[Assessment of cerebral circulation using echo planar imaging--basic analysis in quantitating the mean transit time,...

The mean transit time (MTT), cerebral blood flow (CBF) and cerebral blood volume (CBV) using echo planar imaging (EPI) in 22 aged volunteers were measured based on moment analysis and gamma variate method. The first peak of signal intensity curve (p delta R2.) and the area under the curve after the first peak (AUC) were calculated according to the height over area method, as a convenient quantification. Then, MTT, CBF, and CBV were compared with AUC/p delta R2, p delta R2, and AUC, respectively. There was a good correlation between each other parameter (r = 0.67 - 0.92, every p < 0.001). The slow upward slope and the low peak height, however, caused a larger error between each other parameter.