Real Time Cardiac SPECT and 2D Ultrasound Image Registration

In this paper we present a technique for fully automatic, real-time cardiac SPECT (Single Photon Emitting Computed Tomography) and 2D ultrasound image registration. Our registration algorithm allows a physician to perform an ultrasound exam after a series of ECG-gated SPECT images has been acquired and see in real time the registration of both modalities. A specific ECG segmentation algorithm has been developed in order to associate each US image acquired on the fly with the appropriate SPECT volume representing a heart-beat instant.