click below
click below
Normal Size Small Size show me how
Vascular sonography
Carotid part 2- Scanning and Protocol
Question | Answer |
---|---|
What are the goals of the Extracranial Duplex? | Identify PTs who are at risk for stroke, Facilitate treatment, Document disease progression (plaque), Detection of non-atherosclerotic conditions, Follow-up PTs Post surgery |
What type of Transducer should be used for Carotid scanning? | 7-4 MHz Linear array, High Freq for image quality, adequate "footprint" for access and visualization |
What are some alternative transducers that may be used? | 8-5 MHz Curvilinear, 4-1 MHz sector, 5-2 MHz curvilinear |
What anatomy is generally evaluated in a Carotid Duplex exam? | Common Carotid arteries (CCAs), Internal Carotid arteries (ICAs), External Carotid arteries (ECAs), Vertebral arteries, and Subclavian arteries |
What should you document on a Carotid exam? | Any identified intraluminal echoes (plaque or other intimal defects), Document any other areas of interest |
What are normal B-mode characteristics? | Smooth vessel walls, Intimal-medial layer clearly visible and uniform(thin, white line on innermost part of vessel wall), Lumen is anechoic |
What is the normal Intima-medial thickness measurement? | less than or equal to 0.9 mm is considered normal |
The IMT measurement is a predictor of what? | Cardiovascular disease |
The IMT measurement is measured where? | Far wall on vessel, Often done at the Distal Common Carotid Artery (DCCA), and Proximal Internal Carotid Artery (PICA), Thickens with age |
Turbulent flow produces a what color Doppler pattern? | "mosaic" |
What is Power Doppler extremely helpful in detecting? | Extremely low flow velocities (trickle flow) |
Spectral Doppler provides what? | The most reliable means for assessing vessel patency and classifying degree of stenosis |
Doppler Waveform contour is related to? | Cardiac output, Vessel compliance, and Status of distal vascular bed |
What are the Normal Doppler waveform contours (CCA, ICA, ECA)? | Brisk systolic acceleration, Sharp systolic peak, Clear spectral waveform |
ICA has the highest what? | Diastolic velocities (Lowest resistance) |
ECA has the lowest what? | Diastolic velocities (Highest resistance) |
CCA had intermediate what? | Diastolic velocities (has characteristics of both ICA & ECA) |
ICA facts? | Typically larger (usually contains bulb), Typically lies posterior to ECA, No extracranial branches, typically |
ECA facts? | Multiple branches within the neck (extracranial), Spectral waveform will oscillate with "temporal tap", Typically smaller vessel, Tip TD face toward PT's face (typically on side where thyroid is located) |
How is the ECA different from the ICA? | More pulsatile (rapid upstroke and downstroke), Higher resistance waveform (low diastolic flow component-not much diastole present on waveform), Feeds face and scalp |
The Vertebral has what kind of appearance? | "H" appearance |
Normal Vertebral artery flow is similar to ICA waveform pattern how? | Low resistance, Antegrade flow throughout cardiac cycle, Brisk systolic acceleration, Sharp peak, and relatively high diastolic flow component, Usually lower velocity (lower scale-CF, spectral) |
With a temporal tap the Doppler flow signal is affected by what? | Oscillations on the ipsilateral temporal artery |
What is the normal vertebral artery flow waveform patter? | Low resistance, Antegrade flow throughtout cardiac cycle, Brisk systolic acceleration, sharp peak, and relatively high diastolic flow component, Usually a lower vel (lower scale-CF, spectral) |