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Frantellizzi V, Pani A, Ricci M, Locuratolo N, Fattapposta F, De Vincentis G. Neuroimaging in Vascular Cognitive Impairment and Dementia: A Systematic Review. J Alzheimers Dis 2021; 73:1279-1294. [PMID: 31929166 DOI: 10.3233/jad-191046] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cerebrovascular diseases are well established causes of cognitive impairment. Different etiologic entities, such as vascular dementia (VaD), vascular cognitive impairment, subcortical (ischemic) VaD, and vascular cognitive disorder, are included in the umbrella definition of vascular cognitive impairment and dementia (VCID). Because of the variability of VCID clinical presentation, there is no agreement on criteria defining the neuropathological threshold of this disorder. In fact, VCID is characterized by cerebral hemodynamic alteration which ranges from decreased cerebral blood flow to small vessels disease and involves a multifactorial process that leads to demyelination and gliosis, including blood-brain barrier disruption, hypoxia, and hypoperfusion, oxidative stress, neuroinflammation and alteration on neurovascular unit coupling, cerebral microbleeds, or superficial siderosis. Numerous criteria for the definition of VaD have been described: the National Institute of Neurological Disorders and Stroke Association Internationale pour Recherche'-et-l'Enseignement en Neurosciences criteria, the State of California Alzheimer's Disease Diagnostic and Treatment Centers criteria, DSM-V criteria, the Diagnostic Criteria for Vascular Cognitive Disorders (a VASCOG Statement), and Vascular Impairment of Cognition Classification Consensus Study. Neuroimaging is fundamental for definition and diagnosis of VCID and should be used to assess the extent, location, and type of vascular lesions. MRI is the most sensible technique, especially if used according to standardized protocols, even if CT plays an important role in several conditions. Functional neuroimaging, in particular functional MRI and PET, may facilitate differential diagnosis among different forms of dementia. This systematic review aims to explore the state of the art and future perspective of non-invasive diagnostics of VCID.
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Affiliation(s)
| | - Arianna Pani
- Clinical Pharmacology and Toxicology, University of Milan "Statale", Italy
| | - Maria Ricci
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
| | | | | | - Giuseppe De Vincentis
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
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Viglianti BL, Wale DJ, Ma T, Johnson TD, Bohnen NI, Wong KK, Ky C, Frey KA, Townsend DM, Rubello D, Gross MD. Effects of plasma glucose levels on regional cerebral 18F-fluorodeoxyglucose uptake: Implications for dementia evaluation with brain PET imaging. Biomed Pharmacother 2019; 112:108628. [PMID: 30784923 PMCID: PMC6714976 DOI: 10.1016/j.biopha.2019.108628] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 11/19/2022] Open
Abstract
Purpose: Hyperglycemia affects FDG uptake in the brain, potentially emulating
Alzheimer’s disease in normal individuals. This study investigates
global and regional cerebral FDG uptake as a function of plasma glucose in a
cohort of patients. Methods: 120 consecutive male patients with FDG PET/CT for initial oncologic
staging (July-Dee 2015) were reviewed. Patients with dementia,
cerebrovascular accident, structural brain lesion, prior oncology treatment
or high metabolic tumor burden (recently shown affecting brain FDG uptake)
were excluded. 53 (24 nondiabetic) eligible patients (age 65.7 ± 2.8
mean ± SE) were analyzed with parametric computer software,
MIMneuro™. Regional Z-scores were evaluated as a function of plasma
glucose and age using multi variable linear mixed effects models with false
discovery analysis adjusting for multiple comparisons. If the regression
slope was significantly (p < 0.05) different than zero, hyperglycemia
effect was present. Results: There was a negative inverse relationship (p < 0.001) between
global brain FDG uptake and hyperglycemia. No regional hyperglycemia effect
on uptake were present when subjects were normalized using pons or
cerebellum. However, regional hyperglycemia effects were seen (p <
0.047–0.001) when normalizing by the whole brain. No obvious pattern
was seen in the regions affected. Age had a significant effect using whole
brain normalization (p < 0.04–0.01). Conclusions: Cortical variation in FDG uptake were identified when subjects were
hyperglycemic. However, these variations didn’t fit a particular
pattern of dementia and the severity of the affect is not likely to alter
clinical interpretation.
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Affiliation(s)
- Benjamin L Viglianti
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA.
| | - Daniel J Wale
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA
| | - Tianwen Ma
- Department of Biostatistics, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Timothy D Johnson
- Department of Biostatistics, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Nicolaas I Bohnen
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA
| | - Ka Kit Wong
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Christy Ky
- University of Michigan School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Kirk A Frey
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Danyelle M Townsend
- Department of Physiology, Division of New Drugs Development, University of Southern Carolina, USA
| | - Domenico Rubello
- Department of Nuclear Medicine, Santa Maria della Misericordia Hospital, Rovigo, Italy.
