Paige Fabre

It is important as professionals that we manage our patients effectively before, during and at the completion of our scans. When examining the Carotid Artery System increased patient age, body habitus and the position needed for the scan make it increasingly difficult to balance patient comfort and diagnostic image quality. In this piece I intend to demonstrate the techniques and tips given to me by my tutors and colleagues to ensure that an effective study be completed. Some of the techniques displayed in this piece I have learnt while attending an in-house, hands on tutorial.

Before the Examination As per our department protocol, previous imaging should be reviewed if available. The room should be set up ready for the patient to enter and the examination to begin. The request should be read thoroughly to ensure that the correct examination is performed on the correct patient for the correct reason.

Room Set Up Before the patient is collected from the waiting area the room should be set up so that:  The machine is located at the head of the bed, set at an appropriate height (whether sitting or standing) to ensure that sonographer posture and overall good ergonomics are maintained.  An appropriate variety of probes need to be readily available either connected to the machine or very close by. These should include a vascular transducer that will allow for adequate penetration and resolution. At our practice we primarily utilise a Toshiba 11L4, Phillips 11__ and a GE 9L6. It is also important to have lower and higher frequency probes available for more challenging patients and more superficial structures respectively.

Room Set Up  Machine Pic to show layout  Probe selection

Room Set Up  The bed should be moved into an appropriate approximate location. This is to reduce any need to more the bed once the patient is positioned. Not only can this be uncomfortable for the patient but can cause undue stress on the sonographer and potentially cause injury.  Dependant on sonographer preference a pillow may be positioned at the head of the bed. Its use and position is critical to the examinations success. Too much extension in the neck may cause the to be uncomfortable and make it difficult for them to maintain the position. Too little extension and it may become difficult for the sonographer to acquire the necessary imaging. In room preparation pillows and sponges should at least be readily available so that patient position can be adjusted easily.

Room Set Up  Pic of bed/ pillow and sponges

Room Set Up  The following should also be available as for all ultrasound examinations Gel Towels Blanket  PIC

Greeting the Patient  After the patient has been called from the waiting area they should be taken to a private changing area or location where their identity can be verified.  Correct patient, correct examination, correct location should all be checked at this point.  Once this has been done, the patient should be changed in to a gown if their clothing is not appropriate for the examination.

Changing the Patient  If the patient requires changing they should be given an appropriate gown and instructed on how it is to be worn. It is part of our duty of care that the patient feel comfortable and is covered appropriately.  Consideration should be made for patients who are usually covered for religious or cultural reasons. If the patient is wearing a head dress they may feel uncomfortable with their arms, neck or shoulders bare. In these cases, to ensure patient comfort, if possible the patient should be allowed to change in the examination room so that they are not “uncovered” in the waiting areas.

Explanation of Exam  To ensure that patient consent is obtained, the examination should be explained prior to the examination.  It should be explained that: The examination may take a length of time The patient must remain as still as possible throughout the examination The patient must not talk throughout the examination but they may swallow as normal The patient will hear noises throughout the scan from the machine (it is important to inform the patient of this so they are not startled when they hear the Doppler) The scan will look at both sides of the neck The final reporting will be done by the radiologist and then transmitted to the referring doctor

Obtaining Patient History As with all imaging examinations it is important that a thorough patient history be obtained. Questions that may be asked include but are not limited to:  Have you previously had an examination of the carotid vessels?  Is there any previous history of stenosis?  Is there any previous history of surgery to the carotid vessels or surrounding vascular system?  What symptoms have they experienced?  How long have they experienced symptoms for?  Has there been any recent change in these symptoms?  Are they on any blood thinning medications?

Obtaining Patient History  Care should be taken to use laymen terminology where necessary to allow a more accurate history.  Terms such as: “blood thinning” rather than anticoagulant “clot” or blockage rather than stenosis

Patient Positioning The patient should be positioned so that:  The neck is slightly extended to a comfortable degree and slightly rotated to the contralateral side to the one being scanned.  A blanket may be placed over the patient if they are feeling cold.  If the patient is still in their own clothes, towels should placed in the collar to avoid contact from the gel.

Patient Positioning  PIC here

The following protocol has been taken from the Vascular Protocol Manual

Carotid Artery Protocol  Before images are taken the carotid should be scanned in B-mode to generally assess for plaque.  The same should then briefly done covering the CCA, ICA and ECA.

Carotid Artery Protocol 1. Longitudinal of the proximal CCA with Spectral waveform with velocity measurement. Waveform should be a mix of ICA and ECA patterns – rapid upstoke with brief reversal and a favourable diastolic component

Carotid Artery Protocol 2. Measure distal CCA peak velocity and enter into IC/CC equation

Carotid Artery Protocol 3. Identify the ECA by detecting waveform, the branches, using a temporal tap. Waveform – rapid upstroke, brief systole, post systolic notch and minimal diastolic flow

Carotid Artery Protocol WaveformTemporal Tap

Carotid Artery Protocol 4. Measure peak ICA velocity and enter it IC/CC systolic equation

Carotid Artery Protocol 5. Colour Image of the bifurcation

Carotid Artery Protocol 6. Vertebral artery in long with waveform and velocity reading.

The following is the additional information needed in the presence of plaque or stenosis

Additional Imaging  Measurement of ICA end diastolic flow if stenosis is detected

Additional Imaging  Image of bifurcation with plaque labelled  Ratio data should be included on image  Colour and B-mode image needed

Additional Imaging  B-Mode with direct stenosis measurements and diameter loss

Additional Imaging  Stenosis at bulb measurement to compare with ICA distal to bulb

Additional Imaging  Stenosis at proximal ICA, CCA and ECA direct measurement

Additional Imaging  Transverse image to show eccentric plaques

Additional Imaging  Retro-Orbital waveforms may also be examined

Additional Imaging  In the presence of vertebral reversal, the proximal subclavian should be assessed for stenosis. Brachial artery waveforms may also be examained bilaterally