Hypercarbia‐induced changes in cerebral blood volume in the cat: A 1H MRI and intravascular contrast agent study

Cerebral blood volume changes with arterial carbon dioxide were monitored by proton T1‐weighted MR images following administration of the intravascular contrast agent Gd‐DTPA labeled with human serum albumin. Without MR contrast, no significant image intensity changes were observed with PaCO2. Following contrast, regional brain image intensities increased significantly over control (0% inspired CO2) in cortical gray, white, and basal ganglia regions with increasing PaCO2 and returned to control intensities upon return to 0% inspired CO2. Imaging of through‐plane and in‐plane phantoms was performed to assess flow effects. Signal losses of 2 and 6% (relative to no flow) were observed for bulk velocities of 5 mm/s at TE values of 15 ms. An intravascular contrast agent may be useful for MRI monitoring of local cerebral blood volume changes during cerebral perturbations. © 1992 Academic Press, Inc.