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Konijnenberg E, Carter SF, Ten Kate M, den Braber A, Tomassen J, Amadi C, Wesselman L, Nguyen HT, van de Kreeke JA, Yaqub M, Demuru M, Mulder SD, Hillebrand A, Bouwman FH, Teunissen CE, Serné EH, Moll AC, Verbraak FD, Hinz R, Pendleton N, Lammertsma AA, van Berckel BNM, Barkhof F, Boomsma DI, Scheltens P, Herholz K, Visser PJ. The EMIF-AD PreclinAD study: study design and baseline cohort overview. ALZHEIMERS RESEARCH & THERAPY 2018; 10:75. [PMID: 30075734 PMCID: PMC6091034 DOI: 10.1186/s13195-018-0406-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/12/2018] [Indexed: 12/26/2022]
Abstract
Background Amyloid pathology is the pathological hallmark in Alzheimer’s disease (AD) and can precede clinical dementia by decades. So far it remains unclear how amyloid pathology leads to cognitive impairment and dementia. To design AD prevention trials it is key to include cognitively normal subjects at high risk for amyloid pathology and to find predictors of cognitive decline in these subjects. These goals can be accomplished by targeting twins, with additional benefits to identify genetic and environmental pathways for amyloid pathology, other AD biomarkers, and cognitive decline. Methods From December 2014 to October 2017 we enrolled cognitively normal participants aged 60 years and older from the ongoing Manchester and Newcastle Age and Cognitive Performance Research Cohort and the Netherlands Twins Register. In Manchester we included single individuals, and in Amsterdam monozygotic twin pairs. At baseline, participants completed neuropsychological tests and questionnaires, and underwent physical examination, blood sampling, ultrasound of the carotid arteries, structural and resting state functional brain magnetic resonance imaging, and dynamic amyloid positron emission tomography (PET) scanning with [18F]flutemetamol. In addition, the twin cohort underwent lumbar puncture for cerebrospinal fluid collection, buccal cell collection, magnetoencephalography, optical coherence tomography, and retinal imaging. Results We included 285 participants, who were on average 74.8 ± 9.7 years old, 64% female. Fifty-eight participants (22%) had an abnormal amyloid PET scan. Conclusions A rich baseline dataset of cognitively normal elderly individuals has been established to estimate risk factors and biomarkers for amyloid pathology and future cognitive decline. Electronic supplementary material The online version of this article (10.1186/s13195-018-0406-7) contains supplementary material, which is available to authorized users.
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van der Aart J, Golla SSV, van der Pluijm M, Schwarte LA, Schuit RC, Klein PJ, Metaxas A, Windhorst AD, Boellaard R, Lammertsma AA, van Berckel BNM. First in human evaluation of [ 18F]PK-209, a PET ligand for the ion channel binding site of NMDA receptors. EJNMMI Res 2018; 8:69. [PMID: 30054846 PMCID: PMC6063804 DOI: 10.1186/s13550-018-0424-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 07/06/2018] [Indexed: 12/05/2022] Open
Abstract
Background Efforts to develop suitable positron emission tomography (PET) tracers for the ion channel site of human N-methyl-d-aspartate (NMDA) receptors have had limited success. [18F]PK-209 is a GMOM derivative that binds to the intrachannel phencyclidine site with high affinity and selectivity. Primate PET studies have shown that the volume of distribution in the brain was reduced by administration of the NMDA receptor antagonist MK-801, consistent with substantial specific binding. The purpose of the present study was to evaluate [18F]PK-209 in 10 healthy humans by assessing test–retest reproducibility and binding specificity following intravenous S-ketamine administration (0.5 mg ∙ kg−1). Five healthy subjects underwent a test–retest protocol, and five others a baseline-ketamine protocol. In all cases dynamic, 120-min PET scans were acquired together with metabolite-corrected arterial plasma input functions. Additional input functions were tested based on within-subject and population-average parent fractions. Results Best fits of the brain time-activity curves were obtained using an irreversible two-tissue compartment model with additional blood volume parameter. Mean test–retest variability of the net rate of influx Ki varied between 7 and 24% depending on the input function. There were no consistent changes in [18F]PK-209 PET parameters following ketamine administration, which may be a consequence of the complex endogenous ligand processes that affect channel gating. Conclusions The molecular interaction between [18F]PK-209 and the binding site within the NMDA receptor ion channel is insufficiently reproducible and specific to be a reliable imaging agent for its quantification. Trial registration EudraCT 2014-001735-36. Registered 28 April 2014
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Groot C, Tolboom N, Ikonomovic MD, Lammertsma AA, Boon BDC, Barkhof F, Scheltens P, Klunk WE, Rozemuller AJM, Ossenkoppele R, van Berckel BNM. Quantitative PET and Histology of Brain Biopsy Reveal Lack of Selective Pittsburgh Compound-B Binding to Intracerebral Amyloidoma. J Alzheimers Dis 2018; 65:71-77. [PMID: 30040724 DOI: 10.3233/jad-180316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This single case study examines selective Pittsburgh compound-B (PiB) binding to an intracerebral light-chain amyloidoma using a 90-minute dynamic [11C]PiB-PET scan and brain biopsy tissue. Parametric non-displaceable binding potential (BPND) images showed low specific binding in the amyloidoma (BPND = 0.23), while relative tracer delivery was adequate (R1 = 0.44). Histology of the tissue revealed strong coloring with Congo-red, thioflavin-S, and X-34, indicating presence of amyloid. However, immunological staining with 6F/3D revealed absence of amyloid-β and histofluorescence of 6-CN-PiB, a highly fluorescent derivative of PiB, was at background levels. Our results suggest that PiB does not detect the atypical amyloid pathology associated with an intracerebral light-chain amyloidoma. These findings are of interest to clinicians and researchers applying [11C]PiB-PET to detect atypical forms of amyloid pathology.
