L8: CXR Flashcards
Standard views
PA + lateral
View which magnifies the heart
AP view
Most radiopaque (white)
metal/bone
Least radiopaque (black)
air
Lower lung lobes appear
inferior to the diaphragm, you should see bilateral lung markings below the diaphragm
Where are most abnormalities seen?
Chest wall
What may obscure lung markings?
Obesity
RIP for image quality
Rotation
Inspiration
Penetration
Assess rotation
clavicles are equidistant from the spinous processes
Assess inspiration
diaphragm below ribs 8-10 posteriorly and 5-7 anteriorly
Adequate penetration
disc spaces are seen but bony details of spine cannot be seen
Overexposed CXR
lungs appear too black (radiolucent)
Underexposed CXR
lungs appear whitish, cloudy, lower lobes not seen
Are there many lung lesions? Acronym
A: Abdomen T: thoracic wall: soft tissues and bones M: Mediastinum L: Lung fields (assess individually) L: Lungs comparison
Normal pleural/vascular markings
Extend all the way to the chest wall, all the way to the periphery of the ribcage
More prominent in the central/lower lung fields (bases)
Right vs left hemidiaphragm
Right is 3 cm higher
Gastric bubble
seen below the left diaphragm
normal
Middle Mediastinum
heart and great vessels
Anterior Mediastinum
potential space in front of the heart
Posterior Mediastinum
potential space behind the heart
Superior Mediastinum
potential space above the heart
Normal Cardio:Thoracic Ratio (CTR)
1:2 or less
Cardiomegaly
CTR >1:2
Left cardiac contour
left lateral border of the left ventricle
Right cardiac contour
right lateral border of the right atrium
Aortic knob
Represents the left lateral edge of the aorta as it arches backwards over the left main bronchus and pulmonary vessels
Can be calcified→ more radioopaque
soft tissue/fat vs muscle
soft tissue is less dense than muscle and therefore darker
Which bone is the only bone seen in its entirety?
The clavicle
Where might bone metastasis be visible?
clavicle, scapula, humorus
What should the spinous process of the vertebrae look like?
should lie midway between the medial ends of the clavicles
if not, patient is rotated (positioned oblique to the x-ray beam)
Lung hyperexpansion (hyperinflation) appears
> 7 posterior ribs seen or flattened diaphragm
How is the sternum best seen?
Lateral view
Child bones appear
Immature bones which have not completely ossified
Sail sign
A huge thymus seen in children (do not confuse with spinnaker sign)
Shaken baby syndrome
clavicle fracture + multiple rib fractures
Child abuse
Bone remodeling due to healing rib fractures
Water bottle sign
Pericardial effusion: shape of cardiac silhouette is expanded
Kerley B lines
CHF: vascular markings all the way at the periphery
CHF
Cardiomegaly + increased lung markings +/- Kerley B lines
Unilaterally high diaphragm could indicate
Paralysis of the phrenic nerve (3/4/5)
eventration
atelectasis
pneumothorax
Pulmonary edema appears
Increased vascular markings, “fluffy”
COPD
Low, flat diaphragm
Barrel chest= Kyphosis+Increased AP diameter
Can cause cavitary lesions
TB
Valley fever
Pneumoperitoneum definition
air trapping below diaphragm.
Caused by surgical incision or CO2, ruptured ulcer
Pneumoperitoneum appearance
Crescent shaped bubble of air below the thin membrane of the diaphragm when an erect PA view is taken
Spine sign
lower lobe pneumonia: lower dorsal bodies become more radiodense (whiter)
Infiltrates vs consolidation
Infiltrate: patchy
Consolidation: more solid appearing
Pleural effusion is often secondary to
rib fractures
blunting of the costophrenic angle
pleural effusion
Flail chest
paradoxical breathing caused by multiple rib fractures
Aortic aneurism
widened mediastinum
Feels like rice krispies
subcutaneous emphysema
Widened mediastinum (>8 cm) could be caused by
aortic aneurysm
Hilar adenopathy
mass
metastasis
Subcutaneous emphysema
Air at periphery of CXR, outside of the lung fields
Spinnaker sign
sign of pneumomediastinum
Hemopneumothorax
fluid below the diaphragm
