High-frequency ultrasound for evaluation of intimal thickness

The measurement of carotid intima-medial thickness is a well-validated measure of cardiovascular risk. Although atherosclerosis occurs in the intima, this arterial layer is not measured alone because of the limitation in ultrasound resolution with standard-frequency probes.

We evaluated the feasibility of using a 55-MHz ultrasound system with high resolution to measure intima thickness in several vascular territories compared with a "standard" frequency probe.

The intima-medial thickness was measured in the brachial, radial, and tibial arteries in 10 healthy subjects and 5 subjects with peripheral arterial disease. The high-frequency ultrasound probe showed superior resolution compared with the standard-frequency probe, allowing for measurement of intima separately from media.

The intima can be measured independently of media with a high degree of reproducibility using a high-frequency probe. This technology may allow for early detection of cardiovascular risk and extend knowledge about the physiologic changes in early atherosclerotic development.