Generation of normalization maps for pixelated pinhole SPECT detectors by scanning a uniform cylinder phantom

In this work, a method of generating normalization maps by scanning a large uniform cylindrical object in standard tomography mode (with the collimator on) has been investigated. This method may have several advantages over point-source approaches: First, since the object is not attached to the collimator, the normalization map generated may be less sensitivity to the geometric changes than the point-source-atpinhole approach. Second, it represents the typical photon incident angles during imaging. Third, it can be applied to single-pinhole and multi-pinhole collimators. Combined with the point-source normalization at 360 mm distance, a normalization correction map (to correct for the 360 mm point-source normalization) can be generated for the specific isotope and collimator and thus applied to different scanners of the same type.