Separation of veins from activated brain tissue in functional magnetic resonance images at 1.5T

Author

Singh, M. ; Kim, T. ; Kim, H. ; Khosla, D.

Author_Institution

Dept. of Radiol. & Biomed. Eng., Univ. of Southern California, Los Angeles, CA, USA

Volume

42

Issue

4

fYear

1995

fDate

8/1/1995 12:00:00 AM

Firstpage

1338

Lastpage

1342

Abstract

A feasibility study was conducted to segment 1.5T functional magnetic resonance images (fMRIs) into gray matter and veins using individual pixel intensity difference and temporal phase delay as two correlated parameters in 1.5T gradient echo images. The time-course of each pixel in gradient echo images acquired during visual stimulation with a checkerboard flashing at 8 Hz was correlated to the stimulation on-off sequence to identify activated pixels, and the temporal delay of each activated pixel was computed by fitting its time-course to a reference sinusoidal function. A histogram of the product of each pixel´s intensity (in the activated image) and corresponding temporal delay could be fitted to a bimodal distribution, which was then used to segment the functional image into veins and activated brain tissue. The results show relatively good demarcation between large veins and activated gray matter using this method

Keywords

biomedical NMR; brain; 1.5 T; 1.5T gradient echo images; 8 Hz; activated brain tissue; activated image; bimodal distribution; checkerboard flashing; correlated parameters; fMRIs; functional magnetic resonance images; gray matter; individual pixel intensity difference; pixel time-course; reference sinusoidal function; stimulation on-off sequence; temporal phase delay; vein separation; visual stimulation; Blood; Brain; Delay; Image segmentation; Magnetic resonance; Magnetic resonance imaging; Pixel; Positron emission tomography; Spatial resolution; Veins;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/23.467861

Filename

467861