Automatic Extraction of the 3D Left Ventricular Diastolic Transmitral Vortex Ring from 3D Whole-Heart Phase Contrast MRI Using Laplace-Beltrami Signatures

摘要

In this work, a new method is proposed for automatic extraction of the left ventricular diastolic transmitral vortex ring from 3D whole-heart three directional Phase Contrast MRI. The proposed method consists of two parts, training and extraction. In the training step, an average reference signature of the complex transmitral vortex ring is captured from training subjects using Laplace-Beltrami spectrum and the Lambda2 method. In the vortex extraction step, the trained signature is used to identify the vortex ring by performing an iterative search for the vortex object with minimum distance from the trained signature. The proposed method is validated on a dataset of 8 healthy volunteers with 32 observed diastolic vortex rings. The method was able to successfully extract 27 diastolic vortex rings from a total of 32. Furthermore, the conducted experiments showed the capability of the proposed method in dealing with vortex shape changes that occur between the phases of early and late diastolic filling.