basic cxr mod adam

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

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


oblique PA vs AP erect vs

supine

erect supine

Technical Factors


oblique PA vs AP erect vs supine lordotic vs

kyphotic

lordotic

kyphotic

Technical Factors


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


Old films are your friend!

Elderly man with hypotension

Suddenly septic

Pneumatosis of small bowel


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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basic cxr mod adam

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