Ultrasound Imaging

Will Tweedie & Associates store copies of my ultrasound images?

Yes! We save images from every examination to enable comparisons and assessments at a later date.

All our clients are provided written reports, containing copies of their horses’ images upon request.

When will it be useful to conduct an ultrasound examination of my horse?

Like any imaging modality, the physical examination and associated clinical findings should always guide the appropriate use of ultrasound.

We often use ultrasound as part of a comprehensive medical workup. For example, ultrasound is a good imaging modality to use to examine the surface of the lungs of adults and neonates. As an example, we would routinely use ultrasound in the workup of neonatal respiratory disease or adult travel sickness.

We also use ultrasound to assess soft tissue structures such as tendons and ligaments. Damage to tendons and ligaments will be seen on ultrasound as changes to the fibre pattern and cross sectional area of the structure. Ultrasound allows us to determine the severity of any damage to tendons and ligaments and we use it to guide us in our clinical decision making. For example, we use the ultrasound examination to help us design controlled exercise programs for individual horses. When we diagnose a tendon and ligament injury in our clinic, we always provide the owner with a management plan to return the horse to athletic function.

Dr Mike Tweedie has achieved exceptional results returning thoroughbreds to racing after tendon and ligament injuries. For more information about the use of platelet rich plasma and controlled exercise programs in racehorses, please see here.

How does ultrasound work?

Diagnostic ultrasound employs high-frequency sound waves, which are outside the range of human hearing. Ultrasound waves, like other sound waves, are reflected, refracted, scattered, attenuated and absorbed. When we place the ultrasound transducer against the horse, we transmit ultrasound pulses and ultrasound energy into the horse. When we place the transducer perpendicular to a tissue structure, the ultrasound pulse we have transmitted hits the tissue structure and is reflected back to the transducer. This returning ultrasound energy is received by the transducer and converted into electrical energy producing an image.

The image that is produced is a grey scale image. Different tissue types appear darker and lighter in the ultrasound image depending on how many ultrasound waves they reflect back to the transducer as apposed to how many they absorb. We call this phenomenon, tissue echogenicity. For example, fluid absorbs lots of ultrasound waves and reflects few back, so it appears black on in the image. Bone on the other hand, reflects back lots of ultrasound waves and appears white on the image.

What happens during an ultrasound examination?

Accurate interpretation of the ultrasound examination is dependent on the quality of the image and the experience of the veterinarian. The veterinarian needs a thorough understanding of anatomy and the behaviour of ultrasound in tissues for accurate image interpretation.

The ultrasound examination is an active process that involves interaction between the veterinarian, the horse, the transducer and the ultrasound machine to obtain good quality images.

There are a couple of things we do to ensure the examination goes smoothly. Firstly, we administer a light sedation to the horse. Secondly, we prepare the area for examination. In the case of a tendon examination, this will involve clipping the area to be examined.

We always conduct a thorough and comprehensive study. In the case of a tendon examination, this involves obtaining longitudinal and cross sectional images at 5cm intervals along the entire structure. We save images from every examination to enable comparisons and assessments at a later date.

Finally, based on our findings during the examination, we make a recommendation for treatment and management of the condition, or make a recommendation for further diagnostic imaging.