title: Visual Assessment of Brain Perfusion MRI Scans in Dementia: A Pilot Study.
abstract: Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data.
  
  
  
  Ten patients with a clinical diagnosis of dementia and 11 age-matched cognitively healthy controls were examined with pseudo-continuous ASL (pCASL) and 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET). Three diagnostic physicians visually assessed the pCASL maps after subtraction only, and after postprocessing using Gaussian smoothing and GLM-based beta estimate functions. The assessment scores were compared to FDG PET values. Furthermore, the ability to discriminate patients from healthy elderly controls was assessed.
  
  
  
  Smoothing improved the correlation between visually assessed regional ASL perfusion scores and the FDG PET SUV-r values from the corresponding regions. However, subtracted pCASL maps discriminated patients from healthy controls better than smoothed maps. Smoothing increased the number of false-positive patient identifications. Application of beta estimate functions had only a marginal effect.
  
  
  
  Spatial smoothing of ASL images increased false positive results in the discrimination of hypoperfusion conditions from healthy elderly. It also decreased interreader agreement. However, regional characterization and subjective perception of image quality was improved.
authors.affiliation: Department of Surgical Sciences/Radiology, Uppsala University, Uppsala, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Fällmar
authors.affiliation: Department of Surgical Sciences/Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lilja
authors.affiliation: Department of Surgical Sciences/Radiology, Uppsala University, Uppsala, Sweden.
authors.forename: Vilma
authors.initials: V
authors.lastname: Velickaite
authors.affiliation: Department of Surgical Sciences/Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden.
authors.forename: Torsten
authors.initials: T
authors.lastname: Danfors
authors.affiliation: Department of Surgical Sciences/Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden.
authors.forename: Mark
authors.initials: M
authors.lastname: Lubberink
authors.affiliation: Department of Medical Radiation Physics, Lund University, Lund, Sweden.
authors.forename: André
authors.initials: A
authors.lastname: Ahlgren
authors.affiliation: C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Matthias J P
authors.initials: MJ
authors.lastname: van Osch
authors.affiliation: Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Kilander
authors.affiliation: Department of Surgical Sciences/Radiology, Uppsala University, Uppsala, Sweden.
authors.forename: Elna-Marie
authors.initials: EM
authors.lastname: Larsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging*; D001933:Brain Stem / Q000098:blood supply; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D012039:Regional Blood Flow / Q000502:physiology; D013113:Spin Labels
chemical_list: D013113:Spin Labels; D019788:Fluorodeoxyglucose F18
keywords: Arterial spin labeling; brain perfusion; clinical setting; smoothing; visual assessment