basic cxr mod adam
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Basic Chest X-Ray Interpretation
Adam Guttentag, M.D.
All photos retain the copyrights of their original authors
© 2005 Adam Guttentag, MD
How do you look at a chest x-ray?
Avoid tunnel vision!Avoid tunnel vision!
or
Have a system
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.
• Radiologist'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
cm cm
RLL
RML
LLL
LingulaLLL
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 forthe whole film!
Review 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
Additional Reading
• Chest Roentgenology Felson, B W.B. Saunders Co, Philadelphia 1973 Chapter 2: Localization of Intrathoracic Disease. pp 22-70.
• Pare JAP and Fraser RG Synopsis of Diseases of the Chest W.B. Saunders Co, Philadelphia 1983. Chapter 4: Roentgenologic Signs in the diagnosis of Chest Disease. pp164-187.
The End
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