250 Parramatta Rd
- 02 9758 8666
07 3172 0593
Cnr Kessels Rd & Springfield St
Cnr Kessels Rd & Springfield St
Macgregor, QLD, 4109
Since then we have developed a wealth of experience in this amazing imaging modality that has revolutionised our approach to many conditions. In late 2010 we took the opportunity to upgrade to what is our third CT scanner when we moved into the newpremises at Homebush. We have teamed the new scanner with two new important elements. Firstly, we now have the ability to file serve our PACS stored scans to some of the best overseas veterinary radiology specialists to obtain written opinions and reports on the scans online. Secondly, the production of impressive three dimensional digitally rendered images such as those seen in the gallery below is now possible using our new powerful Linux based imaging computer system. Such images have greatly improved our ability to treat many conditions where complex anatomical structures and disease require a complete perspective to develop a sound treatment plan. From intrahepatic portosytemic shunts to severe spinal fractures, cancers of the head and neck to complex pelvic fractures. The ability to create a navigable three-dimensional image of our patients is a huge advance in understanding diseases and especially for planning surgical interventions.
CT or computerised axial tomography is a system that employs a rotating beam of x-rays produced by a large x-ray tube mounted in a ring that rotates rapidly around the patient enclosed in a large ring shaped housing. The patient lies on a table (gantry) that slowly passes through the exposure field produced by the rotating x-ray tube. The receiver of the x-ray beam also spins opposite to the x-ray generator tube and thus detects changes in the intensity of X-rays that have passed through the body at that point. A powerful computer system then uses the information to recreate an image of a single slice of the patient at that level. It is analogous to cutting a cucumber to look at the slice end on. However, a typical CT scan might produce anything up to several hundred radiographic slices in sequences taken down to a distance of half a millimetre apart. This makes the CT scanner excellent for distinguishing between any structures of varying radiodensity. It lets you look inside a turtle’s shell or the skull of a dog with a brain tumour.
MRI or magnetic resonance imaging is an advanced imaging option employed by the specialists at the Animal Referral Hospital. The physics behind an MRI scanner are vastly complex but the simplest explanation of an MRI scan comes from Prof Hans Schild: “The patient is placed in the magnet, a radio wave is sent in, the radio wave is turned off and the patient emits a signal that is received and used for image reconstruction.”
MRI scans are ideal at showing cross-sectional images of many tissues of varying fat and water content. For example the MRI scanner will do a better job of distinguishing CSF from grey matter from white matter of the brain compared to a CT scanner. However, it is fair to say that CT scans are more impressive when bone detail and sharp radiographic contrasts exist (e.g. fat vs. muscle vs. air vs. bone). In some cases MRI may be the better cross-sectional imaging modality (e.g. brain and lumbosacral spine) than CT scans and in others the opposite is true. Your ARH specialist would be happy to explain the different advantages of the various diagnostic imaging modalities available for the referring veterinarian or owner of any patient. MRI is non-invasive and allows the inspection of slices of the body without physically invading the structure. MRI needs to be performed under an anaesthetic and, like a CT scan, can be made available in digital format for review by owners, their vets and by MRI specialist radiologists around the world.
Patients with problems of the central nervous system (spinal cord and brain) may show a wide variety of clinical signs including but not limited to seizures, lameness, pain, behavioural abnormalities, ataxia (wobbliness), tremors, coma, loss of learned responses, altered eye positions, blindness etc. Most of the specialists working at the Animal Referral Hospital were undergraduates at university before MRI and CT were available to veterinarians. In those days few intracranial diseases were precisely diagnosed before the death of the patient. With MRI scans we can see life like cross sectional pictures of brain and spinal cord tissues that show lesions in great detail. Because of the various manipulations of the process that can be employed we can often determine what a lesion is made of and often pinpoint the exact area of the brain or spinal cord that requires treatment. Peripheral nerve disorders such as peripheral nerve sheath tumours are another indication for MRI.
There are many uses for MRI in diagnosing the previously elusive causes of lameness where basic radiographs showed the bones and joints to be normal. We are now able to see so much more of the shoulder joints and the muscles and tendons of the fore limb so that soft tissue orthopaedic injuries are now far more readily diagnosed than in the past.