The Role of Rest Image in patients Showing Normal Stress Image on Tc-99m Myocardial Perfusion Scan

Tc-99m myocardial perfusion agents such as Tc-99m sestamibi or Tc-99m tetrofosmin has advantages over T1-201 for myocardial perfusion scan such as low attenuation and easy availability. However, Tc-99m agents do not redistribute so they need to 13 be given 2 times, namely after stress and at rest. To evaluate whether rest image is needed in patients showing normal stress images, 43 patients who underwent both myocardial perfusion scan and coronary angiography and showed normal stress images were evaluated. Findings of rest images of them were evaluated whether they change the diagnosis or treatment plans. Among 43 patients who showed normal stress myocardial perfusion imaging, 31 (72.1%) showed no additional information. However, among 5 patients with vasospastic angina 4(80%) showed abnormal rest images in spite of normal stress images. So, when vasospastic angina is suspected clinically, rest image could be helpful identifying patients with coronary vasospasm. In conclusion, rest myocardial perfusion images were not helpful in 72.1 % of patients with angina when stress images were normal. In only exception was those with vasospastic angina.