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MRI: a powerful diagnostic weapon for our pets

What is an MRI scanner?

It is a modern diagnostic tool which was first used in human medicine in the 80s. It obtains anatomical images of any part of the animal in any plain (Sagittal, Coronal and Transverse), thus detecting any size lesions present.

How does an MRI scanner work?

It works on the simple principle of hydrogen atoms in the tissues, as most tissues contain water. Water is composed of hydrogen and oxygen therefore all tissues will give an MRI signal, the signal will be determined by the water content of the tissue.

How dangerous is the resonance? MRI is totally harmless for the patient, the operator and the environment and unlike x-ray and CT does not emit ionising radiation, but radio waves.

The only contraindication for MRI studies is the presence of metal objects in the animal’s body, which may discourage the study or limit the area that can be studied.

Can you do an MRI in all animals?

All species of animals can be studied by resonance, regardless of weight or age, although our hospital serves pets only, ie dogs, cats, birds, reptiles and small mammals. Because it is a completely non-invasive technique it has numerous advantages over other diagnostic techniques.

The resonance is capable of differentiating blood vessels and nerves within an anatomic region and so makes it essential to detect numerous disorders.

When is an MRI necessary?

An MRI is recommended in the study of any organ or diseased tissue, being especially useful in the study of soft tissue since they are the most difficult to diagnose, as they do not appear on x-rays or CAT scans.

Typical systems studied by resonance are the nervous system (brain, spinal cord and nerves) and the musculoskeletal system (muscles, tendons and joints like the knee, hip, shoulder, elbow etc.).

It can also prove extremely useful in diagnosing many diseases of other systems for example:

Ligaments in dogs stifle joint

Vision: retinal detachment, tumours
Hearing: chronic otitis, internal otitis
Renal: tumours, polycystic disease, renal vascular abnormalities, bladder
Reproductive: ovarian disease, prostate
Digestive: liver, pancreas, intestine, stomach
Respiratory: lungs, trachea, pleura
Cardiovascular: lymphatics, heart

And many more.

With one study depending on the size of the animal we can produce images of all structures present in the area being tested. Giving us a whole body image with small patients or images of full head, chest, abdominal or pelvic region etc.

MRI scans provide cross-sectional imaging in any plain with no superimposition of overlying structures. The soft tissue detail and resolution is extremely good allowing observation of lesions (which are easily distinguishable from healthy tissue), and their relationship to adjacent structures (lymph, lymph vessels, arteries, veins, nerves, etc…), assisting the veterinarian in making decisions such as: assessing the infiltration of the injury, the extent of an inflammation or the degree of malignancy, age of an injury and etc.

How much does an MRI cost?
The price is variable, as it depends on the area of the study, duration of the study, the severity of injuries, the size of the animal and so on.

Do you have to anesthetise the patient?
Pets need to be sedated during the scan. With the vet MRI scanner it is easy to monitor the animal during the scan as they are easily accessible, therefore reducing any risks for the patient.

How long does the test take?
It depends on the areas studied, the protocols and sequences used … usually taking an average of 30 minutes per patient.

When do I get the results?
While the vet gets the results immediately, you need a detailed study of medical images
obtained by our specialist, so we normally advise you of the results the next day.

When is it necessary to use contrast in an MRI and is it dangerous?
The contrasts are often necessary in order to highlight the pathological tissues in MRI.
According to our experience and to modern publications, the possibility of allergic reactions to the contrast is remote.

MRI of a dogs spine

How to interpret an MRI?
The interpretation of resonance images is a rather difficult task for the veterinary surgeon, due to its great complexity, requiring specialised training at universities and international conferences.

How is this MRI different to others on the market?
An MRI diagnostic image should be of high quality and capable of dealing with modern
DICOM software. This does not come with most devices on the market, as they have been manufactured for diagnosis in human medicine and are usually second hand ie where obsolete many years ago.

This article was published in Costa Blanca News.