vascular exam 2

Define the Gray scale imaging in duplex exam of the CCA

also called B-mode (Brightness mode) is used to evaluate for the anatomic structures such as the vessel walls and of the surrounding tissues. - With this modality we should note a clear (anechoic) vessel which would indicate no stenotic ASO development. - We will also evaluate the surrounding tissues ruling out other pathologies such as cyst.

What are the limitations of the Periorbital exam?

cannot differentiate between a tight stenosis and an occlusion. ● Is not diagnostic if an HDSL is not present, therefore can only serve to confirm if HDSL is present. (HDSL: D.R. >50% and A.R >75%) ● This study requires great skill.

What does CVA stand for?

cerebrovascular accident

What are the results when interrogating the following vessels by the CWD? (CCA)

common carotid artery feeds blood flow for both ICA and ECA, therefore will present with a waveform characteristics of both. The CCA is moderate resistivity, yes, we still refer to it as low resistance. - End diastolic flow should be above the baseline. - Waveform (signal) should be very similar to contralateral CCA

Define the Continuous Wave Doppler (CWD) exam.

continuous wave Doppler can only produce a blood flow velocity waveform, it lacks the ability to produce gray scale imaging. CWD uses 2 crystals where PWD uses 1. - With CWD one crystal is continuously transmitting U/S while the second crystal is continuously receiving the returning echoes.

Non localized symptoms of CVI

dizzyness syncope aphasia/dysphasia confusion

CVA-non localized symptoms

dizzyness syncope headache confusion difficulty with speech

image

image

Complicated lesion

necrosis of the plaque will lead to ulceration (open wound) where thrombi will form. - This type of plaque is associated to emboli because of this. (Foreign substance made mobile).

Define the OPG-Gee

ocular pneumoplethysmography - This is one type of indirect testing which functions to gather information regarding HDSL of/in the ICA by testing the ophthalmic arteries.

Vertebrobasilar insufficiency (VBI)

symptoms are caused by a disruption to the posterior circulation of the brain, therefore as opposed to the RIND and TIA, symptoms in this case appear bilaterally.

Which circulation is being disturbed in the case of VBI?

systamic

Echogenic

the acoustic property of a medium which renders it capable of producing echos.

How can disease be overestimated with Duplex study of the CCA?

● Artifact is mistaken for plaque. ● Accelerated blood flow is incorrectly attributed to a stenosis. - Other causes of blood flow acceleration: 1) Vessel tortuosity 2) Collateralization 3) Incorrect Doppler angel which must be 450- 600 parallel to flow.

The OPG-Gee exam has 4 limitations, what are they?

● Cannot differentiate between a tight stenosis and an occlusion. ● Cannot determine the exact location of the obstruction. ● Not helpful when well developed collaterals exist. ● Not helpful in the monitoring of the progression of disease over time.

What is the best Doppler angle?

0

What is the cos0? What is the cos30? What is the cos45? What is the cos60? What is the cos90?

1 .87 .71 .50 0

There are non - contributing risk factors in the development of ASO, (NOT CONTROLLABLE)

1) Aging 2) Family history (Genetics) 3) Male gender

Most common locations for the development of ASO;

1) Bifurcations, of the 3 this is the most common 2) Branches 3) Origins of vessels.

What are the 4 Doppler modalities?

1) CD = Color Doppler 2) PWD = Pulse wave Doppler 3) CWD = continuous wave Doppler 4) Power Doppler = Power Doppler

How can disease be underestimated with Duplex study of the CCA?

1) Sonographer misses low-level echoes. Ex. Soft plaque. 2) Sonographer does not evaluate the entire vessel. 3) High bifurcation prevents evaluation of ICA. 4) Incorrect angle used, which must be 450 to 600 parallel to flow.

What are the findings of a TCD exam?

- All vessels must present with low resistivity waveforms. - Vessels must fall within the following velocity scale: MCA ACA PCA = BA=VA - Vessels that must present with blood flow towards the TX: MCA, PCA (P1 segment) - Vessels that must present with blood flow away from the TX: ACA, PCA (P2 segment), BA, and VA.