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Golla SSV, Timmers T, Ossenkoppele R, Groot C, Verfaillie S, Scheltens P, van der Flier WM, Schwarte L, Mintun MA, Devous M, Schuit RC, Windhorst AD, Lammertsma AA, Boellaard R, van Berckel BNM, Yaqub M. Quantification of Tau Load Using [ 18F]AV1451 PET. Mol Imaging Biol 2018; 19:963-971. [PMID: 28374171 PMCID: PMC5662681 DOI: 10.1007/s11307-017-1080-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Purpose The tau tracer [18F]AV1451, also known as flortaucipir, is a promising ligand for imaging tau accumulation in Alzheimer’s disease (AD). Most of the previous studies have quantified tau load using standardized uptake value ratios (SUVr) derived from a static [18F]AV1451 scan. SUVr may, however, be flow dependent and, especially for longitudinal studies, should be validated against a fully quantitative approach. The objective of this study was to identify the optimal tracer kinetic model for measuring tau load using [18F]AV1451. Procedures Following intravenous injection of 225 ± 16 MBq [18F]AV1451, 130 min dynamic PET scans were performed in five biomarker confirmed AD patients and five controls. Arterial blood sampling was performed to obtain a metabolite-corrected plasma input function. Next, regional time–activity curves were generated using PVElab software. These curves were analysed using several pharmacokinetic models. Results The reversible single tissue compartment model (1T2k_VB) was the preferred model for all but one control. For AD patients, however, model preference shifted towards a reversible two tissue compartmental model (2T4k_VB). The simplified reference tissue model (SRTM) derived binding potential (BPND) showed good correlation (AD: r2 = 0.87, slope = 1.06; controls: r2 = 0.87, slope = 0.86) with indirect plasma input binding (distribution volume ratio-1). Standardized uptake value ratios (80–100 min) correlated well with DVR (r2 = 0.93, slope = 1.07) and SRTM-derived BPND (r2 = 0.84, slope = 0.95). In addition, regional differences in tracer binding between subject groups in different tau-specific regions were observed. Conclusions Model preference of [18F]AV1451 appears to depend on subject status and, in particular, VT. The relationship between model preference and VT suggests that (higher) tau load may be reflected by a second tissue compartment. Nevertheless, consistent results can be obtained using a 2T4k_VB model. In addition, SRTM can be used to derive BPND. Electronic supplementary material The online version of this article (doi:10.1007/s11307-017-1080-z) contains supplementary material, which is available to authorized users.
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Scheltens NME, van der Weijden K, Adriaanse SM, van Assema D, Oomen PP, Krudop WA, Lammertsma AA, Barkhof F, Koene T, Teunissen CE, Scheltens P, van der Flier WM, Pijnenburg YAL, Yaqub M, Ossenkoppele R, van Berckel BNM. Hypometabolism of the posterior cingulate cortex is not restricted to Alzheimer's disease. NEUROIMAGE-CLINICAL 2018; 19:625-632. [PMID: 29984170 PMCID: PMC6030576 DOI: 10.1016/j.nicl.2018.05.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 04/18/2018] [Accepted: 05/19/2018] [Indexed: 11/15/2022]
Abstract
When differential diagnosis of dementia includes both Alzheimer's disease (AD) and the behavioural variant of frontotemporal dementia (bvFTD), distribution of cerebral glucose metabolism as measured using [18F]‑2‑fluoro‑2‑deoxy‑d‑glucose positron emission tomography ([18F]FDG-PET) may be helpful. One important clue for differentiation is the presence of hypometabolism in the posterior cingulate cortex (PCC), usually associated with AD. PCC hypometabolism however, could also be present in bvFTD. Therefore, the specificity of PCC hypometabolism was examined. Based on visual reading PCC hypometabolism was present in 69–73/81 probable AD patients, in 10–16/33 probable bvFTD patients, and in 0–1/22 cognitive normal (CN) subjects. Findings were validated using a PCC to reference tissue [18F]FDG standard uptake value ratio (SUVr) cut-off, which was derived from the receiver operating characteristic (ROC) separating probable AD from CN, resulting in 9–14/33 bvFTD patients having PCC hypometabolism, depending on the reference tissue used. In conclusion, PCC hypometabolism is not restricted to AD.
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Mattsson N, Groot C, Jansen WJ, Landau SM, Villemagne VL, Engelborghs S, Mintun MM, Lleo A, Molinuevo JL, Jagust WJ, Frisoni GB, Ivanoiu A, Chételat G, Resende de Oliveira C, Rodrigue KM, Kornhuber J, Wallin A, Klimkowicz-Mrowiec A, Kandimalla R, Popp J, Aalten PP, Aarsland D, Alcolea D, Almdahl IS, Baldeiras I, van Buchem MA, Cavedo E, Chen K, Cohen AD, Förster S, Fortea J, Frederiksen KS, Freund-Levi Y, Gill KD, Gkatzima O, Grimmer T, Hampel H, Herukka SK, Johannsen P, van Laere K, de Leon MJ, Maier W, Marcusson J, Meulenbroek O, Møllergård HM, Morris JC, Mroczko B, Nordlund A, Prabhakar S, Peters O, Rami L, Rodríguez-Rodríguez E, Roe CM, Rüther E, Santana I, Schröder J, Seo SW, Soininen H, Spiru L, Stomrud E, Struyfs H, Teunissen CE, Verhey FRJ, Vos SJB, van Waalwijk van Doorn LJC, Waldemar G, Wallin ÅK, Wiltfang J, Vandenberghe R, Brooks DJ, Fladby T, Rowe CC, Drzezga A, Verbeek MM, Sarazin M, Wolk DA, Fleisher AS, Klunk WE, Na DL, Sánchez-Juan P, Lee DY, Nordberg A, Tsolaki M, Camus V, Rinne JO, Fagan AM, Zetterberg H, Blennow K, Rabinovici GD, Hansson O, van Berckel BNM, van der Flier WM, Scheltens P, Visser PJ, Ossenkoppele R. Prevalence of the apolipoprotein E ε4 allele in amyloid β positive subjects across the spectrum of Alzheimer's disease. Alzheimers Dement 2018; 14:913-924. [PMID: 29601787 DOI: 10.1016/j.jalz.2018.02.009] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/28/2017] [Accepted: 02/07/2018] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Apolipoprotein E (APOE) ε4 is the major genetic risk factor for Alzheimer's disease (AD), but its prevalence is unclear because earlier studies did not require biomarker evidence of amyloid β (Aβ) pathology. METHODS We included 3451 Aβ+ subjects (853 AD-type dementia, 1810 mild cognitive impairment, and 788 cognitively normal). Generalized estimating equation models were used to assess APOE ε4 prevalence in relation to age, sex, education, and geographical location. RESULTS The APOE ε4 prevalence was 66% in AD-type dementia, 64% in mild cognitive impairment, and 51% in cognitively normal, and it decreased with advancing age in Aβ+ cognitively normal and Aβ+ mild cognitive impairment (P < .05) but not in Aβ+ AD dementia (P = .66). The prevalence was highest in Northern Europe but did not vary by sex or education. DISCUSSION The APOE ε4 prevalence in AD was higher than that in previous studies, which did not require presence of Aβ pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location.
