Correlation of Coronary Stenosis Severity by 128-Slice CT Angiography to the Hemodynamic Significance of Coronary Artery Disease by Myocardial Perfusion SPECT
Abstract
Introduction:
The role of CTA in the early detection of coronary artery disease is becoming an established method. SPECT myocardial perfusion imaging is a well known established modality for assessment of hemodynamic significance of coronary stenosis.
Aim:
is to determine the relation of coronary stenosis severity by CTA to the hemodynamic significance of 99mTc- tetrofosmin SPECT MPI.
Material and Methods:
72 patients with multiple high risk factors for CAD, yet with negative history and no ECG signs of coronary artery disease were included. They all underwent 128-slice CT coronary angiography. 28 patients showed abnormal lesions by CT angiography and were referred for myocardial perfusion imaging SPECT by 99mTc- tetrofosmin. The type of the stress was exercise in 10 and adenosine pharmacological in 18 cases. Interpretation of the SPECT was done both visually and by using Semi-quantitative Bull’s eye model to assess for the presence / extent of myocardial ischemia.
Results:
CTA showed no significant lesions (stenosis was < 50%) in 44 patients, while 28 patients showed abnormal findings. The abnormal CT findings were subdivided into equivocal results (stenosis ?50 till ?70%) that were present in 9 cases and 19 cases showed a significant degree of stenosis >70%. The 99mTc-Myoview MPI SPECT showed reversible defects in 4 (44%) cases only from the 9 equivocal patients. The prevalence of reversible ischemia by SPECT reaches 84% (16/19) in the 19 cases who showed >70% stenosis by CT angiography. The relation between the presence of significant coronary artery disease (>70%) and the presence of perfusion defects in SPECT was strong (P < 0.05).
The role of CTA in the early detection of coronary artery disease is becoming an established method. SPECT myocardial perfusion imaging is a well known established modality for assessment of hemodynamic significance of coronary stenosis.
Aim:
is to determine the relation of coronary stenosis severity by CTA to the hemodynamic significance of 99mTc- tetrofosmin SPECT MPI.
Material and Methods:
72 patients with multiple high risk factors for CAD, yet with negative history and no ECG signs of coronary artery disease were included. They all underwent 128-slice CT coronary angiography. 28 patients showed abnormal lesions by CT angiography and were referred for myocardial perfusion imaging SPECT by 99mTc- tetrofosmin. The type of the stress was exercise in 10 and adenosine pharmacological in 18 cases. Interpretation of the SPECT was done both visually and by using Semi-quantitative Bull’s eye model to assess for the presence / extent of myocardial ischemia.
Results:
CTA showed no significant lesions (stenosis was < 50%) in 44 patients, while 28 patients showed abnormal findings. The abnormal CT findings were subdivided into equivocal results (stenosis ?50 till ?70%) that were present in 9 cases and 19 cases showed a significant degree of stenosis >70%. The 99mTc-Myoview MPI SPECT showed reversible defects in 4 (44%) cases only from the 9 equivocal patients. The prevalence of reversible ischemia by SPECT reaches 84% (16/19) in the 19 cases who showed >70% stenosis by CT angiography. The relation between the presence of significant coronary artery disease (>70%) and the presence of perfusion defects in SPECT was strong (P < 0.05).