Semiautomated method for noise reduction and background phase error correction in MR phase velocity data

Journal of Magnetic Resonance Imaging - Tập 3 Số 3 - Trang 521-530 - 1993
Peter G. Walker1, G. Cranney2, Markus B. Scheidegger2, Gena Waseleski1, Gerald M. Pohost2, Ajit P. Yoganathan1
1School of Chemical Engineering, Georgia Institute of Technology, 888 Hemphill Ave. Atlanta, GA 30332-0100
2Department of Cardiovascular Disease, School of Medicine, University of Alabama at Birmingham, Birmingham

Tóm tắt

AbstractBackground phase distortion and random noise can adversely affect the quality of magnetic resonance (MR) phase velocity measurements. A semiauto‐mated method has been developed that substantially reduces both effects. To remove the background phase distortion, the following steps were taken: The time standard deviations of the phase velocity images over a cardiac cycle were calculated. Static regions were identified as those in which the standard deviation was low. A flat surface representing an approximation to the background distortion was fitted to the static regions and subtracted from the phase velocity images to give corrected phase images. Random noise was removed by setting to zero those regions in which the standard deviation was high. The technique is demonstrated with a sample set of data in which the in‐plane velocities have been measured in an imaging section showing the left ventricular outflow tract of a human left ventricle. The results are presented in vector and contour form, superimposed on the conventional MR angiographic images.

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Thông tin
Thông tin xuất bản

Journal of Magnetic Resonance Imaging

Tập 3 Số 3

521-530

Thông tin tác giả