Browsing by Author "Cash, Lisa"

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    Partial Volume Correction in Quantitative Amyloid Imaging.
    (Elsevier, 2015-02-15) Su, Yi; Blazey, Tyler M.; Snyder, Abraham Z.; Raichle, Marcus E.; Marcus, Daniel S.; Ances, Beau M.; Bateman, Randall J.; Cairns, Nigel J.; Aldea, Patricia; Cash, Lisa; Christensen, Jon J.; Friedrichsen, Karl; Hornbeck, Russ C.; Farrar, Angela M.; Owen, Christopher J.; Mayeux, Richard; Brickman, Adam M.; Klunk, William; Price, Julie C.; Thompson, Paul M.; Ghetti, Bernardino; Saykin, Andrew J.; Sperling, Reisa A.; Johnson, Keith A.; Schofield, Peter R.; Buckles, Virginia; Morris, John C.; Benzinger, Tammie LS; Department of Pathology & Laboratory Medicine, IU School of Medicine
    Amyloid imaging is a valuable tool for research and diagnosis in dementing disorders. As positron emission tomography (PET) scanners have limited spatial resolution, measured signals are distorted by partial volume effects. Various techniques have been proposed for correcting partial volume effects, but there is no consensus as to whether these techniques are necessary in amyloid imaging, and, if so, how they should be implemented. We evaluated a two-component partial volume correction technique and a regional spread function technique using both simulated and human Pittsburgh compound B (PiB) PET imaging data. Both correction techniques compensated for partial volume effects and yielded improved detection of subtle changes in PiB retention. However, the regional spread function technique was more accurate in application to simulated data. Because PiB retention estimates depend on the correction technique, standardization is necessary to compare results across groups. Partial volume correction has sometimes been avoided because it increases the sensitivity to inaccuracy in image registration and segmentation. However, our results indicate that appropriate PVC may enhance our ability to detect changes in amyloid deposition.
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    Utility of perfusion PET measures to assess neuronal injury in Alzheimer's disease
    (Elsevier, 2018-09-27) Joseph-Mathurin, Nelly; Su, Yi; Blazey, Tyler M.; Jasielec, Mateusz; Vlassenko, Andrei; Friedrichsen, Karl; Gordon, Brian A.; Hornbeck, Russ C.; Cash, Lisa; Ances, Beau M.; Veale, Thomas; Cash, David M.; Brickman, Adam M.; Buckles, Virginia; Cairns, Nigel J.; Cruchaga, Carlos; Goate, Alison; Jack, Clifford R., Jr.; Karch, Celeste; Klunk, William; Koeppe, Robert A.; Marcus, Daniel S.; Mayeux, Richard; McDade, Eric; Noble, James M.; Ringman, John; Saykin, Andrew J.; Thompson, Paul M.; Xiong, Chengjie; Morris, John C.; Bateman, Randall J.; Benzinger, Tammie L. S.; Dominantly Inherited Alzheimer Network; Radiology and Imaging Sciences, School of Medicine
    Introduction: 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is commonly used to estimate neuronal injury in Alzheimer's disease (AD). Here, we evaluate the utility of dynamic PET measures of perfusion using 11C-Pittsburgh compound B (PiB) to estimate neuronal injury in comparison to FDG PET. Methods: FDG, early frames of PiB images, and relative PiB delivery rate constants (PiB-R1) were obtained from 110 participants from the Dominantly Inherited Alzheimer Network. Voxelwise, regional cross-sectional, and longitudinal analyses were done to evaluate the correlation between images and estimate the relationship of the imaging biomarkers with estimated time to disease progression based on family history. Results: Metabolism and perfusion images were spatially correlated. Regional PiB-R1 values and FDG, but not early frames of PiB images, significantly decreased in the mutation carriers with estimated year to onset and with increasing dementia severity. Discussion: Hypometabolism estimated by PiB-R1 may provide a measure of brain perfusion without increasing radiation exposure.