RT Journal Article
SR Electronic
T1 Test-retest precision of functional MR in sensory and motor task activation.
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 95
OP 98
VO 17
IS 1
A1 F Z Yetkin
A1 T L McAuliffe
A1 R Cox
A1 V M Haughton
YR 1996
UL http://www.ajnr.org/content/17/1/95.abstract
AB PURPOSE To determine the test-retest precision of functional MR maps of regions in the brain "activated" by sensory, motor, and cognitive tasks.METHODS Echo-planar images were acquired at 1.5 T in four subjects during voluntary motor activity involving the thumb and fingers and during tactile stimulation of the palm. Each subject performed the two tasks twice. Functional images of each task were generated at three thresholds. Test-retest precision was calculated in terms of two ratios: 1) the pixels activated in both iterations of the tasks in proportion to the pixels activated by either iteration of the task, and 2) the ratio modified to include first-order neighboring pixels. The first is referred to as pixel precision, and the latter as first-order-neighbor pixel precision.RESULTS In each subject, activation from the first and second iteration of each task was located in the same region of the same gyrus. Pixel precision was .57 for the two tasks (at a threshold of 0.50). First-order-neighbor precision was greater than .80 for the two tasks at the same threshold.CONCLUSION High test-retest precision can be obtained in functional MR.