| | - Milton D Gross
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA
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Viglianti BL, Wong KK, Wimer SM, Parameswaran A, Nan B, Ky C, Townsend DM, Rubello D, Frey KA, Gross MD. Effect of hyperglycemia on brain and liver 18F-FDG standardized uptake value (FDG SUV) measured by quantitative positron emission tomography (PET) imaging. Biomed Pharmacother 2017; 88:1038-1045. [PMID: 28192877 DOI: 10.1016/j.biopha.2017.01.166] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 01/30/2017] [Accepted: 01/30/2017] [Indexed: 02/01/2023] Open
Abstract
PURPOSE Blood glucose is routinely measured prior to 18F-fluorodeoxyglucose (FDG) administration in positron emission tomography (PET) imaging to identify hyperglycemia that may affect image quality. In this study we explore the effects of blood glucose levels upon semi-quantitative standardized uptake value (SUV) measurements of target organs and tissues of interest and in particular address the relationship of blood glucose to FDG accumulation in the brain and liver. METHODS 436 FDG PET/CT consecutive studies performed for oncology staging in 229 patients (226 male) at the Ann Arbor Veterans Administration Healthcare System were reviewed. All patients had blood glucose measured (112.4±34.1mg/dL) prior to injection of 466.2±51.8MBq (12.6±1.4mCi) of FDG. SUV measurements of brain, aortic arch blood-pool, liver, and spleen were obtained at 64.5±10.2min' post-injection. RESULTS We found a negative inverse relationship of brain SUV with increasing plasma glucose, levels for both absolute and normalized (either to blood-pool or liver) values. Higher blood glucose levels had a mild effect upon liver and blood-pool SUV. By contrast, spleen SUV was independent of blood glucose, but demonstrated the greatest variability (deviation on linear regression). In contrast to other tissues, liver and spleen SUV normalized to blood-pool SUV were not dependent upon blood glucose levels. CONCLUSION The effects of hyperglycemia upon FDG uptake in brain and liver, over a range of blood glucose values generally considered acceptable for clinical PET imaging, may have measurable effects on semi-quantitative image analysis.
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Affiliation(s)
- Benjamin L Viglianti
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA.
| | - Ka Kit Wong
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Stephanie M Wimer
- Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA
| | - Aishwarya Parameswaran
- Michigan Institute for Clinical and Health Research (MICHR), University of Michigan, Ann Arbor, MI, USA
| | - Bin Nan
- Department of Biostatistics, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Christy Ky
- University of Michigan School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Danyelle M Townsend
- Department of Drug Discovery and Pharmaceutical Sciences, Medical University of Southern Carolina, USA
| | - Domenico Rubello
- Department of Nuclear Medicine, Radiology, NeuroRadiology, Medical Physics, Clinical Laboratory, Microbiology, Pathology, Santa Maria della Misericordia Hospital, Rovigo, Italy.
| | - Kirk A Frey
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Milton D Gross
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Nuclear Medicine Service, Department of Veterans Affairs Healthcare System, Ann Arbor, MI, USA
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Amyloid imaging: Past, present and future perspectives. Ageing Res Rev 2016; 30:95-106. [PMID: 26827784 DOI: 10.1016/j.arr.2016.01.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 11/23/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterised by the gradual onset of dementia. The pathological hallmarks of the disease are Aβ amyloid plaques, and tau neurofibrillary tangles, along dendritic and synaptic loss and reactive gliosis. Functional and molecular neuroimaging techniques such as positron emission tomography (PET) using functional and molecular tracers, in conjuction with other Aβ and tau biomarkers in CSF, are proving valuable in the differential diagnosis of AD, as well as in establishing disease prognosis. With the advent of new therapeutic strategies, there has been an increasing application of these techniques for the determination of Aβ burden in vivo in the patient selection, evaluation of target engagement and assessment of the efficacy of therapeutic approaches aimed at reducing Aβ in the brain.
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Eisenmenger LB, Huo EJ, Hoffman JM, Minoshima S, Matesan MC, Lewis DH, Lopresti BJ, Mathis CA, Okonkwo DO, Mountz JM. Advances in PET Imaging of Degenerative, Cerebrovascular, and Traumatic Causes of Dementia. Semin Nucl Med 2016; 46:57-87. [DOI: 10.1053/j.semnuclmed.2015.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Abstract
Positron emission tomography (PET) is a minimally invasive imaging procedure with a wide range of clinical and research applications. PET allows for the three-dimensional mapping of administered positron-emitting radiopharmaceuticals such as (18)F-fluorodeoxyglucose (for imaging glucose metabolism). PET enables the study of biologic function in both health and disease, in contrast to magnetic resonance imaging (MRI) and computed tomography (CT), that are more suited to study a body's morphologic changes, although functional MRI can also be used to study certain brain functions by measuring blood flow changes during task performance. This chapter first provides an overview of the basic physics principles and instrumentation behind PET methodology, with an introduction to the merits of merging functional PET imaging with anatomic CT or MRI imaging. We then focus on clinical neurologic disorders, and reference research on relevant PET radiopharmaceuticals when applicable. We then provide an overview of PET scan interpretation and findings in several specific neurologic disorders such as dementias, epilepsy, movement disorders, infection, cerebrovascular disorders, and brain tumors.
