What Happens During the Exam?
SPECT (Single Photon Emission Computed Tomography) imaging is performed during hospitalization on the video-EEG monitoring unit. The primary goal is to capture ictal SPECT—that is, a scan taken during an actual seizure, allowing for the most accurate localization of the seizure onset zone.
You will typically be admitted before the weekend, and your anti-seizure medication will be gradually reduced to increase the likelihood of a seizure during the monitoring period. The goal is to capture a seizure on Tuesday morning, when the radioactive tracer (radiopharmaceutical) is available and ready to be administered intravenously as soon as a seizure begins.
The sooner the tracer is injected after seizure onset, the more precise the SPECT scan will be in highlighting the area of the brain where the seizure originates.
If no seizure occurs by the scheduled time, the tracer will still be administered, and an interictal SPECT (a scan performed between seizures) will be conducted. Although less specific than an ictal scan, interictal SPECT still provides valuable diagnostic information.
After the tracer is administered, you will be transported to University Hospital Brno (FN Brno), where the scan will take place.
The SPECT scanner is a large, ring-shaped machine equipped with a gamma camera. You will lie on a motorized table, and the gamma camera will rotate around your head, capturing detailed images of brain structures. These images are then processed into high-resolution 3D visuals on a computer for evaluation.
After the scan, you will be returned to the epilepsy unit for continued care and medication adjustment.
How Long Does It Take?
The scan itself takes about 30 minutes, but the entire process, including hospitalization, seizure monitoring, tracer administration, and post-scan recovery, usually takes about one week.
This timeline is the same whether the scan is ictal or interictal, and efforts to capture an ictal SPECT scan are typically limited to three attempts.
A standalone interictal SPECT, performed on an outpatient basis, takes approximately 30 minutes.