How to Calculate Cephalic Index and Cvai Index

The cephalic index is calculated as follows:

1. Measurement: The head’s maximum width (biparietal diameter) and maximum length (occipital-frontal diameter) are measured in centimeters.
2. Calculation: The cephalic index is calculated by dividing the maximum width of the head by its maximum length and multiplying by 100:Cephalic index = (Maximum width / Maximum length) x 100
3. Classification: The cephalic index is used to classify head shapes into different categories:
   • Dolichocephaly (CI < 75): Long and narrow head shape
   • Mesocephaly (75 ≤ CI ≤ 80): Intermediate head shape
   • Brachycephaly (CI > 80): Short and broad head shape

The Cranial Vault Index (CVI) is calculated as follows:

1. Measurement: The head’s maximum length (occipital-frontal diameter), maximum width (biparietal diameter), and maximum height (occipital-vertex diameter) are measured in centimeters.
2. Calculation: The Cranial Vault Index is calculated by dividing the volume of the head by the product of the maximum length, width, and height:CVI = (Volume of the head) / (Maximum length x Maximum width x Maximum height)
3. Interpretation: The Cranial Vault Index is used to evaluate the shape of the cranial vault, which is the top part of the skull. A higher Cranial Vault Index indicates a more rounded cranial vault shape, while a lower Cranial Vault Index indicates a more elongated or flattened cranial vault shape. The Cranial Vault Index can be used to diagnose and monitor conditions such as craniosynostosis, plagiocephaly, and brachycephaly.