VNJ Articlesreviewultrasoundwebinar
23 August 2022
Webinar Review: Ultrasound – The grey scale conundrum Presented by Richard Doyle and Samantha Morgan
Overview
This webinar is 58 minutes long and will cover all you need to know about preparing a patient for ultrasonography, using the ultrasound machine and starting to examine the abdomen. It provides a detailed overview of how an ultrasound machine works, the different types of machines, probes and features available. It guides you through the best way to prepare a patient in order to improve ultrasound scan quality. Finally, the webinar explains a guide to scanning the abdomen using some case examples to show abnormal findings.
Preparing the patient
Before starting to examine a patient with ultrasonography they should be as relaxed as possible, Richard recommends using valerian root powder on the scanning table as this works particularly well to help calm cats down. If you need more sedation, then the common premedication agents such as medetomidine work well.
You should clip a generous area in preparation for scanning on the patient, obtain the owner’s full consent to do so. Underclipping could mean that you miss a diagnosis by not being able to obtain a good image in the area that is required. For the abdomen, it is recommended that you clip from the pubis up to the xiphisternum and around to the costal arch.
Degrease the skin using surgical spirit only. Recently it has been protocol to use Hibiscrub in many practices, however, Hibiscrub causes bubbles to form around the small hair shafts left after clipping, these bubbles create air artefacts that will affect the quality of your image.
Ultrasound gel is important to use for acoustic contact but warm the gel up before placing it on your patient, you can use warm water baths, ‘hot hands’ or the warm air vents in your machine to warm the gel. Use plenty of gel as some of it is absorbed by the patient’s skin.
Preparing the machine
There are different types of transducers to use for different areas of examination, you need a linear array transducer for superficial structures like tendons and a curved array for body cavities. Ensure you know which side of your transducer matches with your image. To help with this there will be a raised area or mark on your transducer which matches up to a dot or asterisks on the screen.
Each machine has various functions you can adjust to help get the best image, these include:
• Power: this alters the amount of energy the sound waves have, this increases the reflection and makes the images appear whiter. However, the greater the power the more artefacts you get
• Gain: alters the brightness, this can be an adjustable dial to alter the whole image or a series of sliders that alter the gain at different depths of the image.
Richard recommends using the liver to help you adjust the settings to get the best image as this is a large organ that is a uniform tissue type.
Scanning the abdomen
Remember what you are viewing is a slice through the cavity. Richard describes it as a cut loaf of bread, with the transducer showing you the cut section of the patient. A denser an object is, the whiter it will show up on the screen as it reflects all the sounds waves back. Less dense structures such as fluid or air absorb the sound waves and show up as black areas.
When scanning the abdomen have a system in place to ensure you are looking at all the organs in a logical sequence, this will lessen the chances of you missing anything. Richard starts with the bladder and moves in a clockwise direction to look at the kidneys, stomach, liver, pancreas and the GI tract.
Tip
The sound quality on this webinar is not good as the microphone catches the speakers jacket as he moves, however, this improves after the first four minutes and it is better without headphones (the noise does not become so distracting). I would also recommend you have pictures of ultrasound images of the abdomen printed out so that you can annotate directly on them as Richard is going through the normal features. This is really helpful to identify normal structures so that you can spot the abnormal features.
Take home messages
1. Good preparation of the patient improves the quality of the ultrasound scan
2. Familiarity with the functions of the ultrasound machine will help increase the diagnostic quality
3. Scan the abdomen with a systematic approach to ensure all of the necessary areas are covered
Reflection
After viewing this session, I will review our patient preparation technique, ensuring we consent owners for clipping, even showing photo examples of previous clips so they are fully informed of how much fur we need to remove to obtain good scan images. I will also remove the use of Hibiscrub from our current protocol and just use surgical spirit to degrease the patients.
I am going to develop a how-to guide to scanning the abdomen, using picture examples and a step by step chart so that as RVNs we can become familiar with basic scanning techniques. This will help us save higher quality video and pictures for the veterinary surgeon to diagnose conditions.
This webinar was kindly sponsored by Boehringer Ingelheim.
Author
Samantha Morgan Cert Ed DipAVN (Medical & Surgical) RVN
Sam qualified as a Veterinary Nurse in 1999 and worked in an orthopaedic veterinary referral practice in Birmingham. Sam returned to Cardiff in 2002 and became Head Veterinary Nurse at Park Vets.
Between 2003 and 2008, Sam gained both the Medical and Surgical Diplomas in Advanced Veterinary Nursing. She holds an Examiner's Certificate for the RCVS and spends part of the year assessing the practical examinations. In 2004, Sam gained an assessors qualification and in 2010 she was awarded the Professional Certificate in Education (Cert Ed).
Sam has previously taught at Filton College, Bristol and now she is one of the directors of Abbeydale Vetlink, Monmouth. Previously Sam has also been the South Wales regional coordinator for the BVNA, organising local CPD events before being elected on to the BVNA council.
Veterinary Nursing Journal • VOL 34 • January 2019