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Scheltens P, Prins N, Lammertsma A, Yaqub M, Gouw A, Wink AM, Chu HM, van Berckel BNM, Alam J. An exploratory clinical study of p38 α kinase inhibition in Alzheimer's disease. Ann Clin Transl Neurol 2018; 5:464-473. [PMID: 29687023 PMCID: PMC5899915 DOI: 10.1002/acn3.549] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/07/2018] [Accepted: 02/01/2018] [Indexed: 12/12/2022] Open
Abstract
Objective The aim of this study was to preliminarily evaluate an oral small molecule p38α kinase inhibitor in patients with early Alzheimer's disease (AD) for the effects on brain amyloid plaque load and episodic memory function, and to establish pharmacokinetic-pharmacodynamics correlations if any effects identified on these parameters. Methods Sixteen patients with early AD received a highly selective p38α inhibitor (neflamapimod) for 84 days (12 weeks). To obtain a broad range of plasma drug exposures, subjects randomized to receive either 40 mg (n = 9) or 125 mg (n = 7) twice daily. Dynamic, 11C-PiB positron emission scans were performed at baseline and at Day 84 and quantitatively analyzed by reference parametric mapping. Episodic memory assessed as Wechsler Memory Scale (WMS) immediate and delayed recall composites. Result In the 11C-PiB analyses there were no main group level effects, though in the prespecified responder analysis (>7% reduction in 11C-PiB signal) there were three responders in the 40 mg, and one in the 125 mg group. There were statistically significant increases from baseline in mean WMS immediate recall score and WMS delayed recall at both day 28 (P = 0.03 and P = 0.001) and day 84 (P = 0.001 and P < 0.001). Individual subject plasma drug concentration profiles were significantly positively correlated with the change in combined WMS immediate and delayed recall (P < 0.0001, r2 = 0.70). Within-subject effect size was 0.59 for immediate recall and 0.67 for delayed recall. Interpretation Selective p38α inhibition in patients with early AD may improve episodic memory and potentially impact β-amyloid production. These preliminary clinical findings support conduct of a longer duration placebo-controlled study, particularly to confirm the effects on episodic memory function.
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Jansen WJ, Ossenkoppele R, Tijms BM, Fagan AM, Hansson O, Klunk WE, van der Flier WM, Villemagne VL, Frisoni GB, Fleisher AS, Lleó A, Mintun MA, Wallin A, Engelborghs S, Na DL, Chételat G, Molinuevo JL, Landau SM, Mattsson N, Kornhuber J, Sabri O, Rowe CC, Parnetti L, Popp J, Fladby T, Jagust WJ, Aalten P, Lee DY, Vandenberghe R, Resende de Oliveira C, Kapaki E, Froelich L, Ivanoiu A, Gabryelewicz T, Verbeek MM, Sanchez-Juan P, Hildebrandt H, Camus V, Zboch M, Brooks DJ, Drzezga A, Rinne JO, Newberg A, de Mendonça A, Sarazin M, Rabinovici GD, Madsen K, Kramberger MG, Nordberg A, Mok V, Mroczko B, Wolk DA, Meyer PT, Tsolaki M, Scheltens P, Verhey FRJ, Visser PJ, Aarsland D, Alcolea D, Alexander M, Almdahl IS, Arnold SE, Baldeiras I, Barthel H, van Berckel BNM, Blennow K, van Buchem MA, Cavedo E, Chen K, Chipi E, Cohen AD, Förster S, Fortea J, Frederiksen KS, Freund-Levi Y, Gkatzima O, Gordon MF, Grimmer T, Hampel H, Hausner L, Hellwig S, Herukka SK, Johannsen P, Klimkowicz-Mrowiec A, Köhler S, Koglin N, van Laere K, de Leon M, Lisetti V, Maier W, Marcusson J, Meulenbroek O, Møllergård HM, Morris JC, Nordlund A, Novak GP, Paraskevas GP, Perera G, Peters O, Ramakers IHGB, Rami L, Rodríguez-Rodríguez E, Roe CM, Rot U, Rüther E, Santana I, Schröder J, Seo SW, Soininen H, Spiru L, Stomrud E, Struyfs H, Teunissen CE, Vos SJB, van Waalwijk van Doorn LJC, Waldemar G, Wallin ÅK, Wiltfang J, Zetterberg H. Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia. JAMA Psychiatry 2018; 75:84-95. [PMID: 29188296 PMCID: PMC5786156 DOI: 10.1001/jamapsychiatry.2017.3391] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials. OBJECTIVE To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017. MAIN OUTCOMES AND MEASURES Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype. RESULTS Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P = .16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P < .001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P < .001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years. CONCLUSIONS AND RELEVANCE Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
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Golla SSV, Adriaanse SM, Yaqub M, Windhorst AD, Lammertsma AA, van Berckel BNM, Boellaard R. Model selection criteria for dynamic brain PET studies. EJNMMI Phys 2017; 4:30. [PMID: 29209862 PMCID: PMC5716967 DOI: 10.1186/s40658-017-0197-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/23/2017] [Indexed: 12/04/2022] Open
Abstract
Background Several criteria exist to identify the optimal model for quantification of tracer kinetics. The purpose of this study was to evaluate the correspondence in kinetic model preference identification for brain PET studies among five model selection criteria: Akaike Information Criterion (AIC), AIC unbiased (AICC), model selection criterion (MSC), Schwartz Criterion (SC), and F-test. Materials and Methods Six tracers were evaluated: [11C]FMZ, [11C]GMOM, [11C]PK11195, [11C]Raclopride, [18F]FDG, and [11C]PHT, including data from five subjects per tracer. Time activity curves (TACs) were analysed using six plasma input models: reversible single-tissue model (1T2k), irreversible two-tissue model (2T3k), and reversible two-tissue model (2T4k), all with and without blood volume fraction parameter (VB). For each tracer and criterion, the percentage of TACs preferring a certain model was calculated. Results For all radiotracers, strong agreement was seen across the model selection criteria. The F-test was considered as the reference, as it is a frequently used hypothesis test. The F-test confirmed the AIC preferred model in 87% of all cases. The strongest (but minimal) disagreement across regional TACs was found when comparing AIC with AICC. Despite these regional discrepancies, same preferred kinetic model was obtained using all criteria, with an exception of one FMZ subject. Conclusion In conclusion, all five model selection criteria resulted in similar conclusions with only minor differences that did not affect overall model selection. Electronic supplementary material The online version of this article (10.1186/s40658-017-0197-0) contains supplementary material, which is available to authorized users.
