CAROTID DUPLEX ULTRASOUND Jenelle (General Ultrasound Department) Anatomy Normal Carotid Ultrasound Todd (Vascular Ultrasound Department-Coordinator) Abnormal

CAROTID DUPLEX ULTRASOUND

• Jenelle (General Ultrasound Department)• Anatomy• Normal Carotid Ultrasound

• Todd (Vascular Ultrasound Department-Coordinator)• Abnormal Carotid Ultrasound

• Live Scanning• Demonstration by Todd• Practice time – grab a partner!

CAROTID DUPLEX ULTRASOUNDJenelle Beadle

March, 2015

OBJECTIVES

• Anatomy• Classic• Variants

• Carotid Duplex Ultrasound• Indications• Position/Technique• Required Images• Normal spectral analysis

• Tips/Pitfalls

ANATOMY

Cerebrovascular System• supplies the head

Carotid Duplex Ultrasound• exams the extracranial

portion of the cerebrovascular system

Extracranial Cerebrovascular System• Innominate/brachiocephalic• Subclavian• Vertebral• Common Carotid (CCA)• Internal Carotid (ICA)• External Carotid (ECA)

http://www.slideshare.net/shaffar75/doppler-ultrasound-of-carotid-arteries

Innominate/brachiocephalic(Rt sided only)• Originate: Aortic Arch (1st)• Terminate: Rt CCA / Rt

Subclavian

Subclavian Arteries• Originate:

• Rt – Innominate• Lt – Aortic Arch (3rd)

• Branches: Vertebral• Terminate: Axillary

Vertebral Arteries• Originate: Subclavian

Vertebral Arteries• Originate: Subclavian• Pass through transverse

foramena• C6• Atlas (C1)

• Terminate: join to form basilar (intracranial)

Common Carotid Arteries (CCA)• Originate:

• Rt – Innominate• Lt – Aortic Arch (2nd)

• Terminate: ICA/ECA

External Carotid Arteries (ECA)• Originate: CCA

External Carotid Arteries (ECA)• Branches: numerous

• 1st: Superior Thyroid• Terminate: Superficial Temporal / Maxillary

Internal Carotid Arteries (ICA)• Originate: CCA

• NO extracranial branches

Internal Carotid Arteries (ICA)

• Originate: CCA• Branches:

• Intracranial only

Internal Carotid Arteries (ICA)

• Originate: CCA• Branches:

• Intracranial only

• Terminate: • Circle of Willis

Innominate/Brachiocephalic


Rt Subclavian


Rt Subclavian

Rt Vertebral


Rt Subclavian

Rt Vertebral

Rt CCA


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA

Lt Vertebral


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA

Lt Vertebral

Lt ICA


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA

Lt Vertebral

Lt ICA

Lt ECA


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA

Lt Vertebral

Lt ICA

Lt ECA

Lt CCA


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA

Lt Vertebral

Lt ICA

Lt ECA

Lt CCA

Lt Subclavian


Rt Subclavian

Rt Vertebral

Rt CCA

Rt ICA

Lt Vertebral

Lt ICA

Lt ECA

Lt CCA

Lt Subclavian

Aortic Arch

ANATOMICAL VARIANTS

Numerous anatomical variants involving the aortic arch branches

VARIANTS• Bovine Arch (10%)• Left vertebral arises

from aortic arch (3%)• Aberrant right

subclavian artery (2%)

CLASSIC (85%)• 3 Branches:

Innominate, Lt CCA, Lt Subclavian

*All other aortic arch variants combined (<1%)

Classic 85% Bovine 10%

Aberrant Rt SCl 2%

Lt Vert 3%

BOVINE ARCH (10%)

Bovine Arch: common origin for Innominate and Left CCA

Normal: 3 separate aortic arch branches

• Most common aortic arch branching variant

BOVINE ARCH (10%)

Bovine Arch: common origin for Innominate and Left CCA

• Most common aortic arch branching variant

Normal: 3 separate aortic arch branches

Bovine Arch: Left CCA originates from Innominate

BOVINE ARCH• Type 2

“BOVINE” ARCH

Misnomer:• Erroneous reference to

cow’s anatomy• Actual cow anatomy

consists of a single trunk branch off the aortic arch

LEFT VERTEBRAL – 3RD BRANCH(3%)• Left vertebral: 3rd branch

• Left subclavian: 4th branch

ABERRANT RIGHT SUBCLAVIAN (2%)• Right subclavian: 4th branch

• Right CCA: 1st branch• No innominate

ICA TORTUOSITY VARIANTS• Course variations are common


ICA TORTUOSITY VARIANTS• Course variations are common


ICA/ECA ORIGIN VARIANTS• Variations in origin of the

ECA & ICA are uncommon

• C6 (93%) – most common• C5 (5%) – 2nd most

common

VERTEBRAL ARTERY COURSE VARIANTS

CAROTID DUPLEX ULTRASOUND

INDICATIONS

• Cerebrovascular Accident (CVA)• Transient Ischemic Attacks (TIA)• Cervical Bruit• Pulsatile Mass• Less Specific Symptoms• Dizziness• Headaches

