Table 4.
Frequency of binary vermis‐ and brainstem‐specific imaging markers 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
| Variable | Controls (n = 148) | Group 1 (n = 74) | Group 2 (n = 24) | Group 3 (n = 44) |
|---|---|---|---|---|
| Declive, folium and tuber distinguishable | 99 (66.9) | 24 (32.4) | 2 (8.3) | 0 (0.0) |
| Uvula and nodulus distinguishable | 130 (87.8) | 28 (37.8) | 4 (16.7) | 6 (13.6) |
| Vermian tail sign | 0 (0.0) | 1 (1.4) | 11 (45.8) | 33 (75.0) |
| Mechanical pressure on vermis | 0 (0.0) | 4 (5.4) | 0 (0.0) | 16 (36.4) |
Data are given as n (%).
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).