2. What is an x ray?
An X-ray machine is basically like a camera.It uses
X-rays to expose the film, instead of visible light.
X-rays are similar to light in that they are
electromagnetic waves, but they are more energetic so
they can penetrate many materials to varying degrees.
When the X-rays hit the film, they expose it just as light
would. Various structures such as bone, fat, muscle,
tumors and all other masses absorb X-rays at different
levels (they do not let the x ray energy pass through).
The image on the film lets you view distinct structures
inside the body because of the different levels of
exposure on the film.
3. How were x ray discovered?
• In late 1895 A.D. a German physicist, Wilhelm Conrad
Röntgen accidentally discover a new light or ray.
• He named the new ray ‘X ray’ because in mathematics ‘X’ is
used to indicated unknown quantity.
• This Xray has identical property to pass through solid object
and react to a special photographic plate to capture an
image.
• It gives the scientists a door way to look inside human body.
• He got the Nobel Prize in Physics 1901 for discovery of Xray.
7. The 12-Step:
1: Name
2: Date
3: Old films
4: What type of view(s)
5: Penetration
6: Inspiration
7: Rotation
8: Angulation
9: Soft tissues / bony structures
10: Mediastinum
11: Diaphragms
12: Lung Fields
Quality Control
Findings
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8. Film Quality
1. PA or AP view.
2. Upright/Erect or Supine
3. Breath : Inspiration or Expiration
4. X-ray penetration : Under- or Over-
5. Rotation
9. PA vs AP views
PA view
• Scapula is seen in
periphery of thorax
• Clavicles project over
lung fields
• Posterior ribs are
distinct
• Position of markers
AP view
• Scapulae are over
lung fields
• Clavicles are above
the apex of lung
fields
• Anterior ribs are
distinct
• Position of markers
10. NORMAL CHEST X-RAY
PA LATERAL
Two (2) projections are needed for most x-rays to locate
structures in 3 planes
(1)Right or Left , (2) Anterior or Posterior) or (3)
Superior or Inferior.
13. 1. R Atrium
2. R Ventricle
3. Apex of L Ventricle
4. Superior Vena Cava
5. Inferior Vena Cava
6. Tricuspid Valve
7. Pulmonary Valve
8. Pulmonary Trunk
9. R PA 10. L PA
16. Penetration
With correct exposure you should barely see
the intervertebral disc through the heart
• If you see them very clearly
the film is overpenetrated
• If you do not see them it is
underpenetrated
20. Pitfalls to Chest X-ray Interpretation
• Poor inspiration
• Over or under penetration
• Rotation
• Forgetting the path of the x-ray beam
21. Normal Chest X-ray
• Cardiac Structures
– Position
• More central in younger infants and children
• More on the L side in older infants and teens
– Size
• CARDIO-THORACIC RATIO!
• Cardiac diameter :
– normal individuals < 15.5 cm in males; <14.5 cm in females.
– A change in diameter of greater than 1.5 cm between two
X-rays is significant.
27. Silhouette Sign
• The loss of the lung/soft tissue interface due
to the presence of fluid in the normally air-
filled lung.
• If an intrathoracic opacity is in anatomic
contact with a border, then the opacity will
obscure that border.
• Commonly seen with the borders of the heart,
aorta, chest wall, and diaphragm.
28.
29.
30. • Used to describe the location of a lesion at the inlet of the thoracic cavity.
• In this anatomical space, the posterior portions of the lung apices are located more
superiorly than the anterior portions .
• A lesion clearly visible above the clavicles on the frontal view must lie posteriorly and be
entirely within the thorax.
• If the cranial border of the lesion is obscured at or below the level of the clavicles, it is
located at the anterior mediastinum
Cervicothoracic Sign
31.
32. Air Bronchogram
A tubular outline of an airway made visible due to the filling of
the surrounding alveoli by fluid or inflammatory exudates
Conditions in which air bronchograms are seen:
• Lung consolidation
• Pulmonary edema
• Non-obstructive pulmonary atelectasis
• Interstitial disease
• Neoplasm
• Normal expiration
38. Hilum Overlay Sign
• The hilum overlay sign refers to an appearance on frontal
chest radiographs of patients with a mass projected at the
level of the hilum which is in fact either anterior or posterior
to the hilum.
• When a mass arises from the hilum, the pulmonary vessels
are in contact with the mass and as such their silhouette is
obliterated.
• The sign was first described by Benjamin Felson
39.
40.
41. Deep Sulcus Sign
• The deep sulcus sign describes the radiolucency extending from
the lateral costophrenic angle to the hypochondrium
• It is an important clue indicating possible pneumothorax in
chest x-rays obtained in the supine position.
• When plain films are taken with the subject in an upright
position, the free air in the pleural space gathers at the
apicolateral space.
• In the supine position, the air accumulating at the anterior
space forms a triangular radiolucency that makes the inferior
borders of the lateral costophrenic angle conspicuous
42.
43. Air crescent (“meniscus”) sign
• The air crescent (“meniscus”) sign is the
result of air accumulation between a
mass or nodule and normal lung
parenchyma.
