Low dose Neurovascular CT

This study is being performed to develop methods to reduce radiation dose in CT exams. There is increasing concern over the individual and population burden of radiation exposure related to medical imaging, particularly CT scans. New CT reconstruction algorithms (‘HYPR’ and ‘PICCS’) under development at UW show promise to reduce radiation exposure by 10- to 50-fold for certain types of CT acquisitions. Some of these cannot be tested directly at the moment due to CT scanner hardware and software limitations, while others require direct acquisition of low dose data sets. However by collecting the raw scanner data from already performed CT scans we can directly study the effects of dose reduction and also simulate low dose CT and test the reconstruction techniques. While this will not affect or benefit subjects enrolled in this study, the knowledge gained will help physicists and commercial partners such as GE Healthcare develop next-generation CT scanners capable of scanning with markedly lower radiation exposure. If successful, this would provide a new way to reduce future population risk of cancer, cataracts, and other known complications of radiation exposure.