5. Quality Control
• Inspiration:
• Ant. end of 5th - 6th or post. end of 10th rib above the
diaphragm
• Centering:
• Medial end of the clavicles equidistant from T4-5
spinous process
• Exposure:
• Vertebral bodies and disc spaces behind the heart must
be barely visible and bronchovascular marking should
be visible through the heart
7. Rotation Effect
• Anterior structures (e.g. heart) shift to the side farther from the film
• The lung farther from the film appears more lucent and the ipsilateral
hemithorax appears wider
• In this rotated film skin folds can be mistaken for a tension
pneumothorax (blue arrows)
12. Trachea
• Exact midline in the upper part& deviating to the
right around the aortic knob
• Even diameter up to M:25mm F:21mm
• Right paratracheal stripe <4-5mm
• Azygos vein at the anlge between the RMB&
trachea (less than 10mm in diameter)
• Carina at T6-7 angle: 60-75
13. Trachea in Superior Mediastinum
• Left side of the trachea is not border forming on
CXR it is not surrounded by aerated lung
17. The Heart
• 1/3(1/5-1/2) to the right& 2/3 to the left of
midline
• CT ratio 50% on PA and 60% on AP view
• Diameter up to F:14.5cm M:15.5cm
• 1-1.5cm increase on two consecutive films
is significant
• Enlarges in expiration& when diaphragm is
high
28. Diaphragm
• Right hemidiaphragm is usually higher
• More than 3cm difference between heights
of the hemidiaphragms may be abnormal
• Dome of the hemidiaphragms is usually
posteriorly located but on the right it may be
anterior 40% of the times
• Contour should be sharp except where heart
lies on the diaphragm
31. High Hemidiaphragm DDx
• Normal esp. when there is much gas in the bowel,
normal motion on fluoroscopy or sonography
• Diaphragmatic Paralysis esp. after thoracic
surgery, paradoxical motion of the diaphragm
• Eventration usu.paradoxical motion on fluoroscopy
37. Pleural Space
• Lateral Costophrenic Angles should be acute,
blunting indicate effusion (250ml at least),
flattening or thickening
• Posterior Costophrenic Angles can become
blunted by as little as 75ml fluid on lateral view
• Fissures are double layered pleura separating
lobes
38.
39. Fissures
• Oblique (major) visible only on lateral view
From T4-5 to just posterior to costophrenic angel
on the right and 5cm posterior on the left
• Horizontal (minor) visible on both PA& lateral
views
From right hilum to the 6th rib at axillary line
41. Fluid-filled fissures
•
•
The patient below has a pleural effusion extending into the fissure. Which
fissure is which?
What is the bright loop near the center of the films?
42. Segmental Lung Anatomy
• Lung
lobes
are
separated by fissures
which are composed of
two adjacent layers of
parietal pleura
• A lung segment is the
lung
parenchyma
surrounding
a
segmental bronchus
49. The Lungs
• Opacity
• Symmetry in marking& lucency
• Vasculature
– Inferior vessels are more prominent
– No vessel>3mm in diameter in the 1st anterior intercostal space
– Concave lateral border of Rt descending pulmonary A
• Hidden Areas
– Apex
– Posterior Recess
– Areas superimposed by mediastinum, hila& bones
51. Lung Hila
•
•
•
•
Left hilum higher 97%
Symmetric in size and density
Concave lateral border
Contour made up of superior pulmonary vein&
descending branch of main pulmonary artery
• Descending branch of main pulmonary artery on
the Rt has concave lateral contour and measures
less than 16mm in diameter
• Normal LNs not visible
69. Lateral CXR
• Clear Spaces
• Vretebral
Translucency
• Diaphragm Outline
• The fissures
• The lung Hila
• The Trachea& Upper
Lobe Bronchi
• The Sternum
70. Clear Spaces& Vertebral
Translucency
• Ant. Clear Space
– Ant. medistinal masses, LNs& aortic aneurysm
may fill this space
– In emphysema it widens (>3cm)
• Post. Clear Space
– Vertebral translucency increases progressively
downward in this space
79. Lateral Decubitus Films
•
•
•
•
•
To differentiate pleural effusion from thickening in case of a blunt
costophrenic angle
To assess the volume of pleural effusion
Demonstrates whether a pleural effusion is mobile or loculated
Detection of a pneumothorax in the nondependent hemithorax in a patient
who could not be examined erect
The dependant lung should increase in density due to atelectasis from the
weight of the mediastinum putting pressure on it. Failure to do so indicates
air trapping
82. Recommended order of reading a
CXR
• It is recommended to start from the regions
of least radiologic interest to decrease the
likelihood of missing details.
1- Abdomen
2- Thorax (soft tissues and bones)
3- Mediastinum
4- Lung-unilateral
5- Lungs-bilateral
This order can be memorized by the breviation
ATMLL
84. Thorax (soft tissues and bones)
• The path again starts
from the right lower
corner of the x-ray
85. Mediastinum
• Mediastinum can be assessed in two consecutive runs
one for the trachea And bronchi and the other for the
soft-tissue structures and pulmonary hila
86. Lung
• It is recommended to look at the lungs one by one at
first and then a look that compares the two lungs
87. Lateral Film
• The same order that was mentioned (ATMLL) is
applicable to lateral films too
88.
89.
90. Proposed reading order for a
CXR
•
•
•
•
•
•
•
•
•
•
•
•
•
Turn off stray lights, optimize room lighting, view images in order
Patient Data (name history #, age, sex, old films)
Routine Technique: AP/PA, exposure, rotation, supine or erect
Trachea: midline or deviated, caliber, mass
Lungs: abnormal shadowing or lucency
Pulmonary vessels: artery or vein enlargement
Hila: masses, lymphadenopathy
Heart: thorax: heart width > 2:1 ? Cardiac configuration?
Mediastinal contour: width? mass?
Pleura: effusion, thickening, calcification
Bones: lesions or fractures
Soft tissues: don’t miss a mastectomy
ICU Films: identify tubes first and look for pneumothorax
91. Atelectasis vs Lobar Pneumonia
Atelectasis
•
Volume Loss Associated
Ipsilateral Shift
• Linear, Wedge-Shaped
• Apex at Hilum
Pneumonia
• Normal or Increased Volume
No Shift, or if Present
Contralateral
• Consolidation, Air Space
Process
• Not Centered at Hilum