Carotid Imaging IT S ABOUT MORE THAN JUST OBTAINING THE IMAGES

Transcription

1 Carotid Imaging IT S ABOUT MORE THAN JUST OBTAINING THE IMAGES

2 No financial or commercial relationships to disclose

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4 Carotid artery disease: Stroke is one of the most serious causes of mortality and morbidity in the United States and throughout the world. It is ranked as the 3 rd most common cause of death in the United States Approx 1/3 of all strokes are related to carotid occlusive disease 150,000 patients/year die as a direct result of a CVA 600,000 patients experience aphasia, blindness, or paralysis Ischemic strokes are the most common etiology in the US Approximately 1/4 of ischemic strokes involve posterior or vertebrobasilar circulation

5 The goal of carotid imaging: early detection clinical staging surgical road mapping postoperative therapeutic surveillance The detection of a clinically significant carotid stenosis represents an important first step in the prevention of cerebral infarction

6 Carotid artery disease: Patients can be asymptomatic from carotid artery disease Plaque builds up in the carotid arteries over time with no warning signs until a TIA or a CVA occurs Signs of a stroke may include: sudden loss of vision (in one or both eyes) blurred vision difficulty speaking (aphasia) facial drooping weakness, tingling, or numbness on one side of the face/body/extremity sudden difficulty with gait loss of balance lack of coordination sudden dizziness and/or confusion sudden severe headache problems with memory difficulty swallowing (dysphagia)

7 As sonographers, we all know our job means more than routinely just taking the same pictures day in and day out We should help our patients get the treatment they NEED Sometimes we can give more information to our physicians to ensure correct treatment is provided to our patient

8 Carotid artery duplex exam per order CAD. New patient to our facility. AOG showed 80% lesion

9 Native criteria: 1-49% < 150 cm/s PSV 50-69% > 150 cm/s PSV 70-99% > 150cm/s PSV < 90cm/s EDV < 90 cm/s EDV > 90 cm/s EDV < 2 ratio ratio > 4 ratio

10 We made the statement that it was a Grade II (50-69%) stenosis.

11 AOG Showed 80% Lesion

12 *This resulted in a miss for our lab* THIS STUDY IS AN EXAMPLE OF RELYING TOO HEAVILY ON # S VELOCITY CRITERIA WOULD SUGGEST 50-69% STENOSIS, HOWEVER,PLAQUING ON B- MODE MAY SUGGEST GREATER DEGREE OF STENOSIS

13 Look again at plaque

14 How can we fix it? OUR LAB HAS ADOPTED A WAY TO HOPEFULLY FURTHER SUPPORT OUR FINDINGS TAKE MEASUREMENTS OF PLAQUE IN LONG AND TRANSVERSE VIEWS: Diameter of the lumen Diameter of the residual lumen Native artery distal

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16 1. Outer to outer lumen 2. Residual lumen 3. Native distal to plaque

17 Another example:

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20 Ulcerative plaque:

21 Ulcerative Plaque: Be especially descriptive when you see this type of plaque Our docs may treat these patients a little more aggressively

22 Ulcerative plaque: SINCE WE CANNOT SAY ULCERATIVE PLAQUE IN OUR NOTES OR INTERP, WE TRY TO DESCRIBE IT WITH OUR WORDS: CRATER TYPE IRREGULARITY OF THE ANTERIOR/POSTERIOR WALL OF THE ICA WITH MIXED ECHOGENICITY. COLOR FLOW IS DEMONSTRATED FILLING INTO THE SPACE

23 Ulcerative plaque: plaque ulceration is an important factor in lesions with high-grade stenosis their detection may dictate which treatment method will be used ulceration is more frequently found in symptomatic carotid plaques and is also associated with the occurrence of new symptoms in asymptomatic patients Carotid ulcerations are thought to increase the risk for cerebral embolism even when the degree of stenosis is less than 70% US studies have shown that ulcerated plaques are related to a seven-fold increase in ipsilateral stroke risk hypoechoic ulcerated plaques are associated with a nine-fold increase in ipsilateral stroke risk ulceration increases the risk for neurologic symptoms by approximately four times

24 Carotid Body Tumor (CBT):

25 Carotid Body Tumor (CBT): Carotid body tumors (CBTs) are rare neoplasms They represent about 65% of head and neck paragangliomas. These tumors develop within the adventitia of the medial aspect of the carotid bifurcation. The carotid body, which originates in the neural crest, is important in the body's acute adaptation to fluctuating concentrations of oxygen, carbon dioxide, and ph. The carotid body protects the organs from hypoxic damage by releasing neurotransmitters that increase the ventilatory rate when stimulated.

