A Retrospective Offline Respiratory Gating Method for Cardiac Image Sequences

Abstract

The invention provides a retrospective off-respirator respiration gating method of a cardiac image sequence. According to the method, firstly the Laplacian eigenmap in a manifold learning method is used to carry out dimensionality reduction processing on a matrix with the storage of ECG gating cardiac image sequence data to obtain a low-dimensional coordinate matrix embed in a high-dimensional observation data point set, then the Euclidean distance between adjacent feature vectors in the low-dimensional coordinate matrix is calculated, the local maxima of the Euclidean distance is detected and is used as the selection position of a gated frame, and thus a gating image sequence with the removal of respiration motion artifact is obtained. According to the method, the matrix formed by the gray values of all pixels in an image is directly analyzed, and the respiration motion information in the cardiac image sequence is obtained. According to the method, only the solution of the feature value of a sparse matrix is needed, the manual involvement of an operator is not needed, and the method has the advantages of low computational complexity, high degree of automation, and low application cost. Furthermore, only local distance information is used in the method, and a gating result is not sensitive to noise.

Description

technical field [0001] The invention relates to a method for performing retrospective off-line respiratory gating on a cardiac image sequence collected under free breathing conditions to obtain an image sequence in which respiratory motion artifacts are removed, and belongs to the technical field of medical imaging. Background technique [0002] Currently, imaging technology plays a vital role in the clinical diagnosis and treatment of cardiac diseases. When imaging the heart and coronary vessels, the rhythmic contraction and relaxation of the heart causes cardiac motion artifacts in the image, which affects the accurate diagnosis of diseases and the effect of interventional therapy. Cardiac motion artifacts can be suppressed by electrocardiogram (ECG) gating technology, that is, images are acquired at the same phase of each cardiac cycle (generally when the R wave arrives). [0003] Respiratory movement will cause the heart to move in the up-down, left-right and front-back...

AI Technical Summary

Problems solved by technology

This method is not applicable in many cases due to limited time for image acquisition or intervention

For example, this method is not applicable when the patient's respiratory control ability is poor, which seriously affects the temporal and spatial resolution of the image; or the patient can only maintain a short breath-hold time, but the image acquisition takes a long time

The online gating method includes respiratory gating and navigation gating. Respiratory gating is to control the image acquisition equipment to acquire images within a specific time on the basis of using an external breathing detection pad or abdominal belt to detect respiratory movement. The disadvantage is that the operation is relatively Complicated; navigation gating does not require any external components, but it needs to scan the diaphragm in sagittal and coronal positions under normal breathing in advance, and find the top position of the diaphragm as the navigation window position at the end of respiration. This technique is complicated to operate , the scanning period is longer and the scope of application is smaller

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