PET evaluation of cerebral hemodynamics in occlusive cerebrovascular disease pre- and postsurgery.
We studied cerebral blood flow (CBF), oxygen extraction fraction (OEF), transit time (TT) and hemodynamic reserve capacity using acetazolamide (ACZ) in both the pre- and postoperative states, and evaluated the effect of surgery on the cerebral hemodynamics.


METHODS
Twelve patients with a unilateral occlusive cerebral artery were studied. Among them, seven patients had extracranial-intracranial (EC-IC) bypass surgery, while the remaining five patients had carotid endarterectomies. The CBF was measured using the (15)O-water bolus injection method in a resting state, 5 and 20 min after intravenous ACZ (1 g), while the OEF and TT were measured by the (15)O steady state method. The values of these parameters were obtained by regions of interest set over the cerebral hemisphere on both sides, and which then were compared between the pre- and postoperative states using the paired Student's t-test.


RESULTS
The t values were 1.36 (CBF at rest), 2.97 (CBF at 5 min after intravenous ACZ), 1.40 (CBF at 20 min after intravenous ACZ), 2.00 (OEF) and -0.86 (TT) on the surgical side, and -0.16, 0.21, 0.22, -0.47 and 0.61 on the nonsurgical side, respectively. The t values of the ACZ response (% increase in CBF) were 3.07 (5 min after intravenous ACZ) and 0.72 (20 min) on the surgical side, and 1.03 and 0.90 on the nonsurgical side, respectively. A significant change was observed only in the CBF studies 5 min after intravenous ACZ.


CONCLUSIONS
PET can demonstrate significant cerebral hemodynamic change after surgery, especially in CBF measurement 5 min after intravenous ACZ, and may therefore be useful for evaluating cerebral hemodynamics pre- and postsurgery.
Kuwabara
Y
Y
Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Ichiya
Y
Y
Sasaki
M
M
Yoshida
T
T
Fukumura
T
T
Masuda
K
K
Fujii
K
K
Fukui
M
M
D000086:Acetazolamide; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D001921:Brain / Q000000981:diagnostic imaging; D002548:Cerebral Revascularization; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010104:Oxygen Radioisotopes; D014055:Tomography, Emission-Computed; D014867:Water
D010104:Oxygen Radioisotopes; D014867:Water; D000086:Acetazolamide