We present a new technique to overcome a major disadvan- tage of SPECT-guided surgery, where a 3D image of the distribution of a radiotracer augments the live view of the surgical situs in order to identify radiopositive tissue for resection and subsequent histological analysis. In current systems, the reconstructed SPECT volume is outdated as soon as the situs is modified by further surgical actions, due to tissue dis- placement. Our technique intraoperatively estimates the displacement of radiopositive tissue, which enables the update of the SPECT image augmentation. After the initial SPECT reconstruction is complete, we deploy a 2D γ-camera along with a technique to optimize its placement. We automatically establish a correspondence between regions of interest in the reconstructed volume and the near real-time 2D γ images. The 3D displacement of the radiopositive nodules is then continuously estimated based on the processing of the aforementioned γ-camera's output. Initial results show that we can estimate displacements with ±1 mm accuracy.
['Francisco Roberto Pinto', 'Bernhard Fuerst', 'Benjamin Frisch', 'Nassir Navab']
Radiopositive Tissue Displacement Compensation for SPECT-guided Surgery