Higher Validity, Lower Radiation: A New Ictal Single-Photon Emission Computed Tomography Framework

Area of Science:

• Neuroimaging
• Epilepsy diagnostics
• Radiology

Background:

• Ictal single-photon emission computed tomography (SPECT) is crucial for epilepsy presurgical evaluation.
• Arterial spin labeling (ASL) offers a non-invasive method for perfusion imaging.

Purpose of the Study:

• To evaluate if ASL perfusion images from healthy controls can improve ictal SPECT analysis.
• To determine if interictal SPECT imaging can be omitted in epilepsy evaluations.

Main Methods:

• Developed two pipelines: one using ictal/interictal SPECT with ASL controls, another using only ictal SPECT with ASL controls.
• Compared pipelines against gold standard analysis using Dice score and Euclidean distance on epilepsy patient data.

Main Results:

• Both ASL-enhanced pipelines showed significantly higher accuracy (Dice score) and precision (lower distance) than the gold standard.
• The combined ASL and ictal SPECT approach localized hyperperfusion in 85/116 cases, significantly outperforming current methods.

Conclusions:

• A novel ictal SPECT protocol incorporating ASL perfusion imaging substantially improves the detection of ictal hyperperfusion.
• This new protocol can potentially reduce radiation dose by half for approximately 50% of individuals undergoing epilepsy evaluation.