Arterial Spin Labeling MRI Focal Abnormalities in Refractory Epilepsy

"The Arterial Spin Labeled (ASL) MRI sequence is an MRI technique in which arterial blood undergoes spatially selective inversion to label the arterial blood.~This is a magnetic technique and does not require contrast. The tagged blood is imaged and areas of hypoperfusion or hyperperfusion are revealed on the MRI sequence."