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Affiliation(s)
- Katherine Lameka
- Department of Radiology, Tufts University, Boston and Department of Radiology, Baystate Medical Center, Springfield, MA, USA.
| | - Michael D Farwell
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA, USA
| | - Masanori Ichise
- Molecular Neuroimaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa, Inage, Chiba, Japan
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Brown RKJ, Bohnen NI, Wong KK, Minoshima S, Frey KA. Brain PET in Suspected Dementia: Patterns of Altered FDG Metabolism. Radiographics 2014; 34:684-701. [DOI: 10.1148/rg.343135065] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
The present review describes brain imaging technologies that can be used to assess the effects of nutritional interventions in human subjects. Specifically, we summarise the biological relevance of their outcome measures, practical use and feasibility, and recommended use in short- and long-term nutritional studies. The brain imaging technologies described consist of MRI, including diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI, as well as electroencephalography/magnetoencephalography, near-IR spectroscopy, positron emission tomography and single-photon emission computerised tomography. In nutritional interventions and across the lifespan, brain imaging can detect macro- and microstructural, functional, electrophysiological and metabolic changes linked to broader functional outcomes, such as cognition. Imaging markers can be considered as specific for one or several brain processes and as surrogate instrumental endpoints that may provide sensitive measures of short- and long-term effects. For the majority of imaging measures, little information is available regarding their correlation with functional endpoints in healthy subjects; therefore, imaging markers generally cannot replace clinical endpoints that reflect the overall capacity of the brain to behaviourally respond to specific situations and stimuli. The principal added value of brain imaging measures for human nutritional intervention studies is their ability to provide unique in vivo information on the working mechanism of an intervention in hypothesis-driven research. Selection of brain imaging techniques and target markers within a given technique should mainly depend on the hypothesis regarding the mechanism of action of the intervention, level (structural, metabolic or functional) and anticipated timescale of the intervention's effects, target population, availability and costs of the techniques.
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McClure RA, Chumbley CW, Reyzer ML, Wilson K, Caprioli RM, Gore JC, Pham W. Identification of promethazine as an amyloid-binding molecule using a fluorescence high-throughput assay and MALDI imaging mass spectrometry. Neuroimage Clin 2013; 2:620-9. [PMID: 24179813 PMCID: PMC3778261 DOI: 10.1016/j.nicl.2013.04.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 01/22/2023]
Abstract
The identification of amyloid-binding compounds is a crucial step in the development of imaging probes and therapeutics for the detection and cure of Alzheimer's disease. Unfortunately, the process typically lags during the translation from in vitro to in vivo studies due to the impenetrable nature of the blood brain barrier (BBB). Here, we integrate fluorescence assay with MALDI imaging mass spectrometry to screen known compounds and repurpose their properties to enable the second function of binding to amyloid plaques. Through this approach, we identified an antihistamine compound, promethazine, that can bind to amyloid plaques. Finally, we demonstrate that promethazine is retained in the amyloid-burdened brain compared to a normal brain and that its distribution within the brain corroborates with that of amyloid plaques.
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Affiliation(s)
- Richard A. McClure
- Institute of Imaging Science, Vanderbilt University, 1161, 21st Avenue South, Nashville, TN 37232, USA
- Department of Radiology and Radiological Sciences, Vanderbilt School of Medicine, USA
- Vanderbilt Brain Institute, USA
| | - Chad W. Chumbley
- Department of Chemistry, Vanderbilt University, USA
- Mass Spectrometry Research Center, Vanderbilt University, USA
| | - Michelle L. Reyzer
- Mass Spectrometry Research Center, Vanderbilt University, USA
- Department of Biochemistry, Vanderbilt University, USA
| | - Kevin Wilson
- Institute of Imaging Science, Vanderbilt University, 1161, 21st Avenue South, Nashville, TN 37232, USA
- Department of Radiology and Radiological Sciences, Vanderbilt School of Medicine, USA
| | - Richard M. Caprioli
- Department of Chemistry, Vanderbilt University, USA
- Mass Spectrometry Research Center, Vanderbilt University, USA
- Department of Biochemistry, Vanderbilt University, USA
- Vanderbilt Ingram Cancer Center, Vanderbilt University, USA
| | - John C. Gore
- Institute of Imaging Science, Vanderbilt University, 1161, 21st Avenue South, Nashville, TN 37232, USA
- Department of Radiology and Radiological Sciences, Vanderbilt School of Medicine, USA
- Vanderbilt Ingram Cancer Center, Vanderbilt University, USA
- Molecular Physiology and Biophysics, Vanderbilt University, USA
| | - Wellington Pham
- Institute of Imaging Science, Vanderbilt University, 1161, 21st Avenue South, Nashville, TN 37232, USA
- Department of Radiology and Radiological Sciences, Vanderbilt School of Medicine, USA
- Vanderbilt Ingram Cancer Center, Vanderbilt University, USA
- Vanderbilt Institute of Chemical Biology, USA
- Vanderbilt Brain Institute, USA
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Modzelewski R, Janvresse E, de la Rue T, Vera P. Comparison of heterogeneity quantification algorithms for brain SPECT perfusion images. EJNMMI Res 2012; 2:40. [PMID: 22818866 PMCID: PMC3508867 DOI: 10.1186/2191-219x-2-40] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 06/18/2012] [Indexed: 11/21/2022] Open
Abstract
Background Several algorithms from the literature were compared with the original random walk (RW) algorithm for brain perfusion heterogeneity quantification purposes. Algorithms are compared on a set of 210 brain single photon emission computed tomography (SPECT) simulations and 40 patient exams. Methods Five algorithms were tested on numerical phantoms. The numerical anthropomorphic Zubal head phantom was used to generate 42 (6 × 7) different brain SPECT simulations. Seven diffuse cortical heterogeneity levels were simulated with an adjustable Gaussian noise function and six focal perfusion defect levels with temporoparietal (TP) defects. The phantoms were successively projected and smoothed with Gaussian kernel with full width at half maximum (FWHM = 5 mm), and Poisson noise was added to the 64 projections. For each simulation, 5 Poisson noise realizations were performed yielding a total of 210 datasets. The SPECT images were reconstructed using filtered black projection (Hamming filter: α = 0.5). The five algorithms or measures tested were the following: the coefficient of variation, the entropy and local entropy, fractal dimension (FD) (box counting and Fourier power spectrum methods), the gray-level co-occurrence matrix (GLCM), and the new RW. The heterogeneity discrimination power was obtained with a linear regression for each algorithm. This regression line is a mean function of the measure of heterogeneity compared to the different diffuse heterogeneity and focal defect levels generated in the phantoms. A greater slope denotes a larger separation between the levels of diffuse heterogeneity. The five algorithms were computed using 40 99mTc-ethyl-cysteinate-dimer (ECD) SPECT images of patients referred for memory impairment. Scans were blindly ranked by two physicians according to the level of heterogeneity, and a consensus was obtained. The rankings obtained by the algorithms were compared with the physicians' consensus ranking. Results The GLCM method (slope = 58.5), the fractal dimension (35.9), and the RW method (31.6) can differentiate the different levels of diffuse heterogeneity. The GLCM contrast parameter method is not influenced by a focal defect contrary to the FD and RW methods. A significant correlation was found between the RW method and the physicians' classification (r = 0.86; F = 137; p < 0.0001). Conclusions The GLCM method can quantify the different levels of diffuse heterogeneity in brain-simulated SPECT images without an influence from the focal cortical defects. However, GLCM classification was not correlated with the physicians' classification (Rho = −0.099). The RW method was significantly correlated with the physicians' heterogeneity perception but is influenced by the existence of a focal defect.
