Quantitative measurements of regional cerebral blood volume using MRI in rats: effects of arterial carbon dioxide tension and mannitol.
A three-dimensional (3D) T1-weighted sequence was used to acquire high spatial resolution whole brain images in rats before and after the injection of an intravascular contrast agent. These T1-weighted images were used to estimate regional cerebral blood volume (rCBV) as a percentage of blood volume in each voxel. Ventilation was manipulated to investigate the effects of altered arterial carbon dioxide tension (PaCO2) on rCBV. In addition, different doses of a hypertonic mannitol solution were used to investigate the sensitivity of the proposed method in a serial monitoring paradigm. An rCBV of 2.40% +/- 0.34% was obtained before any physiological manipulation, in good agreement with literature values using alternative techniques. Using this method, it was found that there exists a linear relationship between PaCO2 and rCBV (R2 = 0.77) and that rCBV increased in a dose and time dependent fashion in mannitol-treated rats. High signal-to-noise was available due to the substantial increase in blood signal from the intravascular contrast agent.
Lin
W
W
Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110, USA.
Paczynski
R P
RP
Kuppusamy
K
K
Hsu
C Y
CY
Haacke
E M
EM
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D001784:Blood Gas Analysis; D001810:Blood Volume / Q000187:drug effects / Q000502:physiology*; D001812:Blood-Brain Barrier; D001921:Brain / Q000098:blood supply* / Q000187:drug effects / Q000378:metabolism; D002199:Capillary Permeability; D002245:Carbon Dioxide / Q000378:metabolism*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media; D004234:Diuretics, Osmotic / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008353:Mannitol / Q000494:pharmacology*; D051381:Rats
D003287:Contrast Media; D004234:Diuretics, Osmotic; D002245:Carbon Dioxide; D008353:Mannitol; D019786:Gadolinium DTPA