rad553 2010 on line3 sillohette sign · 4/28/2010 1 silhouette sign frontal x-ray signs of lobar...

4/28/2010

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Silhouette Sign

Frontal X-ray Signs of Lobar Consolidation

• RUL – loss of upper right mediastinalborder

• RML – loss of right heart border• RLL – loss of right hemidiaphram• LUL – loss of upper left mediastinal

border• LINGULA loss of left heart border• LINGULA – loss of left heart border• LLL – loss of left hemidiaphram

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Frontal X-ray Signs of Lobar Consolidation

• SILHOUETTE SIGN – for localizing lesion from frontal chest film Intra-thoracic airfrom frontal chest film. Intra-thoracic air space occupying lesions touching a soft tissue structure will obliterate the air soft tissue interface

• Examples include:– Atelectasis– Pneumonia– Neoplasm

RLL Pneumonia

Densit at the• Density at the right lateral diaphragm

• Obliteration of lateral diaphragm border

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RLL Pneumonia

• Density at the mid diaphragmmid diaphragm

• Sharp margination at the major fissure (arrows)( )

Right Middle Lobe Pneumonia

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LUL Lingular

Pneumonia

• Obliterated left cardiac border

LULLingular

Pneumonia Lateral

• Consolidation anterior to the major fissure

• Compare to PA exam

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LLL Pneumonia

• Air space diseaseAir space diseaseleft lower lobe

• Density behind heart

• Obliteration of leftdiaphragm atdiaphragm at edge of heart

• Left heart border preserved

LLL Pneumonia• Note

obliteration of the posterior portion of the left diaphragm (arrows)( )

• Right diaphragm clearly seen