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Affiliation(s)
- Romain Modzelewski
- Laboratoire d'Informatique, de Traitement de l'Information et des Systemes (EA-LITIS 4108), QUANT, I, F, (Quantification en Imagerie Fonctionnelle, Faculty of Medicine, Rouen University, Saint Etienne du Rouvray, 76801, France.
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Abstract
Dementia is a common illness with an incidence that is rising as the aged population increases. There are a number of neurodegenerative diseases that cause dementia, including Alzheimer's disease, dementia with Lewy bodies, and frontotemporal dementia, which is subdivided into the behavioral variant, the semantic variant, and nonfluent variant. Numerous other neurodegenerative illnesses have an associated dementia, including corticobasal degeneration, Creutzfeldt-Jakob disease, Huntington's disease, progressive supranuclear palsy, multiple system atrophy, Parkinson's disease dementia, and amyotrophic lateral sclerosis. Vascular dementia and AIDS dementia are secondary dementias. Diagnostic criteria have relied on a constellation of symptoms, but the definite diagnosis remains a pathologic one. As treatments become available and target specific molecular abnormalities, differentiating amongst the various primary dementias early on becomes essential. The role of imaging in dementia has traditionally been directed at ruling out treatable and reversible etiologies and not to use imaging to better understand the pathophysiology of the different dementias. Different brain imaging techniques allow the examination of the structure, biochemistry, metabolic state, and functional capacity of the brain. All of the major neurodegenerative disorders have relatively specific imaging findings that can be identified. New imaging techniques carry the hope of revolutionizing the diagnosis of neurodegenerative disease so as to obtain a complete molecular, structural, and metabolic characterization, which could be used to improve diagnosis and to stage each patient and follow disease progression and response to treatment. Structural and functional imaging modalities contribute to the diagnosis and understanding of the different dementias.
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Affiliation(s)
- Maria Carmela Tartaglia
- University of California, San Francisco Memory and Aging Center, San Francisco, California 94143, USA.
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Pagani M, Salmaso D, Rodriguez G, Nardo D, Nobili F. Principal component analysis in mild and moderate Alzheimer's disease--a novel approach to clinical diagnosis. Psychiatry Res 2009; 173:8-14. [PMID: 19443186 DOI: 10.1016/j.pscychresns.2008.07.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 07/11/2008] [Accepted: 07/11/2008] [Indexed: 11/30/2022]
Abstract
Principal component analysis (PCA) provides a method to explore functional brain connectivity. The aim of this study was to identify regional cerebral blood flow (rCBF) distribution differences between Alzheimer's disease (AD) patients and controls (CTR) by means of volume of interest (VOI) analysis and PCA. Thirty-seven CTR, 30 mild AD (mildAD) and 27 moderate AD (modAD) subjects were investigated using single photon emission computed tomography with (99m)Tc-hexamethylpropylene amine oxime. Analysis of covariance (ANCOVA), PCA, and discriminant analysis (DA) were performed on 54 VOIs. VOI analysis identified in both mildAD and modAD subjects a decreased rCBF in six regions. PCA in mildAD subjects identified four principal components (PCs) in which the correlated VOIs showed a decreased level of rCBF, including regions that are typically affected early in the disease. In five PCs, including parietal-temporal-limbic cortex, and hippocampus, a significantly lower rCBF in correlated VOIs was found in modAD subjects. DA significantly discriminated the groups. The percentage of subjects correctly classified was 95, 70, and 81 for CTR, mildAD and modAD groups, respectively. PCA highlighted, in mildAD and modAD, relationships not evident when brain regions are considered as independent of each other, and it was effective in discriminating groups. These findings may allow neurophysiological inferences to be drawn regarding brain functional connectivity in AD that might not be possible with univariate analysis.
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Affiliation(s)
- Marco Pagani
- Institute of Cognitive Sciences and Technologies, CNR, Rome & Padua, Italy.
