Vascular filters of functional MRI: spatial localization using BOLD and CBV contrast.
The spatial distributions of functional activation of rat somatosensory cortex by forepaw stimulation were quantitatively compared using blood oxygen level dependent (BOLD) signal and signal weighted by cerebral blood volume (CBV). The BOLD contrast to noise (CNR) distribution showed a significant dorsal shift with respect to the CBV method at fields strengths of 2 T (0.69 +/- 0.09 mm) and 4.7 T (0.44 +/- 0.15 mm). These shifts were attributed to the gradient of resting state blood volume across somatosensory cortex and the different CNR characteristics of the two image methods. The underlying principles suggest that the CBV method has a more uniform sensitivity to percent changes in functional indicators (blood volume or deoxygenated hemoglobin) across regions of variable resting state CBV. Magn Reson Med 42:591-598, 1999.
Mandeville
J B
JB
NMR Center, Massachusetts General Hospital, Charlestown, Massachusetts,USA. jbm@nmr.mgh.harvard.edu
Marota
J J
JJ
D000818:Animals; D001783:Blood Flow Velocity; D001810:Blood Volume; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media / Q000008:administration & dosage; D004558:Electric Stimulation; D052203:Ferrosoferric Oxide; D005552:Forelimb; D007275:Injections, Intravenous; D007501:Iron / Q000008:administration & dosage; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010087:Oxides / Q000008:administration & dosage; D051381:Rats; D013003:Somatosensory Cortex / Q000098:blood supply* / Q000378:metabolism
D003287:Contrast Media; D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide