7. Intro to radiographic interpretation

Question 1

Explain the difference between optica, physical and radiographic density

Answer 1

• Optical: FILM BLACKNESS -> related to historic film production. Less dense structures produce higher optical density
• Radiographic: DENSITY OF SUBJECT as visible in imate-> inverse of optical, as denser material absorb more xrays, and produce white regions on radiograph (areas of low optical density)
• Radiographic density corresponds to inherent PHYSICAL DENSITY, relates to attenuation of xrays due to properties of material

Question 2

Define contrast resolution

Answer 2

Ability to display / distinguish differences in absoprtion between different tissues

-> Limited in XR (5 opacities)