List the symptoms of TIA and RIND

- Amaurosis fugax - blindness of one eye - Dysphasia or aphasia - difficulty speech or loss of speech. - Contralateral hemiparesis - opposite side of paralysis. - Behavioral disturbance

Define ACA

- Anterior cerebral artery - Usually found at a depth between 60-80 mm. - The direction of blood flow must be away from the TX to indicate normal. - The blood flow velocities are 50 cm/s - The blood flow characteristics must be low resistance.

List the symptoms of VBI and define them

- Ataxia - unstable walking/walking like a drunk - Drop attacks - leg drop - Paresthesia - limbs are numb/needle like feeling - Vertigo - equilibrium problem - Diplopia - seeing double/double vision

Atherosclerosis (ASO)

- Atherosclerosis Obliterans - Endothelial injury followed by deposition of low-density lipoproteins (fats) upon the intima layer. - There will be an inflammatory response with smooth muscle (media layer) proliferation. ● The arterial walls will thicken and harden, which will result in the loss of the vessel wall elasticity. - Plaque then accumulates upon the intima layer which will protrude into the vessel lumen causing stenosis. ● The plaque may become altered by hemorrhage, cell necrosis, or ulcerations. - Plaque can also proliferate into the media layer damaging it resulting in aneurysms.

What are the normal results of a duplex exam of the CCA?

- Gray scale Images present clear vessel lumen with no other pathology of the surrounding tissues. - CD presents with filling of the vessel lumen from anterior to posterior wall. - PWD presents with PSV and EDV velocities within normal ranges.

What are all abnormal results with the duplex exam of the CCA?

- Gray scale images present plaque build-up upon the vessel walls, measure TL and RL for HDSL determination, and or other pathologies of the surrounding tissues. - CD presents with filling in deficit, leaving gaps at the vessel wall indicating plaque buildup, or no color signature indicating occlusion. CD can also be used to evaluate the surrounding tissues for other pathologies such as __________. - PWD presents with blood flow velocities of PSV and EDV out of the normal ranges. ● Stenotic vessels create a higher pitched sound (during PWD evaluation there is also a sound) . ● Waveforms have higher amplitude (PSV is higher) because of the accumulated blood flow. ● Spectral broadening which is the loss of the spectral window indicates turbulent flow. ● The greater the degree of stenosis, the greater velocities, up to a point. ● Distal to a stenosis disturbed flow patterns are noticed with dampened waveforms. ● The loss of the diastolic component of an ICA is consistent with a high grade stenosis to near occlusion of the ipsilateral CCA. ● Unilateral diminished velocities suggest proximal disease (occlusion of innominate artery or proximal CCA).

What are the five symptoms associated with anterior circulation obstruction? Are the effect found unilaterally or bilaterally?

- Hemiparesis - muscle weakness/partial paralysis on one side - Hemiparesthesia - numbness or abnormal sensation on one side of the body. - Aphasia and dysphasia - Behavioral abnormalities - Amaurosis fugax - loss of vision in one eye (Unilaterally)

Hypertension (Controllable)

- Hypertension is high blood pressure. - Causes an increased stress on vessel walls. - With this added stress it contributes to the development of ASO.

Subclavian Seal Syndrome

- In this case blood that is destined for the brain is shunted/redirected away from the cerebral circulation towards the blood flow of the arm. - This is the result of a high grade stenosis or an occlusion of the proximal subclavian arteries (one or the other) or the innominate artery/Brachiocephalic artery. - When suspecting an SSS we take bilateral brachial artery BP and compare RT to LT. ● The RT to LT BP must not differ by more than 15-20 mmHg from each other, should the difference be greater than 15-20 mmHg this could indicate SSS. - Normal VA: blood flow characteristics will present with low resistance and antegrade flow. - Abnormal VA (SSS): blood flow characteristics will now present with high resistance because blood is no longer feeding the brain but the arms and therefore we find retrograde flow.

