Intima-media thickness (IMT), also called intimal medial thickness, is a measurement of the thickness of tunica intima and tunica media, the innermost two layers of the wall of an artery. The measurement is usually made by external ultrasound and occasionally by internal, invasive ultrasound catheters.

There is positive and significant correlation between the IMT of the internal carotid artery and the vertebral and femoral arteries and abdominal aorta. Routine examinations of either one of these arteries can ad important findings regarding early diagnosis for higher risk patients concerning atherosclerotic disease ¹⁾.