Estimation of cerebral blood flow using 123I-IMP acquisition data without any blood sampling

2360 Objectives In quantification of the cerebral blood flow (CBF) using 123I-IMP autoradiography (ARG), we usually need to take an arterial blood sample (ABS) 10 min after injection of 123I-IMP (Ca10) by arterial puncture. Patients to be examined benefit from avoidance of the arterial puncture. The purpose of this study is to establish a noninvasive method for estimation of 123I-IMP ABS activity for quantification of CBF without any blood sampling. CBF calculated by 123I-IMP ARG using measured or estimated Ca10 was compared with the reference CBF measured by 15O-water PET ARG. Methods Multiple regression analysis was employed to calculate Ca10 using planar dynamic lung and static brain images obtained on an initial circulation of 123I-IMP and brain SPECT. The 123I-IMP study was applied to 23 patients and 15O-water ARG was simultaneously applied to 20 patients of them. Lung washout counts and the time course of brain counts were used for explanatory variables and Ca10 was used for the dependent variable. The regression equation was calculated with these variables. Results A significant correlation (r=0.907, p Conclusions Ca10 can be accurately estimated using 123I-IMP images without any blood sampling. CBF can be obtained using the estimated Ca10 instead of Ca10 measured with an actual ABS