Comparison of T2*-weighted and QSM contrasts in Parkinson's disease to visualize the STN with MRI

Alkemade, Anneke; Hollander, Gilles de; Keuken, Max C.; Schäfer, Andreas; Ott, Derek V. M.; Schwarz, Johannes; Weise, David; Kotz, Sonja A.; Forstmann, Birte U.

doi:10.1371/journal.pone.0176130

Cited by 61 publications

(66 citation statements)

References 46 publications

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“…In PSP, elevated free water diffusion, increased iron content using R2* relaxometry, and elevated tau tracer binding using PET were reported. In PD, the MRI results were discordant, showing no changes or a reduction in STN volume . It should be noted that these studies were performed at 3T, where the spatial resolution was not as high as that attained at 7T, with a higher risk of large partial volume effects.…”

Section: Discussionmentioning

confidence: 97%

Multimodal Magnetic Resonance Imaging Quantification of Brain Changes in Progressive Supranuclear Palsy

et al. 2019

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Background Progressive supranuclear palsy (PSP) is a neurodegenerative clinically heterogeneous disorder, formal diagnosis being based on postmortem histological brain examination. Objective We aimed to perform a precise in vivo staging of neurodegeneration in PSP using quantitative multimodal MRI. The ability of MRI biomarkers to differentiate PSP from PD was also evaluated. Methods Eleven PSP patients were compared to 26 age‐matched healthy controls and 51 PD patients. Images were acquired at 3 Tesla (three‐dimensional T1‐weighted, diffusion tensor, and neuromelanin‐sensitive images) and 7 Tesla (three‐dimensional‐T2* images). Regions of interest included the cortical areas, hippocampus, amygdala, basal ganglia, basal forebrain, brainstem nuclei, dentate nucleus, and cerebellum. Volumes, mean diffusivity, and fractional anisotropy were measured. In each region, a threshold value for group categorization was calculated, and four grades of change (0–3) were determined. Results PSP patients showed extensive volume decreases and diffusion changes in the midbrain, SN, STN, globus pallidus, basal forebrain, locus coeruleus, pedunculopontine nucleus, and dentate nucleus, in close agreement with the degrees of impairment in histological analyses. The predictive factors for the separation of PSP and healthy controls were, in descending order, the neuromelanin‐based SN volume; midbrain fractional anisotropy; volumes of the midbrain, globus pallidus, and putamen; and fractional anisotropy in the locus coeruleus. The best predictors for separating PSP from PD were the neuromelanin‐based volume in the SN, fractional anisotropy in the pons, volumes of the midbrain and globus pallidus, and fractional anisotropy in the basal forebrain. Conclusions These results suggest that it is possible to evaluate brain neurodegeneration in PSP noninvasively, even in small brainstem nuclei, in close agreement with previously published histological data. © 2019 International Parkinson and Movement Disorder Society

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Section: Discussionmentioning

confidence: 97%

Multimodal Magnetic Resonance Imaging Quantification of Brain Changes in Progressive Supranuclear Palsy

et al. 2019

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“…The CNR of QSM maps was determined in subject space, by creating an internal mask that completely covered each structure in set of ROIs B, together with an external (disjunct) mask containing the voxels just bordering the internal mask. 19 The CNR was then obtained as the difference between the mean signal of the internal mask (S I ) and external mask (S O ), divided by the standard deviation of the external mask (r O ):…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, the analysis was applied on the A set of ROIs, to QSM maps of every subject normalized to MNI space. The CNR of QSM maps was determined in subject space, by creating an internal mask that completely covered each structure in set of ROIs B , together with an external (disjunct) mask containing the voxels just bordering the internal mask . The CNR was then obtained as the difference between the mean signal of the internal mask ( S I ) and external mask ( S O ), divided by the standard deviation of the external mask ( σ O ):

C N R = \frac{S_{I} - S_{O}}{σ_{O}}

The weighted average of the CNR (

\bar{C N R}

) and relative weighted standard deviation (

σ_{\bar{C N R}}

) was then derived for every ROI across subjects, which considered as weights the number of voxels present in each subject's mask.…”

Section: Methodsmentioning

confidence: 99%

Quantitative susceptibility mapping across two clinical field strengths: Contrast‐to‐noise ratio enhancement at 1.5T

