Diagnostic Imaging

Each imaging method provides different diagnostic information and they can be used individually or in combination to help us identify the cause of clinical problems.

Radiography uses x-rays which are projected towards the area being imaged. The density of the tissue determines how much radiation is absorbed and this information is converted into a 2-D image. Radiography is very useful for imaging bones, but less so for soft tissue.

Ultrasonography creates sound waves which are projected into the body and reflected by internal structures, creating ‘echoes’. These are then recorded and displayed as an image without the use of radiation. This technique is particularly useful for tendons, muscles and internal organs but requires a high level of experience and expertise to interpret the images.

Nuclear scintigraphy is used primarily to assess functional rather than anatomical changes, predominantly in the skeleton of the horse. The technique involves the injection of a radioactive substance which is taken up in greater quantities in areas where a disease process is present. Gamma cameras are then passed over the body to capture images of these ‘hot spots’ or areas of pathology.

Computed tomography (CT) scanners take a series of very thin x-ray images from different angles and, using a sophisticated computer, converts them into 3-D images. The technique involves the use of low levels of radiation.

Magnetic resonance imaging (MRI) is a complex technique. The patient’s limb is placed in a strong magnetic field and pulsed radiowaves are applied. Computer software then converts the returning signals into detailed images. MRI does not involve radiation and horses need to be sedated to minimise movement during the procedure.

The choice of diagnostic imaging technique(s) is critical and the advanced level of clinical expertise available at NEH Referrals ensures that the most appropriate methods are used, thereby enhancing the likelihood of an accurate diagnosis while minimising costs.