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Comparison of Alzheimer’s disease with vascular dementia and non-dementia using specific voxel-based Z score maps. Ann Nucl Med 2009; 23:25-31. [DOI: 10.1007/s12149-008-0210-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 07/29/2008] [Indexed: 10/21/2022]
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Pupi A, Mosconi L, Nobili FM, Sorbi S. Toward the validation of functional neuroimaging as a potential biomarker for Alzheimer's disease: implications for drug development. Mol Imaging Biol 2008; 7:59-68. [PMID: 15912277 DOI: 10.1007/s11307-005-0953-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Despite investments carried out in the research since Alzheimer's disease (AD) was firstly defined as an isolated clinical entity, there is still a lack of appropriate cure and effective therapies to halt or slow the disease progression. While fundamental research has provided a better characterization of AD, much remains to be done for the development of new biological treatment strategies. It is now being debated whether functional neuroimaging (FNI) could help improve diagnostic accuracy and become a possible biomarker of AD. The primary purpose of this review was to determine whether data already published in the literature meet formal technology assessment standards for using regional cerebral blood flow (rCBF) or glucose metabolism (rCMRGlu) as a biomarker for AD. The secondary purpose was to identify any remaining gaps that might need to be systematically addressed before drug developers and regulators accept FNI as a biomarker for AD. The present paper reviews the literature regarding metabolic positron emission tomography (PET) and perfusion single photon emission computed tomography (SPECT) studies in AD. There is evidence that treatment with acetylcholinesterase inhibitors (AChEI) leads to changes in brain physiology within the brain regions critical to AD pathology, i.e. the temporal, parietal and frontal association cortex. However, a thorough analysis combining functional and neuropsychological data has not yet been attempted, and much research is needed to validate the role of FNI as a surrogate endpoint for AD clinical trials.
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Affiliation(s)
- Alberto Pupi
- Department of Clinical Pathophysiology, Nuclear Medicine Unit, University of Florence, Viale Morgagni 85, 50134, Florence, Italy.
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Development and validation of the random walk algorithm: application to the classification of diffuse heterogeneity in brain SPECT perfusion images. J Comput Assist Tomogr 2008; 32:651-9. [PMID: 18664857 DOI: 10.1097/rct.0b013e31814fae48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED Heterogeneity analysis has been studied for radiological imaging, but few methods have been developed for functional images. Diffuse heterogeneous perfusion frequently appears in brain single photon emission computed tomography (SPECT) images, but objective quantification is lacking. An automatic method, based on random walk (RW) theory, has been developed to quantify perfusion heterogeneity. We assess the robustness of our algorithm in differentiating levels of diffuse heterogeneity even when focal defects are present. METHODS Heterogeneity is quantified by counting R (percentage), the mean rate of visited pixels in a fixed number of steps of the stochastic RW process. The algorithm has been tested on the numerical anthropomorphic Zubal head phantom. Seven diffuse cortical heterogeneity levels were simulated with an adjustable Gaussian function and 6 temporoparietal focal defects simulating Alzheimer Disease, leading to 42 phantoms. Data were projected and smoothed (full width at half maximum, 5.5 mm), and Poisson noise was added to the 64 projections. The SPECT data were reconstructed using filtered backprojection (Hamming filter, 0.5 c/p). R values for different levels of perfusion defect and diffuse heterogeneity were evaluated on 3 parameters: the number of slices studied (20 vs 40), the use of Talairach normalization versus original space, and the use of a cortical mask within the Talairach space. For each parameter, regression lines for heterogeneity and temporoparietal defect quantification were analyzed by covariance statistics. R values were also evaluated on SPECT images performed on 25 subjects with suspected focal dementia and on 15 normal controls. Scans were blindly ranked by 2 experienced nuclear physicians according to the degree of diffuse heterogeneity. RESULTS Variability of R was smaller than 0.17% for repeated measurements. R was more particularly influenced by diffuse heterogeneity compared with focal perfusion defect. The Talairach normalization had a significant influence on the heterogeneity quantification. The number of slices visited by the RW and the cortical masking have a weak influence on the heterogeneity quantification but only for very low heterogeneity levels. The Spearman coefficient between physicians' consensus and RW automatic ranking is 0.85, in the same order of magnitude as the Spearman coefficient between the rankings of the 2 senior physicians (0.86). CONCLUSIONS Random walk is an original and objective method and is able to quantify heterogeneous brain perfusion, even in presence of cortical defects. This method is repeatable, robust, and mainly influenced by spatial normalization.
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Villemagne VL, Fodero-Tavoletti MT, Pike KE, Cappai R, Masters CL, Rowe CC. The ART of loss: Abeta imaging in the evaluation of Alzheimer's disease and other dementias. Mol Neurobiol 2008; 38:1-15. [PMID: 18690556 DOI: 10.1007/s12035-008-8019-y] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 03/28/2008] [Indexed: 01/15/2023]
Abstract
Molecular neuroimaging based on annihilation radiation tomographic (ART) techniques such as positron emission tomography (PET), in conjunction with related biomarkers in plasma and cerebrospinal fluid (CSF), are proving valuable in the early and differential diagnosis of Alzheimer's disease (AD). With the advent of new therapeutic strategies aimed at reducing beta-amyloid (Abeta) burden in the brain to potentially prevent or delay functional and irreversible cognitive loss, there is increased interest in developing agents that allow assessment of Abeta burden in vivo. Abeta burden as assessed by molecular imaging matches histopathological reports of Abeta plaque distribution in aging and dementia and appears more accurate than FDG for the diagnosis of AD. Abeta imaging is also a very powerful tool in the differential diagnosis of AD from fronto-temporal dementia (FTD). Although Abeta burden as assessed by PET does not correlate with measures of cognitive decline in AD, it does correlate with memory impairment and rate of memory decline in mild cognitive impairment (MCI) and healthy older subjects. Approximately 30% of asymptomatic controls present cortical (11)C-PiB retention. These observations suggest that Abeta deposition is not part of normal ageing, supporting the hypothesis that Abeta deposition occurs well before the onset of symptoms and is likely to represent preclinical AD. Further longitudinal observations are required to confirm this hypothesis and to better elucidate the role of Abeta deposition in the course of Alzheimer's disease.
