Cardiac silhouette

Cardiac silhouette refers to the outline of the heart as seen on frontal and lateral chest radiographs and forms part of the cardiomediastinal contour. The size and shape of the cardiac silhouette provide useful clues for underlying disease.

Radiographic features

From the frontal projection, the cardiac silhouette can be divided into right and left borders:

On the lateral projection the cardiac silhouette is formed by 1:

Size

The cardiac silhouette is considered enlarged if the cardiothoracic ratio is greater than 50% on a PA view of the chest 1. See main article: enlargement of the cardiac silhouette for more information.

Shape

The shape of the cardiac silhouette can be used as clues to the underlying disease. For example 1:

Chest
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Article information

rID: 34222
System: Chest, Cardiac
Section: Approach
Tag: refs
Synonyms or Alternate Spellings:

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Cases and figures

  • Figure 1: cardiomediastinal contour
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  • Figure 2: cardiomediastinal contour
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  • Figure 3: cardiovascular anatomy
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  • Figure 4: cardiovascular anatomy
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  • Case 1: mild cardiomegaly
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  • Case 2: water bottle sign of pericardial effusion
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