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P4‐044: Pseudo‐continuous arterial spin‐labelling at 3T in Alzheimer disease ‐ initial experience in a memory clinic
Author(s) -
Binnewijzend Maja,
Kuijer Joost,
Benedictus Marije,
Wattjes Mike,
Van der Flier Wiesje,
Scheltens Philip,
Barkhof Frederik
Publication year - 2011
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2011.05.2064
Subject(s) - cerebral blood flow , medicine , precuneus , posterior cingulate , nuclear medicine , cardiology , radiology , functional magnetic resonance imaging
Background: 3D pseudo-continuous arterial spin labeling (PCASL) is a non-invasive scan technique that measures cerebral blood perfusion. We aimed to investigate overall quality of this recently implemented sequence. Second aim was to compare cerebral blood flow (CBF) of subjects with Alzheimer’s disease (AD) and subjective memory complaints (SMC). Methods:MRI scans, including 3D PCASL sequence (post-label delay 2.0s, 3D FSE, TR 1⁄4 4.8s, TE 1⁄4 4.7ms, spiral readout 8arms 3 512samples; 36 x 5.0mm axial slices, total scan time 4min) were acquired on a 3T GE HDxt scanner. Image quality was visually assessed in 68 patients (22 AD, 13 SMC, 33 other diagnoses). All subjects underwent Mini Mental State Examination (MMSE). Scans were linearly registered to standard space and segmented to obtain grey matter (GM) masks. Analysis-of-variance was used to compare GM-CBF of AD and SMC subjects. Since previous studies in AD showed metabolic and structural changes in precuneus and posterior cingulate cortex (PrcPCC), GM-CBF in PrcPCC was additionally calculated and compared. Correlations with cognition were investigated using linear regression analyses. Results: Overall, PCASL scans were of good quality. Only five scans (3 AD, 1 SMC, 1 other) showed severe artifacts with different causes and were excluded from further analyses. 47% of remaining scans displayed a surprisingly high signal in the carotid arteries, despite 2s post-label delay time. This finding correlated with the presence of lacunar infarctions (p 1⁄4 0.032), but not with age, diagnosis or gender. GMCBF values did correlate with age, GM density and gender, and were used as covariates in the group comparisons. Compared to SMC subjects, AD patients showed a decreased global GM-CBF (28 6 5 vs. 37 6 6ml/ 100g/min; p 1⁄4 0.001) and a decreased PrcPCC GM-CBF (32 6 7 vs. 45 6 7ml/100g/min; p < 0.001). Whole brain and PrcPCC GM-CBF correlated with MMSE both across diagnostic groups (stß 1⁄4 0.42; stß 1⁄4 0.52) and within the AD patient group (stß 1⁄4 0.47; stß 1⁄4 0.59). Conclusions: PCASL is a promising technique, showing CBF changes in AD that correlate with cognition. Longitudinal studies in prodromal AD patients are needed to confirm the additional value of PCASL for an early diagnosis of AD. Findings of unexpected high signal in carotid arteries, and its relation with vascular pathology, need to be further explored to optimize scan quality.