Magnetic resonance imaging of cerebral perfusion using DSC and ASL techniques at 3T

Abstract

Magnetic resonance imaging (MRI) of cerebral perfusion is used as a complementary procedure in diagnosis of cerebral lesions. In this work, cerebral perfusion and perfusion related parameters are measured in terms of arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) techniques using MRI. All scans were performed at 3T in two healthy volunteers and two patients with cerebral lesions. In DSC, contrast agent concentration- time curves were obtained from the measurements. Then, singular value decomposition (SVD) method with constant threshold is used on the arterial and tissue pixels. As a result, relative quantitative values of cerebral blood ow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were calculated. In ASL, both the single and multiple subtraction methods are used in the subjects. Quantitative CBF maps are obtained as a result of both methods; additionally, transit delay of blood was quanti ed using multiple-subtraction method. For the patient and volunteer scans, perfusion values obtained by ASL were observed to be in good agreement with relative DSC results or with quantitative PET results in literature which are used as the gold standard. Comparisons were based on the mean CBF values in various tissue kinds of brain.|Keywords: Brain, MRI, Perfusion, CBF, multiple subtraction, ASL, DSC.