ORCID Profile
0000-0003-1820-3378
Current Organisation
VU medisch centrum
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Publisher: Cold Spring Harbor Laboratory
Date: 04-06-2022
DOI: 10.1101/2022.06.02.22275916
Abstract: A significant number of COVID-19 patients develop ‘long COVID’, a condition defined by long-lasting debilitating, often neurological, symptoms. The pathophysiology of long COVID is unknown. Here we present in-vivo evidence of widespread neuroinflammation in long COVID, using a quantitative assessment, [ 18 F]DPA-714 PET, in two long COVID patients. We reanalyzed historical data from three matched healthy control subjects, for comparison purposes. Both patients with long COVID had widespread increases in [ 18 F]DPA-714 binding throughout the brain. Quantitative measures of binding (BP ND values) were increased on average by 121% and 76%, respectively. This implicates profound neuroinflammation in the pathophysiology of long COVID.
Publisher: JMIR Publications Inc.
Date: 07-07-2023
Abstract: o address the growing prevalence of youth mental health problems in the Netherlands, prevention and early intervention is crucial to minimize in idual, societal, and economic impacts. Indicative prevention aims to target emerging mental health complaints before the onset of a full-blown disorder. By intervening at this early stage, fewer psychosocial and neurobiological consequences occur, and in iduals are more responsive to treatment, resulting in cost-effective outcomes. The Moderated Online Social Therapy (MOST) platform, that was successfully implemented and proven effective in Australia, is a digital peer- and clinically moderated treatment platform designed for young people. The Netherlands is the first country outside Australia to implement this platform, under the name ENgage YOung people earlY (ENYOY) and it has the potential to reduce the likelihood of young people developing serious mental health disorders. he objective of our study was to investigate the long-term outcomes in youngsters using the ENYOY-platform in relation to psychological distress, psychosocial functioning, and positive health parameters, such as quality of life. utch-speaking young people with emerging mental health complaints (N = 131) participated on the ENYOY-platform for six months in a longitudinal within-subjects study. Psychological distress, psychosocial functioning and positive health parameters were assessed at baseline, three-, six-, and 12-months. Repeated Measures Analysis of Variance was conducted and adjusted for age, gender, therapy- and community activity. Reliable Change Index (RCI) and Clinically Significant Index (CSI) were computed to compare baseline measurement with six-month and 12-month measurements. The missing data rate was 22.54% and drop-out rate 37%. total of N = 81youngster completed all measurements. Over time, psychological distress reduced, and psychosocial functioning improved with large effect sizes (both p .001, ηp² =.239 and .318 respectively) independent of age, gender, therapy- and community activity (p .05). Likewise, secondary analyses showed significant effects of time on positive health parameters quality of life, well-being, and meaningfulness (p .05 and ηp² = .062, .140, and .121 respectively). Improvements were found between baseline, 3 and 6 months (p .05) and sustained at 12-months follow-up (p .05). RCI showed improvements in psychological distress for approximately 38% of cases, no change in 55%, and worsening in 6%. For psychosocial functioning, the percentages were 51%, 43%, and 6% respectively. CSI demonstrated clinically significant change in 76% of cases for distress and 90% for functioning. his trial has demonstrated that the ENYOY-platform holds promise as a transdiagnostic intervention for addressing emerging mental health complaints among young people in the Netherlands and has laid the groundwork for further clinical research. Additionally, it would be of great relevance to expand the population on - and service delivery of the platform. rial Register ID NL8966, retrospectively registered. R2-10.1186/s12888-021-03315-x
Publisher: SAGE Publications
Date: 13-06-2018
Abstract: Accumulation of amyloid beta can be visualized using [ 18 F]florbetapir positron emission tomography. The aim of this study was to identify the optimal model for quantifying [ 18 F]florbetapir uptake and to assess test–retest reliability of corresponding outcome measures. Eight Alzheimer’s disease patients (age: 67 ± 6 years, Mini-Mental State Examination (MMSE): 23 ± 3) and eight controls (age: 63 ± 4 years, MMSE: 30 ± 0) were included. Ninety-minute dynamic positron emission tomography scans, together with arterial blood s ling, were acquired immediately following a bolus injection of 294 ± 32 MBq [ 18 F]florbetapir. Several plasma input models and the simplified reference tissue model (SRTM) were evaluated. The Akaike information criterion was used to identify the preferred kinetic model. Compared to controls, Alzheimer’s disease patients had lower MMSE scores and evidence for cortical Aβ pathology. A reversible two-tissue compartment model with fitted blood volume fraction (2T4k_V B ) was the preferred model for describing [ 18 F]florbetapir kinetics. SRTM-derived non-displaceable binding potential (BP ND ) correlated well (r 2 = 0.83, slope = 0.86) with plasma input-derived distribution volume ratio. Test–retest reliability for plasma input-derived distribution volume ratio, SRTM-derived BP ND and SUVr (50–70) were r = 0.88, r = 0.91 and r = 0.86, respectively. In vivo kinetics of [ 18 F]florbetapir could best be described by a reversible two-tissue compartmental model and [ 18 F]florbetapir BP ND can be reliably estimated using an SRTM.