• It is most frequently encountered in
neutropenic patients with aspergillosis.
44.
45. Spinnaker Sign
The spinnaker sign (the angel wing sign) is a sign of
pneumomediastinum seen on neonatal chest radiographs.
It refers to the thymus being outlined by air with each lobe
displaced laterally and appearing like spinnaker sails.
46.
47.
48. Hampton Hump Sign
• It is a wedge-shaped, pleura-based consolidation with a
rounded convex apex directed towards the hilus.
• This sign was first described by Aubrey Otis Hampton.
• It is usually encountered at the lower lobes and heals with
scar formation
49.
50. Westermark Sign
• Decrease of vascularization at the periphery of the
lungs due to mechanical obstruction or reflex
vasoconstriction in pulmonary embolism .
53. Bulging Fissure Sign
The bulging fissure sign refers to lobar consolidation where the affected
portion of the lung is expanded.
It is now rarely seen due to the widespread use of antibiotics.
54.
55.
56.
57. Continuous Diaphragm Sign
Continuous lucency outlining the base
of the heart, representing
pneumomediastinum .
Air in the mediastinum tracks
extrapleurally, between the heart and
diaphragm .
Pneumopericardium can have a similar
appearance but will show air
circumferentially outlining the heart.
58. Fallen Lung Sign
• This sign refers to the appearance
of the collapsed lung occurring
with a fractured bronchus .
• The bronchial fracture results in
the lung to fall away from the
hilum, either inferiorly and
laterally in an upright patient or
posteriorly, as seen on CT in a
supine patient.
• DD:
Pneumothorax causes a lung to
collapse inward toward the hilum.
59. Flat Waist Sign
• This sign refers to flattening of the contours of the aortic knob and adjacent main
pulmonary artery .
• It is seen in severe collapse of the left lower lobe and is caused by leftward
displacement and rotation of the heart
60. Finger in Glove Sign
The finger in glove sign can be seen on either chest radiograph or CT chest and refers to the
characteristic sign of a bronchocele
In bronchial obstruction, the portion of the bronchus distal to the obstruction is dilated
with the presence of mucous secretions (mucus plugging ).
61.
62. GOLDEN “S” SIGN
• When a lobe collapses around a large central mass, the peripheral lung collapses
and the central portion of lung is prevented from collapsing by the presence of the
mass.
• The relevant fissure is concave toward the lung peripherally but convex centrally,
and the shape of the fissure resembles an S or a reverse S .
63. Juxtaphrenic Peak Sign
• This sign refers to a small triangular shadow that obscures the dome of the
diaphragm secondary to upper lobe atelectasis .
• The shadow is caused by traction on the lower end of the major fissure, the
inferior accessory fissure, or the inferior pulmonary ligament.
64. Luftsichel Sign
This peri-aortic lucency has been termed the luftsichel sign, derived from the
German words luft (air) and sichel (sickle).
65. Doughnut Sign
• Occurs when mediastinal lymphadenopathy occurs behind
the bronchus intermedius in the subcarinal region
• Lymphadenopathy is seen as lobulated densities on lateral
radiographs
66.
67. Scimitar Sign
• Indicates anomalous venous return of the right inferior pulmonary vein (total or
segmental) directly to the hepatic vein, portal vein or inferior vena cava.
• A tubular-shaped opacity extending towards the diaphragm along the right side
of the heart is seen (Fig. 9).
• The abnormal pulmonary vein resembles a Turkish sword called a “pala”.
• The scimitar sign is associated with congenital hypogenetic lung syndrome
(scimitar syndrome)
76. • Lobar consolidation:
– Alveolar space filled with
inflammatory exudate
– Interstitium and
architecture remain
intact
– The airway is patent
– Radiologically:
• A density corresponding to
a segment or lobe
• Air bronchogram, and
• No significant loss of lung
volume
Consolidation
78. Atelectasis
• Loss of air
• Obstructive atelectasis:
– No ventilation to the lobe
beyond obstruction
– Radiologically:
• Density corresponding to a
segment or lobe
• Significant loss of volume
• Compensatory
hyperinflation of normal
lungs
79. • No ventilation to lobe beyond
the obstruction
• Trapped air absorbed by
pulmonary circulation
• Segmental/lobar density
• Compensatory hyper-inflation
of normal lungs.
Atelectasis
80. Congestive Heart Failure
• Increased heart size:
cardiothoracic ratio >0.5
Large hila with
indistinct markings
Fluid in interlobar
fissures
Pleural effusions,
alveolar edema
93. A single, 3cm relatively thin-walled cavity is noted in the left
midlung. This finding is most typical of squamous cell carcinoma
(SCC). One-third of SCC masses show cavitation
103. COPD: increase in heart diameter, flattening of the diaphragm,
and increase in the size of the retrosternal air space. In addition
the upper lobes will become hyperlucent due to destruction of
the lung tissue.
106. CHF:a great deal of accentuated interstitial markings,
Curly lines, and an enlarged heart. Normally indistinct
upper lobe vessels are prominent but are also masked
by interstitial edema.
