Click on Images for Enlarged View
Clinical History: Forty-eight year old with numbness of right arm and leg.
Procedure: Following acquisition of a 3D volume T1-weighted gradient echo study of the brain, a series of 10 axial slices parallel to the anterior-posterior commisural line were obtained using a susceptibility/sensitive sequence during rest and during self-paced rapid alternative finger motion bilaterally. The two sets of images were subsequently post-processed using a nonparametric Mann-Whitney pixel-by-pixel algorithm and centroid linkage to provide statistical maps of activated cortex. A single slice was similarly obtained during face movement. The data were color coded and overlayed on T1-weighted images.
Radiologic Findings: Functional data generated during bilateral hand motion demonstrates pronounced activation on both sides of the central sulcus, more prominent on the left. This is consistent with the expected location of primary motor and primary sensory cortex. Minimal activation is also noted within the left parietal lobes. Activation tracking within the central sulcus is noted extending towards the vertex, consistent with the draining veins of the adjacent cortex. A parenchymal lesion suspicious for a focus of demyelination was noted on T2-weighted images (not shown) in the left frontal lobe approximately two centimeters anterior to this region of motor activation.
Diagnosis: Demyelination
References:
1. Ogawa S, Lee MT, Kay AR, Tank DW. Brain magnetic resonance
imaging with contrast dependent on blood oxygenation.
Proc Natl Acad Sci USA 1990; 87:9868-9872.
2. Ogawa S, Tank DW, Menon R, Ellerman JM, Kim S-G, Merkle H, Ugurbil K.
Intrinsic signal changes accompanying sensory stimulation: functional brain mapping
with magnetic resonance imaging. Proc Natl Acad Sci USA 1992; 89:5951-5955.
3. Kwong KK, Belliveau JW, Chestler DA, Goldberg IE, Weisskoff RM, Poncelet BP,
Kennedy DN, Hoppel BE, Cohen MS, Turner R, Cheng H-M, Brady TJ, Rosen BR.
Dynamic magnetic resonance imaging of human brain activity during primary
sensory stimulation. Proc Natl Acad Sci USA 1992; 89:5675-5679.
4. Schneider W, Noll DC, Cohen JD. Functional topographic mapping
of the cortical ribbon in human vision with conventional MRI scanners. Nature 1993; 356:150-153.
5. Bandettini PA, Wong EC, Hinks RS, Tikofsky RS, Hyde JS.
Time course EPI of human brain function during task activation. Magn Reson Med 1992; 25: 390-397.
6. Lai S, Hopkins AL, Haacke EM, Li D, Wasserman B, Buckley P, Friedman L,
Meltzer H, Hedera P, Friedland R. Identification of vascular structures as a major
source of signal contrast in high resolution 2D and 3D functional activation imaging
of the motor cortex at 1.5T: preliminary results. Magn Reson Med 1993; 30:387-392.
7. Kim S-G, Ashe J, Hendrich K, Ellerman JM, Merkle H, Ugurbil K, Georgopolus AP.
Functional magnetic resonance imaging of motor cortex: hemispheric asymmetry
and handedness. Science 1993; 261:615-517.
8. Hedera P, Lai S, Haacke EM, Lerner AJ, Hopkins AL, Lewin JS, Friedland RP.
Abnormal connectivity of the visual pathways in human albinos demonstrated by
susceptibility sensitized magnetic resonance imaging. Neurology 1994; 44:1921-1926.