NIMG-03. USE OF ARTERIAL SPIN LABELING TO DIFFERENTIATE ICTAL PHENOMENON FROM TUMOR PROGRESSION IN HIGH GRADE ASTROCYTOMA

Abstract A 39-year-old female with grade-3 left parietal IDH-mutant astrocytoma following resection presented with convulsive status. EEG showed electrographic seizures arising from the left parietal region. MRI-brain showed the left temporoparietal post-treatment bed without any contrast enhancement (Fig-1A). Arterial spin labeling (ASL) – MR perfusion showed markedly increased cerebral blood flow (CBF) in the left temporoparietal lobe (Fig-1 C, D) with corresponding diffusion restriction (Fig-1B). Repeat imaging two weeks after the seizure control showed complete resolution (Fig-2) suggesting the imaging abnormalities to be a peri-ictal phenomenon.1 ASL-MR perfusion is a highly sensitive marker of increased CBF with its emerging application in distinguishing tumor progression (increased CBF) from post-treatment changes such as radiation necrosis (reduced CBF).1,2 This case highlights the utility of ASL-MR perfusion in differentiating peri/post-ictal phenomenon (increased CBF without T1-contrast enhancement) from tumor progression (increased CBF with T1-contrast enhancement) when employed routinely in clinical oncology practice.