[Examination of normal database in three-dimensional SSP].

The results of statistical image analyses, such as three-dimensional stereotactic surface projection (3D-SSP), are affected by the normal database (NDB) used. As a general rule, each institution must establish its own NDB for analysis. However, the numbers of institutions with the ability to establish their own NDB are limited. Therefore, it would be ideal if an NDB suitable for other institutions could be established from standard volunteer data gathered at a single institution. In this study, we examined the validity of establishing an NDB suitable for other institutions from the standard volunteer data gathered at our institution, using E.CAM (used as a reference) and IRIX. We established three NDBs. One was established from E.CAM, and the other two were from IRIX (in which overall FWHM was the same as that of E.CAM with Butterworth filter cutoff frequency and using an identical algorithm for image-reconstruction of E.CAM). We then compared the mean values and standard deviations of the NDBs, and also examined the effects on the Z-score map. We determined that the NDB that had been established was suitable for other institutions, using identical FWHM (resolution of SPECT imaging) and an algorithm for image-reconstruction.