9. Cont…
• Lateral:
• localizes an abnormality seen on the PA view.
• Anteroposterior (AP):
• used for ill patients
• Supine:
• used in infants and ill patients
• Erect:
• detects gas under the diaphragm in a suspected abdominal viscus perforation.
The following projections are occasionally used.
• Oblique:
• useful to demonstrate pleural, chest wall and rib abnormalities.
• Apical:
• the patient stands erect and leans backwards to give a bone - free view of the lung apices.
• Expiratory:
• a pneumothorax becomes more prominent.
Disadvantage:
Magnification of the heart size
10. THE LATERAL CHEST PROJECTION
Note that the lesion projected over the chest on the PA
projection ( a ), assumed to be an intrathoracic mass, is
actually in the soft tissues of the back, seen on the lateral ( b )
11. Cont…
• Advantages:
• Quick test, widely available, inexpensive
• can usually identify pneumonia, TB, CHF, ...
• Disadvantages:
• Not as comprehensive as a chest CT. For example, it cannot rule out
processes such as a pulmonary embolus.
• When to order:
• Shortness of breath
• Chest pain
• Trauma
• Cough (sometimes)
12. CXR Quality Assessment
Before assessing technical quality, check patient’s name, age, date and erect or supine marks and
then check for 5 things:
• Orientation
• R or L marking
• Adequate penetration
• lower thoracic spine just visible
• over penetrated :too clearly visible
• under penetrated:: lung fields will appear falsely white.
• Inspiration
• diaphragms at level of 5th ,6th or 7th ribs anteriorly
• Rotation
• the spinous processes of the upper thoracic vertebrae lie midway between the medial ends of the clavicles.
• Motion
• Outline of the chest structures should be sharp.
17. How to read & interpret a Chest X-ray?
• Systematic approach: ABCDE-F
• Airway:
• Check to see if the trachea is midline.
• Bone:
• Look for fractures, metastasis.
• Cardiac:
• Look to see if the heart is enlarged.
• Diaphragm:
• Check for free air under the diaphragm
• and pleural effusions.
• Extras:
• Identify all tubes and lines.
• Fields of the lung:
• Check the lung parenchyma
• for an atelectasis or consolidation.
24. Key points
• There should be a decrease in
density from superior to inferior in
the posterior mediastinum.
• The retrosternal airspace should be
of the same density as the
retrocardiac airspace.
25.
26. Attenuation of the x-ray beam
Tissue
absorpti
on
Least
Most
Air or gas
Fat
Soft tissue
Bone or
calcium
Black image
Dark grey image
Grey image
White image
Effect on the radiograph
52. • Silhouette sign (+):
• An intrathoracic lesion touching a border of the heart, aorta, or
diaphragm will obliterate that border on the CXR.
• Silhouette sign (-):
• An intrathoracic lesion not anatomically contiguous with a border will not
obliterate that border.
Bronchial carcinoma.Pericardial cyst.
61. Consolidation
• The lung is said to be consolidated when the alveoli and
small airways are filled with dense material.
This dense material may consist of:
• Pus (pneumonia)
• Fluid (pulmonary edema)
• Blood (pulmonary hemorrhage)
• Cells (cancer)
82. Primary tuberculosis. Magnified PA CXR demonstrates a right mid
lung calcified nodule (Ghon focus) together with ipsilateral right
hilar lymph node calcification (Ranke complex).
98. )Pleural effusion(
A fluid collection in the space between the parietal and visceral layers of the pleura.
• Contents
• Usually contains serous fluid.
• Haemothorax: Blood, usually following trauma.
• Empyema: Purulent fluid from extension of pneumonia or lung abscess.
• Chylothorax: Chyle from thoracic duct rupture or from malignant invasion.
• Hydropneumothorax: Fluid and air.
• Radiological investigations
• Chest film
• Ultrasound
• CT
99.
100. Pleural effusion …
Radiological appearances:
Plain x-ray:
Erect position
Fluid gravitates to the lower-most part of the thorax
homogeneous opacification, similar density as the cardiac shadow;
loss of the diaphragm outline;
no visible pulmonary or bronchial markings;
concave upper border with the highest level in the axilla.
⇧ fluid collection ⇩ lung volume retracts towards the hilum.
Initially the fluid accumulates in the posterior, then the lateral costophrenic space.
Larger effusions mediastinal shift to the opposite side.
102. Pleural effusion …
• Subpulmonary effusion
• Fluid accumulating between the diaphragm and the inferior part of the lung.
