Basic Chest X-Ray
Interpretation
Adam Guttentag, M.D.
©
Copyright Adam Guttentag, MD
All Photos Retain the Copyrights of Their Original Authors
How do
you
look at a
chest x-ray?
Avoid tunnel vision!
Avoid tunnel vision!
or
Chest wall, bones and abdomen
Mediastinum, heart and hila
Lungs
The Lateral Chest Film
•
Find abnormalities
hidden on the frontal
film
•
Confirm
abnormalities
suspected from
frontal film
•
Don’t be afraid to
look at it!
Our best friend!
Looking at the lateral CXR
Hilar structures on the lateral film:
“Ring around the
bronchus”
Technical Factors
•
Positioning
straight vs
oblique
(How we’ll try to fool you)
Effect of obliquity on heart size
Technical Factors
•
Positioning
straight
vs oblique
PA vs AP
Technical Factors
•
Positioning
straight vs
oblique
PA vs AP
erect vs
supine
erect
supine
Technical Factors
•
Positioning
straight vs
oblique
PA vs AP
erect vs supine
lordotic vs
kyphotic
lordotic
kyphotic
Technical Factors
•
Positioning
straight vs
oblique
PA vs AP
erect vs
supine
lordotic vs
kyphotic
Effect on mediastinal contour
Technical Factors
•
Depth of inspiration
•
Visualization of
pathology depends on
contrast provided by air
in the lungs
•
Count ribs!
10
8
Short of breath
One minute
later
8
Technical Factors
Body habitus
Radiographic technique:
Is it really different?
Changing technique can make
disease look better or worse.
Is the heart large? Is the
mediastinum wide
?
Same patient, 4 films within one month
Recognizing air space disease
•
Alveolar spaces filled with…something.
•
Radiologists’s report:
“consolidation”
“air space opacity”
“fluffy density”
“infiltrate”
•
Nonspecific:
Atelectasis, pneumonia, bleeding, edema, tumor
The Silhouette Sign
•
Indicates air space disease.
•
Obscuration of a normally seen
border, e.g. diaphragm or heart.
•
Opacity with sharp edge along a
fissure.
Localizing disease from the
silhouette sign
RLL
RML
LLL
Lingula
LLL
Localizing disease from the
silhouette sign
RUL
RML
UL
LL
RML or
lingula
16 hours later
What happened here?
What happened here?
Lobar Atelectasis
•
Best sign -- shift of a fissure
•
Rapid development and clearance
•
Air bronchograms if non-obstructive
•
Secondary signs:
Mediastinal shift
Elevated diaphragm
Ribs closer together
Vague increased density
LLL Atx
Next day
RUL Atx
RML Atx
LUL Atx
Pneumonia
•
Signs
Air bronchogram
Silhouette - “positive” or “negative”
Dense hilum
“Spine” sign
•
All are signs of
any
air space process
•
Dx of pneumonia depends on appropriate
clinical scenario.
Air bronchogram sign
Pseudomonas
pneumonia
Lung cancer
Air bronchograms—CT
Pneumonia
Lung cancer
Right middle lobe
Right upper lobe
Right lower lobe
Posterior diaphragm silhouetted
Dense hilum, spine sign
Dense hilum, spine sign again
Four days later
Final Exam
21 y.o. with fever and cough
Hyperlucent
hemithorax: why?
Did you notice the mass?
Lymphoma
Take home message #1
It’s a
chest
x-ray,
not a
lung
x-ray.
6 cm lung mass missed. How?
2 years ago
Take home message #2
Old films are your friend!
Elderly man with hypotension
Suddenly septic
Pneumatosis of small bowel
Take home message #3
The patient pays for
the whole film!
Questions
All are kinds of air space
disease except
•
Hemorrhage
•
Pneumonia
•
Tumor
•
Sarcoidosis
•
Atelectasis
The most specific sign of
atelectasis is:
•
Obscuration of a diaphragm
•
Shift of a fissure
•
Air bronchograms
•
Density over the spine
•
Mediastinal shift
This can make the heart look
larger than it is:
•
Lordotic positioning
•
AP positioning
•
Expiratory film
•
Supine positioning
•
All of the above
Reading