1. Basics of Radiology
A pre-clinician needs an organized introduction to
the fundamentals of radiology to appreciate the
content & usefulness of radiological images. The
focus of this material is the plain-film radiograph—
the beginning of radiology.
Remember, the instructor is not a radiologist; neither
he nor the course material suggest that you need to
be, or even should be, interpreting diagnostic images
- - for that is the responsibility of the Radiologist.
2. Radiograph
X-ray film with an image of an anatomy
X-rays emanating from a localized source
pass through a portion of the body onto a
detector that records the density of x-rays
as an image
Plain Film/ Conventional Radiograph
Made without contrast enhancement
80% of imaging examinations
3. Radiodensity
Amount of x-irradiation absorbed by a
substance
Determined by composition (atomic weight)
and thickness
Greater the atomic weight and thickness,
the greater the radiodensity
Increased radiodensity, increased
absorption of x-rays
As radiodensity increases, objective
appears more white on image
8. Image Distortion
Magnification
The closer a structure is to the film, the
less magnification there is and the
detail & sharpness is better.
Shortening & Lengthening
due to the angle of x-ray beam or angle of the structure.
. . . relative to the film
9. Viewing Plain Radiographs
Always need at least 2
views
Close to 90 degrees
from each other
“One View Is No View”
Film Markers: Patient
ID & anatomical side:
Do not orient film to
view a correctly
positioned letter
10. Radiographs: Common Views
Anteroposterior (AP): beam passes
anterior to posterior.
Posteroanterior (PA): beam passes
posterior to anterior (common chest view)
Lateral
Oblique
11. Placing Radiographs on View Box
For AP views (extremity, head/spine) and
chest PA:
place in the viewing box with the patient facing
you in anatomical position (except wrist-hand-
fingers and feet-toes). The patient’s right is on
your left.
Hand-fingers (PA) or foot/toes (AP):
point the digits up; hands and feet are oriented
right on right and left on left (rather than
anatomical position).
Spine AP views: orient in anatomical position
with the “R” on the patient’s right side
12. Placing Radiographs on View Box
In general for Lateral & Oblique views
typically face them to your LEFT,
or you can also attempt to orient in the
same direction that the beam traveled
(easy to say, hard to do).
If it is a multi-view film and there is an
AP or PA view accompanying, then use
the AP or PA view to correctly orient the
entire film.
