A Comparison of Accelerated and Non-accelerated MRI Scans for Brain Volume and Boundary Shift Integral Measures of Volume Change: Evidence from the ADNI Dataset.
The aim of this study was to assess whether the use of accelerated MRI scans in place of non-accelerated scans influenced brain volume and atrophy rate measures in controls and subjects with mild cognitive impairment and Alzheimer's disease. We used data from 861 subjects at baseline, 573 subjects at 6 months and 384 subjects at 12 months from the Alzheimer's Disease Neuroimaging Initiative (ADNI). We calculated whole-brain, ventricular and hippocampal atrophy rates using the k-means boundary shift integral (BSI). Scan quality was visually assessed and the proportion of good quality accelerated and non-accelerated scans compared. We also compared MMSE scores, vascular burden and age between subjects with poor quality scans with those with good quality scans. Finally, we estimated sample size requirements for a hypothetical clinical trial when using atrophy rates from accelerated scans and non-accelerated scans. No significant differences in whole-brain, ventricular and hippocampal volumes and atrophy rates were found between accelerated and non-accelerated scans. Twice as many non-accelerated scan pairs suffered from at least some motion artefacts compared with accelerated scan pairs (p ≤ 0.001), which may influence the BSI. Subjects whose accelerated scans had significant motion had a higher mean vascular burden and age (p ≤ 0.05) whilst subjects whose non-accelerated scans had significant motion had poorer MMSE scores (p ≤ 0.05). No difference in estimated sample size requirements was found when using accelerated vs. non-accelerated scans. Accelerated scans reduce scan time and are better tolerated. Therefore it may be advantageous to use accelerated over non-accelerated scans in clinical trials that use ADNI-type protocols, especially in more cognitively impaired subjects.
Dementia Research Centre, Institute of Neurology, University College London, London, UK. e.manning@ucl.ac.uk.
Emily N
EN
Manning
Dementia Research Centre, Institute of Neurology, University College London, London, UK.
Kelvin K
KK
Leung
Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK.
Jennifer M
JM
Nicholas
Dementia Research Centre, Institute of Neurology, University College London, London, UK.
Ian B
IB
Malone
Dementia Research Centre, Institute of Neurology, University College London, London, UK.|Centre for Medical Image Computing, University College London, London, UK.
M Jorge
MJ
Cardoso
Dementia Research Centre, Institute of Neurology, University College London, London, UK.
Jonathan M
JM
Schott
Dementia Research Centre, Institute of Neurology, University College London, London, UK.
Nick C
NC
Fox
Dementia Research Centre, Institute of Neurology, University College London, London, UK.
Josephine
J
Barnes
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000000981:diagnostic imaging*; D001284:Atrophy / Q000000981:diagnostic imaging / Q000209:etiology; D001921:Brain / Q000000981:diagnostic imaging*; D060825:Cognitive Dysfunction / Q000473:pathology; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales
Accelerated acquisition; Alzheimer’s disease; Boundary shift integral; Brain atrophy; Image quality; Non-accelerated acquisition