Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET

• Published in: European radiology Vol. 27; no. 10; pp. 4237 - 4246
• Main Authors: Fällmar, David, Haller, Sven, Lilja, Johan, Danfors, Torsten, Kilander, Lena, Tolboom, Nelleke, Egger, Karl, Kellner, Elias, Croon, Philip M., Verfaillie, Sander C. J., van Berckel, Bart N. M., Ossenkoppele, Rik, Barkhof, Frederik, Larsson, Elna-Marie
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2017; Springer Nature B.V
• Subjects: 18F-FDG; Aged; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - metabolism; Alzheimer Disease - pathology; Alzheimer's disease; Arterial spin labeling MRI; Arteries; Brain - diagnostic imaging; Brain - metabolism; Brain - pathology; Dementia; Dementia disorders; Diagnostic Radiology; Disease control; Female; Fluorodeoxyglucose F18; Frontotemporal dementia; Frontotemporal Dementia - diagnostic imaging; Frontotemporal Dementia - metabolism; Frontotemporal Dementia - pathology; Humans; Hypometabolism; Imaging; Internal Medicine; Interventional Radiology; Labeling; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Marking; Medical personnel; Medicine; Medicine & Public Health; Middle Aged; Neuro; Neurodegenerative; Neurodegenerative diseases; Neuroradiology; Normal distribution; Patients; Perfusion; Physicians; Positron emission; Positron emission tomography; Positron-Emission Tomography - methods; Predictive control; Predictive Value of Tests; Radiology; Sensitivity; Sensitivity and Specificity; Spin labeling; Spin Labels; Tomography; Ultrasound; Visual assessment; Visual discrimination; Visual assessment; 18F-FDG; Arterial spin labeling MRI; Neurodegenerative; Dementia
• ISSN: 0938-7994; 1432-1084; 1432-1084
• DOI: 10.1007/s00330-017-4784-1

Objective Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. Methods Data were combined from two separate sites, each cohort consisting of patients with Alzheimer’s disease ( n  = 18 + 7), frontotemporal dementia ( n  = 12 + 8) and controls ( n  = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis. Results Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p  < 0.001). Among true-positive cases, correct diagnoses were made in 76% (ASL) and 84% (FDG-PET) ( p  = 0.168). Conclusion ASL-based Z-maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET. Key points • ASL-based Z-maps yielded high specificity and positive predictive value in neurodegenerative dementia. • ASL-based Z-maps had significantly lower sensitivity compared to FDG-PET-based Z-maps. • FDG-PET might be reserved for ASL-negative cases where clinical suspicion persists. • Findings were similar at two study sites.