Publisher: Wiley
Date: 13-12-2019
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.NEUROIMAGE.2012.03.074
Abstract: Brain atrophy studies often use FSL-BET (Brain Extraction Tool) as the first step of image processing. Default BET does not always give satisfactory results on 3DT1 MR images, which negatively impacts atrophy measurements. Finding the right alternative BET settings can be a difficult and time-consuming task, which can introduce unwanted variability. To systematically analyze the performance of BET in images of MS patients by varying its parameters and options combinations, and quantitatively comparing its results to a manual gold standard. Images from 159 MS patients were selected from different MAGNIMS consortium centers, and 16 different 3DT1 acquisition protocols at 1.5 T or 3T. Before running BET, one of three pre-processing pipelines was applied: (1) no pre-processing, (2) removal of neck slices, or (3) additional N3 inhomogeneity correction. Then BET was applied, systematically varying the fractional intensity threshold (the "f" parameter) and with either one of the main BET options ("B" - bias field correction and neck cleanup, "R" - robust brain center estimation, or "S" - eye and optic nerve cleanup) or none. For comparison, intracranial cavity masks were manually created for all image volumes. FSL-FAST (FMRIB's Automated Segmentation Tool) tissue-type segmentation was run on all BET output images and on the image volumes masked with the manual intracranial cavity masks (thus creating the gold-standard tissue masks). The resulting brain tissue masks were quantitatively compared to the gold standard using Dice overlap coefficient (DOC). Normalized brain volumes (NBV) were calculated with SIENAX. NBV values obtained using for SIENAX other BET settings than default were compared to gold standard NBV with the paired t-test. The parameter reprocessing/options combinations resulted in 20,988 BET runs. The median DOC for default BET (f=0.5, g=0) was 0.913 (range 0.321-0.977) across all 159 native scans. For all acquisition protocols, brain extraction was substantially improved for lower values of "f" than the default value. Using native images, optimum BET performance was observed for f=0.2 with option "B", giving median DOC=0.979 (range 0.867-0.994). Using neck removal before BET, optimum BET performance was observed for f=0.1 with option "B", giving median DOC 0.983 (range 0.844-0.996). Using the above BET-options for SIENAX instead of default, the NBV values obtained from images after neck removal with f=0.1 and option "B" did not differ statistically from NBV values obtained with gold-standard. Although default BET performs reasonably well on most 3DT1 images of MS patients, the performance can be improved substantially. The removal of the neck slices, either externally or within BET, has a marked positive effect on the brain extraction quality. BET option "B" with f=0.1 after removal of the neck slices seems to work best for all acquisition protocols.
Publisher: SAGE Publications
Date: 22-04-2020
Abstract: Accumulation of amyloid beta (Aβ) is one of the pathological hallmarks of Alzheimer’s disease (AD), which can be visualized using [ 18 F]florbetapir positron emission tomography (PET). The aim of this study was to evaluate various parametric methods and to assess their test-retest (TRT) reliability. Two 90 min dynamic [ 18 F]florbetapir PET scans, including arterial s ling, were acquired ( n = 8 AD patient, n = 8 controls). The following parametric methods were used (reference:cerebellum) Logan and spectral analysis (SA), receptor parametric mapping (RPM), simplified reference tissue model2 (SRTM2), reference Logan (rLogan) and standardized uptake value ratios (SUV r(50–70) ). BP ND +1, DVR, V T and SUVr were compared with corresponding estimates (V T or DVR) from the plasma input reversible two tissue compartmental (2T4k_V B ) model with corresponding TRT values for 90-scan duration. RPM ( r 2 = 0.92 slope = 0.91), Logan ( r 2 = 0.95 slope = 0.84) and rLogan ( r 2 = 0.94 slope = 0.88), and SRTM2 ( r 2 = 0.91 slope = 0.83), SA ( r 2 = 0.91 slope = 0.88), SUVr ( r 2 = 0.84 slope = 1.16) correlated well with their 2T4k_V B counterparts. RPM (controls: 1%, AD: 3%), rLogan (controls: 1%, AD: 3%) and SUV r(50–70) (controls: 3%, AD: 8%) showed an excellent TRT reliability. In conclusion, most parametric methods showed excellent performance for [ 18 F]florbetapir, but RPM and rLogan seem the methods of choice, combining the highest accuracy and best TRT reliability.
Publisher: JMIR Publications Inc.
Date: 07-07-2023
DOI: 10.2196/50636
No related grants have been discovered for Sander Verfaillie.