Table 1.

Distribution of number of vermian lobules on magnetic resonance imaging in fetuses with cystic posterior fossa malformations, according to group defined by standard criteria (vermian size and brainstem–vermis (BV) angle), and in brain‐normal controls

Number of lobules	Controls (n = 148)	Group 1 (n = 74)	Group 2 (n = 24)	Group 3 (n = 44)
1–3	0 (0.0)	0 (0.0)	0 (0.0)	13 (29.5)
4–5	18 (12.2)	28 (37.8)	14 (58.3)	20 (45.5)
6–7	130 (87.8)	46 (62.2)	10 (41.7)	11 (25.0)

Data are given as n (%).

In Groups 1–3, number of lobules is based on mean value of three observers.

Groups defined as follows: normal vermian area and BV angle < 25° (Group 1); reduced vermian area and/or BV angle of 25–45° (Group 2); reduced vermian area and BV angle > 45° (Group 3; Dandy–Walker malformation group).