrasonic speckles in gray scale 2D images. Two-dimensional STE is a relatively angle independent technology that can measure global and regional strain, strain rate, displacement, and velocity in longitudinal, radial, and circumferential directions. It can also quantify rotational movements such as rotation, twist, and torsion of the myocardium. Two-dimensional STE has been validated against hemodynamics, tissue Doppler, tagged magnetic resonance imaging, and sonomicrometry studies. Two-dimensional STE has been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies, and identifying early subclinical changes in various pathologies. A large number of studies have evaluated the role of 2D STE in predicting response to cardiac resynchronization therapy in patients with severe heart failure. However, the clinical utility of 2D STE in the above mentioned conditions remains controversial because of conflicting reports from different studies. Emerging areas of application include prediction of rejection in heart transplant patients, early detection of cardiotoxicity in patients receiving chemotherapy for cancer, and effect of intracoronary injection of bone marrow stem cells on left ventricular function in patients with acute myocardial infarction. The emerging technique of three-dimensional STE may further extend its clinical usefulness.

As decisions in cardiology increasingly rely on noninvasive methods, fast and precise image processing tools have become a crucial component of the analysis workflow. To the best of our knowledge, we propose the first automatic system for patient-specific modeling and quantification of the left heart valves, which operates on cardiac computed tomography (CT) and transesophageal echocardiogram (TEE) data. Robust algorithms, based on recent advances in discriminative learning, are used to estimate patient-specific parameters from sequences of volumes covering an entire cardiac cycle. A novel physiological model of the aortic and mitral valves is introduced, which captures complex morphologic, dynamic, and pathologic variations. This holistic representation is hierarchically defined on three abstraction levels: global location and rigid motion model, nonrigid landmark motion model, and comprehensive aortic-mitral model. First we compute the rough location and cardiac motion applying marginal space learning. The rapid and complex motion of the valves, represented by anatomical landmarks, is estimated using a novel trajectory spectrum learning algorithm. The obtained landmark model guides the fitting of the full physiological valve model, which is locally refined through learned boundary detectors. Measurements efficiently computed from the aortic-mitral representation support an effective morphological and functional clinical evaluation. Extensive experiments on a heterogeneous data set, cumulated to 1516 TEE volumes from 65 4-D TEE sequences and 690 cardiac CT volumes from 69 4-D CT sequences, demonstrated a speed of 4.8 seconds per volume and average accuracy of 1.45 mm with respect to expert defined ground-truth. Additional clinical validations prove the quantification precision to be in the range of inter-user variability. To the best of our knowledge this is the first time a patient-specific model of the aortic and mitral valves is automatically estimated from volumetric sequences.

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