Hollenhorst plaque

- It originates from somewhere and traveled to and is occluding the retinal artery. - Will result in temporary or permanent blindness. *Know the route: CCA prox, mid, dist, bifurcation, ICA prox, mid, dist, bifurcation, ophthalmic artery, bifurcation, retinal artery

What are the five symptoms associated with posterior circulation obstruction? Are the effect found unilaterally or bilaterally?

- Paresthesia - pins and needles in arms and legs - Paresis - partial paralysis - Vertigo - double vision - Drop attacks with loss of consciousness - Ataxia - impaired balance, loss of gate. (Bilaterally)

What are the results of the Periorbital exam?

- Retrograde blood flow in the frontal artery indicates disease in the ipsilateral (same side) ICA. - If blood flow diminishes or reverses while performing the compressions of the arteries mentioned, then that artery that was compressed is the blood supply for the frontal artery.

Define MCA (Middle cerebral artery)

- Supplies blood flow to the lateral surface of the brain. - Usually found at a depth range between 30-60 mm. - The flow direction must be towards the TX to indicate normal. - The blood flow velocities are 65 cm/s - The blood flow characteristics must be low resistance

Define PCA (Posterior cerebral artery)

- These are the terminal branches of the Basilar artery. - The PCA are located at a depth range of 60-70 mm. - The blood flow in the P1 segment is towards the TX and the P2 segment way from the TX. - The blood flow velocities are 40 cm/s - The blood flow characteristics must be low resistance.

Define VA (Vertebral arteries)

- These arteries are located at a depth of 60-80 mm. - The blood flow direction must be away from the TX to indicate normal. - The blood flow velocities are 40 cm/s - The blood flow presents with low resistance. - The transition of the vertebral arteries confluence to form Basilar artery is 80-90mm.

What is Transcranial Doppler (TCD)?

- This is a non-invasive technique that measures the blood flow velocities of the major intracranial arteries, the circle of Willis. - We use these exams to R/O brain death ● Measure blood flow velocities ● Assess collateral pathways ● Evaluate for CVA - Ischemic - Hemorrhage

Define distal ICA (distal (terminal) Internal carotid artery)

- This vessel is located at a depth range of 55-65 mm - The terminal ICA presents with low resistance waveforms. - The blood flow velocities are 61 cm/s

Define BA (Basilar Artery)

- This vessel is usually found at a depth range between 80-120 mm. - The blood flow direction must be away from the TX. - The blood flow velocities are 40 cm's - The blood flow waveform must be low resistance.

Homogenous plaque

- all echoes from the plaque are uniform in brightness (echogenecity). - Boarders are usually smooth and regular. - Brightness of the entire plaque can range from hyperechoic to hypoechoic.

Arteritis

- also referred to as vasculitis, which is the result of an autoimmune disease, such as Takayasu arteritis, temporal arteritis. - This can also be the result of a patient undergoing radiation changes such as a patient undergoing cancer treatment. - The U/S appearance is a vessel that has limited blood flow through it lumen, the result of diffuse concentric thickening of the media layer of the arteries.

Hyperlipidemia (Controllable)

- high saturated lipids (fats) in the blood, which will increase the chances of development of ASO. - It will contribute to the progression of ASO accumulation

Calcified plaque

- hyperechoic, therefore very easy to identify, especially because it will cast a posterior shadow.

Aneurysm

- is an abnormal dilation of the wall of a vessel, all 3 vessel walls are intact. - It is a rare finding in the cervical carotid. - It is the result of congenital defects, trauma, or ASO infection. - A dilation of greater than 50% in diameter as compared to adjacent segment is considered aneurismal.

Soft Plaque

- still hypoechoic difficult to identify, however because it is a bit more progressed we can/must use CD to identify it.

Thrombosis

- the formation of a blood clots, and is one of the most common causes of CVA (Cerebrovascular accident) or in other words stroke.

Dense Fibrous Plaque

- this is more echogenic and therefore easy to identify in grey scale. - There is a fatty core surrounded by a protective capsule, which is made up of smooth muscles.

