Radiation dose reduction strategies for intraoperative guidance and navigation using CT

Abstract

The advent of 64-slice computed tomography (CT) with high speed scanning makes CT a highly attractive and powerful tool for navigating image guided procedures. Interactive navigation needs scanning to be performed over extended time periods or even continuously. However, continuous CT is likely to expose the patient and the physician to potentially unsafe radiation levels. Before CT can be used appropriately for navigational purposes, the dose problem must be solved. Simple dose reduction is not adequate, because it degrades image quality. This study proposes two strategies for dose reduction; the first is the use of a statistical approach representing the stochastic nature of noisy projection data at low doses to lessen image degradation and the second, the modeling of local image deformations in a continuous scan. Taking advantage of modern CT scanners and specialized hardware, it may be possible to perform continuous CT scanning at acceptable radiation doses for intraoperative navigation.