Cortical hypoperfusion in Parkinson's disease assessed using arterial spin labeled perfusion MRI

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2012-02, Vol.59 (3), p.2743-2750
• Main Authors: Fernández-Seara, María A., Mengual, Elisa, Vidorreta, Marta, Aznárez-Sanado, Maite, Loayza, Francis R., Villagra, Federico, Irigoyen, Jaione, Pastor, María A.
• Format: Article
• Language: English
• Subjects: Aged; Arterial spin labeling; Brain; Brain Mapping; Cerebral Arteries - anatomy & histology; Cerebral Arteries - physiology; Cerebral Cortex - blood supply; Cerebral Cortex - physiopathology; Cerebrovascular Circulation - physiology; Cluster Analysis; Data Interpretation, Statistical; Female; Functional Laterality - physiology; Global mean normalization; Humans; Magnetic Resonance Imaging - methods; Male; Medical imaging; Middle Aged; Neuropsychological Tests; Parkinson Disease - physiopathology; Parkinson's disease; Perfusion; Spin Labels; Studies; Tomography
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2011.10.033

Alterations in cerebral perfusion and metabolism in Parkinson's disease have been assessed in several studies, using nuclear imaging techniques and more recently magnetic resonance imaging. However, to date there is no consensus in the literature regarding the extent and the magnitude of these alterations. In this work, arterial spin labeled perfusion MRI was employed to quantify absolute cerebral blood flow in a group of early-to-moderate Parkinson's disease patients and age-matched healthy controls. Perfusion comparisons between the two groups showed that Parkinson's disease is characterized by wide-spread cortical hypoperfusion. Subcortically, hypoperfusion was also found in the caudate nucleus. This pattern of hypoperfusion could be related to cognitive dysfunctions that have been previously observed even at the disease early stages. The present results were obtained by means of whole brain voxel-wise comparisons of absolute perfusion values, using statistical parametric mapping, thus avoiding the potentially biased global mean normalization procedure. In addition, this work demonstrates that between-group comparison of relative perfusion values after global mean normalization, introduced artifactual relative perfusion increases, where absolute perfusion was in fact preserved. This has implications for perfusion studies of other brain disorders. ► Cortical perfusion is abnormal in Parkinson's disease. ► We evaluated perfusion abnormalities using ASL perfusion MRI. ► Absolute cortical perfusion is decreased in Parkison's disease. ► ASL has enough sensitivity to detect changes in absolute perfusion. ► We demonstrated artifacts introduced by global mean normalization.