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Tijms BM, Willemse EAJ, Zwan MD, Mulder SD, Visser PJ, van Berckel BNM, van der Flier WM, Scheltens P, Teunissen CE. Unbiased Approach to Counteract Upward Drift in Cerebrospinal Fluid Amyloid-β 1-42 Analysis Results. Clin Chem 2017; 64:576-585. [PMID: 29208658 DOI: 10.1373/clinchem.2017.281055] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/20/2017] [Indexed: 11/06/2022]
Abstract
BACKGROUND Low cerebrospinal fluid (CSF) amyloid-β 1-42 (Aβ 1-42) concentrations indicate amyloid plaque accumulation in the brain, a pathological hallmark of Alzheimer disease (AD). Innotest assay values of Aβ 1-42 have gradually increased over the past 2 decades, which might lead to misclassification of AD when a single cutpoint for abnormality is used. We propose an unbiased approach to statistically correct for drift. METHODS We determined year-specific cutpoints with Gaussian mixture modeling, based on the cross-section of bimodal distributions of Aβ 1-42 concentrations in 4397 memory clinic patients. This allowed us to realign year-specific cutpoints as an unbiased method to remove drift from the data. Sensitivity and specificity to detect AD dementia were compared between corrected and uncorrected values. RESULTS Aβ 1-42 values increased 22 pg/mL annually, and this could not be explained by changes in cohort composition. Our approach removed time dependencies [β (SE) = 0.07 (0.59); P = 0.91]. Statistically correcting for drift improved the sensitivity to detect AD dementia to 0.90 (95% CI, 0.89-0.92) from at least 0.66 (95% CI, 0.64-0.69) based on uncorrected data. Specificity became lower (0.69; 95% CI, 0.67-0.70) vs at most 0.80 (95% CI, 0.79-0.82) for uncorrected data. CONCLUSIONS This approach may also be useful to standardize Aβ 1-42 CSF concentrations across different centers and/or platforms, and to optimize use of CSF biomarker data collected over a long period.
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Scheltens NME, Kuyper IS, Boellaard R, Barkhof F, Teunissen CE, Broersen LM, Lansbergen MM, van der Flier WM, van Berckel BNM, Scheltens P. Design of the NL-ENIGMA study: Exploring the effect of Souvenaid on cerebral glucose metabolism in early Alzheimer's disease. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2017; 2:233-240. [PMID: 29067310 PMCID: PMC5651347 DOI: 10.1016/j.trci.2016.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Introduction Alzheimer's disease is associated with early synaptic loss. Specific nutrients are known to be rate limiting for synapse formation. Studies have shown that administering specific nutrients may improve memory function, possibly by increasing synapse formation. This Dutch study explores the Effect of a specific Nutritional Intervention on cerebral Glucose Metabolism in early Alzheimer's disease (NL-ENIGMA, Dutch Trial Register NTR4718, http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4718). The NL-ENIGMA study is designed to test whether the specific multinutrient combination Fortasyn Connect present in the medical food Souvenaid influences cerebral glucose metabolism as a marker for improved synapse function. Methods This study is a double-blind, randomized controlled parallel-group single-center trial. Forty drug-naive patients with mild cognitive impairment or mild dementia with evidence of amyloid deposition are 1:1 randomized to receive either the multinutrient combination or placebo once daily. Main exploratory outcome parameters include absolute quantitative positron emission tomography with 18F-fluorodeoxyglucose (including arterial sampling) and standard uptake value ratios normalized for the cerebellum or pons after 24 weeks. Discussion We expect the NL-ENIGMA study to provide further insight in the potential of this multinutrient combination to improve synapse function. This study explores the Effect of a specific Nutritional Intervention on cerebral Glucose Metabolism in early Alzheimer's disease (AD). Forty drug-naive patients with mild cognitive impairment or mild dementia because of AD will be analyzed. Synapse function is explored using positron emission tomography with 18F-fluorodeoxyglucose including arterial sampling.
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Vijverberg EGB, Dols A, Krudop WA, Peters A, Kerssens CJ, van Berckel BNM, Wattjes MP, Barkhof F, Gossink F, Prins ND, Stek ML, Scheltens P, Pijnenburg YAL. Diagnostic Accuracy of the Frontotemporal Dementia Consensus Criteria in the Late-Onset Frontal Lobe Syndrome. Dement Geriatr Cogn Disord 2017; 41:210-9. [PMID: 27160162 DOI: 10.1159/000444849] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/19/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS We aimed to prospectively assess the diagnostic accuracy of the revised criteria for behavioural variant frontotemporal dementia (bvFTD) among subjects presenting with a frontal lobe syndrome in middle-late adulthood. METHODS Patients were included based on a predominant behavioural clinical presentation, a Frontal Behavioural Inventory (FBI) score of ≥11 and/or a Stereotypy Rating Inventory (SRI) score of ≥10. At baseline, the fulfilment of the international consensus criteria for behavioural variant FTD (FTDC) was systematically recorded. The 2-year follow-up consensus diagnosis was used as the gold standard to calculate sensitivity and specificity of the FTDC criteria for possible and probable bvFTD. RESULTS Two-year follow-up data were available for 116 patients (85%). Two-year follow-up consensus diagnoses consisted of probable/definite bvFTD (n = 27), other dementia (n = 30), psychiatric disorders (n = 46) and other neurological disorders (n = 13). Sensitivity for possible bvFTD was 85% (95% CI 70-95%) at a specificity of 27% (95% CI 19-37%). Sensitivity for probable bvFTD was 85% (95% CI 69-95%), whereas their specificity was 82% (95% CI 73-89%). CONCLUSIONS We found a good diagnostic accuracy for FTDC probable bvFTD. However, the specificity for FTDC possible bvFTD was low. Our results reflect the symptomatic overlap between bvFTD, other neurological conditions and psychiatric disorders, and the relevance of adding neuroimaging to the diagnostic process.
