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| 43. |
- Cavallin, L, et al.
(författare)
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Can dynamic susceptibility contrast magnetic resonance imaging replace single-photon emission computed tomography in the diagnosis of patients with Alzheimer's disease? A pilot study
- 2006
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 47:9, s. 977-985
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer's disease (AD). Material and Methods: Twenty-four patients, eight with AD, 10 with MCI, and six controls were investigated with SPECT using 99mTc-hexamethylpropyleneamine oxime (HMPAO) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with gadobutrol. Three observers performed a visual interpretation of the SPECT and MR images using a four-point visual scale. Results: SPECT was superior to DSC-MRI in differentiating normal from pathological. All three observers showed statistically significant results in discriminating between the control group, AD, and MCI by SPECT, with a P value of 0.0006, 0.04, and 0.01 for each observer. The statistical results were not significant for MR ( P values 0.8, 0.1, and 0.2, respectively). Conclusion: DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer's disease. Several patient- and method-related improvements should be made before this method can be recommended for clinical practice.
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| 44. |
- Cavallin, L, et al.
(författare)
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Overtime reliability of medial temporal lobe atrophy rating in a clinical setting
- 2012
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 53:3, s. 318-323
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Tidskriftsartikel (refereegranskat)abstract
- Medial temporal lobe atrophy (MTA) is one of the first magnetic resonance imaging (MRI) signs in patients with Alzheimer's disease (AD) and used as a measure of disease progression. Visual assessment of MTA is easy to perform but the reliability of MTA rating over time has not been studied. Purpose To investigate what happens to the MTA rating scores if two radiologists rate the same MRI scans six times over a period of 1 year. Material and Methods One hundred outpatients were included in this study. All patients underwent MRI with a protocol and sequences used for geriatric patients, according to local clinical standards. One neuroradiologist and one general radiologist independently of each other performed retrospective visual assessments of MTA six times, using the same scans, over a period of 1 year. Results Intra-rater kappa varied between κ 0.65 and 0.84 for the neuroradiologist and κ 0.38 and 0.74 for the general radiologist. Intra-rater weighted kappa (wκ) values showed almost perfect agreement for both investigators (wκ 0.83–0.94). Inter-rater reliability showed fair to moderate agreement, with the kappa value varying from κ 0.29 to 0.48 and weighted kappa values ranging from wκ 0.72 to 0.84. There was a statistically significant difference in rating between the two investigators. Conclusion Visual assessment of MTA repeated over time has a high grade of reproducibility when performed by an experienced investigator. The reproducibility drops when assessment is rarely performed. Inter-rater reliability is low when two investigators not working together are compared.
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| 45. |
- Cavallin, L, et al.
(författare)
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Voxel-based correlation between coregistered single-photon emission computed tomography and dynamic susceptibility contrast magnetic resonance imaging in subjects with suspected Alzheimer disease
- 2008
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 49:10, s. 1154-1161
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Tidskriftsartikel (refereegranskat)abstract
- Background: Current diagnosis of Alzheimer disease is made by clinical, neuropsychologic, and neuroimaging assessments. Neuroimaging techniques such as magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) could be valuable in the differential diagnosis of Alzheimer disease, as well as in assessing prognosis. Purpose: To compare SPECT and MRI in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer disease (AD). Material and Methods: 24 patients, eight with AD, 10 with MCI, and six controls, were investigated with SPECT using 99mTc-hexamethylpropyleneamine oxime (HMPAO, Ceretec; GE Healthcare Ltd., Little Chalsont UK) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a contrast-enhancing gadobutrol formula (Gadovist; Bayer Schering Pharma, Berlin, Germany). Voxel-based correlation between coregistered SPECT and DSC-MR images was calculated. Region-of-interest (ROI) analyses were then performed in 24 different brain areas using brain registration and analysis of SPECT studies (BRASS; Nuclear Diagnostics AB, Stockholm, Sweden) on both SPECT and DSC-MRI. Results: Voxel-based correlation between coregistered SPECT and DSC-MR showed a high correlation, with a mean correlation coefficient of 0.94. ROI analyses of 24 regions showed significant differences between the control group and AD patients in 10 regions using SPECT and five regions in DSC-MR. Conclusion: SPECT remains superior to DSC-MRI in differentiating normal from pathological perfusion, and DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer disease.
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| 46. |
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| 47. |
- Cedres, N, et al.
(författare)
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Brain Atrophy Subtypes and the ATN Classification Scheme in Alzheimer's Disease
- 2021
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Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 20:4, s. 153-164
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Introduction:</i></b> We investigated the association between atrophy subtypes of Alzheimer’s disease (AD), the ATN classification scheme, and key demographic and clinical factors in 2 cohorts with different source characteristics (a highly selective research-oriented cohort, the Alzheimer’s Disease Neuroimaging Initiative [ADNI]; and a naturalistic heterogeneous clinically oriented cohort, Karolinska Imaging Dementia Study [KIDS]). <b><i>Methods:</i></b> A total of 382 AD patients were included. Factorial analysis of mixed data was used to investigate associations between AD subtypes based on brain atrophy patterns, ATN profiles based on cerebrospinal fluid biomarkers, and age, sex, Mini Mental State Examination (MMSE), cerebrovascular disease (burden of white matter signal abnormalities, WMSAs), and <i>APOE</i> genotype. <b><i>Results:</i></b> Older patients with high WMSA burden, belonging to the typical AD subtype and showing A+T+N+ or A+T+N− profiles clustered together and were mainly from ADNI. Younger patients with low WMSA burden, limbic-predominant or minimal atrophy AD subtypes, and A+T−N− or A+T−N+ profiles clustered together and were mainly from KIDS. <i>APOE</i> ε4 carriers more frequently showed the A+T−N− and A+T+N− profiles. <b><i>Conclusions:</i></b> Our findings align with the recent framework for biological subtypes of AD: the combination of risk factors, protective factors, and brain pathologies determines belonging of AD patients to distinct subtypes.
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