DC-01530 Rev A

TCD Basic Training Basics of TCD Testing

This course will provide the user with a basic overview of how TCD is performed, including :

• Where and how the vessels are examined

• The basic techniques used to find each artery

Objectives

DC-01530 Rev A

Anatomical Directions

DC-01530 Rev A

Transcranial Doppler exams are commonly performed through particular access sites along the neck and head, through the following acoustic windows:

• The trans-temporal window

• The trans-foraminal or sub-occipital window

• The sub-mandibular or retro-mandibular window

• The trans-orbital window

TCD examinations sites

Sub-occipitalSubmandibular

Orbital

Temporal

DC-01530 Rev A

These acoustic windows are used to evaluate the vessels of the

intracranial circulation.

Intracranial windows

DC-01530 Rev A

Trans-temporal window

MIDDLE CEREBRAL ARTERY(MCA)

ANTERIOR CEREBRAL ARTERY(ACA)

POSTERIOR CEREBRAL ARTERY(PCA1/2)

TERMINAL INTERNAL CAROTID ARTERY(TICA)

The trans-temporal windows can be used to evaluate the arteries

of the Circle of Willis.

DC-01530 Rev A

Sub-occipital or Trans-foraminal window

VERTEBRAL ARTERY(VA)

BASILAR ARTERY(BAS)

The trans-foraminal or sub-occipital window can be used to

evaluate the intracranial vertebral and basilar arteries.

DC-01530 Rev A

Orbital window

SIPHON CAROTID ARTERY(SIP)

OPHTLHALMIC ARTERY(OPHT)

The orbital window can be used to evaluate the ophthalmic and

carotid siphon arteries

DC-01530 Rev A

These acoustic windows are used to evaluate the vessels of the

extracranial circulation.

Extracranial windows

DC-01530 Rev A

The sub-occipital window is used to evaluate the extracranial vertebral

arteries near the atlas loop.

Sub-occipital window

DC-01530 Rev A

The sub-mandibular window is used to evaluate the extracranial internal carotid artery, also referred to as the distal ICA.

Sub-mandibular window

DC-01530 Rev A

The trans-temporal window is located on the temporal aspect of the head, cephalad to the zygomatic arch and immediately anterior and slightly superior to the tragus of the ear conch. It’s divided into four separate positions.

Evaluation through the temporal window

4

Zygomatic arch

Tragus

DC-01530 Rev A

The middle and anterior cerebral arteries are usual insonated through the mid or anterior temporal windows by angling anteriorly towards the contralateral eye.

Insonating the MCA and ACA

DC-01530 Rev A

The posterior cerebral arteries are insonated through the same position as the MCA by angling slightly posterior and inferior.

Insonating the PCA

DC-01530 Rev A

The probe angle for the MCA is pointing anteriorly, compared to the angle for the PCA1 which is slightly posterior, and even more posterior for the PCA2 segment.

Probe angle, MCA vs PCA

DC-01530 Rev A

The terminal internal carotid arteries are usually insonated through the mid or anterior temporal windows, and by angling inferiorly towards the feet after insonating the very proximal MCA.

Insonating the TICA

DC-01530 Rev A

Although slight at times, looking at the angle of the probe can be a useful way in identifying the insonated signal.

Temporal window angles

DC-01530 Rev A

The orbital window is located over the closed eyelid.

Evaluation through the orbital window

DC-01530 Rev A

The sub-occipital window is located just below the edge of the back of the skull. The vertebral and basilar arteries are found about two finger spaces from the middle of the head. The basilar artery is insonated by pointing superiorly, and the vertebral arteries laterally from the same location. The atlas loops can be insonated by sliding the probe along the skull laterally on each side.

Evaluation through the sub-occipital window

DC-01530 Rev A

The sub-mandibular window is located beside the angle of the jaw (posterior and medial to the sternocleidomastoid muscle) angling superior and slightly medially.

Evaluation through the sub-mandibular window

DC-01530 Rev A

Vessel values (normal state)Listed below are the typical values, locations and probe angles for the arteries we just discussed:

DC-01530 Rev A

Click on the terms below to be directed to their reference slides.

• Acoustic window: The area defined by the pathway of the ultrasound beam between the transducer and the acoustic reflector.

• Anteriorly: Situated or directed toward the front of the body

• Cephalad: Toward the head or anterior end of the body

• Inferiorly: Situated or directed away from the head.

• Posteriorly: Situated or directed toward the back of the body

• Superiorly: Situated or directed toward the head.

• Sternocleidomastoid muscle:

• Tragus:

• Zygomatic arch:

Definitions

DC-01530 Rev A

Test

DC-01530 Rev A