26 Carotid Body Tumor: The following 3 different types of carotid body tumors (CBTs) have been described in the literature: Familial Sporadic Hyperplastic Most common type is the sporadic form represents approximately 85% of CBTs The familial type is more common in younger patients represents 10-50% The hyperplastic form is very common in patients with chronic hypoxia includes patients living at a high altitude (> 5000 feet above sea level) like those patients living in New Mexico, Peru, and Colorado. also seen in patients who have COPD or cyanotic heart disease. About 5% of CBTs are bilateral and 5-10% are malignant rates are much higher in patients with inherited disease

27 Carotid Body Tumors: As the tumor enlarges and compresses the carotid artery and the surrounding nerves, other symptoms may also be present pain tongue paresis hoarseness Horner syndrome caused by the disruption of a nerve pathway from the brain to the face and eye on one side of the body difficulty swallowing

28 CBT Imaging features: Neck ultrasound with color Doppler is a reliable modality to image the extent of carotid body tumors. Features commonly recognized on ultrasound: A well-defined solid mass in the neck that may be unilateral or bilateral. The mass is hypoechoic. Anechoic tubular channels representing small vessels may be seen within the mass. The mass is seen classically in close proximity to the carotid bifurcation, widening the bifurcation and splaying of the vessels. It may also appear to compress or encase the common, external and/or internal carotid vessels. Color Doppler demonstrates vascularity within the mass in about 75% of all carotid body tumors. The feeders arise from the external carotid artery, although the internal carotid and the vertebral artery may also supply the carotid body tumor. On spectral analysis, low resistance flow may be detected within the mass.

29 Carotid Body Tumor on Ultrasound:

30 Interesting case: Tech was scanning CUS per protocol and saw this SCA waveform Not your typical SCA waveform characteristics

31 INNOMINATE ARTERY DILATION: So tech went more proximal to interrogate the INNOM A Again, this waveform warranted additional interrogation

32 INNOMINATE ARTERY DILATION: Even more abnormal waveform proximally

33 INNOMINATE ARTERY DILATION: Mid (1.63 cm) Dst (1.21 cm) almost doubled and more than doubled in size

34 INNOMINATE ARTERY: The reported normal size of the innominate/brachiocephalic artery is between cm with 1.4 cm or greater considered dilated. Normal arch diameter: 2.2 cm-3.6 cm This diameter could have been obtained at the aortic arch which would be considered normal but it warranted more investigation to explain the waveforms.

35 Anatomy: The innominate artery is the first branch of the arch of the aorta, and is usually 4 to 5 cm long

36 Innominate artery aneurysm: Types of Innominate artery aneurysms: Type A: confined to the innominate artery distal to its origin Type B: the most common and involves the innominate artery and its origin Type C: involves both the innominate artery and the ascending aorta

37 Innominate artery aneurysm: Innominate artery aneurysms represent 3% of all arterial aneurysms. The majority of IA aneurysms are atherosclerotic in etiology (~60%) Infective etiology is decreasing syphilis mycotic aneurysm tuberculosis Autoimmune diseases and post traumatic forms are increasing Beçhet Syndrome Takayasu arteritis connective tissue disorders Marfan and Ehlers-Danlos syndromes

38 Innominate artery aneurysm: Often are associated with a coexisting ascending or thoracoabdominal aortic aneurysm Signs/symptoms include: upper extremity acute and chronic ischemic symptoms from thromboembolism chest, neck, and shoulder pain from acute expansion or rupture difficulty swallowing difficult or labored breathing respiratory insufficiency from tracheal compression hoarseness from compression of the right recurrent laryngeal nerve TIA and CVA from thromboembolism in the vertebral and carotid circulations pulsatile mass on one side of the neck A large aneurysm may also present with symptoms of compression on mediastinal structures.

