An 18-year-old man with posttraumatic recurrent meningitis. Coronal precontrast T1WI shows irregularity and heterogeneity of the left cribriform plate (A). Early-phase postcontrast T1WI demonstrates passage of the contrast material from left cribriform plate through anterior ethmoid cells (arrows in B-K). Presence of the left cribriform plate defect was confirmed at surgery.
A 34-year-old man with headache. Sagittal early-phase postcontrast T1WI reveals an arachnoid cyst at the septum pellicidum (A). Early-phase postcontrast T1WI shows passage of the intrathecally administered contrast to the fourth ventricle (arrow) and basal cisterns, whereas there is no contrast in the arachnoid cyst (A). Coronal (B) and axial (C) late-phase postcontrast images show passage of the contrast to the lateral ventricles (arrow in B), but not to the arachnoid cyst. Imaging findings are consistent with a non-communicating arachnoid cyst.
A 20-year-old man with headache. Sagittal 3D-CISS (A) and precontrast T1WI (B) shows hydrocephalus. Sagittal 3D-CISS image demonstrates a linear hypointense band at the cerebral aqueduct (arrow in A). The inferior wall of the third ventricle cannot be depicted clearly on 3D-CISS image (A). Early-phase postcontrast sagittal and coronal T1WI shows passage of the intrathecally administered contrast to the fourth ventricle, but not to the third ventricle (arrows) (C, D). Imaging findings are consistent with aqueductal stenosis and hydrocephalus secondary to a web. A 12-hour post injection axial sequential T1WI showed no relation between the basal cisterns and the third ventricle (E-G). The intact third ventricular floor implies absence of a STV, and tells us ETV or shunt procedures are necessary.