What is radiological density?

Radiographic density (AKA optical, photographic, or film density) is a measure of the degree of film darkening. Technically it should be called “transmitted density” when associated with transparent-base film since it is a measure of the light transmitted through the film.

What are the four natural radiographic densities in the body?

There are four densities on a radiograph. They are from black to white: gas, fat, water and mineral.

What is contrast in radiology?

Contrast radiography is a method of studying organs using X-rays and the administration of a special dye, called a contrast medium. This test allows the radiologist to evaluate structures that are not clearly evident on conventional X-ray exams.

What causes density in the lungs?

Lung density on CT is associated with cell concentration in BAL in smokers and may mirror an inflammatory response in the lung. Gender difference in lung density is dependent on height. In COPD with emphysema, loss of lung tissue may counterbalance the expected increase in density due to inflammation.

What controls radiographic density?

The degree of blackness on a radiograph depends on the amount of x-rays reaching the film. Density is influenced by the quantity and quality of the x-ray beam, as well as the type and thickness of the tissue under examination.

What is radiographic film?

X-ray films for general radiography consist of an emulsion-gelatin containing radiation sensitive silver halide crystals, such as silver bromide or silver chloride, and a flexible, transparent, blue-tinted base.

What is contrast CT?

A special dye called contrast material is needed for some CT scans to help highlight the areas of your body being examined. The contrast material blocks X-rays and appears white on images, which can help emphasize blood vessels, intestines or other structures. Contrast material might be given to you: By mouth.

What is lucency on a CT scan?

On a CT scan, lucencies in the liver would indicate areas of a different density from the surrounding tissue.