Question

All the radiographs at your facility are turning out gray in your facility with little differences between body tissues. What would you refer to this image? What factors could be causing the graying?

Answer 1

Radiography is a technique of producing images on sensitive film by using radiation such as X-rays, gamma rays and other form of radiation. The degree of blackness on a radiograph is called "radiographic density. A radiograph with the long scale of contract has many shades of gray with a few black and white shades. In contrast the radiographs with a short scale of contract have few gray shades and many black and white shades. Generally gray shades are referred to as water density and the soft tissues, organs and muscles are shades of gray, ranging from light to dark gray depending on the structure’s density. Most of the studies require a long scale of contrast.

The four factors affecting the proper scale of contrast are,

1. Subject density

2. Kilo voltage peak level (kvp level)

3. Film contrast

4. Film fogging

Four basic radiographic densities:
a. Air - black
b. Fat - gray/black
c. Soft tissues and organs - gray
d. Metal, calcium, and bone - white