Dissection

- this is the dissection of the intima layer, usually the result of trauma. - May occur spontaneously in a patient with ASO development. - The U/S appearance presents with a fixed or mobile echogenic.

Fatty Streak

- this is the earliest form of plaque. - It is hypoechoic and is very difficult to identify even with CD.

Heterogeneous plaque

- we find a complex echo pattern. ● Hypoechoic areas of the plaque may be related to intra-plaque hemorrhage. ● Hyperechoic areas of the plaque may be related to intra-plaque calcifications.

Kinking and tortuosity

-Kinking or tortuosity refers to a sharp angle of 90 % or less usually located 2-4 cm above the bifurcation. -Blood flow is compromised in kinked arteries and is often associated with plaque and arterial stenosis.

Anechoic

-We use this term to describe portions of an image entirely without echos or black out. -This is an extreme case of hypoechoic

Diabetes (Controllable)

-contributes to the hardening of the arterial wall structure, which results in the loss of the elasticity of the vessel (medial calcinosis). - Blood will travel much faster down a stiff walled vessel vs. an elastic vessel.

Carotid Body Tumor(cbt)

-is a highly vascularized tumor which arises between the ECA and ICA at the location of the carotid body. The carotid body is a location between ECA and ICA, and is a collection of nerves (ganglion), which serves to regulate pH and blood pressure and other blood factors. The tumor affects this area. - May occur bilaterally - Prognosis is good, but surgery is very long. May come back and another surgery may be required. - Often misdiagnosed as a goiter

Smoking (Controllable)

-is a strong risk factor for the development of ASO. - It is the nicotine in the tobacco that will cause a recurrent vasoconstriction of the arteries and arterioles. - Blood travels much faster in these vessels.

Fibromuscular Dysplasia (FMD)

-is the overgrowth of the medial layer, the collagen in the muscle. - More common in young females. - Primary found in the renal arteries, it is found as a rare secondary finding in the ICA's. - Present in U/S as a string of beads:

Pseudoaneurysm

-may occur after a trauma, however it is usually the result of an iatrogenic procedure (surgical procedure) or a specific one designed to remove plaque in the carotid arteries (CCA, ICA, ECA) called endarterectomy. ● Endarterectomy is the surgical removal of the plaque and intima layer or plaque intima or media layers. -A pseudoaneurysm is a false aneurysm in that it looks like an aneurysm, however there is an opening (called the neck) connected to a pocket of blood outside of the vessel

What are the three windows for performing TCD?

1) Transorbital window - uses the eye sockets as an entry point for the sound beam. - Evaluate the ICA (carotid siphon) and ophthalmic artery 2) Transtemporal window - uses the temples as entry point for the sound beam. - Evaluate the MCA, ACA, PCA, and distal ICA (terminal) 3) Suboccipital/Transforaminal window -uses the foramen magnum. - Evaluate the VA and BA. 3) Submandibular window - also uses the foramen magnum - Evaluates the distal ICA

What are the 5 parameters vital to identify specific vessels?

1) Window used 2) Depth Range 3) Direction of blood flow 4) Mean/Average blood flow velocities 5) Direction or angle of U/S beam

What is the usable angle range for vascular? And Why?

45 degree to 60 degree

What is the worst Doppler angle?

90

Define the Doppler Shift

This is calculated by taking the change in frequency as a result of relative motion. The change of frequency from the received by the initial or operating Freq.

symptoms are usually found "blank" for VBI

Bilaterally

which two Doppler modalities present the Doppler information as color?

CD = Color Doppler Power Doppler

Define a CVI?

Cerebrovascular insufficiency is very similar to a CVA

Define the color Doppler in duplex exam of the CCA

Color Doppler - with the scale set to (0.32-0.34 m/s) we will further prove that the vessel is disease free (ASO free) by providing color signature within the vessel lumen with color filling in form anterior to posterior wall. Gaps by the vessel wall would indicate plaque called Filling in deficit. - The CD modality is also used to rule out other pathologies in surrounding tissues such as lesions.

