Contributions
Abstract: P493
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Fractional anisotropy (FA) from diffusion tensor MRI (DTI) is used as a white matter (WM) integrity marker. Similarly, Pittsburg compound-B (PiB) uptake on PET has been proposed as a WM integrity marker, particularly in demyelinating diseases. We have shown that PiB uptake in WM hyperintensities (WMH) and normal appearing WM (NAWM) correlate with cognitive function in patients with MS (Zeydan et al. MSJ-2017).
Objectives: To compare WM PiB binding and FA as WM integrity markers.
Aims: To evaluate the association of PiB-PET and DTI-FA in WMH and NAWM with cognitive function.
Methods: Healthy adults (n=537) from the population-based Mayo Clinic Study of Aging were included. MRI-FLAIR images were segmented into WMH and NAWM via a semi-automated algorithm. After registration of DTI, FLAIR and PET images to the T1-weighted image, FA values and PiB standard uptake value ratios (SUVr; referenced to cerebellar crus) were calculated for regions within the WMH and NAWM masks. Global cognitive z-scores were calculated in each participant from nine cognitive tests. Paired t-test was used for comparisons within subjects. Linear regressions and correlations were adjusted for age and global cortical PiB-SUVr.
Results: The WMH PiB-SUVr (mean±SD=1.88±0.20) was lower compared to NAWM PiB-SUVr (mean±SD=2.08±0.20; p< 0.001). The WMH FA (mean±SD=0.37±0.05) was lower compared to NAWM FA (mean±SD=0.45±0.02; p< 0.001). In the WMH, there was a correlation between PiB-SUVr and FA (r=0.22; p≤0.001), with a trend in the NAWM (r=0.08; p=0.052). In the WMH, both the PiB-SUVr (r=0.14; p=0.002) and FA (r=0.11; p=0.018) correlated with global cognitive z-scores without a significant difference in slopes (p=0.17). In the NAWM, PiB-SUVr correlated with global cognitive z-scores (r=0.1; p=0.022), while a trend was observed with FA (r=0.09; p=0.058).
Conclusion: As a potential WM integrity marker, PiB-PET appears to be as informative as DTI-FA when utilized for associations with global cognitive function in adults.
Disclosure: Dr. Zeydan has nothing to disclose. Dr. Schwarz receives funding from the NIH. Dr. Lowe consults for Bayer Schering Pharma, Piramal Life Sciences and Merck Research and receives research support from GE Healthcare, Siemens Molecular Imaging, AVID Radiopharmaceuticals and the NIH (NIA, NCI). Dr. Reid has nothing to disclose. SA Przybelski has nothing to disclose. TG Lesnick has nothing to disclose. Dr. Kremers has nothing to disclose. ML Senjem discloses equity/options ownership in medical companies: Gilead Sciences Inc., Inovio Pharmaceuticals, Medtronic, and PAREXEL International Corporation. Dr. Vemuri receives funding from the NIH. Dr. Knopman receives funding from the NIH. Dr. Petersen receives funding from the NIH, GHR Foundation and Alexander Family Foundation. Dr. Jack receives funding from the NIH and research support from the Alexander Family Professorship of Alzheimer's Disease Research. Dr. K Kantarci receives funding from the NIH. Dr. OH Kantarci receives grant support from Biogen Inc.
Abstract: P493
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Fractional anisotropy (FA) from diffusion tensor MRI (DTI) is used as a white matter (WM) integrity marker. Similarly, Pittsburg compound-B (PiB) uptake on PET has been proposed as a WM integrity marker, particularly in demyelinating diseases. We have shown that PiB uptake in WM hyperintensities (WMH) and normal appearing WM (NAWM) correlate with cognitive function in patients with MS (Zeydan et al. MSJ-2017).
Objectives: To compare WM PiB binding and FA as WM integrity markers.
Aims: To evaluate the association of PiB-PET and DTI-FA in WMH and NAWM with cognitive function.
Methods: Healthy adults (n=537) from the population-based Mayo Clinic Study of Aging were included. MRI-FLAIR images were segmented into WMH and NAWM via a semi-automated algorithm. After registration of DTI, FLAIR and PET images to the T1-weighted image, FA values and PiB standard uptake value ratios (SUVr; referenced to cerebellar crus) were calculated for regions within the WMH and NAWM masks. Global cognitive z-scores were calculated in each participant from nine cognitive tests. Paired t-test was used for comparisons within subjects. Linear regressions and correlations were adjusted for age and global cortical PiB-SUVr.
Results: The WMH PiB-SUVr (mean±SD=1.88±0.20) was lower compared to NAWM PiB-SUVr (mean±SD=2.08±0.20; p< 0.001). The WMH FA (mean±SD=0.37±0.05) was lower compared to NAWM FA (mean±SD=0.45±0.02; p< 0.001). In the WMH, there was a correlation between PiB-SUVr and FA (r=0.22; p≤0.001), with a trend in the NAWM (r=0.08; p=0.052). In the WMH, both the PiB-SUVr (r=0.14; p=0.002) and FA (r=0.11; p=0.018) correlated with global cognitive z-scores without a significant difference in slopes (p=0.17). In the NAWM, PiB-SUVr correlated with global cognitive z-scores (r=0.1; p=0.022), while a trend was observed with FA (r=0.09; p=0.058).
Conclusion: As a potential WM integrity marker, PiB-PET appears to be as informative as DTI-FA when utilized for associations with global cognitive function in adults.
Disclosure: Dr. Zeydan has nothing to disclose. Dr. Schwarz receives funding from the NIH. Dr. Lowe consults for Bayer Schering Pharma, Piramal Life Sciences and Merck Research and receives research support from GE Healthcare, Siemens Molecular Imaging, AVID Radiopharmaceuticals and the NIH (NIA, NCI). Dr. Reid has nothing to disclose. SA Przybelski has nothing to disclose. TG Lesnick has nothing to disclose. Dr. Kremers has nothing to disclose. ML Senjem discloses equity/options ownership in medical companies: Gilead Sciences Inc., Inovio Pharmaceuticals, Medtronic, and PAREXEL International Corporation. Dr. Vemuri receives funding from the NIH. Dr. Knopman receives funding from the NIH. Dr. Petersen receives funding from the NIH, GHR Foundation and Alexander Family Foundation. Dr. Jack receives funding from the NIH and research support from the Alexander Family Professorship of Alzheimer's Disease Research. Dr. K Kantarci receives funding from the NIH. Dr. OH Kantarci receives grant support from Biogen Inc.