Fetal cardio thoracic circumference ratio

Dr Henry Knipe and Radswiki et al.

Fetal cardio-thoracic (C/T) circumference ratio is parameter than can be used in assessment of fetal cardiac and thoracic/chest wall anomalies. It is essentially the ratio of the cardiac circumference of the thoracic circumference and may be easily measured on ultrasound/fetal echocardiography. 

Radiographic assessment


The CT circumference ratio should be always less then 0.5 throughout gestation. It slowly increased through gestation

  • ~ 11 weeks: 0.38
  • ~ 17-20 weeks: 0.45
  • term: 0.5

Increased C/T circumferential ratios can be be observed with either cardiac or thoracic pathology:

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Article Information

rID: 15006
Sections: Approach, Signs
Tag: cases
Synonyms or Alternate Spellings:
  • Fetal cardio thoracic (C-T) circumference ratio
  • Fetal cardio-thoracic circumference ratio
  • Fetal CT circumference ratio

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