Large-vessel distensibility measurement with electrocardiographically gated multidetector CT: phantom study and initial experience.

The purpose of this study was to prospectively examine vessel distensibility measurements by using electrocardiographically gated multidetector computed tomography (CT) in a phantom compared with measurements by using a digital camera and to examine feasibility in humans. Large-vessel phantoms were constructed, using a pulsatile flow pump, and absolute diameter and percentage diameter changes during pulsation were measured. After institutional review board approval and patient consent were obtained, the abdominal aorta of four patients was scanned with an electrocardiographically gated CT protocol. The mean difference in percentage diameter change between CT and optical measurements for the phantom ranged from -0.47% to 0.14%. The range of area changes in five locations along the abdominal aorta in four patients was 2.97%-37.16%. Findings of this study indicate that electrocardiographically gated CT angiography data reconstructed across cardiac phases permit measurements of large-vessel distensibility in a phantom model and that vessel distensibility measurement in humans may be possible. Copyright (c) RSNA, 2007.