Normal myocardial perfusion on 64-detector resting cardiac CT

Area of Science:

• Cardiovascular imaging
• Radiology
• Cardiac CT

Background:

• Cardiac CT is increasingly utilized for coronary arteries, cardiac structure, and function assessment.
• Myocardial perfusion imaging using CT is an active area of research.

Purpose of the Study:

• To define the normal pattern of myocardial perfusion using resting 64-detector cardiac CT.
• Establish reference values for myocardial perfusion on cardiac CT angiography.

Main Methods:

• 33 patients with normal radionuclide perfusion imaging and CT angiography underwent 64-detector cardiac CT.
• Myocardial perfusion was quantified in Hounsfield units (HU) using manual and automated methods for the 17-segment model.
• Perfusion segments were analyzed by coronary territory, apex-to-base, and myocardial wall.

Main Results:

• Mean myocardial perfusion ranged from 92-98 HU depending on the method and cardiac phase (systole/diastole).
• The septum exhibited significantly higher attenuation values compared to other myocardial walls.
• Lower attenuation values were observed in the left circumflex artery territory and the apex.

Conclusions:

• Normal resting myocardial perfusion on cardiac CT angiography corresponds to 92-98 HU in the coronary arterial phase.
• The interventricular septum consistently shows higher CT attenuation values, reflecting normal perfusion patterns.