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Klein PJ, Schuit RC, Metaxas A, Christiaans JAM, Kooijman E, Lammertsma AA, van Berckel BNM, Windhorst AD. Synthesis, radiolabeling and preclinical evaluation of a [ 11C]GMOM derivative as PET radiotracer for the ion channel of the N-methyl-D-aspartate receptor. Nucl Med Biol 2017; 51:25-32. [PMID: 28528265 DOI: 10.1016/j.nucmedbio.2017.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/29/2017] [Accepted: 05/04/2017] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Presently available PET ligands for the NMDAr ion channel generally suffer from fast metabolism. The purpose of this study was to develop a metabolically more stable ligand for the NMDAr ion channel, taking [11C]GMOM ([11C]1) as the lead compound. METHODS [11C]1, its fluoralkyl analogue [18F]PK209 ([18F]2) and the newly synthesized fluorovinyloxy analogue [11C]7b were evaluated ex vivo in male Wistar rats for metabolic stability. In addition, [11C]7b was subjected to a biodistribution study and its affinity (Ki) and lipophilicity (logD7.4) values were determined. RESULTS The addition of a vinyl chain in the fluoromethoxy moiety did not negatively alter the affinity of [11C]7b for the NMDAr, while lipophilicity was increased. Biodistribution studies showed higher uptake of [11C]7b in forebrain regions compared with cerebellum. Pre-treatment with MK-801 decreased the overall brain uptake significantly, but not in a region-specific manner. 45min after injection 78, 90 and 87% of activity in the brain was due to parent compound for [11C]1, [18F]2 and [11C]7b, respectively. In plasma, 26-31% of activity was due to parent compound. CONCLUSION Complete substitution of the alpha-carbon increased lipophilicity to more favorable values. Substitution of one or more hydrogens of the alpha-carbon atom in the methoxy moiety improved metabolic stability. In plasma, more parent compound was found for [18F]2 and [11C]7b then for [11C]1, although differences were not significant. At 45min, significantly more parent [18F]2 and [11C]7b was measured in the brain compared with [11C]1.
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Golla SSV, Lubberink M, van Berckel BNM, Lammertsma AA, Boellaard R. Partial volume correction of brain PET studies using iterative deconvolution in combination with HYPR denoising. EJNMMI Res 2017; 7:36. [PMID: 28432674 PMCID: PMC5400775 DOI: 10.1186/s13550-017-0284-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 04/07/2017] [Indexed: 11/10/2022] Open
Abstract
Background Accurate quantification of PET studies depends on the spatial resolution of the PET data. The commonly limited PET resolution results in partial volume effects (PVE). Iterative deconvolution methods (IDM) have been proposed as a means to correct for PVE. IDM improves spatial resolution of PET studies without the need for structural information (e.g. MR scans). On the other hand, deconvolution also increases noise, which results in lower signal-to-noise ratios (SNR). The aim of this study was to implement IDM in combination with HighlY constrained back-PRojection (HYPR) denoising to mitigate poor SNR properties of conventional IDM. Methods An anthropomorphic Hoffman brain phantom was filled with an [18F]FDG solution of ~25 kBq mL−1 and scanned for 30 min on a Philips Ingenuity TF PET/CT scanner (Philips, Cleveland, USA) using a dynamic brain protocol with various frame durations ranging from 10 to 300 s. Van Cittert IDM was used for PVC of the scans. In addition, HYPR was used to improve SNR of the dynamic PET images, applying it both before and/or after IDM. The Hoffman phantom dataset was used to optimise IDM parameters (number of iterations, type of algorithm, with/without HYPR) and the order of HYPR implementation based on the best average agreement of measured and actual activity concentrations in the regions. Next, dynamic [11C]flumazenil (five healthy subjects) and [11C]PIB (four healthy subjects and four patients with Alzheimer’s disease) scans were used to assess the impact of IDM with and without HYPR on plasma input-derived distribution volumes (VT) across various regions of the brain. Results In the case of [11C]flumazenil scans, Hypr-IDM-Hypr showed an increase of 5 to 20% in the regional VT whereas a 0 to 10% increase or decrease was seen in the case of [11C]PIB depending on the volume of interest or type of subject (healthy or patient). References for these comparisons were the VTs from the PVE-uncorrected scans. Conclusions IDM improved quantitative accuracy of measured activity concentrations. Moreover, the use of IDM in combination with HYPR (Hypr-IDM-Hypr) was able to correct for PVE without increasing noise. Electronic supplementary material The online version of this article (doi:10.1186/s13550-017-0284-1) contains supplementary material, which is available to authorized users.
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Fällmar D, Haller S, Lilja J, Danfors T, Kilander L, Tolboom N, Egger K, Kellner E, Croon PM, Verfaillie SCJ, van Berckel BNM, Ossenkoppele R, Barkhof F, Larsson EM. Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET. Eur Radiol 2017; 27:4237-4246. [PMID: 28374078 PMCID: PMC5579184 DOI: 10.1007/s00330-017-4784-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/23/2017] [Accepted: 02/16/2017] [Indexed: 11/30/2022]
Abstract
Objective Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. Methods Data were combined from two separate sites, each cohort consisting of patients with Alzheimer’s disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis. Results Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p < 0.001). Among true-positive cases, correct diagnoses were made in 76% (ASL) and 84% (FDG-PET) (p = 0.168). Conclusion ASL-based Z-maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET. Key points • ASL-based Z-maps yielded high specificity and positive predictive value in neurodegenerative dementia. • ASL-based Z-maps had significantly lower sensitivity compared to FDG-PET-based Z-maps. • FDG-PET might be reserved for ASL-negative cases where clinical suspicion persists. • Findings were similar at two study sites.
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van der Aart J, van der Doef TF, Horstman P, Huisman MC, Schuit RC, van Lingen A, Windhorst AD, van Berckel BNM, Lammertsma AA. Human Dosimetry of the N-Methyl-d-Aspartate Receptor Ligand 11C-GMOM. J Nucl Med 2017; 58:1330-1333. [PMID: 28183990 DOI: 10.2967/jnumed.116.188250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/02/2017] [Indexed: 11/16/2022] Open
Abstract
The methylguanidine derivative 11C-GMOM (11C-labeled N-(2-chloro-3-thiomethylphenyl)-N'-(3-methoxyphenyl)-N'-methylguanidine) has been used successfully to quantify N-methyl-d-aspartate (NMDA) receptor binding in humans. The purpose of the present study was to estimate the 11C-GMOM radiation dose in healthy humans. Methods: After 11C-GMOM injection, 3 female and 2 male subjects underwent 10 consecutive whole-body PET scans in approximately 77 min. Seven source organs were defined manually, scaled to a sex-specific reference, and residence times were calculated for input into OLINDA/EXM software. Accepted tissue-weighting factors were used to calculate the effective dose. Results: The mean absorbed radiation doses in source organs ranged from 7.7 μGy·MBq-1 in the brain to 12.7 μGy·MBq-1 in the spleen. The effective dose (±SD) was 4.5 ± 0.5 μSv·MBq-1Conclusion: The effective dose of 11C-GMOM is at the lower end of the range seen for other 11C-labeled ligands, allowing for serial PET scanning in a single subject.