39 Innominate artery aneurysm: Although neurological manifestations due to embolism or thrombosis are by far the most frequent devastating events associated with these aneurysms, rupture has also been reported. Surgical repair is usually recommended on an early elective basis. A surgical approach has largely been the conventional treatment via a thoracotomy or median sternotomy with or without cardiopulmonary bypass. however, an open approach has a significant morbidity rate An endovascular approach offers the advantage of being minimally invasive and having a decreased morbidity rate, although long-term follow-up and evaluation of the durability are still to be determined.

40 Case Studies

41 CASE #1 RCCA: Prx 132/20 cm/s Mid 97/17 cm/s

42 LCCA: Prx 81/5 cm/s Mid 126/11 cm/s

43 EDV = reduced by ½ Side by side Of CCA:

44 1/2ing of velocities (PSV and EDV) on the left Dampened waveform on the left What do you notice about these 2 images?

45 These findings suggest what? PROBABLE NEAR OCCLUSIVE LESION SOMEWHERE BUT WHERE?

46 Significant ICA stenosis making CCA waveforms higher resistant and ICA waveforms dampened.

47 CASE #2 Turbulent prx waveform Reduced velocities mid Somewhat dampened waveform mid Tell me about the waveforms in the CCA

48 Have you ever seen this waveform? Where?

49 What s different about this ECA waveform from right to left? Increased EDV Dampened

50 SCA waveform is abnormal: Loss of sharp upstroke (leaning) To fro vertebral flow

51 BP gradient right to left

52 It s possible that this could just be SCA disease, however, the CCA, ECA, and ICA waveforms are abnormal. What should we be thinking? stenosis of the innominate artery or CCA origin

53 Upon further investigation, (notice use of curved probesometimes needed) INNOMA demonstrates significant stenosis

54 Look again side by side These can be difficult as you have to pay attention to right side waveforms VS left side waveforms WHILE you are scanning. In this case, could have easily just thought SCA stenosis.

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56 Things to look for: INNOMA stenosis It is very important to be mindful of what waveforms look like from right to left Dampened CCA and/or turbulent waveforms Also a change in waveform characteristics leaning peak on the right, sharp upstroke on the left in this particular patient Change in ICA waveform dampened early systolic deceleration to-fro Increased EDV in the ECA from right to left Monophasic SCA waveforms To-fro, retrograde, early systolic deceleration of the vertebral artery Blood pressure gradient from right to left It is common to see abnormal SCA waveforms (and/or a stenosis), abnormal vertebral artery waveforms, and a BP gradient with significant innominate artery stenosis

57 Case #3

58 What do you think is Going on here with a retrograde vert? SCA steal

59 What does this waveform tell you? More proximal disease (SCA).

60 Imaging things to look for: SCA dz Abnormal SCA waveforms dampened monophasic absent turbulent BP gradient from right to left Abnormal vertebral artery waveforms Early systolic deceleration To-fro Retrograde With to-fro flow or early systolic deceleration, you should perform challenge if you have complete reversal of flow (retrograde) post deflation= + steal Retrograde vertebral flow at rest= + steal

61 SCA stenosis/steal: Subclavian artery stenosis can be a cause of significant morbidity it can lead to symptomatic ischemic issues affecting the upper extremities, brain, and in some cases the heart Atherosclerosis is the most common cause but other etiologies include: arteritis inflammation due to radiation exposure compression syndromes FMD neurofibromatosis The incidence of subclavian stenosis in the general population ranges from 3% to 4% can be as high as 11 18% in patients with documented PAD

62 In summary it s important to think about what you are seeing when you scan There could be more going on than just the typical ICA stenosis it s important to ensure that your patient receives the proper care and/or treatment as my sonography professor would say Be better than the average bear!

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