Table 3. Category 3 Findings in 431 Participantsa.
| Category 3 incidental finding | No. (%)b |
|---|---|
| Periventricular nodular heterotopia | 110 (0.94) |
| White matter abnormalities concerning for infection, inflammation, or ischemic injury | 58 (0.50) |
| Arachnoid/intraventricular cyst with mass effect | 28 (0.24) |
| Possible glial neoplasm | 27 (0.23) |
| Head and neck findings | 26 (0.22) |
| Large pineal cyst with mass effect | 26 (0.22) |
| Cerebellar tonsillar ectopia (without Chiari I malformation) | 25 (0.21) |
| Parotid lymphoepithelial cysts | 22 (0.19) |
| Chiari I malformation | 20 (0.17) |
| Vascular abnormalities | 13 (0.11) |
| Cerebellar hypoplasia, volume loss, signal abnormality | 11 (0.09) |
| Pituitary abnormality | 11 (0.09) |
| Dilated central canal | 10 (0.09) |
| Ventriculomegaly | 7 (0.06) |
| Focal cortical dysplasia | 7 (0.06) |
| Suspected cavernous malformation | 6 (0.05) |
| Findings suggestive of intracranial hypertension | 5 (0.04) |
| Callosal agenesis/hypogenesis | 4 (0.03)c |
| Syrinx | 3 (0.03) |
| Encephalocele | 3 (0.03) |
| Susceptibility artifact concerning for metal in scalp/face | 2 (0.02) |
| Malformations | 2 (0.02) |
| Polymicrogyria | 2 (0.02) |
| Morphologic abnormality of cervical spine | 2 (0.02) |
| Porencephalic cyst | 1 (0.01) |
a
Category 3 findings occurred in 3.7% (431 of 11 679) participants. Seventeen participants had more than 1 incidental finding that warranted nonurgent follow-up.
b
Percentage value based on 11 679 participants.
c
Two cases of agenesis of the corpus callosum and 2 cases of hypogenesis of the corpus callosum.