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Affiliation(s)
- Victor L Villemagne
- Department of Nuclear Medicine, Centre for PET, Austin Health, 145 Studley Road, Heidelberg, Victoria 3084, Australia.
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18
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Principal component analysis of FDG PET in amnestic MCI. Eur J Nucl Med Mol Imaging 2008; 35:2191-202. [DOI: 10.1007/s00259-008-0869-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Accepted: 06/01/2008] [Indexed: 10/21/2022]
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Utilization of the 3-D Stereotaxic Atlas and Normal Database Analysis to Further Investigate HIV-Related Neurocognitive Impairment and Follow-up Response to Highly Active Antiretroviral Therapy. Clin Nucl Med 2008; 33:122-4. [DOI: 10.1097/rlu.0b013e31815ef7d4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Tatsch K. Imaging of the dopaminergic system in differential diagnosis of dementia. Eur J Nucl Med Mol Imaging 2008; 35 Suppl 1:S51-7. [DOI: 10.1007/s00259-007-0702-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Levy-Cooperman N, Lobaugh NJ, Caldwell C, Gao F, Black SE. Subcortical hyperintensities in Alzheimer's disease: no clear relationship with executive function and frontal perfusion on SPECT. Dement Geriatr Cogn Disord 2008; 24:380-8. [PMID: 17934273 DOI: 10.1159/000109570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/28/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS To investigate relationships between subcortical hyperintensities (SH), frontal perfusion and executive function (EF) in a sample of Alzheimer's disease (AD) patients with varying severities of SH. METHODS A sample of 63 AD patients underwent brain imaging with magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) scans. Severity of SH was assessed using a standardized visual rating scale on MRI. Patients were classified into severe (n=20), moderate (n=23) or no SH (n=20) groups. Four frontal SPECT regions of interest (anterior cingulate cortex, dorsolateral prefrontal cortex) and neuropsychological assessment of EF were analyzed. RESULTS Overall, no significant relationships were found between severity of SH and measures of SPECT perfusion or EF, except for one subsection of the Dementia Rating Scale, with severe SH scoring slightly worse than the other two groups. CONCLUSION These findings support previous studies which suggest minimal adverse effects of SH on brain function and cognition. Global severity of SH on MRI in AD was not associated with decline in frontal perfusion and only mildly related to a decline in a specific EF task. More accurate measures of SH volume, not just global severity of SH, may be necessary to capture such complex brain behavior relationships; if they do indeed exist.
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Affiliation(s)
- Naama Levy-Cooperman
- L.C. Campbell Cognitive Neurology Research Unit, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada.
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22
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Van Heertum RL, Ichise M. Brain. Clin Nucl Med 2007. [DOI: 10.1007/978-3-540-28026-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Villemagne VL, Ng S, Cappai R, Barnham KJ, Fodero-Tavoletti MT, Rowe CC, Masters CL. La lunga attesa: towards a molecular approach to neuroimaging and therapeutics in Alzheimer's disease. Neuroradiol J 2006; 19:453-74. [PMID: 24351248 DOI: 10.1177/197140090601900406] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2006] [Accepted: 04/08/2006] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterised by the gradual onset of dementia. The pathological hallmarks of the disease are Aβ amyloid plaques, neurofibrillary tangles (NFT), synaptic loss and reactive gliosis. Current diagnosis of AD is made by clinical, neuropsychologic, and neuroimaging assessments. Routine structural neuroimaging evaluation with computed tomography (CT) and magnetic resonance imaging (MRI) is based on non-specific features such as atrophy, a late feature in the progression of the disease, hence the crucial importance of developing new approaches for early and specific recognition at the prodromal stages of AD. Functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI), magnetic resonance spectroscopy (MRS), positron emission tomography (PET) and single photon emission computed tomography (SPECT), possibly in conjuction with other related Aβ biomarkers in plasma and CSF, could prove to be valuable in the differential diagnosis of AD, as well as in assessing prognosis. With the advent of new therapeutic strategies aimed at reducing the Aβ amyloid burden in the brain, there is increasing interest in the development of MRI contrast agents and PET and SPECT radioligands that will permit the assessment of Aβ amyloid burden in vivo. - ma dov'è / la lenta processione di stagioni / che fu un'alba infinita e senza strade, / dov'è la lunga attesa e qual è il nome / del vuoto che ci invade. - Eugenio Montale.
