In the transtemporal approach, which vessels are assessed?

• A. MCA, ACA, PCA, and ICA
• B. MCA only
• C. ACA and MCA
• D. ICA and PCA

Answer: (A)

The transtemporal ultrasound window is used to insonate the major intracranial arteries that lie near the base of the brain. From this window, you can visualize the MCA as it travels laterally in the Sylvian fissure, and with the right angles you can also assess the ACA as it moves medially toward the frontal lobes and the PCA as it curves toward the occipital region. In addition, the terminal portion of the internal carotid artery, where it bifurcates into the MCA and ACA, can be accessed through this window in many patients. Because this approach allows evaluation of all four vessels—MCA, ACA, PCA, and ICA—it is considered capable of assessing them together.