[Principles of duplex ultrasound diagnosis of the internal thoracic artery].

Because of its better long term patency the internal thoracic artery has become the conduit of choice for myocardial revascularization. Thirty healthy young volunteers were investigated to prove the suitability of the duplex system for investigating the internal thoracic artery. The mean systolic peak flow velocity was 1.15 m/s in the proximal vessel decreasing to 0.55 m/s in the peripheral course of the artery. Mean internal thoracic artery diameters at the origin were calculated as 2.18 mm for the left and 2.43 mm for the right internal thoracic artery. The flow curves represent those of elastic-type vessels, whereas in a small number resistance curves occurred representing the muscular type. The combination of two-dimensional B-mode and Doppler unit allows visualization of the internal thoracic artery and assessing the flow velocities within the vessel. Ultrasonic duplex scanning is a noninvasive diagnostic tool for investigation of the internal thoracic artery.