Updates on CT Dosimetry Abstract
Accurate measurement and assessment of CT Dose indices is vital for equipment constancy and acceptance testing, estimating patient absorbed doses, and comparison of imaging protocols across scanners. In this educational session, updates on several key topics in CT dosimetry will be discussed. Recent scientific and regulatory developments in CT dosimetry offer new indices to better approach patient dose and new approaches to measure dose outside of the “traditional” 4 cm or less beam width scenario.
The first talk will be focused on Size Specific Dose Estimate (SSDE) updates, including how SSDE may be calculated for examinations focused on the head as described by AAPM Report 293. In addition, prospects for scanner implementations of SSDE following approval of a new IEC standard will be discussed. The 2nd presentation will review the findings of AAPM Report 200 and highlight options for measuring dose indices in long phantoms to ensure scatter tails for wide beam geometries are captured. Further discussion of dose index measurement under non-conventional scenarios will follow in the third talk, which will focus on approaches to measure CT dose from helical acquisitions. Finally, approaches to measuring CT dose in air will be discussed, including approaches described by manufacturers in technical manuals when measurements in phantoms alone are not sufficient to assess CTDIvol.
Learning Objectives:
1. Understand how SSDE is calculated in head and body and how it will be implemented on scanners in the future.
2. Understand how CT dose may be measured in a long phantom as described by AAPM report 200
3. Understand how CT dose may be measured without a CTDI phantom or when axial acquisition modes are not available.
Not Applicable / None Entered.
Not Applicable / None Entered.