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Affiliation(s)
- V L Villemagne
- Department of Nuclear Medicine, Centre for PET, Austin Health; Heidelberg, VIC, Australia - Department of Pathology, The University of Melbourne; VIC, Australia. - The Mental Health Research Institute of Victoria, Parkville; VIC, Australia -
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Claassen JAHR, Jansen RWMM. Cholinergically Mediated Augmentation of Cerebral Perfusion in Alzheimer's Disease and Related Cognitive Disorders: The Cholinergic-Vascular Hypothesis. J Gerontol A Biol Sci Med Sci 2006; 61:267-71. [PMID: 16567376 DOI: 10.1093/gerona/61.3.267] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The treatment of Alzheimer's disease (AD) with cholinesterase inhibitors (ChEIs) is based on the cholinergic hypothesis. This hypothesis fails to account for the global nature of the clinical effects of ChEIs, for the replication of these effects in other dementias, and for the strong and unpredictable intraindividual variation in response to treatment. These findings may be better explained by the premise that ChEIs primarily act by augmenting cerebral perfusion: the cholinergic-vascular hypothesis. This article will review the evidence from preclinical and clinical investigations on the vascular role of the cholinergic neural system. The clinical relevance of this hypothesis is discussed with respect to its interactions with the vascular and amyloid hypotheses of AD. Implications for treatment are indicated. Finally, we propose that the role of the cholinergic system in neurovascular regulation and functional hyperemia elucidates how the cholinergic deficit in AD contributes to the clinical and pathological features of this disease.
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Affiliation(s)
- Jurgen A H R Claassen
- Department of Geriatric Medicine, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
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Ishii K, Kono AK, Sasaki H, Miyamoto N, Fukuda T, Sakamoto S, Mori E. Fully automatic diagnostic system for early- and late-onset mild Alzheimer’s disease using FDG PET and 3D-SSP. Eur J Nucl Med Mol Imaging 2006; 33:575-83. [PMID: 16470370 DOI: 10.1007/s00259-005-0015-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Accepted: 10/01/2005] [Indexed: 11/29/2022]
Abstract
PURPOSE The purpose of this study was to design a fully automatic computer-assisted diagnostic system for early- and late-onset mild Alzheimer's disease (AD). METHODS Glucose metabolic images were obtained from mild AD patients and normal controls using positron emission tomography (PET) and( 18)F-fluorodeoxyglucose (FDG). Two groups of 20 mild AD patients with different ages of onset were examined. A fully automatic diagnostic system using the statistical brain mapping method was established from the early-onset (EO) and late-onset (LO) groups, with mean ages of 59.1 and 70.9 years and mean MMSE scores of 23.3 and 22.8, respectively. Aged-matched normal subjects were used as controls. We compared the diagnostic performance of visual inspection of conventional axial FDG PET images by experts and beginners with that of our fully automatic diagnostic system in another 15 EO and 15 LO AD patients (mean age 58.4 and 71.7, mean MMSE 23.6 and 23.1, respectively) and 30 age-matched normal controls. A receiver operating characteristic (ROC) analysis was performed to compare data. RESULTS The diagnostic performance of the automatic diagnostic system was comparable with that of visual inspection by experts. The area under the ROC curve for the automatic diagnostic system was 0.967 for EO AD patients and 0.878 for LO AD patients. The mean area under the ROC curve for visual inspection by experts was 0.863 and 0.881 for the EO and LO AD patients, respectively. The mean area under the ROC curve for visual inspection by beginners was 0.828 and 0.717, respectively. CONCLUSION The fully automatic diagnostic system for EO and LO AD was able to perform at a similar diagnostic level to visual inspection of conventional axial images by experts.
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Affiliation(s)
- Kazunari Ishii
- Department of Radiology and Nuclear Medicine, Hyogo Brain and Heart Center, 520 Saisho-Ko, Himeji, Hyogo, 670-0981, Japan.
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Beuthien-Baumann B, Holthoff VA, Rudolf J. Functional imaging of vegetative state applying single photon emission tomography and positron emission tomography. Neuropsychol Rehabil 2006; 15:276-82. [PMID: 16350971 DOI: 10.1080/09602010443000290] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Nuclear medicine techniques, such as single photon emission tomography (SPECT) and positron emission tomography (PET) have been applied in patients in a vegetative state to investigate brain function in a non-invasive manner. Parameters investigated include glucose metabolism, perfusion at rest, variations of regional perfusion after stimulation, and benzodiazepine receptor density. Compared to controls, patients in a vegetative state show a substantial reduction of glucose metabolism and perfusion. While patients post-anoxia exhibit a rather homogenous cortical reduction of glucose metabolism, patients after head trauma often show severe cortical and sub-cortical reductions at the site of primary trauma. To distinguish reduced glucose metabolism due to neuronal inactivation from neuronal loss, flumazenil-PET, an indicator of benzodiazepine receptor density, could add valuable information on the extent of brain damage. Activation studies focus on the evaluation of residual brain network, looking for processing in secondary projection fields. So far the predictive strength concerning possible recovery for the individual patient is limited, and PET and SPECT are not routine procedures in the assessment of patients in a vegetative state.