Ippoliti

Adams

Brenner

et al. 2018

Magnetic Resonance Imaging

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“…Group specific PD and elderly probabilistic atlases of the STN were obtained for the respective groups from [59] (Figure 2) (see https://www.nitrc.org/projects/atag_pd/ for probabilistic atlases and ATAG data) and were transformed from MNI152 1mm space to individual b0 space using a nonlinear transform and thresholded by 25%. The non-zero voxel volume in mm 3 for each atlas was as follows: PD left = 77; PD right = 70.13; HC left = 164.75; HC right = 138.38 and for the center of gravity (CoG) in MNI152 1mm space: PD left x = −10.44, y = −13.04, z = −8.16; PD right x = 11.84, y = −13.18, z = −89; HC left x = −10.56, y = −13.87, z = −7.10; HC right x = 12.10, y = −12.97, z = −6.20.…”

Section: Methodsmentioning

confidence: 99%

Cortico-basal white matter alterations occurring in Parkinson’s disease

Isaacs

Trutti

Pelzer

et al. 2019

Preprint

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32Magnetic resonance imaging studies typically use standard anatomical atlases for identification and 33 analyses of (patho-)physiological effects on specific brain areas; these atlases often fail to incorporate 34 neuroanatomical alterations that may occur with both age and disease. The present study utilizes Parkinson's 35 disease and age-specific anatomical atlases of the subthalamic nucleus for diffusion tractography, assessing tracts 36 that run between the subthalamic nucleus and a-priori defined cortical areas known to be affected by Parkinson's 37 disease. The results show that the strength of white matter fiber tracts appear to remain structurally unaffected by 38 disease. Contrary to that, Fractional Anisotropy values were shown to decrease in Parkinson's disease patients for 39 connections between the subthalamic nucleus and the pars opercularis of the inferior frontal gyrus, anterior 40 cingulate cortex, the dorsolateral prefrontal cortex and the pre-supplementary motor, collectively involved in 41 preparatory motor control, decision making and task monitoring. While the biological underpinnings of fractional 42 anisotropy alterations remain elusive, they may nonetheless be used as an index of Parkinson's disease. Moreover, 43 we find that failing to account for structural changes occurring in the subthalamic nucleus with age and disease 44 reduce the accuracy and influence the results of tractography, highlighting the importance of using appropriate 45 atlases for tractography. 46 47 Introduction 48The subthalamic nucleus (STN) is a small region located in the basal ganglia (BG) that is integral to a 49 range of motor behaviors and cognitive functions [1]. Abnormal activity of the STN is implicated in a number of 50 neurodegenerative and neurological disorders including Parkinson's disease (PD). Here, increased indirect 51 pathway activity is thought to increase the inhibition of motor plans rather than reducing inhibitory control [2]. 52 Accordingly, the STN is a common neurosurgical target for deep brain stimulation (DBS) for PD patients who no 53 longer appropriately respond to pharmacological interventions, where standard targeting is facilitated by the use 54 of MRI and stereotaxic atlases [3]. 55 56 However, these atlases are often based on a normal population and fail to account for neuroanatomical 57 variability occurring for a variety of reasons, including age and disease [4][5][6][7][8][9] It is widely acknowledged that the 58 anatomy of the STN varies substantially across healthy individuals, with in-vivo size estimates ranging from 3 59 50mm 3 to 270mm 3 (See [10] and references therein). Additionally, age-related changes associated with the STN 60 show the location in standard MNI space shifts in lateral direction in the elderly population [11][12][13][14] with additional 61 alterations of STN volume and location occurring PD [15]. 62 63 Moreover, the STN demonstrates a complex connectivity profile both within the BG and with the rest of 64 the cortex [16][17][18][19][20][21][22][23][24]...

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Comparison of T2*-weighted and QSM contrasts in Parkinson's disease to visualize the STN with MRI

Cited by 61 publications

References 46 publications

Multimodal Magnetic Resonance Imaging Quantification of Brain Changes in Progressive Supranuclear Palsy

Multimodal Magnetic Resonance Imaging Quantification of Brain Changes in Progressive Supranuclear Palsy

Quantitative susceptibility mapping across two clinical field strengths: Contrast‐to‐noise ratio enhancement at 1.5T

Cortico-basal white matter alterations occurring in Parkinson’s disease

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