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What is MRI?

MRI has for many years been the imaging method of choice in human medicine making it the gold standard for diagnosing pathology. Hallmarq’s EQ2 system brings the same diagnostic capability to the equine clinical practice.
 

MRI images closely reflect true anatomy whereas x-rays show bone only and ultrasound shows soft tissues only. This is demonstrated in the three images below.

saggital section through cadaver foot
Section through a horses hoof at post mortem

Foot X-ray - side view

Foot MRI - side view

 

How does it work?

When tissue is placed in a strong magnetic field and a short pulse of radio waves is applied, a weak signal echoes back and is used to create an image

The tissue examined must be completely inside the magnet, limiting MRI in the horse to limbs (standing) and heads (under anaesthesia).

Because MRI transmits and receives radio signals, scanning must take place in a screened room MRI.

MRI does not use ionising radiation (as used in X-rays) and has no known hazardous biological effects

The images appear as black-and-white slices through the tissue. The position of the slice is chosen by the scanner operator.

What do MR images look like ?
 

Vertical slice through the midline of the hoof, pastern and fetlock from front to back

 

Vertical slice through the fetlock joint from side to side

 

Two different slices through the fetlock joint from front to back

 

Horizontal slice through the knee (carpus)

 

Vertical slice through the hoof (from side to side) showing the coffin and pedal bone

 

Horizontal slice through the top of the cannon bone showing bone and tendons