Image registration accuracy with low-dose CT: how low can we go?

Image-guided interventions are known to lead to improved outcomes and significantly faster patient recovery as compared with conventional open, invasive procedures. Common intraoperative imaging techniques such as endoscopy and fluoroscopy are two-dimensional (2D), and provide a 2D representation of the 3D anatomy. Use of recently emerged multislice computed tomography (CT) can facilitate 3D visualization of anatomy during an intervention. The speed and dimensionality of these CT scanners make their use in image-guided interventions technically feasible. For clinical acceptance, however, the net radiation dose to the patient and the interventionist must be minimized. This article suggests a strategy to reduce radiation dose and describes an evaluation scheme to identify the optimal dose which does not sacrifice the specificity of the image-guided procedure. Our work indicates at least a tenfold reduction in radiation dose