What cause Cerebrovascular insufficiency (CVI)

Embolism, stenosis, aneurysms, thrombosis, trauma

What are the results when interrogating the following vessels by the CWD? (ECA)

External carotid arteries provide blood flow for the scalp, deep and superficial structures of the face, and neck. - This vessel's waveform presents with high resistance characteristics. - The signal (waveform) is more pulsatile than ICA. - The dicrotic notch is prominent with this waveform. - The maneuver called Temporal Tap is used to distinguish between the ECA and ICA waveform. ● The diastolic component of the ECA oscillates, and the ICA has no reaction to temporal tap.

HDSL (hemodynamically significant lesion)

HDSL: D.R > 50 % and A.R>75%

In the OPG-Gee exam how do I know what vacuum pressure to use if its 500mmHg?

If the pt's BP was greater than 140 mmHg

In the OPG-Gee exam how do I know what vacuum pressure to use if its 300 mmHg?

If the pt's BP was less than 140 mmHg,

Define ICA or carotid siphon

Increase the depth to 60-80 mm in order to isnate the carotid siphon. Flow direction may very due to tortuosity of this vessel in many individuals. Obtain and record the highest velocity.

What are the results when interrogating the following vessels by the CWD? (ICA)

Internal carotid arteries provide blood supply for the anterior portion of the brain, forehead, eyes and nose. - This vessel's waveform is present with low resistance characteristics. - On the spectral display we note a sharp rise to systole and a gradual deceleration as the heart cycle moves into diastole. - The waveform of this vessel does not present with a dicrotic notch. - The diastolic flow remains above the baseline.

Define Periorbital testing.

This is another indirect exam of the ICA by testing one of its terminal branches, in this case the frontal artery (branch off of the ophthalmic artery).

Which two doppler modalities present the Doppler information as a graph where we can measure PSV and EDV as needed?

PWD = Pulse wave Doppler CWD = continuous wave Doppler

Define OA

Place the prove on the orbital window,position lateral and pint the probe medially. Adjust the depth to 40-60mm and make small movements of hte prove to access the OA.

Which type of transient ischemia lasts at least 24 hours and less than 72 hours? The patient returns to normal.

RIND - Reversible ischemic neurological deficit

Which type of transient ischemia does not exceed 24 hours? The patient returns to normal.

TIA - Transient ischemic attack

Define spectral broadening.

The width of the Doppler spectrum on a sonogram display corresponds to the range of Doppler shift freq presents at a given time. Spectral broadening will be seen when this range is increased; an example is the Doppler signal obtained when laminar flow with a blunt flow profile become disturbed.

What are the results when interrogating the following vessels by the CWD? (Vertebral arteries)

Vertebral arteries supply blood flow for the posterior portion of the brain. - Waveform is very similar to ICA waveform, in that they are both low resistance, however the ICA has faster blood flow velocities (being larger) and the VA has slower blood flow velocities (being smaller). - As with the ICA, the VA does not present with a dicrotic notch.

What does VBI stand for?

Vertebrobasilar insufficiency

Hyperechoic

We use this term to describe portions of an image that are brighter than the surrounding tissue,or the tissue itself if its brighter than normal. -It signifies having relatively strong echoes

Hypoechoic

We use this term to describe portions of an image that are not as bright as the surrounding tissue, or the tissue itself is less bright that normal. -It signifies having relatively weak echos

Define the duplex exam of the CCA

With this study we have 3 modalities that we use in order to gather information regarding pathology within the CCA and its branches.

CVA (Stroke)

in common terms this is a stroke and it is the 3rd leading cause of death. - There are 2 major types of CVAs; A) Ischemic - This is the result of decreased blood flow for the brain. B) Hemorrhage - This is the result of a vessel rupture. Usually an aneurysm that had ruptured which will result in 2 effects. ● First the blood supply to the tissue of the brain is now not being delivered. ● Second the pressure in the skull cavity will increase. This leads to coma. (High pressure in the brain and no blood supply). - 80% to 85% of all strokes are ischemic the result of a thromboembolic event (usually involving ASO).