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Staffen W, Schönauer U, Zauner H, Spindler I, Mair A, Iglseder B, Bernroider G, Ladurner G. Brain perfusion SPECT in patients with mild cognitive impairment and Alzheimer's disease: comparison of a semiquantitative and a visual evaluation. J Neural Transm (Vienna) 2005; 113:195-203. [PMID: 15959843 DOI: 10.1007/s00702-005-0321-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Accepted: 04/17/2005] [Indexed: 11/30/2022]
Abstract
Due to the increasing importance of early recognition and differential diagnosis of dementias, cerebral perfusion scans using "single photon emission computed tomography" (SPECT) are increasingly integrated into the examination routine. The goal of this study was to check the diagnostic validity of SPECT scans of MCI- and DAT-patients, two subgroups out of 369 persons with etiologically unclear cognitive dysfunction, which underwent an assessment program for probable dementia including cognitive testing, cranial computed tomography, ultrasound, routine laboratory testing including vascular risk factors. After exclusion of patients with no or other forms of dementia we analyzed SPECT data of patients with mild cognitive impairment (MCI; n = 85) and dementia of the Alzheimer type (DAT; n = 78) in comparison with a healthy control group (n = 34).Visual assessment as well as a manual "regions of interest" (ROI) regionalization of the cortex were performed, whereby a ROI/cerebellum ratio was calculated as a semi-quantitative value. Association cortex areas were assessed regarding frontal, temporal, and parietal lobes of both hemispheres. When comparing the ratios of patients with DAT and controls, we found a statistically significant reduction of the cerebral perfusion in all measured cortex areas (p < 0.001). The comparison of patients with MCI with the selected control group also established a statistically significant difference in the cerebral perfusion for the evaluated cortex areas with the exception of the left hemispheric frontal and parietal cortex.A considerable number of the MCI patients showed an MMSE-score within the normal range, but with regard to the perfusion in the right hemispheric association cortex these patients also could be distinguished unambiguously from controls. Sensitivity levels found by visual assessment were at least as high as those found by the ROI method (pathological assessment: visual 49.4% vs. ROI 47.1% for MCI; visual 75.6% vs. ROI 73.1% for DAT). High experienced visual assessment of cerebral perfusion scans using SPECT provides an useful additional tool in diagnosis of cognitive impairment. The used semiquantitative ROI-method is nearly equivalent and does not depend on the experience of the investigator.
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Affiliation(s)
- W Staffen
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus University, Salzburg, Austria.
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Alavi A, Lakhani P, Mavi A, Kung JW, Zhuang H. PET: a revolution in medical imaging. Radiol Clin North Am 2004; 42:983-1001, vii. [PMID: 15488553 DOI: 10.1016/j.rcl.2004.08.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
FDG-PET has had remarkable influence on the assessment of physiologic and pathologic states. The authors predict that FDG-PET imaging could soon become the most common procedure used by nuclear medicine laboratories and could remain so for an extended period of time. The power of molecular imaging lies in the vast potential for using biochemical and pharmacologic probes to extend applications arising from an understanding of cell biology to a large number of well-characterized pathologic states. Molecular imaging based upon tracer kinetics with positron-emitting radiopharmaceuticals could become the main source of information for the management of cancer patients. In that case, nuclear medicine procedures might become the most common imaging studies performed in the practice of medicine. This speculation is not farfetched when one realizes the enormous change that a single biologically important compound, FDG, has brought to the medical arena. The major challenge today is to attract the highly qualified individuals and to secure the resources needed to harness the opportunities in the specialty of molecular imaging.
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Affiliation(s)
- Abass Alavi
- Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
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Alavi A, Kung JW, Zhuang H. Implications of PET based molecular imaging on the current and future practice of medicine. Semin Nucl Med 2004; 34:56-69. [PMID: 14735459 DOI: 10.1053/j.semnuclmed.2003.09.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The last quarter century has witnessed the introduction of a variety of powerful techniques that have allowed visualization of organ structure and function with exquisite detail. This in turn has brought about a true revolution in the day-to-day practice of medicine. Structural imaging with x-ray computerized tomography and magnetic resonance imaging has added tremendously to many areas of medicine, including preoperative evaluation of patients. Many surgical procedures have been replaced by minimally invasive techniques, which have become a reality only because of the availability of modern imaging modalities. However, despite such accomplishments, structural imaging is quite insensitive for detecting early disease in which there often are no gross structural alterations in organ anatomy. Therefore, these modalities should be complemented by methodologies that can detect abnormalities at the molecular and cellular levels. The introduction of [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) in 1976 as a molecular imaging technique clearly has shown the power of this approach for treating a multitude of serious disorders. The impact of FDG-PET has been particularly impressive in patients with cancer diagnosis, for whom it has become important in staging, monitoring response to treatment, and detecting recurrence. In this review, we emphasize the role of FDG-PET in the assessment of central nervous system maladies, malignant neoplastic processes, infectious and inflammatory diseases, and cardiovascular disorders. New radiotracers are being developed and promise to expand further the list of indications for PET. These include novel tracers for cancer diagnosis and treatment capable of detecting hypoxia and angiogenesis. Prospects for developing new tracers for imaging other organ diseases also appear very promising.
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Affiliation(s)
- Abass Alavi
- Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104, USA
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Abstract
Early detection of neurodegenerative disorders would provide clues to the underlying pathobiology of these diseases and would enable more effective diagnosis and treatment of patients. Recent advances in molecular neuroscience have begun to provide the tools to detect diseases like Alzheimer's disease, Parkinson's disease, and others early in their course and potentially even before the development of clinical manifestations of disease. These genetic, imaging, clinical, and biochemical tools are being validated in a number of studies. Early detection of these slowly progressive diseases offers the promise of presymptomatic diagnosis and, ultimately, of disease-modifying medications for use early in disease and during the presymptomatic period.
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Affiliation(s)
- Steven T DeKosky
- Department of Neurology and Alzheimer Disease Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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Current awareness in geriatric psychiatry. Int J Geriatr Psychiatry 2003; 18:661-8. [PMID: 12879898 DOI: 10.1002/gps.789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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