The bifrontal index in a head CT image can help to detect enlargement of the lateral ventricles as is seen in hydrocephalus.
Exam: axial section in brain CT
Parameters:
(1) internal diameter of the cranium at the level of the anterior horns
(2) distance between the lateral extents of the left and right anterior horns
bifrontal index =
= (distance between lateral extents) / (intracranial diameter)
|
Age
|
Mean Index (Wilk et al)
|
|
<= 12 months
|
0.318
|
|
1.01 to 3 years
|
0.316
|
|
3.01 to 6 years
|
0.310
|
|
6.01 to 9 years
|
0.305
|
|
9.01 to 12 years
|
0.308
|
|
12.01 to 15 years
|
0.306
|
|
15.01 to 18 years
|
0.310
|
