Uncommon pathology of the Carotid System

Question 1

What pathology is known as the abnormal growth and development of the muscular layer of an artery wall with fibrosis and collagen deposition causing a localized series of stenoses?

Answer 1

Fibromuscular dysplasia

Question 2

What are the other names for a carotid body tumour?

Answer 2

1. Paraganglioma
2. Chemodectoma

Question 3

Where are carotid artery tumours located?

Answer 3

At the carotid bifurcation

Question 4

What vessel is most commonly affected by tortuosity?

Answer 4

ICA

Question 5

In the case of a tortuous vessel, where should you document doppler velocities?

Answer 5

Before, in, and beyond the curve/kink

Question 6

What type of waveform may be seen if a tortuous vessel is producing a stenosis?

Answer 6

Tardus parvus in the case of a distal stenosis

Question 7

What pathology is known as a separation of layers of an artery by a tear in the intima?

Answer 7

Arterial dissection

Question 8

In what 3 clinical situation are dissections seen?

Answer 8

1. Extension into the CCA from aortic dissection
2. Trauma to the ICA
3. From underlying disease such as FMD, arteritis, or defects in the vessel wall collagen

Question 9

What is the hallmark appearance of an ICA dissection?

Answer 9

1. Intramural hematoma
2. Luminal narrowing or occlusion of true lumen

Question 10

In a dissection, if blood exits the false lumen via a secondary tear PROXIMAL to the original tear, will flow appear antegrade or retrograde?

Answer 10

Retrograde

Question 11

In a dissection, if blood exits the false lumen via a secondary tear DISTAL to the original tear, will flow appear antegrade or retrograde?

Answer 11

Antegrade

Question 12

What is the MOST COMMON cause of stroke in young and middle aged individuals?

Answer 12

Dissection

Question 13

Patient symptoms with an ICA dissection vs CCA dissection?

Answer 13

1. ICA:
   - Unilateral pain of head, neck, and face
   - Partial Horner syndrome (ptosis: drooping of eyelid), miosis: constriction of the pupil)
   - Cerebral or retinal ischemia
2. CCA: headaches and neck pain

Question 14

In a dissection, where is the true lumen in relation to the false lumen?

Answer 14

True lumen is anterior to the false lumen

Question 15

Where in the ICA are most cases of dissection?

Answer 15

Very superior and not identifiable on a carotid scan

Question 16

What pathology contains abnormal growth of smooth muscle cells and fibrous tissue?

Answer 16

FMD

Question 17

What is the most common sonographic presentation of FMD?

Answer 17

“String of beads” and dilation

Question 18

What arteries are typically affected by FMD?

Answer 18

ICA and renal arteries

Question 19

In what population does FMD usually occur?

Answer 19

Young females

Question 20

What is the most common symptom of renal FMD?

Answer 20

Hypertension

Question 21

What is the most common symptom of cerebrovascular FMD?

Answer 21

Headaches

Question 22

When a patient presents with symptoms of FMD, what artery is very crucial to try and image?

Answer 22

Distal ICA

Question 23

Where are carotid body tumour located?

Answer 23

Adventitia of the carotid bifurcation

Question 24

What type of cells do carotid body tumours (paraganglioma) arise from?

Answer 24

Chemoreceptor cells

Question 25

What does the carotid body control?

Answer 25

Blood pressure and pH

Question 26

SF of carotid body tumour?

Answer 26

1. Hypoechoic mass between the ICA and ECA 2. Highly vascular and are fed by branches off ECA 3. Low-resistance waveform

Question 27

What arterial layers are affected in a carotid aneurysm?

Answer 27

All three layers

Question 28

Where are carotid aneurysms mostly found?

Answer 28

CCA and ICA bifurcation and are FUSIFORM

Question 29

What is the main cause for a carotid aneurysm to occur?

Answer 29

Atherosclerosis

Question 30

Patient presentation with a carotid aneurysm?

Answer 30

Non-tender, pulsatile mass

Question 31

What is the difference between a true aneurysm and a pseudoaneurysm?

Answer 31

True aneurysm - involves all three wall layers Pseudoaneurysm - only involves intimal layer

Question 32

What usually causes a pseudoaneurysm?

Answer 32

Trauma

Question 33

What should be documented with a pseudoaneurysm?

Answer 33

1. The PA itself 2. The neck of the PA 3. The feeding artery 4. Measure outer size of the PA to include any thrombosed component 5. Measure the width and length of the neck

Question 34

What kind of doppler flow pattern is seen with a pseudoaneurysm?

Answer 34

To and Fro flow in the neck of the PA

Question 35

What type of colour sign is seen in a pseudoaneurysm mass?

Answer 35

yin-yang sign

Question 36

What does RIAI stand for?

Answer 36

Radiation-Induced Arterial Injury

Question 37

What can be caused at the site of treatment with RIAI? What artery will this occur?

Answer 37

Atherosclerosis in the CCA which can cause stenosis

Question 38

The maximum area of stenosis in radiation-induced lesions tends to be located where?

Answer 38

Distal end of the stenotic area

Question 39

Are radiation induced or NON-radiation induced stenotic lesions longer?

Answer 39

Radiation induced - significantly longer

Question 40

What pathology is the inflammation of the artery wall?

Answer 40

Arteritis - may produce thickening, stenosis, and occlusion

Question 41

What are the two types of arteritis? What population are they most common?

Answer 41

1. Takayasu's - affect aortic arch in a specific order: Subclavian --> CCA --> Aorta --> renal arteries (most common in younger women) 2. Giant cell arteritis - affects medium and large vessels - aortic arch, axillary, carotid (most common in elderly people)

Question 42

SF of takayasu's arteritis?

Answer 42

Long, smooth, homogenous thickening of arterial walls

Question 43

What additional arteries are scanned with giant cell arteritis? (hint: higher in the head)

Answer 43

Common superficial temporal artery and it's branches: Parietal and frontal branches

Question 44

What sonographic sign is seen with takayasu's arteritis?

Answer 44

Macaroni sign in TRV - concentric and evenly distributed around vessel

Question 45

What is a common sonographic feature in the temporal artery that is indicative of temporal arteritis?

Answer 45

Echolucent halo around temporal artery

Question 46

What vessel layer do carotid body tumours arise in?

Answer 46

Adventitia

Question 47

What is the main cause of a carotid aneurysm?

Answer 47

Atherosclerosis

Question 48

For a scan ordered for giant cell arteritis, what artery MUST be looked at?

Answer 48

Superficial temporal artery (STA)

Question 49

When examining Takayasu's arteritis, what vessel must you pay extra attention to?

Answer 49

Proximal CCA

Question 50

When examining Giant cell arteritis, what vessel should you make sure to assess?

Answer 50

Superficial temporal