Prabhakar Rajiah MBBS, Presenter: Nothing to Disclose

Theodore J. Dubinsky MD, Abstract Co-Author: Nothing to Disclose

Lee M. Mitsumori MD, MS, Abstract Co-Author: Nothing to Disclose

Bill H. Warren MD, Abstract Co-Author: Nothing to Disclose

Kelley Branch MD, Abstract Co-Author: Research grant, General Electric Company, Milwaukee, WI

To compare a cohort of patients who had both coronary CT angiography and stress thallium testing, to determine characteristic findings in CT angiography that will predict reversible and fixed ischemia.

The PACS database of our University hospital was reviewed for all coronary CT angiographies, performed from Jan 1, 2006 till April 1, 2007. Of the 344 CTAs, 62 patients had thallium stress tests as well. Of these, 46 had both studies done within 4 weeks of each other and were included in the study group. The CTAs and thallium scans were reviewed to determine severity, extent and number of vessels involved with coronary artery disease on CT. Chi square contingency table analysis is utilized to analyse data.

There were 47 patients(31 males, 16 females) who had both Cardiac CT and thallium stress test.26 of these had normal Thallium tests. Of these 26, CT was normal in 11, showed diffuse calcification without stenosis in 6, diffuse calcification with mild stenosis in 7 and occlusion of native vessels with patent grafts in 2.21 patients had abnormal thallium scans (15 ischemia, 11 infarcts). CT correlated well in 17 patients (12 had ischemia in thallium with high grade stenosis in CT, 5 had infarction in thallium with occlusion in CT). CT didn’t correlate well in 4 patients (ischemia in thallium, calcification in CT with no stenosis in CT). There was a good correlation between the number of vessels involved and severity of disease with the reversible defects in thallium(p< 0.005).

Presence of occlusion or stenosis > 50 % on CT angiography in patients with diffuse calcific plaque is a good predictor for location and presence of ischemic defects in thallium scans. However, diffuse calcification on its own or with mild stenosis does not predict the presence or location of ischemic defects.

Coronary CT angiography is a good predictor for presence and location of ischemic defects in thallium

Rajiah, P, Dubinsky, T, Mitsumori, L, Warren, B, Branch, K, Comparison of Retrospectively-gated 64-slice Coronary CT Angiography and Gated Thallium SPECT Stress Test in Evaluation of Coronary Artery Disease.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5001716.html