A simplified method for measuring cerebral blood flow with xenon-enhanced computed tomography.
The measurement of cerebral blood flow using the xenon-enhanced computed tomography (XECT) technique requires that the build-up of xenon in both brain tissue and end-tidal expired air be determined as a function of time. Monitoring of the former is carried out using CT scanning and the latter, most often, using a thermoconductivity analyser or mass spectrometer. This paper examines the possibility of greatly simplifying the XECT technique by eliminating the need for either thermoconductivity analyser or mass spectrometer. In the proposed approach, the patient's expired air is channelled through the scan field using a flexible plastic tube and sampled by the CT scanner in conjunction with the build-up of xenon in brain tissue. Phantom measurements have demonstrated the ability of the CT scanner to detect variations in the xenon concentration in expired air while computer simulations have shown that errors arising as a result of the proposed methodology are small compared to other inherent sources in the XECT technique.
Department of Medical Physics, Manitoba Cancer Treatment and Research Foundation, Winnipeg, Canada.
J
J
Bews
K
K
St Lawrence
P
P
Dunscombe
B
B
McClarty
M
M
Kroeker
D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D006801:Humans; D011877:Radionuclide Imaging; D012119:Respiration; D014057:Tomography, X-Ray Computed / Q000379:methods; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes