RADIOPAQUE CONTRAST MEDIA

Table of Contents

Contrast media is the substance used to enhance the contrast of an image, hence, making an image more detailed and apparent. Contrast media is increasingly being used in various medical imaging techniques, such as MRI and CT.

Radiopaque media are chemical compounds containing elements of high atomic number which will stop the passage of x-rays. These types of compounds are used as diagnostic aids in radiology or roentgenology.

Roentgenoiogy involves the use of x-rays (roentgen-rays), which are short wavelength electromagnetic radiation, in the imaging or shadowing of various internal organ structures.

X-rays are capable of passing through most soft tissue so that when special photographic film or a photosensitive plate is placed on the side of the patient opposite to the x-ray source, the film or plate will become darkened in an amount proportional to the number of x-rays that are able to pass bone and teeth are the only types of tissue capable of significantly arresting the passage of x-rays. These structures will appear light on exposed x-ray film, allowing their visualization for the diagnosis of fractures, malformations.

Barium Sulfate

Barium sulfate is the agent of choice in roentgenographic studies of the GIT. Its insolubility in acidic gastric juice is a major criterion for this use, since soluble salts
would produce toxic barium ion.
Barium sulfate is employed as suspensions of various concentrations for use in the GIT.
A paste of the compound will remain in the oesophagus long enough for roentgenographic or fluoroscopic study.
The suspensions are administered orally or by enema after fasting.

Organoiodine Radiopaque Compounds

There are a number of official iodine-containing organic compounds used in diagnosis by roentgenography.
Meglumine Diatriwate, and Sodium Diatriwate
Depending upon concentrations of the particular salt and mixtures of the two salts, these agents are used in cerebral angiography, urography, pyelography, and
gastrointestinal studies.
Meglumine lodipamide, andSodium Iodipamide
Both of these are used in cholangiography (roentgenography of the bile duct).