Ten Top Tips in Veterinary Small Animal Abdominal Ultrasound

Angie Lloyd-Jones, CEO for Aspire Ultrasound Consultancy Services Ltd, offers some great tips in veterinary small animal abdominal ultrasound. 

1. Make sure that the scan site has been clipped adequately – a full ventral clip with cranio-lateral extension to allow for intercostal assessment of the deep cranial structures of the abdomen (liver and spleen).

2. Use plenty of gel as the coupling agent as this will expel air and provide good skin contact and ultrasound through transmission. Use surgical spirit as a coupling fluid only when necessary (e.g., for tissue sampling) with a probe cover to protect your transducer from damage caused by the spirit.

3. Ensure your system is fit for purpose (electrically safe, regularly serviced, and wellmaintained). Select the correct probe and preset choice to undertake the abdominal examination. For dogs, a low to mid frequency microconvex probe is ideal as it has decent penetration with a wide far field for large structures. For cats, use a higher frequency linear probe as structures are more superficial and image resolution is better with higher frequency transducers.

4. Optimise your image at the very start of the scan and then as you move from structure to structure – you can’t rely on a ‘point and shoot’ mentality for scanning structures of varying depths and echogenicities. The focus, depth, zoom, TGC and Overall Gain will need to be adjusted as a minimum when optimising the image.

5. Adopt a methodical and systematic approach to your abdominal survey. This will mitigate the risk of missing pathology. Having a systematic method for undertaking the scan will improve your diagnostic potential ensuring the best diagnostic outcomes, keeping you and your patient safe.

6. Always keep the region of interest in the centre of your screen by adjusting the depth first and then the zoom/magnification function second.

7. Incorrect/poor use of overall gain and/or TGC will result in an under or oversaturated image which can mask or mimic pathology. Aim for a nice even greyscale throughout the depth of your image (assuming the tissue is disease-free).

8. When assessing the GI tract, look for peristalsis, sharp definition of the normal wall layer architecture. Loss of distinct layering, blurring of the wall layers, subjective thickening or increase in the echogenicity of the hypoechoic wall layers (mucosa and muscularis) can be indicative of focal or diffuse gastrointestinal disease.

9. Gently ballot the urinary bladder and gallbladder whilst scanning to reveal any gravity-dependent debris suspended within the urine pool or bile.

10. Most importantly, never forget that there is a patient at the end of the probe. Patients are far more compliant when sedated or anaesthetised but this isn’t always possible. They may be uncomfortable/in pain and frightened. Always document any difficulties in performing a scan in your report