Differential diagnosis for a small cardiothoracic ratio

A small cardiothoracic ratio (CTR) as defined as <42%/0.42 when assessed on a PA chest radiograph, and can be due to number of entities:

A pathologically-small heart is known as microcardia. 

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Article information

rID: 9884
Systems: Chest, Cardiac
Section: Gamuts
Synonyms or Alternate Spellings:
  • Differential diagnosis for a small heart size
  • Small cardiothoracic ratio (CTR)
  • Microcardia

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