文档介绍：Overview of Diagnostic Radiology
Wang Yongdong,MD,Professor
Wilhelm Conrad Röentgen
Professor of Experimental Physics
Würzburg University
Discovered x-rays
8 November, 1895
Awarded first Nobel
Prize for Physics
1901
Production of X-rays
High speed e- strike metal x-rays
e- = electron
X-ray property
ration
Photographic effect
Phosphorescent efect
Ionization effect
Making a Radiograph
Animal between x-ray tube and x-ray film
Low energy photons absorbed by patient
Not useful for image production
Filters reduce patient exposure
Only possible because of differential absorption of x-rays
Photoelectric effect
Film Blackness
Emulsion crystals exposed
X-rays or light
Precipitate on film during development
Black spot
Emulsion crystals not exposed
Removed during fixing process
White spot
Film Blackness
Degree of blackness affected by number of photons striking film
mA number to film
kVp energy number to film