Novel Techniques in Projection-based Motion Tracking in Cardiac Magnetic Resonance Imaging

magnetic resonance imaging;MRI;heart;motion tracking;cine;dynamic imaging;projections;T2;T2 Prep;SSFP;Biomedical Engineering

Guo, LihengMcVeigh, Elliot R. ;

Johns Hopkins University

关键词: magnetic resonance imaging;    MRI;    heart;    motion tracking;    cine;    dynamic imaging;    projections;    T2;    T2 Prep;    SSFP;    Biomedical Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/40833/GUO-DISSERTATION-2017.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Magnetic resonance imaging (MRI) is indispensable to the medical imaging of the heart because of its ability to manipulate soft tissue contrast, to image both 2D and 3D regions in arbitrary orientations, and its lack of ionizing radiation. These advantages make MRI a highly flexible imaging modality that is used extensively to examine, for example, the heart’s congenital defects, myocardial infarctions, vascular perfusion, coronary patency, and contractile performance. However, the heart exhibits constant motion due to cardiac contraction and normal human respiration, both of which lead to significant image corruption, making the heart a particularly challenging target to image.Existing cardiac MRI techniques account for this challenge by using some kind of motion avoidance or motion tracking. Such techniques all incur some degree of cost in terms of imaging efficiency, procedural complexity (e.g. setup of electrocardiogram and respiratory bellows) and/or patient stress (i.e. breath holding). In this work, several new MRI motion-tracking techniques were developed and evaluated. They track cardiac and/or respiratory motion, produce multi-frame cine images or contrast-prepared diastolic images of the heart. A common theme is that they all track motion purely from MR-acquired signals, without external devices, cost to imaging efficiency, or added patient stress. Moreover, they all utilize a particular type of MRI data known as the projections. These techniques were implemented through extensive development of customized MR sequences and the associated post-processing to reconstruct motion-free images. Imaging studies of phantoms, animals, and healthy human volunteers were performed to evaluate the motion-tracking abilities of these techniques. It was found that they produced image quality and cardiac functional measurements comparable to existing MR techniques. These techniques hold significant potentials of enhancing the patient experience, image quality, and imaging efficiency of cardiac MRI in clinical practices.