Comparison between 1.5-Tesla pseudocontinuous and pulsed arterial spin labeling in visualizing peri-ictal hyperperfusion: A case report

Abstract

Arterial spin labeling (ASL) imaging with multiple postlabeling delays (PLD) can demonstrate the hemodynamics of peri-ictal hyperperfusion. Labeling methods include pulsed ASL (PASL) and pseudocontinuous ASL (pCASL). Although PASL is more widely used in daily clinical practice, it has several disadvantages because of lower delivery of labeled magnetization. We compared pCASL and PASL images acquired after a 24-h interval, using a 1.5-Tesla machine, in a 62-year-old man with non-convulsive status epilepticus. The pCASL during electrographic status epilepticus clearly demonstrated that ASL signals in the grey matter of the right hemisphere, particularly in the posteromedial part of the right temporal lobe, increased at PLDs of 1.5 s and 1.75 s and were almost washed out at 2.0 s. Although PASL, which was obtained during the ictal-interictal continuum when there were no changes in ictal findings on diffusion-weighted images, showed a similar trend, the increased signals were less pronounced than those of pCASL, with more contamination of arte-rial transit artifact in the subarachnoid space. Although the electroencephalographic findings were not the same when both ASLs were performed, the present study confirms that PASL is somewhat inferior to pCASL in detecting peri-ictal hyperperfusion because of the greater effect of arterial transient artifacts.