Investigation of the dynamic SPECT (dSPECT) method for Teboroxime using a 4-D kinetic thorax model dMCAT

Tomographic SPECT allows us to visualize, in 3D, the distribution of radiopharmaceuticals in the body which are reconstructed from a series of two dimensional measurements performed around the investigated object. The dSPECT method extends these capabilities into the fourth dimension and creates a series of dynamic 3D images which can be obtained from a single set of dynamic data acquired using only a single rotation of the camera. In order to test the performance of the method for Teboroxime cardiac images, we have modified the 3D MCAT digital phantom to model dynamic changes of activity distributions in different organs of the thorax. Experiments using different acquisition protocols were performed and the resulting data were reconstructed using static (FBP and OSEM) and dynamic (dEM) methods. The images obtained by summing the data from dynamic reconstructions over all time-frames were as good as or better than those from static reconstructions (for the scans which begun 60 or 120 seconds post injection i.e. after the bolus of activity left the heart). Including the bolus in the reconstructions produced distorted images. An important advantage of the dSPECT method is that it reconstructs images in a form of 3D movies that may be used to extract additional diagnostic information, mainly temporal information which is not available in static images and 3D spatial information not present in planar studies.