Feasibility of dynamic myocardial CT perfusion using single-source 64-row CT

Area of Science:

• Cardiovascular imaging
• Radiology
• Medical diagnostics

Background:

• Dynamic myocardial computed tomography perfusion (CTP) is an emerging technique for diagnosing significant coronary artery stenosis.
• Previous reports on CTP have not utilized single-source 64-row CT technology.

Purpose of the Study:

• To evaluate the radiation dose associated with dynamic CTP.
• To assess the diagnostic performance of dynamic CTP in identifying significant coronary stenosis, using catheterization as a reference standard.

Main Methods:

• Prospective study involving 165 patients undergoing adenosine stress dynamic CTP with a 64-row CT scanner.
• Myocardial blood flow (MBF) calculated using deconvolution; Quantitative Perfusion Ratio (QPR) defined as the ratio of MBF in stenotic to non-stenotic regions.
• Diagnostic performance assessed against quantitative coronary angiography (QCA) in 44 patients for detecting ≥50% stenosis.

Main Results:

• Average effective radiation dose for dynamic CTP was 2.5 ± 0.7 mSv.
• MBF was significantly reduced in areas with ≥50% stenosis (0.98 ± 0.24 ml/min/g) compared to non-stenotic areas (1.20 ± 0.32 ml/min/g).
• Diagnostic accuracy for ≥50% stenosis improved from 82% with CT angiography alone to 87% when QPR was included (p<0.05).

Conclusions:

• Dynamic myocardial CTP is feasible with a 64-row CT scanner.
• The procedure can be performed with a low radiation dose.
• Incorporating QPR from dynamic CTP enhances diagnostic performance for significant coronary stenosis compared to CT angiography alone.