The REICA method for quantification of cerebral blood flow is less affected by lung washout of [123I] IMP than the graph-plot method.

OBJECTIVE

The [Formula: see text]-Ray Evaluation with Iodoamphetamine for Cerebral blood flow Assessment (REICA) method is a new method for cerebral blood flow (CBF) quantification with SPECT and [123I] IMP, which does not require invasive arterial blood sampling, or the use of a regression formula. Moreover, it takes into consideration tracer retention, while the Graph-Plot (GP) method does not. This study aims to confirm the reliability of the REICA method in calculating CBF by accounting for pulmonary tracer retention artefact.

METHODS

Data of 100 patients were retrospectively analyzed. Washout rate (WR) was defined as 1- (max count /min count) in the lungs. The bias due to WR was analyzed by dividing the data into high/low WR groups and a multiple regression analysis was also performed.

RESULTS

The REICA method did not show significant bias according to the [Formula: see text] test ([Formula: see text]), while the GP method showed significant bias ([Formula: see text]). Both the REICA and GP methods showed significant correlation with autoradiography (ARG) method ([Formula: see text], [Formula: see text]) and WR ([Formula: see text], [Formula: see text]) when analyzed via multiple regression analysis with covariates of age and sex.

CONCLUSIONS

The REICA method is a reliable method for CBF quantification, which is unaffected by tracer washout through the lungs unlike the GP method.