THE PLAIN FILM
• The PA (postero-anterior) view:
It is the most frequently required radiological
examination. Comparison of current film with old
films is valuable.
Position: Patient facing the
film, chin up with the shoulders
rotated forwards to displaced
the scapulae from the lungs.
Exposure is made on full
inspiration, centering at T5.
kVp = Energy of x-rays = higher penetrability, it moves
The energy determines the QUALITY of x-ray
1. increase in kVp = electrons gain high energy
2. higher the energy of electrons = greater quality of x-
3. greater quality = greater penetrability
kVp Low kVp
Produces High contrast films Low contrast films
Better •Miliary shadowing
Comparison with PA view:
Advantages : Anterior mediastinal
Encysted pleural fluids
Posterior basal consolidation
Disadvantages : Lung collapse
Large pleural effusion.
Collapse of the Left lung. Only the right hemidiaphragm is visible.
PA View Lateral View
This is a PA film on the left compared with a AP supine film on the
The AP shows magnification of the heart and widening of the
AP film is taken mostly in very ill patients who cannot stand erect.
Oblique view is better for:
• Retrocardiac area
• Posterior costophrenic
• Chest wall
• Pleural plaques
Lateral decubitus position:
It is helpful to assess the volume of pleural effusion
and demonstrate whether a pleural effusion is mobile
Lateral decubitus position film showing mobile pleural effusion (arrows)
Viewing the PA film:
• Well centered
• Clavicles should be equidistant
from the vertebral body's at
• Side markers should be place.
Poor inspiration can
crowd lung markings
“disease process” at
the lung bases has
About 8 posterior ribs are showing
9-10 posterior ribs are showing
If spinous process appears closer to the
right clavicle (red arrow), the patient is
rotated toward their own left side
If spinous process appears closer to the
left clavicle (red arrow),
the patient is rotated toward their own
• It should be examined for narrowing, displacement,
caliber and intraluminal lesions.
It is in midline in upper part, then deviates slightly to the
right around the aortic knuckle.
The mediastinum and heart:
• Two-third of the cardiac shadow lies to the left of
midline and one-third to the right.
• CT ratio is less then 50% on PA film & 60% in AP film.
• In young children triangular sail shaped ‘Thymus’
makes ‘wave sign of Mulvey’.
Tissues along side of breasts
Air under diaphragm
Soft tissue mass
Check the bones for any
fracture , lesions, density
Heart size on PA
Inferior vena cava
Superior vena cava
Subclavian artery and vein
The right middle lobe is
typically the smallest of
the three, and appears
triangular in shape, being
narrowest near the hilum.
The right lower lobe is the
largest of all three lobes,
separated from the others
by the major fissure.
Posteriorly, the RLL
extend as far superiorly as
the 6th thoracic vertebral
body, and extends
inferiorly to the
Review of the lateral plain
film surprisingly shows
the superior extent of the
• On inspiration the domes of the diaphragms are at the
level of the 6th rib anteriorly and 10th rib posteriorly.
• Check sharpness of borders.
• Right is normally higher than left.
• Check for free air, gastric bubble, pleural effusions.
The main fissures:
Horizontal fissure: On the PA film it running from the
hilum to the 6th rib in the axillary line.
Oblique fissure: It separates the three lobes of right
side with horizontal fissure and two lobes of left side.
• Azygos fissure: It is a comma shaped fissure.
• The superior accessory fissure
• The inferior accessory fissure
• The left-sided horizontal fissure
The hidden areas:
• The apices
• Mediastinum and hila
Hila: Look for nodes and masses in the hila of both
lungs. On the frontal view, most of the hilar shadows
represent the left and right pulmonary arteries. The
left pulmonary artery is always more superior than the
right, making the left hilum higher. Look for calcified
lymph nodes in the hilar, which may be caused by an
old tuberculosis infection.
• Right and Left Pulmonary
• Secondary Bronchi
• Tertiary Bronchi
• Alveolar Duct
Anatomy of main bronchi and segmental