John Nema Mafi BS, Presenter: Nothing to Disclose

Baowei Fei PhD, Abstract Co-Author: Nothing to Disclose

Robert C. Gilkeson MD, Abstract Co-Author: Research grant, General Electric Company Research support, Siemens AG

Sharon Roble MD, Abstract Co-Author: Nothing to Disclose

Anthony Dota MD, Abstract Co-Author: Nothing to Disclose

Prashanth Katrapati MD, Abstract Co-Author: Nothing to Disclose

Hiram Bezerra MD, Abstract Co-Author: Nothing to Disclose

Hesheng Wang MS, Abstract Co-Author: Nothing to Disclose

John Coletta MD, Abstract Co-Author: Nothing to Disclose

Wei Wang MS, Abstract Co-Author: Nothing to Disclose

Leslie Ciancibello RT, ARRT, Abstract Co-Author: Former employee, Koninklijke Philips Electronics NV Grant, Siemens AG

Marco Costa MD, Abstract Co-Author: Nothing to Disclose

Daniel I. Simon MD, Abstract Co-Author: Nothing to Disclose

Carl Orringer MD, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

The computed tomography (CT) calcium score predicts risk of cardiovascular events. However, relatively high cost ($250-1000) and radiation dose (1-3 mSv) limit its universal utility as a screening tool. Dual Energy Subtraction Digital Radiography is an inexpensive (<$60) and low radiation technique (0.07 mSv) that enables improved detection of calcified structures when compared to conventional chest radiographs. In this pilot study, we evaluated the feasibility of a coronary artery calcium (CAC) score system based on dual energy subtraction digital radiography (DEDR).

We identified 39 patients with documented CAC for DEDR scoring who underwent non-contrast CT and DEDR chest imaging performed within 12 months. A semi-automated calcium score system was developed based on pixel intensity multiplied by the area of the region of interest. DEDR scores were plotted against CT scores and a receiver operating characteristic (ROC) curve was performed to determine a DEDR score threshold that predicted a CT score ≥400. A relatively high DEDR score threshold would be chosen in order to maximize positive predictive value (PPV).

The DEDR score yielded a correlation coefficient of 0.87 (p<0.0001) when compared to the CT score. Of all 39 patients in the cohort, 14 had a DEDR score of ≥270, and 26 had a CT score ≥400. This DEDR threshold demonstrated a PPV of 100% and a negative predictive value of 52% in predicting a CT score ≥400.

This pilot study supports the hypothesis that DEDR can quantify CAC and correlates with the CT score. DEDR also demonstrates excellent PPV for CT scores ≥400. Further refinement of DEDR as a safe and inexpensive supplemental tool to assess CAC appears warranted.

Although the CT score independently predicts cardiovascular risk, its high cost and radiation dose (1-3 mSv) limit its universal use. DEDR (0.07 mSv) can quantify CAC and correlates with the CT score.

Mafi, J, Fei, B, Gilkeson, R, Roble, S, Dota, A, Katrapati, P, Bezerra, H, Wang, H, Coletta, J, Wang, W, Ciancibello, L, Costa, M, Simon, D, Orringer, C, et al, 0, Quantification of Coronary Artery Calcium Using Dual-energy Subtraction Digital Radiography.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007374.html