Objective: To investigate the communication between intracranial arachnoid cysts and subarachnoid space using CT cisternography (CTC) and consecutive CT scans.
Methods: CTC were performed in 38 symptomatic patients with arachnoid cysts before treatment decisions were made. Consecutive CTC images were obtained 2 days after intrathecal omnipaque administrations. The enhancement in cysts was measured quantitatively and compared with neighbouring subarachnoid spaces. Patients with cysts showing early fillings (n = 10) were followed up without surgeries. Whereas, patients with cysts showing non-early fillings (n = 28) were given surgical treatment through craniotomy. Another 36 patients with arachnoid cysts were given craniotomy without CTC evaluation.
Results: Arachnoid cysts were classified into complete, incomplete and noncommunicating cysts based on the CTC results. The symptoms of all surgical patients with CTC evaluations were relieved. Only one patient without surgery showed clinical deterioration. In the 36 patients without CTC evaluation, 6 patients did not gain benefit from surgeries.
Conclusion: The classification of arachnoid cysts based on CTC is useful for the diagnosis and treatment of intracranial arachnoid cysts.