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Indications for imaging
Localisation of structures seen on PA film
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Anatomy Demonstrated
Lungs & diaphragms (superimposed), trachea,
bronchus, major vessels, heart thoracic cage.
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Basic Patient Position
The patient stands (feet slightly apart for stability) erect
left (normally unless right lateral is indicated) side to the
film / bucky, median saggital plane parallel to the film. The
patient may need to flex forward from the waist to ensure the
limits of the examination fit on the film. The patients arms are
folded across the top of the head and the elbows gripped with
the hand of the opposite side. The chin is raised up. The top of
the film should be positioned about 3 cm above the tops of the
shoulders.
Meschan, I. 1955 An Atlas of Normal
Radiographic Anatomy Saunders, London
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Radiation protection
Direct lead rubber protection using a half apron
around the waist.
Correct centering should avoid irradiation of the thyroid gland.
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Central Ray
The horizontal central ray is centered midway between the
anterior and posterior skin surfaces at the level of T6/7 at a
level midway between the xiphisternum and the sternal angle.
Exposure is made on suspended full inspiration.
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Exposure Factors
| Kv |
mAS* |
FFD (cm)* |
Grid* |
Focus |
AEC* |
Cassette |
| 90 |
15 |
130 |
Yes |
Fine |
Yes |
35x43 |
| 85 |
15 |
180 |
No |
Fine |
No |
35x43 |
The use of a grid depends on department practice but is
almost always required in larger patient.
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Evaluation of the Image
ID and markers must be present and correct in the appropriate
area of the film.
Limits of anatomy, superiorly the lung apices, inferiorly the
posterior costaphrenic angle, anteriorly and posteriorly the
appropriate chest wall.
Rotation, the image should not be rotated, the vertebral
outlines must be in profile.
The chin and arms should be raised sufficiently to visualise the
lung apices.
There should be no evidence of movement.
Penetration the cardiac shadow should be penetrated.
Density the average density of the lung fields should be
approximately 1
Normal
Left
Lateral
Chest (from)
http://www.vh.org/Providers/TeachingFiles/NormalRadAnatomy/Images/
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Related Projections
PA
Apical
Thoracic inlet
Trachea
Oblique for upper ribs
Lower Ribs
Decubitus
Additional modalities
CT, RNI, MRI
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