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de Wilde A, van Maurik IS, Kunneman M, Bouwman F, Zwan M, Willemse EAJ, Biessels GJ, Minkman M, Pel R, Schoonenboom NSM, Smets EMA, Wattjes MP, Barkhof F, Stephens A, van Lier EJ, Batrla-Utermann R, Scheltens P, Teunissen CE, van Berckel BNM, van der Flier WM. Alzheimer's biomarkers in daily practice (ABIDE) project: Rationale and design. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2017; 6:143-151. [PMID: 28239639 PMCID: PMC5318541 DOI: 10.1016/j.dadm.2017.01.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Introduction The Alzheimer's biomarkers in daily practice (ABIDE) project is designed to translate knowledge on diagnostic tests (magnetic resonance imaging [MRI], cerebrospinal fluid [CSF], and amyloid positron emission tomography [PET]) to daily clinical practice with a focus on mild cognitive impairment (MCI) Methods ABIDE is a 3-year project with a multifaceted design and is structured into interconnected substudies using both quantitative and qualitative research methods. Results Based on retrospective data, we develop personalized risk estimates for MCI patients. Prospectively, we collect MRI and CSF data from 200 patients from local memory clinics and amyloid PET from 500 patients in a tertiary setting, to optimize application of these tests in daily practice. Furthermore, ABIDE will develop strategies for optimal patient-clinician conversations. Discussion Ultimately, this will result in a set of practical tools for clinicians to support the choice of diagnostic tests and facilitate the interpretation and communication of their results.
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Zwan MD, Bouwman FH, Konijnenberg E, van der Flier WM, Lammertsma AA, Verhey FRJ, Aalten P, van Berckel BNM, Scheltens P. Diagnostic impact of [ 18F]flutemetamol PET in early-onset dementia. ALZHEIMERS RESEARCH & THERAPY 2017; 9:2. [PMID: 28093088 PMCID: PMC5240413 DOI: 10.1186/s13195-016-0228-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/08/2016] [Indexed: 12/20/2022]
Abstract
Background Early-onset dementia patients often present with atypical clinical symptoms, hampering an accurate clinical diagnosis. The purpose of the present study was to assess the diagnostic impact of the amyloid-positron emission tomography (PET) imaging agent [18F]flutemetamol in early-onset dementia patients, in terms of change in (confidence in) diagnosis and patient management plan. Methods This prospective bi-center study included 211 patients suspected of early-onset dementia who visited a tertiary memory clinic. Patients were eligible with Mini Mental State Examination ≥ 18 and age at diagnosis ≤ 70 years and in whom the diagnostic confidence was <90% after routine diagnostic work-up. All patients underwent [18F]flutemetamol PET, which was interpreted as amyloid-negative or amyloid-positive based on visual rating. Before and after disclosing the PET results, we assessed the diagnostic confidence (using a visual analog scale of 0–100%) and clinical diagnosis. The impact of [18F]flutemetamol PET on the patient management plan was also evaluated. Results [18F]flutemetamol PET scans were positive in 133 out of 211 (63%) patients, of whom 110 out of 144 (76%) patients had a pre-PET Alzheimer’s disease (AD) diagnosis and 23 out of 67 (34%) patients had a non-AD diagnosis. After disclosure of PET results, 41/211 (19%) diagnoses changed. Overall, diagnostic confidence increased from 69 ± 12% to 88 ± 15% after disclosing PET results (P < 0.001; in 87% of patients). In 79 (37%) patients, PET results led to a change in patient management and predominantly the initiation of AD medication when PET showed evidence for amyloid pathology. Conclusions [18F]flutemetamol PET changed clinical diagnosis, increased overall diagnostic confidence, and altered the patient management plan. Our results suggest that amyloid PET may have added value over the standardized diagnostic work-up in early-onset dementia patients with uncertain clinical diagnosis. This study provides evidence for the recommendations put forward in the appropriate use criteria for amyloid PET in clinical practice. Trial registration Nederlands Trial Register NTR3743. Registered 7 December 2012.
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Krudop WA, Dols A, Kerssens CJ, Prins ND, Möller C, Schouws S, Barkhof F, van Berckel BNM, Teunissen CE, van der Flier WM, Scheltens P, Sikkes SAM, Stek ML, Pijnenburg YAL. Impact of Imaging and Cerebrospinal Fluid Biomarkers on Behavioral Variant Frontotemporal Dementia Diagnosis within a Late-Onset Frontal Lobe Syndrome Cohort. Dement Geriatr Cogn Disord 2016; 41:16-26. [PMID: 26473985 DOI: 10.1159/000441023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/10/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The criteria for behavioral variant frontotemporal dementia (bvFTD) incorporate MRI and [18F]-FDG-PET. Cerebrospinal fluid (CSF) analysis is merely advised for excluding Alzheimer's disease. AIMS We aimed to assess the impact of biomarkers on diagnostic certainty and contingent changes of bvFTD diagnosis within the clinically relevant neuropsychiatric differential diagnosis of subjects with a late-onset frontal lobe syndrome (LOF). METHODS We included 137 patients with LOF, aged 45-75 years, 72% males. Biomarker disclosure was considered contributing after any substantial difference in diagnostic certainty or a diagnostic change. Percentages of contributing biomarkers were compared between three major diagnostic groups (bvFTD, psychiatry, other neurological disorders). Certainty levels in stable diagnostic groups were compared to those with a diagnostic change. RESULTS Biomarkers contributed in 53, 60 and 41% of the LOF patients for MRI, [18F]-FDG-PET and CSF, respectively. Biomarkers changed the diagnosis in 14% of cases towards bvFTD and in 13% from bvFTD into an alternative. Those that changed had a lower level of a priori diagnostic certainty compared to stable diagnoses. CONCLUSION Our study not only supports the widely accepted use of MRI and [18F]-FDG-PET in diagnosing or excluding bvFTD, but also shows that CSF biomarkers aid clinicians in the diagnostic process.
