Michinobu Nagao MD, Presenter: Nothing to Disclose

Hiroshi Matsuoka MD, PhD, Abstract Co-Author: Nothing to Disclose

Hideo Kawakami MD, PhD, Abstract Co-Author: Nothing to Disclose

Hiroshi Higashino MD, Abstract Co-Author: Nothing to Disclose

Teruhito Mochizuki MD, Abstract Co-Author: Nothing to Disclose

Masahiko Uemura MD, PhD, Abstract Co-Author: Nothing to Disclose

Kenya Murase PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Assessment of hemodynamic change on myocardial ischemia at rest using cardiac CT has not been elucidated yet. We hypothesized that variations in subendocardial perfusion during the cardiac cycle might be related to appearances of myocardial ischemia. The purpose is to investigate the ability of contrast-enhanced 64-slice multidector computed tomography (MDCT) at rest in detecting myocardial ischemia, conventionally depicted by stress/rest myocardial perfusion scintigraphy (MPS).

Thirty-three patients with myocardial ischemia, were diagnosed by stress/rest thallium-201 MPS; contrast-enhanced cardiac MDCT was performed at rest (coronary CT-angiography, and end-diastolic and end-systolic cardiac images). We reconstructed 2D long and short axis cardiac images in end-diastolic and end-systolic phases using the raw data from coronary CT angiography. CT number (HU) in the myocardium was used as a parameter for myocardial perfusion. Myocardium was expressed using a color scale that depicts faint low density areas more clearly than gray scale. Myocardium was divided into 17 segments according to the AHA classification in each case. We evaluated the variation in blood flow distribution in end-systole and end-diastole in the segments depicted as ischemia on stress/rest MPS.

Stress/rest MPS detected 126 of 561 ischemic segments in 33 patients. In 110 of 126 (87%) segments, and in 32 of 33 (97%) patients, cardiac CT of end-diastolic and end-systolic phases showed a pattern of endocardial hypoperfusion at systole and normal perfusion at diastole.

Our results suggest that myocardial ischemia is characterized by systolic endocardial hypoperfusion and normal perfusion at diastole. Cardiac CT with 64-slice MDCT has a significant advantage in the assessment of coronary artery disease because it enables non-invasive evaluation of both coronary artery stenosis and myocardial perfusion using the one modality.

We introduce a new method that uses high-resolution myocardial perfusion images with 64-slice contrast-enhanced MDCT. CT perfusion imaging has a good performance of detecting myocardial ischemia.

Nagao, M, Matsuoka, H, Kawakami, H, Higashino, H, Mochizuki, T, Uemura, M, Murase, K, et al, , et al, , Detection of Myocardial Ischemia Using Contrast-enhanced 64-slice MDCT: Comparison with Stress/Rest Myocardial Scintigraphy.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5008320.html