Voxel-level comparison of arterial spin-labeled perfusion MRI and FDG-PET in Alzheimer disease

Abstract

Objective:We compared the ability of arterial spin labeling (ASL), an MRI method that measures cerebral blood flow (CBF), to that of FDG-PET in distinguishing patients with Alzheimer disease (AD) from healthy, age-matched controls.Methods: Fifteen patients with AD (mean age 72 Ϯ 6 years, Mini-Mental State Examination score[MMSE] 20 Ϯ 6) and 19 age-matched controls (mean age 68 Ϯ 6 years, MMSE 29 Ϯ 1) underwent structural MRI. Participants were injected with 5 mCi of FDG during pseudocontinuous ASL scan, which was followed by PET scanning. Statistical parametric mapping and regions of interest (ROI) analysis were used to compare the ability of the 2 modalities in distinguishing patients from controls. Similarity between the 2 modalities was further assessed with linear correlation maps of CBF and metabolism to neuropsychological test scores. Results:Good agreement between hypoperfusion and hypometabolism patterns was observed, with overlap primarily in bilateral angular gyri and posterior cingulate. ROI results showed similar scales of functional deficit between patients and controls in both modalities. Both ASL and FDG-PET were able to distinguish neural networks associated with different neuropsychological tests with good overlap between modalities. Conclusions:

Diagnostic utility of ASL‐MRI and FDG‐PET in the behavioral variant of FTD and AD

“…Our results are consistent with prior work, which showed that regional CBF is tightly coupled with regional cerebral metabolic rate for glucose,51 and that patterns of regional perfusion abnormalities are very similar to the patterns of hypometabolism in AD 27. In addition, prior studies have indicated that the diagnostic value of ASL‐MRI is similar to that of FDG‐PET in AD 25, 26.…”

“…Despite these limitations, the practical clinical implications of this report add to other reports25, 26, 27 suggesting that ALS‐MRI has a similar sensitivity and specificity to FDG‐PET for detecting brain changes due to AD and bvFTD. MRI examinations are noninvasive without ionizing radiation.…”

“…One study has demonstrated that ASL‐MRI improves diagnostic classification of bvFTD versus age‐matched controls 19. In AD, studies have demonstrated that patterns of CBF deficits detected with ASL‐MRI are roughly similar to metabolic deficits identified using FDG‐PET,25, 26, 27 and that both imaging modalities have similar diagnostic value in AD 26. Although recent studies have indicated that patterns of CBF abnormalities and patterns of metabolic deficits are also similar in bvFTD,25 no studies have yet compared the diagnostic value of CBF measures from ASL‐MRI with the diagnostic utility of CMRgl measures from FDG‐PET in differentiating bvFTD from other dementias such as AD.…”

Clinical Application of 3D Arterial Spin-Labeled Brain Perfusion Imaging for Alzheimer Disease: Comparison with Brain Perfusion SPECT

“…21,22 HMPAO SPECT and FDG-PET showed hypoperfusion and decreased metabolism in the temporoparietal and posterior cingulate gyrus in AD, which indicates a direct coupling in AD between these 2 effects. 23 In addition, a recent study to compare 3D ASL MR imaging with FDG-PET in the same subjects showed similar degrees of functional deficits in the affected areas, 24 which indicates that 3D ASL MR imaging may be a more easily accessible alternative perfusion technique than SPECT in the diagnosis of AD.…”

Functional NeuroCognitive ImagingTM and Notus NeuroCogsTM: A Novel Use of fMRI in the Assessment of Cognitive Function in Major Neurocognitive Disorder

“…Specifically, studies using arterial spin labeling, an MRI technique that measures blood flow through arterioles and capillaries, have found cerebral hypoperfusion in patients with mild MND [13]. Interestingly, the same areas of cerebral hypoperfusion found on arterial spin labeling demonstrated hypometabolism on 18 F-2-flouro-2-deoxy-Dglucose (FDG)-PET images [13,14]. Chronic NVU, as seen in MND, can hasten neurodegeneration via several proposed processes including neuroinflammation and oxidative stress induction with associated amyloid beta (Aβ) deposition, tau hyperphosphorylation, and synaptic malfunction leading to eventual neuronal injury [10,[15][16][17][18].…”