• Pre-operative• Post-operative• Monitor known carotid arterial disease

POSITION/TECHNIQUE

Patient Position

• Supine

• Head angled to the side

• Rolled towel under neck

• Position adjusted to optimize sonographic window

POSITION/TECHNIQUE

Patient Position

• Supine

• Head angled to the side

• Rolled towel under neck

• Position adjusted to optimize sonographic window

Technique

• Highest frequency, penetrating transducer

• Keep angle at 60 degrees• Diagnostic Criteria• Reproducibility

• 3-5 cycles/waveform

• Waveform 2/3 of image• Lower baseline• Decrease scale

EXAM PROTOCOL• Protocol will be available on Sharepoint

• Written and Image formats• Protocol still needs to be approved to be made

official



official• Scan Assistant protocol has been set up in

accordance with written protocol• Protocol will also be set up on Siemens

machine at SH





machine at SH• Examine all accessible portions of the CCA/ICA

• Basic assessment of the ECA/Vert/Subcl





machine at SH• Examine all accessible portions of the CCA/ICA

• Basic assessment of the ECA/Vert/Subcl• Protocol is designed to be the minimal required

images• Additional images will often be necessary when

the exam is normal• Additional images will always be necessary

when pathology is encountered

CCA Proximal• Trans

*Image at the most proximal, straight segment

CCA Proximal• Long

CCA Proximal• Color Doppler

CCA Proximal• Spectral Doppler

CCA Distal• Trans

*2-3cm below the bifurcation

CCA Distal• Long

CCA Distal• Color Doppler

CCA Distal• Spectral Doppler

CCA Spectral Analysis:• EDV should be above zero• EDV should be similar to the contralateral CCA, taken at

approximately the same level

Bifurcation• Trans (bulb)

Bifurcation• Trans (just

above bulb)

ECA Prox• Long

*Look for branches

ECA Prox• Color Doppler

ECA Prox• Spectral Doppler

ECA Spectral Analysis• Higher resistance than the ICA • PSV normally greater ICA• Sharp upstroke• Prominent dicrotic notch (may reverse)• EDV approach/reach zero

*Include bulb

ICA Prox• Long

ICA Prox• Color Doppler

*Obtained just below the bulb where vessel is no longer dilated

ICA Prox• Spectral Doppler

*Waveform may reflect flow disturbances of the bulb extending into the prox ICA

ICA Mid• Color Doppler

ICA Mid• Spectral Doppler

ICA Dist• Color Doppler

ICA Dist• Spectral

Doppler

ICA Spectral Analysis• Low resistance• Continuous forward flow• EDV well above zero

Vertebral• Color Doppler

Vertebral• Spectral

Doppler

Vertebral Spectral Analysis• Low resistance• Slightly more resistive than the ICA

• Antegrade, bidirectional, retrograde

Subclavian• Color Doppler

*Sampled close to the origin

Origin

Subclavian• Spectral Doppler

Subclavian Spectral Analysis• High resistance• Reversal late systole/early diastole

REPEAT ON LEFT

ONLINE FORM

PSV EDV

PSV

TIPS/TRICKS

Long ECA/ICA• Two for the

price of one

Long ECA/ICA• Two for the

price of one

Branches = ECA

Temporal Tap• Tap on superficial temporal artery • ant/sup to ear

• Indicates ECA• Not reliable http://www.slideshare.net/shaffar75/doppler-ultrasound-of-carotid-arteries


Bulb• “ICA Prox”• Widened portion of the proximal ICA• Disturbed flow• Unidirectional along the flow divider of the birfurcation• Zero/reversed flow at outer wall

Vertebral Origin• Most common

location for stenoses

Innominate• Not required

unless pathology is suspected

CCA

Subclav

Innominate• Not required

unless pathology is suspected

• Distal ICA• can be difficult to

demonstrate

• Prox/Mid ICA Doppler settings are not adequate to optimize the distal ICA• adjustments must be

made

IMAGE QUALITY

Lowered Color Frequency

Increase Color Gain

Decreased Steer Box Angle

BeforeAfter

THE END

Documents

CAROTID DUPLEX ULTRASOUND Jenelle (General Ultrasound Department) Anatomy Normal Carotid Ultrasound Todd (Vascular Ultrasound Department-Coordinator) Abnormal