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van der Doef TF, de Witte LD, Sutterland AL, Jobse E, Yaqub M, Boellaard R, de Haan L, Eriksson J, Lammertsma AA, Kahn RS, van Berckel BNM. In vivo (R)-[(11)C]PK11195 PET imaging of 18kDa translocator protein in recent onset psychosis. NPJ SCHIZOPHRENIA 2016; 2:16031. [PMID: 27602389 PMCID: PMC5007116 DOI: 10.1038/npjschz.2016.31] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 07/23/2016] [Accepted: 07/26/2016] [Indexed: 12/12/2022]
Abstract
Evidence is accumulating that immune dysfunction is involved in the pathophysiology of schizophrenia. It has been hypothesized that microglia activation is present in patients with schizophrenia. Various in vivo and post-mortem studies have investigated this hypothesis, but as yet with inconclusive results. Microglia activation is associated with elevations in 18 kDa translocator protein (TSPO) levels, which can be measured with the positron emission tomography (PET) tracer (R)-[11C]PK11195. The purpose of the present study was to investigate microglia activation in psychosis in vivo at an early stage of the disease. (R)-[11C]PK11195 binding potential (BPND) was measured in 19 patients with recent onset psychosis and 17 age and gender-matched healthy controls. Total gray matter, as well as five gray matter regions of interest (frontal cortex, temporal cortex, parietal cortex, striatum, and thalamus) were defined a priori. PET data were analysed using a reference tissue approach and a supervised cluster analysis algorithm to identify the reference region. No significant difference in (R)-[11C]PK11195 BPND between patients and controls was found in total gray matter, nor one of the regions of interest. These findings suggest that microglia activation is not present in recent onset psychosis or that it is a subtle phenomenon that could not be detected using the design of the present study.
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Mansor S, Boellaard R, Huisman MC, van Berckel BNM, Schuit RC, Windhorst AD, Lammertsma AA, van Velden FHP. Impact of New Scatter Correction Strategies on High-Resolution Research Tomograph Brain PET Studies. Mol Imaging Biol 2016; 18:627-35. [PMID: 26728160 PMCID: PMC4927607 DOI: 10.1007/s11307-015-0921-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE The aim of this study is to evaluate the impact of different scatter correction strategies on quantification of high-resolution research tomograph (HRRT) data for three tracers covering a wide range in kinetic profiles. PROCEDURES Healthy subjects received dynamic HRRT scans using either (R)-[(11)C]verapamil (n = 5), [(11)C]raclopride (n = 5) or [(11)C]flumazenil (n = 5). To reduce the effects of patient motion on scatter scaling factors, a margin in the attenuation correction factor (ACF) sinogram was applied prior to 2D or 3D single scatter simulation (SSS). RESULTS Some (R)-[(11)C]verapamil studies showed prominent artefacts that disappeared with an ACF-margin of 10 mm or more. Use of 3D SSS for (R)-[(11)C]verapamil showed a statistically significant increase in volume of distribution compared with 2D SSS (p < 0.05), but not for [(11)C]raclopride and [(11)C]flumazenil studies (p > 0.05). CONCLUSIONS When there is a patient motion-induced mismatch between transmission and emission scans, applying an ACF-margin resulted in more reliable scatter scaling factors but did not change (and/or deteriorate) quantification.
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Collij LE, Heeman F, Kuijer JPA, Ossenkoppele R, Benedictus MR, Möller C, Verfaillie SCJ, Sanz-Arigita EJ, van Berckel BNM, van der Flier WM, Scheltens P, Barkhof F, Wink AM. Application of Machine Learning to Arterial Spin Labeling in Mild Cognitive Impairment and Alzheimer Disease. Radiology 2016; 281:865-875. [PMID: 27383395 DOI: 10.1148/radiol.2016152703] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Purpose To investigate whether multivariate pattern recognition analysis of arterial spin labeling (ASL) perfusion maps can be used for classification and single-subject prediction of patients with Alzheimer disease (AD) and mild cognitive impairment (MCI) and subjects with subjective cognitive decline (SCD) after using the W score method to remove confounding effects of sex and age. Materials and Methods Pseudocontinuous 3.0-T ASL images were acquired in 100 patients with probable AD; 60 patients with MCI, of whom 12 remained stable, 12 were converted to a diagnosis of AD, and 36 had no follow-up; 100 subjects with SCD; and 26 healthy control subjects. The AD, MCI, and SCD groups were divided into a sex- and age-matched training set (n = 130) and an independent prediction set (n = 130). Standardized perfusion scores adjusted for age and sex (W scores) were computed per voxel for each participant. Training of a support vector machine classifier was performed with diagnostic status and perfusion maps. Discrimination maps were extracted and used for single-subject classification in the prediction set. Prediction performance was assessed with receiver operating characteristic (ROC) analysis to generate an area under the ROC curve (AUC) and sensitivity and specificity distribution. Results Single-subject diagnosis in the prediction set by using the discrimination maps yielded excellent performance for AD versus SCD (AUC, 0.96; P < .01), good performance for AD versus MCI (AUC, 0.89; P < .01), and poor performance for MCI versus SCD (AUC, 0.63; P = .06). Application of the AD versus SCD discrimination map for prediction of MCI subgroups resulted in good performance for patients with MCI diagnosis converted to AD versus subjects with SCD (AUC, 0.84; P < .01) and fair performance for patients with MCI diagnosis converted to AD versus those with stable MCI (AUC, 0.71; P > .05). Conclusion With automated methods, age- and sex-adjusted ASL perfusion maps can be used to classify and predict diagnosis of AD, conversion of MCI to AD, stable MCI, and SCD with good to excellent accuracy and AUC values. © RSNA, 2016.