• The upper margin of the shadow of the fluid runs parallel to the diaphragm.
• On the PA chest film mimics a high diaphragm.
• Loculated effusion
• Fluid can loculate in the fissures or against the chest wall.
• Occasionally seen in cardiac failure.
Key point:
• The minimum fluid volume that can be visualized on a chest film is 200-300ml;
this will blunt the costophrenic angle.
106. White out.
A large left pleural effusion is displacing
the mediastinum to the right.
White out.
The mediastinum and trachea are
displaced to the right. Major collapse of
the right lung.
107. White out.
The mediastinum is not displaced and the trachea is midline.
Large left pleural effusion with major compression collapse of the left lung.
The CT section confirms the effusion and the collapsed left lung.
108. Large right subpulmonary effusion
• Almost all the fluid is between the lung and the diaphragm.
• The right hemidiaphragm cannot be seen, but its estimated
position has been pencilled in.
112. Pneumothorax
• Air enters the pleural cavity via a
tear in either the parietal or visceral
pleura;
• The lung subsequently relaxes and
retracts to a varying extent towards
the hilum.
• Type:
• Severity
113. Pneumothorax …
Radiological features
• Best demonstrated on an
underpenetrated chest film.
• The following may be seen.
• Lung edge: a thin white line of the lung
margin, the visceral pleura.
• Absent lung markings between the
lung edge and chest wall.
• Mediastinal shift: when a tension
pneumothorax develops.
114. Pneumothorax …
Causes
• latrogenic (one of the commonest causes):
• Following lung biopsy, chest aspiration, thoracic surgery…
• Spontaneous:
• Rupture of a small pleural bleb.
• Trauma:
• Stab wounds, rib fractures
• Pre-existing lung disease:
• emphysema, cystic fibrosis or interstitial lung disease.
117. Tension pneumothorax with complete
collapse of the right lung (arrows) and
mediastinal shift to the left.
118. Pneumothorax …
• Complications
• Tension pneumothorax
• Hydropneumothorax
• fluid in a pneumothorax
• Key point:
• As air rises in an upright patient, a pneumothorax is most
commonly seen at the apex.
119.
120. Bronchial carcinoma
1- Bronchial carcinoma (peripheral):
• Main types: small cell lung cancer (SCLC) and non - small cell lung cancer (NSCLC).
Bronchoscopy may be negative in peripheral lesions, as visualization is not possible distal
to the segmental bronchi. The following features may be present on a plain chest film.
• Radiological features
• ● Lobulated or spiculated mass but sometimes with a smooth outline.
• ● Associated hilar gland enlargement, pleural effusion, areas of collapse or consolidation.
• ● Cavitation found in 15% with central air lucency, an air/fluid level and a wall of variable
thickness. Squamous carcinomas frequently cavitate.
• ● Tumours at the lung apex (Pancoast’s tumour) can invade the brachial plexus, resulting in
shoulder and arm pain with wasting of the hand, or invasion of the sympathetic chain may give
rise to Horner’s syndrome.
121. Cont…
2- Bronchial carcinoma (central):
Central bronchial carcinoma arises from the major bronchi, causing a
mass in the hilar region.
• Radiological features
• On a CXR, the central mass causes the hilar shadow to enlarge,
assume an increased density or an irregular outline. As the tumour
increases in size, narrowing of the bronchial lumen may cause collapse
of the distal lung and consolidation due to secondary infection.
• A large tumour often gives rise to complete collapse of a lung and may
result in opacification of the entire hemithorax.
122. Appearance of peripheral lung carcinoma.
A lobulated mass (a) and a cavitating mass
(b) are shown on plain films.
a b
123.
124. Typical appearance and small size of a carcinoma
of the bronchus discovered incidentally at CT.
125. Right hilar mass due to carcinoma of the bronchus.
There is also a patch of consolidation in the right upper
lobe laterally, from the central obstruction.
126. Metastatic neoplasms
• Primary source:
• Tumours of the lung, breast, renal tract, testis, GI tract, thyroid and bone.
Radiological features:
Metastatic disease to the chest may involve one or more of the following:
• Lungs
• Well-defined, multiple, round opacities of differing sizes in the lung fields.
• CT
• more sensitive than CXR
• monitoring response to chemotherapy.
• cavitation is occasionally present (indicating SCC)
• Key point
• Multiple lung lesions of varying size are invariably metastases
• Pleura:
• Lymph nodes:
• Skeletal system: