Optic Flow Computation from Cardiac MR Tagging Using a Multiscale Differential Method: A Comparative Study with Velocity-Encoded MRI
نویسندگان
چکیده
The computation of an optic flow field to reconstruct a dense velocity field from a sequence of tagged MR images faces a major difficulty: a non-constant pixel intensity. In this paper, we resolved this problem by regarding the MRI sequence as density images, which adhere to a principle of conservation of intensity. Based on this principle, optic flow equations are developed based on Gaussian derivatives as differential operators. The multiscale optic flow method is applied to cardiac tagged MRI. A quantitative analysis is presented comparing the reconstructed dense velocity field with a directly acquired velocity field using the velocity-encoded (VEC) MRI.
منابع مشابه
Purely Evidence Based Multiscale Cardiac Tracking Using Optic Flow
Heart disease can negatively influence cardiac pump function. To assess cardiac tissue function, a method based on classical optical flow theory applied in the spectral domain is presented. Assumption of pixel intensity conservation is replaced by assumption of spatial phase conservation. Simultaneous application to two independent observations of the same optical flow field removes the necessi...
متن کاملA New Methodology for Multiscale Myocardial Deformation and Strain Analysis Based on Tagging MRI
Myocardial deformation and strain can be investigated using suitably encoded cine MRI that admits disambiguation of material motion. Practical limitations currently restrict the analysis to in-plane motion in cross-sections of the heart (2D + time), but the proposed method readily generalizes to 3D + time. We propose a new, promising methodology, which departs from a multiscale algorithm that e...
متن کاملEffect of Breath Holding on Blood Flow Measurement using Fast Velocity Encoded Cine MR Imaging
Introduction Velocity encoded tine (VEC) MR imaging provides quantitative assessment of blood flow in the cardiovascular system. With use of segmented k-space fast VEC MR imaging, noninvasive assessment of blood flow and vasodilator flow reserve in the coronary artery and coronary arterial bypass graft can be obtained within a single breath-hold time. However, it has been pointed out that blood...
متن کاملObjective method for assessment of reliability of particle tracing visualization in 4D FLOW MRI
Background Three-dimensional (3D) velocity-encoded MRI (4DFLOW) of the heart may be used for the assessment of systolic and diastolic function. Particle tracing is frequently used as a technique for visualization of 3D intra-cardiac flow patterns. As the obtained velocity data may suffer from imperfections in the acquisition technique, it is important to have a means for image quality control. ...
متن کاملAdvanced Analysis Techniques for Intra-cardiac Flow Evaluation from 4D Flow MRI
PURPOSE OF THE REVIEW Time-resolved 3D velocity-encoded MR imaging with velocity encoding in three directions (4D Flow) has emerged as a novel MR acquisition technique providing detailed information on flow in the cardiovascular system. In contrast to other clinically available imaging techniques such as echo-Doppler, 4D Flow MRI provides the 3D Flow velocity field within a volumetric region of...
متن کامل