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Chételat G, Ossenkoppele R, Villemagne VL, Perrotin A, Landeau B, Mézenge F, Jagust WJ, Dore V, Miller BL, Egret S, Seeley WW, van der Flier WM, La Joie R, Ames D, van Berckel BNM, Scheltens P, Barkhof F, Rowe CC, Masters CL, de La Sayette V, Bouwman F, Rabinovici GD. Atrophy, hypometabolism and clinical trajectories in patients with amyloid-negative Alzheimer's disease. Brain 2016; 139:2528-39. [PMID: 27357349 DOI: 10.1093/brain/aww159] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 05/16/2016] [Indexed: 11/14/2022] Open
Abstract
See O'Sullivan and Vann (doi:10.1093/aww166) for a scientific commentary on this article.About 15% of patients clinically diagnosed with Alzheimer's disease do not show high tracer retention on amyloid positon emission tomography imaging. The present study investigates clinical and demographic features, patterns of brain atrophy and hypometabolism and longitudinal clinical trajectories of these patients. Forty amyloid-negative patients carrying a pre-scan diagnosis of Alzheimer's disease dementia from four centres were included (11/29 females/males; mean age = 67 ± 9). Detailed clinical histories, including the clinical diagnoses before and after the amyloid scan and at follow-up, were collected. Patients were classified according to their pre-scan clinical phenotype as amnestic (memory predominant), non-amnestic (predominant language, visuospatial or frontal symptoms), or non-specific (diffuse cognitive deficits). Demographic, clinical, neuropsychological, magnetic resonance imaging and (18)F-fluorodeoxyglucose positon emission tomography data were compared to 27 amyloid-positive typical Alzheimer's disease cases (14/13 females/males; mean age = 71 ± 10) and 29 amyloid-negative controls (15/14 females/males; mean age = 69 ± 12) matched for age, gender and education. There were 21 amnestic, 12 non-amnestic, and seven non-specific amyloid-negative Alzheimer's disease cases. Amyloid-negative subgroups did not differ in age, gender or education. After the amyloid scan, clinicians altered the diagnosis in 68% of amyloid-negative patients including 48% of amnestic versus 94% of non-amnestic and non-specific cases. Amnestic amyloid-negative cases were most often reclassified as frontotemporal dementia, non-amnestic as frontotemporal dementia or corticobasal degeneration, and non-specific as dementia with Lewy bodies or unknown diagnosis. The longer-term clinical follow-up was consistent with the post-scan diagnosis in most cases (90%), including in amnestic amyloid-negative cases whose post-positon emission tomography diagnosis remained Alzheimer's disease. While the non-amnestic and non-specific amyloid-negative cases usually showed patterns of atrophy and hypometabolism suggestive of another degenerative disorder, the amnestic amyloid-negative cases had subtle atrophy and hypometabolism, restricted to the retrosplenial/posterior cingulate cortex. Patients with a negative amyloid positon emission tomography scan following an initial clinical diagnosis of Alzheimer's disease have heterogeneous clinical presentations and neuroimaging profiles; a majority showed a clinical progression that was consistent with a neurodegenerative condition. In contrast, in the subgroup of amnestic amyloid-negative cases, the clinical presentation and follow-up usually remained consistent with Alzheimer's disease. An alternative diagnosis was not made in about half of the amnestic amyloid-negative cases, highlighting the need for a clinical framework and terminology to define these patients, who may have underlying limbic-predominant, non-amyloid-related pathologies.
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Golla SSV, Boellaard R, Oikonen V, Hoffmann A, van Berckel BNM, Windhorst AD, Virta J, Te Beek ET, Groeneveld GJ, Haaparanta-Solin M, Luoto P, Savisto N, Solin O, Valencia R, Thiele A, Eriksson J, Schuit RC, Lammertsma AA, Rinne JO. Parametric Binding Images of the TSPO Ligand 18F-DPA-714. J Nucl Med 2016; 57:1543-1547. [PMID: 27261521 DOI: 10.2967/jnumed.116.173013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 04/25/2016] [Indexed: 01/23/2023] Open
Abstract
18F-labeled N,N-diethyl-2-(2-[4-(2-fluoroethoxy)phenyl]-5,7-dimethylpyrazolo[1,5-α]pyrimidine-3-yl)acetamide (DPA-714) is a radioligand for the 18-kDa translocator protein. The purpose of the present study was to identify the best method for generating quantitative parametric images of 18F-DPA-714 binding. METHODS Ninety-minute dynamic 18F-DPA-714 PET scans with full arterial sampling from 6 healthy subjects and 9 Alzheimer disease (AD) patients were used. Plasma-input-based Logan graphical analysis and spectral analysis were used to generate parametric volume of distribution (VT) images. Five versions of Ichise, reference Logan, and 2 basis function implementations (receptor parametric mapping and simplified reference tissue model 2 [SRTM2]) of SRTM, all using gray matter cerebellum as the reference region, were applied to generate nondisplaceable binding potential (BPND) images. RESULTS Plasma-input Logan analysis (r2 = 0.99; slope, 0.88) and spectral analysis (r2 = 0.99, slope, 0.93) generated estimates of VT that correlated well with values obtained using nonlinear regression. BPND values generated using SRTM2 (r2 = 0.83; slope, 0.95) and reference Logan analysis (r2 = 0.88; slope, 1.01) correlated well with nonlinear regression-based estimates. CONCLUSION Both Logan analysis and spectral analysis can be used to obtain quantitatively accurate VT images of 18F-DPA-714. In addition, SRTM2 and reference Logan analysis can provide accurate BPND images. These parametric images could be used for voxel-based comparisons.
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van der Doef TF, Golla SSV, Klein PJ, Oropeza-Seguias GM, Schuit RC, Metaxas A, Jobse E, Schwarte LA, Windhorst AD, Lammertsma AA, van Berckel BNM, Boellaard R. Quantification of the novel N-methyl-d-aspartate receptor ligand [11C]GMOM in man. J Cereb Blood Flow Metab 2016; 36:1111-21. [PMID: 26661185 PMCID: PMC4904354 DOI: 10.1177/0271678x15608391] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 06/26/2015] [Indexed: 11/17/2022]
Abstract
[(11)C]GMOM (carbon-11 labeled N-(2-chloro-5-thiomethylphenyl)-N'-(3-[(11)C]methoxy-phenyl)-N'-methylguanidine) is a PET ligand that binds to the N-methyl-d-aspartate receptor with high specificity and affinity. The purpose of this first in human study was to evaluate kinetics of [(11)C]GMOM in the healthy human brain and to identify the optimal pharmacokinetic model for quantifying these kinetics, both before and after a pharmacological dose of S-ketamine. Dynamic 90 min [(11)C]GMOM PET scans were obtained from 10 subjects. In six of the 10 subjects, a second PET scan was performed following an S-ketamine challenge. Metabolite corrected plasma input functions were obtained for all scans. Regional time activity curves were fitted to various single- and two-tissue compartment models. Best fits were obtained using a two-tissue irreversible model with blood volume parameter. The highest net influx rate (Ki) of [(11)C]GMOM was observed in regions with high N-methyl-d-aspartate receptor density, such as hippocampus and thalamus. A significant reduction in the Ki was observed for the entire brain after administration of ketamine, suggesting specific binding to the N-methyl-d-aspartate receptors. This initial study suggests that the [(11)C]GMOM could be used for quantification of N-methyl-d-aspartate receptors.
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