Characterization of radiation doses in computed tomography

11/01/2010 - 5:00pm to 6:00pm
Dr. David Hinterlang (Nuclear Science)
McKnight Brain Institute LG110A/B

Computed Tomography (CT) is increasingly relied upon as the diagnostic tool of choice for a wide variety of medical conditions.  Recent advances in CT technology permit the rapid acquisition of large amounts of volumetric data.  Unfortunately, this widespread use has also lead to the overprescription of CT examinations, disregard for concurrent patient dose, and in some cases significant overexposures to patients.  Recent testimony before the US Congress on these issues highlighted some of the limitations in knowledge and training that can result in unnecessarily large doses of ionizing radiation being deilvered to patients.  The University of Florida has been a leader in the accurate characterization of CT doses and this seminar presents an overview regarding empirical techniques and findings related to these medical radiation exposures.  Dr. Hintenlang has developed novel empirical techniques for the evaluation of doses in CT.  The fundamental parameters of interest for accurate dosimetry are the specific organ doses.  Measurement systems have been developed to permit the evaluation of organ doses, consisting of a series of anthropomorphic phantoms representing a distribution of patient sizes, and a novel radiation dosimetry system to unobtrusively measure organ doses within these phantoms.  Examples comparing results for patients of varying demographics and CT scanner applications are presented.   Applications spanning multiple generations of diagnostic CT (axial To multi-detector CT) as well as applications specific to image guided radiation therapy (cone beam CT) will be presented.

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