Embolism

is a foreign substance or a bit of thrombosis (solid, liquid, or gas) that moves through the circulatory system until it becomes lodged in a distal (smaller) vessel. - Result in partial or complete obstruction of the vessel. - Usually is embolized ASO in arteries

CVA continued

is a persistent severe neurological deficit. dysphasia or aphasia hemiparesis other neurological deficit death

Stenosis

is the narrowing of the blood vessel caused by the process of ASO (Atherosclerosis obliterans) or in other words plaque development.

Define the PWD in duplex exam of the CCA

is used as a modality in order to measure PSV (peak systolic velocities) and EDV (end diastolic velocity). We set the scale correctly in order to measure the PSV and the sweep speed to medium 50-100 mm/s. Gate placed in the center of the vessel and the angle 45 to 60 degrees parallel to flow is used. ● This study is very accurate in localizing the presence of arterial disease, even if it is not HDSL. ● Can differentiate between a tight stenosis and an occlusion. ● Can document the progression of disease through time. ● Can provide information regarding the surface characteristics of the plaque formation upon the vessel walls.

What is the method by which we perform the Periorbital exam?

pt is supine and we use an 8-10 MHz CWD (continuous wave doppler) Tx ● Locate with the TX the frontal artery in the inner canthus of the eye. ● This will produce a blood flow velocity waveform (CWD lacks the ability to produce a gray scale image). ● Flow should be antegrade, in this case is defined as being towards the TX, therefore waveform will appear above the baseline. ● Perform a series of compression on the following vessels to determine which is the supply to the frontal artery, : - Facial artery - Superficial temporal artery - Intraorbital artery (Supraorbital artery) - CCA

Define each variable in the Doppler equation and units.

● Fo = operating Freq (same as Fi), units: MHz ● 2 = constant value, unitless (2 is because of round trip) ● V = Velocity of RBC, units: m/s or cm/s ● ϴ = Doppler angle, unitless ● Cosϴ = Cosine of Doppler angle, unitless ● C = Propagation speed of sound in soft tissues, units: 1540 m/s, 1.54 mm/μs, or 0.1546 cm/μs

What are the limitations of using CWD, for examination purposes?

● No imaging ● Increases spectral broadening with related to turbulent flow, but rather the result of a large sample volume. ● May mistake ECA for ICA in case of a high grade stenosis in the ICA, the ECA collateralization will have ECA waveform present with high resistivity, use temporal tap to confirm.

Which are the top 6 risk factor for stroke and say why they are risk factors, how do they lead to a stroke?

● Plaque build-up ● HTN ● Diabetes ● Hyperlipidemia ● Ages 55-60 years ● Genetics

What is the method and protocol of performing a Duplex exam of the CCA?

● Pt is supine ● Use 4-7 MHz linear TX. ● Scan in TRV plane with gray and CD, this is the best plane in order to catch ASO ● Scan in SAG plane with use of gray, CD and PWD with PSV and EDV measurements.

When should I not perform the OPG-Gee exam?

● Pt w/ glaucoma ● Pt w/ allergies to local anesthetics ● Pt w/ a history of retinal detachment ● Pt that has had eye surgery within the past 6 months

What are the limitations of the Duplex exam of the CCA?

● Staples ● Size of neck ● Pt movement ● Acoustic shadowing from calcifications.

what is a Complete Stroke?

● Stroke is no longer occurring ● Patient is stable ● Symptoms are no longer changing ● Persistent neurological deficit.

What is a Stroke in evolution?

● Stroke is still occurring ● Patient is unstable ● Symptoms keep changing ● Outcome for patient is uncertain

What is indirect cerebrovascular testing?

● These are exams that identify HDSL of the ICA by evaluating some of its terminal branches. ● These exams (like all exams) have some limitations; - Cannot differentiate between a tight stenosis and an occlusion. - Only helpful when HDSL is present.