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- Comley, Robert A., et al.
(författare)
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A Comparison of Gray Matter Density in Restless Legs Syndrome Patients and Matched Controls Using Voxel-Based Morphometry
- 2012
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Ingår i: Journal of Neuroimaging. - : WILEY-BLACKWELL. - 1051-2284 .- 1552-6569. ; 22:1, s. 28-32
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Restless legs syndrome (RLS) is a common neurological disorder the pathophysiology of which is incompletely understood. Four studies have examined structural differences between the brains of RLS patients and healthy controls, using voxel-based morphometry (VBM). All 4 studies have provided different results. METHODS Optimized VBM was used to search for structural differences in gray matter density. Sixteen RLS patients naive to dopaminergic drugs and 16 age-and sex-matched controls received structural T1-weighted MR scans. Structural data were analyzed using FSL-VBM. RESULTS No difference in gray matter density was detected between the two groups (voxel-wise significance: no significant voxels at P = .89 (whole brain Family Wise Error (FWE) corrected); no significant voxels at P < .05 (whole brain False Discovery Rate (FDR) corrected; smallest achievable FDR threshold .99). CONCLUSION/DISCUSSION The present study did not replicate (confirm) previous findings of structural brain changes in RLS, but instead supported the findings of a recent study showing a lack of gray matter alteration in an elderly RLS population. More specifically, the results do not support neuronal loss as an underlying disease mechanism in RLS. Potential limitations in the application of VBM are also discussed.
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- Fällmar, David, et al.
(författare)
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Visual Assessment of Brain Perfusion MRI Scans in Dementia : a Pilot Study
- 2016
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Ingår i: Journal of Neuroimaging. - : Wiley. - 1051-2284 .- 1552-6569. ; 26:3, s. 324-330
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data.METHODS: Ten patients with a clinical diagnosis of dementia and 11 age-matched cognitively healthy controls were examined with pseudo-continuous ASL (pCASL) and 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET). Three diagnostic physicians visually assessed the pCASL maps after subtraction only, and after postprocessing using Gaussian smoothing and GLM-based beta estimate functions. The assessment scores were compared to FDG PET values. Furthermore, the ability to discriminate patients from healthy elderly controls was assessed.RESULTS: Smoothing improved the correlation between visually assessed regional ASL perfusion scores and the FDG PET SUV-r values from the corresponding regions. However, subtracted pCASL maps discriminated patients from healthy controls better than smoothed maps. Smoothing increased the number of false-positive patient identifications. Application of beta estimate functions had only a marginal effect.CONCLUSION: Spatial smoothing of ASL images increased false positive results in the discrimination of hypoperfusion conditions from healthy elderly. It also decreased interreader agreement. However, regional characterization and subjective perception of image quality was improved.
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- Georgiopoulos, Charalampos, et al.
(författare)
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Quantitative brain stem assessment in discriminating neurodegenerative disorders from normal pressure hydrocephalus
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Ingår i: Journal of Neuroimaging. - 1051-2284.
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Differentiating idiopathic normal pressure hydrocephalus (iNPH) from neurodegenerative disorders such as progressive supranuclear palsy (PSP), Multiple System Atrophy—parkinsonian type (MSA-P), and vascular dementia (VaD) is challenging due to overlapping clinical and neuroimaging findings. This study assesses if quantitative brain stem and cerebellum metrics can aid in this differentiation. Methods: We retrospectively compared the sagittal midbrain area, midbrain to pons ratio, MR parkinsonism index (MRPI), and cerebellar atrophy in 30 PSP patients, 31 iNPH patients, 27 MSA-P patients, 32 VaD patients, and 25 healthy controls. Statistical analyses determined group differences, sensitivity, specificity, and the area under the receiver operating characteristic curves. Results: There was an overlap in midbrain morphology between PSP and iNPH, as assessed with MRPI, midbrain to pons ratio, and midbrain area. A cutoff value of MRPI > 13 exhibited 84% specificity in distinguishing PSP from iNPH and 100% in discriminating PSP from all other conditions. A cutoff value of midbrain to pons ratio at <0.15 yielded 95% specificity for differentiating PSP from iNPH and 100% from all other conditions. A cutoff value of midbrain area at <87 mm2 exhibited 97% specificity for differentiating PSP from iNPH and 100% from all other conditions. All measures showed low sensitivity. Cerebellar atrophy did not differ significantly among groups. Conclusion: Our study questions MRPI's diagnostic performance in distinguishing PSP from iNPH. Simpler indices such as midbrain to pons ratio and midbrain area showed similar or better accuracy. However, all these indices displayed low sensitivity despite significant differences among PSP, MSA-P, and VaD.
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- Haller, Sven, et al.
(författare)
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MRI of nigrosome-1 : A potential triage tool for patients with suspected parkinsonism
- 2022
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Ingår i: Journal of Neuroimaging. - : John Wiley & Sons. - 1051-2284 .- 1552-6569. ; 32:2, s. 273-278
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose Susceptibility-weighted imaging (SWI) of nigrosome-1 is an emerging and clinically applicable imaging marker for parkinsonism, which can be derived from routinely performed brain MRI. The purpose of the study was to assess whether SWI can be used as a triage tool for more efficient selection of subsequent Dopamine Transporter Scan (DaTSCAN) single-photon emission computed tomography (SPECT). Methods We examined 72 consecutive patients with suspected parkinsonism with both DaTSCAN SPECT and SWI (48 in Philips Ingenia, 24 in GE Signa). Additionally, we examined 24 healthy controls with SWI (14 in Philips Ingenia, 10 in GE Signa). Diagnostic performance of SWI and DaTSCAN SPECT was assessed on the basis of clinical diagnosis, in terms of sensitivity, specificity, and diagnostic accuracy. Results A total of 54 parkinsonism patients (69 years +/- 9, 32 men), 18 nonparkinsonism patients (69.4 years +/- 9, 10 men), and 24 healthy controls (62 years +/- 8, 10 men) were recruited. SWI had a specificity of 92% and a sensitivity of 74%, whereas DaTSCAN SPECT had 83% and 94%, respectively. By preselecting patients with abnormal or inconclusive SWI, the diagnostic performance of DaTSCAN SPECT improved (specificity 100%, sensitivity 95%). Scans from Philips were associated with significantly lower image quality compared to GE (p < .001). The experienced rater outperformed the less experienced one in diagnostic accuracy (82% vs. 68%). Conclusions SWI can be used as triage tool because normal SWI can in most cases rule out parkinsonism. However, the performance of SWI depends on acquisition parameters and rater's experience.
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