Cine MRI Is Useful for the Diagnosis of Intradural Arachnoid Cyst with Spinal Arachnoid Web: A Case Report.

CASE: A 28-year-old woman developed gait disturbance due to lower limb weakness 3 years before presentation. Conventional magnetic resonance imaging (MRI) findings were inconclusive; therefore, we performed cine MRI, which confirmed the presence of a pulsatile cyst on the posterior thoracic spinal cord. The cyst compressed the spinal cord, and its pulsations synchronized with the patient's heartbeats. We resected the intradural arachnoid cyst and thickened arachnoid membrane. The gait disturbance improved after surgery. CONCLUSIONS: Cine MRI can be used to identify a pulsating arachnoid cyst that cannot be visualized with a conventional MRI. Cine MRI is useful in patients with unexplained spinal symptoms.