Presenter: Dr Robert Williams B.Vet.Med. Member of the Australian College of Veterinary Scientists (M.A.C.V.S) Emergency and Critical Care
It was only last week that the power of the webinar really hit me. Getting an eminent speaker to discuss the basics of ultrasound whilst looking at his view of Queensland, Australia can only be described as impressive. Dr Williams gave an incredibly fact-filled and comprehensive presentation on basic ultrasound techniques along with everything should know about this subject before even thinking about picking up an ultrasound probe.
Ensuring that you’re performing ultrasound at the right time and for the appropriate reasons is crucial. Ultrasound is a dynamic process where functions such as blood flow and intestinal movement can be assessed and, unlike radiography, it is almost impossible to interpret a static image after the event.
Recording images and writing up a detailed report can prove very useful, not only from a litigious point of view but also in steering the ultrasonographer to adopt a methodical and thorough approach to ultrasonography. Dr Williams suggested using the S.S.M.E.E.L. pseudonym when writing detailed descriptions: S for size, S for shape, M for margins, E for echogenicity, E for echo-texture and L for location.
Allocating time is also essential when performing ultrasound, and Dr Williams suggested a full abdominal ultrasound can take up to 60minutes. The animal should always be made as comfortable as possible throughout this procedure and Dr Williams recommends sedating patients with acp and butorphanol. Sedation not only makes patients more compliant but it also offers some analgesia for, what can be, an uncomfortable procedure.
Understanding the physics of ultrasound plays an important role in getting the most from your image and helps to explain what is in fact an artefact and what is real. Dr Williams goes into the physics of ultrasound in great depth with explanations for all those fancy terms you so often hear banded about such as ‘acoustic shadowing’, ‘mirror image’ and ‘edge shadowing’. I now understand what they mean and I had never realised how useful they could be in helping with diagnosis. For instance, a mirror image can be seen when looking at the liver in a particular plane. This mirror image is seen at the air interface between the thoracic cavity and abdomen, and it looks as though the liver is in the thoracic cavity. If this mirror image is lost, it indicates that there may be pleural fluid present which can be a very useful diagnostic indicator.
Dr Williams managed to convey a huge amount of information over the space of an hour but as a summary he was insistent about giving some ‘take home’ messages. The first is to always remember to freeze an image or turn off the machine when it is not in use. Also, the probe must never be connected when the machine is turned on. By not setting up the ultrasound machine correctly, no end of damage can be done to ‘expensive’ equipment.
Another key point is to always use the highest frequency you can get to achieve the penetration you need. This helps to give the best image and its explanation lies within the physics discussions earlier in the webinar. The final take home message that Dr Williams was keen to stress was that neoplasia cannot be diagnosed through sole use of ultrasound. Cytology will always be necessary to make a final diagnosis. Your suspicions may well be right but occasionally you will be wrong and he emphasised again that whilst ultrasonography is a really useful tool, other diagnostic techniques are also likely to be necessary.
The Stethoscope (MRCVS)
Access to the recording can be purchased at the following link http://thewebinarvet.com/webinar-archive/