Changes

==Introduction==

==Introduction==

Contrast procedures have been developed to '''increase the native contrast of organs''' in order to separate them from surrounding tissues.

Contrast procedures have been developed to '''increase the native contrast of organs''' in order to separate them from surrounding tissues. There are many situations where they can be a useful supplement to the information gained from routine radiographic examination. They can provide information on the '''size, shape and position''' of structures. They might help outline the internal structure of an organ, including its mucosal pattern, and sometimes help assess its function.

 

There are many situations where they can be a useful supplement to the information gained from routine radiographic examination.

 

They can provide information on the '''size, shape and position''' of structures. They might help outline the internal structure of an organ, including its mucosal pattern, and sometimes help assess its function.

In small animal practice, contrast radiography is mainly used for the '''diagnosis of gastrointestinal and urogenital disorders''', although it is also used in myelography, angiography and in the assessment of joints and sinus tracts.

In small animal practice, contrast radiography is mainly used for the '''diagnosis of gastrointestinal and urogenital disorders''', although it is also used in myelography, angiography and in the assessment of joints and sinus tracts.

The agents can also be combined to produce a '''double-contrast''' study which is often the best way to give optimal mucosal detail.

The agents can also be combined to produce a '''double-contrast''' study which is often the best way to give optimal mucosal detail.

==Gastrointestinal studies==

==Gastrointestinal Studies==

Barium or iodine-based solutions can be used for positive contrast studies. Barium is contra-indicated if there is suspected perforation anywhere in the gastrointestinal tract as leakage can result in a granulomatous reaction and adhesions.

Barium or iodine-based solutions can be used for positive contrast studies. Barium is contra-indicated if there is suspected perforation anywhere in the gastrointestinal tract as leakage can result in a granulomatous reaction and adhesions.

Air is naturally present in the GI tract and provides some natural contrast, but air can also be introduced and provide negative contrast images.

Air is naturally present in the GI tract and provides some natural contrast, but air can also be introduced and provide negative contrast images.

===Patient preparation===

===Patient Preparation===

If the condition is chronic, there is usually adequate time to ensure a good preparation of the patient.

If the condition is chronic, there is usually adequate time to ensure a good preparation of the patient.

'''Large intestine''': pneumocolon or barium enema

'''Large intestine''': pneumocolon or barium enema

==Urogenital studies==

==Urogenital Studies==

Iodine-containing agents are usually used, ionic or non-ionic. Air can also be used although is contraindicated if rupture is suspected due to the potential for a fatal air embolism.

Iodine-containing agents are usually used, ionic or non-ionic. Air can also be used although is contraindicated if rupture is suspected due to the potential for a fatal air embolism.

'''Bladder''': usually retrograde cystrography (pneumocystogram, positive contrast cystrogram, double contrast cystogram)

'''Bladder''': usually retrograde cystrography (pneumocystogram, positive contrast cystrogram, double contrast cystogram)

'''Urethra''': retrograde urethrogram in males, retrograde vaginourethrogram in females. It should not be performed in females in oestrus unless essential due to the patency of the cervix and increased sensitivity of the vaginal mucosa.

'''Urethra''': retrograde urethrogram in males, retrograde vaginourethrogram in females. It should not be performed in females in oestrus unless essential due to the patency of the cervix and increased sensitivity of the vaginal mucosa.

==Myelography==

==Myelography==

Contrast should be injected under aseptic conditions into the '''subarachnoid space''' either at the cerebellomedullary cistern or at the lumbar cistern.

Contrast should be injected under aseptic conditions into the '''subarachnoid space''' either at the cerebellomedullary cistern or at the lumbar cistern.

==Vascular studies==

==Vascular Studies==

'''Portal venography''' can be used to diagnose a porto-systemic shunt.

'''Portal venography''' can be used to diagnose a porto-systemic shunt.

==Articular studies==

==Articular Studies==

'''Shoulder arthrography''' is useful in cases of suspected biceps tendon injury, for evaluation of shoulder Osteochondrosis Dissecans and for any other joint pathology such as tumours.

'''Shoulder arthrography''' is useful in cases of suspected biceps tendon injury, for evaluation of shoulder [[Osteochondrosis Dissecans]] and for any other joint pathology such as tumours.

==Dacryocystorhinography==

==Dacryocystorhinography==

==Contrast studies in horses==

==Contrast Studies in Horses==

Contrast studies are mainly used to investigate '''orthopaedic conditions''' such as OCD in the shoulder, stifle and tarsus, and degenerative joint disease. Contrast medium is injected aseptically into the joint and orthogonal radiographs are taken.

Contrast studies are mainly used to investigate '''orthopaedic conditions''' such as [[OCD]] in the shoulder, stifle and tarsus, and degenerative joint disease. Contrast medium is injected aseptically into the joint and orthogonal radiographs are taken.

Contrast studies are also extremely useful for the assessment of joint and tendon sheath integrity following a '''traumatic incident'''. Contrast can either be injected into the penetrating wound tract to assess dispersal of the medium. Alternatively, contrast can be injected into a joint or tendon sheath in an area away from the puncture, and leakage through the wound can be assessed.

Contrast studies are also extremely useful for the assessment of joint and tendon sheath integrity following a '''traumatic incident'''. Contrast can either be injected into the penetrating wound tract to assess dispersal of the medium. Alternatively, contrast can be injected into a joint or tendon sheath in an area away from the puncture, and leakage through the wound can be assessed.

[[Category:To Do - Helen]]

[[Category:To Do - Helen]]