Correlation between cerebral blood flow values obtained by Xenon/CT and Kety-Schmidt (N2O) methods.
The means of the cerebral blood flow (CBF) values obtained by the stable xenon enhanced CT (Xe/CT) method using two different CT scanners were compared with global CBF value obtained by the Kety-Schmidt (N2O) method as a reference. Xe/CT CBF values were obtained using a GE CT9200 (31 patients, 2 flow maps, 120 kV, absorption constant of 0.040) as well as a GE ProSeed Accell (38 patients, 4 flow maps, 80 kV, absorption constant of 0.028). The protocol of inhalation in the Xe/XT method consisted of 4 min wash-in and 4-min wash-out of 35% stable xenon. In the Kety-Schmidt method, 15% N2O gas was inhaled for 10 min. The N2O content of blood samples was measured using a van Slyke-Neill blood gas analyzer. We corrected all obtained CBF values for a PaCO2 of 34 mmHG (CBF34). The global CBF34 values obtained by the Kety-Schmidt method were linearly correlated with the CBF34 values obtained using the CT9200 and with those obtained using the ProSeed Accell, and the regression line equations were, respectively, Y = 0.64X + 13.7 (X: CT9200, Y: Kety-Schmidt, r = 0.666, p < 0.01) and Y = 0.99X + 11.2 (X: ProSeed Accell, Y: Kety Schmidt, r = 0.756, p < 0.01). Since the CBF values obtained by the Xe/CT method using different CT scanners are not always the same as the global CBF values obtained by the Kety-Schmidt method, CBF values obtained by the Xe/CT method should be corrected referring to the regression line obtained by applying both methods for each patient.
Tone
O
O
Department of Neurosurgery, Musashino Red Cross Hospital, Tokyo Japan.
Ito
U
U
Tomita
H
H
Akimoto
H
H
Sakemi
H
H
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D001930:Brain Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide; D011877:Radionuclide Imaging; D012039:Regional Blood Flow / Q000502:physiology; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes; D009609:Nitrous Oxide