Ultrasound protocols to measure carotid intima-media thickness: one size does not fit all.

Carotid intima-media thickness (CIMT) is frequently used as a measure of atherosclerosis in various research areas. Despite its frequent use, there are still no accepted standards for the most optimal ultrasound protocol for single or repeat CIMTassessments. Hence, choices of the CIMT ultrasound protocol to be used are generally based on experience and expert opinion rather than on solid evidence from methodologic studies. Even though some methodologic issues have begun to be addressed, there are many outstanding topics that require further evaluation. Anticipating the availability of solid evidence, there is lively debate on what constitutes the ideal ultrasound protocol, which is illustrated by the point-counterpoint discussion presented in this issue of JASE. According to Polak, there are no firm data to support the view that complex CIMT protocols improve the likelihood of detecting differences between intervention groups in trials. This viewpoint seems to be based partly on personal experience rather than on methodologic evidence. In the next sections, we aim to provide a balanced appraisal of the value of extensive ultrasound protocols in both observational and intervention studies.