A Software Tool for Heart AVJ Motion Tracking Using Cine Cardiovascular Magnetic Resonance Images

Abstract

One important index to assess left ventricular diastolic function is the quantitative measurement of atrioventricular junction (AVJ) motion in one cardiac cycle including systole and diastole. The best way to perform the measurement is to use a software tool that can conduct AVJ motion tracking from cine cardiovascular magnetic resonance (CMR) images. In this paper, a software tool for this purpose is presented by using the insight segmentation and registration toolkit (ITK), the visualization toolkit (VTK), and Qt. We propose a surface area-based tracking approach in the software tool. In the tracking approach to obtain the surface area swept by six points being tracked, we manually select six points from four-, three- and two-chamber views of CMR images. After that, we reconstruct the 3-D coordinates of the six points from image acquisition parameters extracted from DICOM files. We perform interpolation by using parametric cubic curve fitting techniques. From the curve fitting results, we finally obtain the surface areas for all time points in one cardiac cycle. The software tool has been successfully implemented. The functionality include single point-based tracking, surface area-based tracking by using 6 tracked points, generation of displacement, sweep surface area and velocity, and generation of tracking movies. From the software engineering practice, it is concluded that ITK, VTK, and Qt are very handy software systems to implement automatic image analysis functions for CMR images, such as quantitative measure of motion by visual tracking. The software tool provides a convenient and efficient way to measure AVJ motion and extends the scope of methods for ventricular function assessment.

Validation of a rapid semi-automated method to assess left atrial longitudinal phasic strains on cine cardiovascular magnetic resonance imaging

“…1 right column). The atrioventricular junctions were selected as the mitral valve insertion points at the septal and lateral borders of the annulus on the 4-chamber view, and the anterior and inferior annular insertion points on the 2-chamber view [ 12 – 15 ]. The mid-point of posterior LA wall was defined as the intersection point of the LA posterior wall and the LA long-axis (the length of which is used for estimating the LA volume based on area-length formula) [ 16 ].…”

Imaging 4D morphology and dynamics of mitral annulus in humans using cardiac cine MR feature tracking

“…The tracking method in this study was enhanced with some latest development of an integrated software tool 33 , which is ready for clinical usage. In this software tool, we used the Insight Segmentation and Registration Toolkit (ITK) for image processing part of the MA tracking, the Visualization Toolkit (VTK) for interaction and visualization of the processed images, and Qt for graphical user interface.…”

“…The MA located at the junction of the left atrium and ventricle was tracked for all 18 radially rotational long-axis slices and subsequently reconstructed in 3D over the entire cardiac cycle. This was performed semi-automatically using an in-house developed program at National Heart Centre Singapore 33 – 35 . The whole process is shown in Fig.…”

Age-related changes in four-dimensional CMR-derived atrioventricular junction velocities and displacements: Implications for the identification of altered annular dynamics for ventricular function assessment

“…A spline curve interpolation was performed to reconstruct the 3D AVJ geometry, using a fully automated smoothing procedure based on a penalized least squares method [ 12 ]. Two CMR-based indices, sweep surface area (SSA) and sweep surface area velocity (SSAV), were adopted to further quantitatively characterize 3D AVJ motion [ 5 , 7 ]. Following the AVJ reconstruction by a curve at each CMR frame, the SSA (area bounded between the corresponding curves) was computed as the surface area swept out by the AVJ at successive CMR frames by Delaunay triangulation.…”

“…Cardiovascular magnetic resonance (CMR) imaging has emerged as a new way of quantifying long-axis function of the atrioventricular junction (AVJ) with good reproducibility [ [1] , [2] , [3] , [4] , [5] , [6] , [7] ]. Advantages of CMR over conventional tissue Doppler imaging (TDI) include absence of angle dependency [ 8 ], and higher robustness to mask (similar to sample volume in TDI) size and location [ 9 , 10 ].…”