Quantification of cerebral arterial blood volume and cerebral blood flow using MRI with modulation of tissue and vessel (MOTIVE) signals.
Regional cerebral arterial blood volume (CBVa) and blood flow (CBF) can be quantitatively measured by modulation of tissue and vessel (MOTIVE) signals, enabling separation of tissue signal from blood. Tissue signal is selectively modulated using magnetization transfer (MT) effects. Blood signal is changed either by injection of a contrast agent or by arterial spin labeling (ASL). The measured blood volume represents CBVa because the contribution from venous blood was insignificant in our measurements. Both CBVa and CBF were quantified in isoflurane-anesthetized rats at 9.4T. CBVa obtained using a contrast agent was 1.1 +/- 0.5 and 1.3 +/- 0.6 ml/100 g tissue (N = 10) in the cortex and caudate putamen, respectively. The CBVa values determined from ASL data were 1.0 +/- 0.3 ml/100 g (N = 10) in both the cortex and the caudate putamen. The match between CBVa values determined by both methods validates the MOTIVE approach. In ASL measurements, the overestimation in calculated CBF values increased with MT saturation levels due to the decreasing contribution from tissue signals, which was confirmed by the elimination of blood with a contrast agent. Using the MOTIVE approach, accurate CBF values can also be obtained.
Kim
Tae
T
Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15203, USA.
Kim
Seong-Gi
SG
D000818:Animals; D001810:Blood Volume; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media; D052203:Ferrosoferric Oxide; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010087:Oxides; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D013113:Spin Labels
D003287:Contrast Media; D010087:Oxides; D013113:Spin Labels; D007501:Iron; D052203:Ferrosoferric Oxide