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van der Thiel, M., Rodriguez, C., Giannakopoulos, P., Burke, M. X., Lebel, R. M., Gninenko, N., . . . Haller, S. (2018). Brain Perfusion Measurements Using Multidelay Arterial Spin-Labeling Are Systematically Biased by the Number of Delays.. American Journal of Neuroradiology, 39(8), 1432-1438
Open this publication in new window or tab >>Brain Perfusion Measurements Using Multidelay Arterial Spin-Labeling Are Systematically Biased by the Number of Delays.
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2018 (English)In: American Journal of Neuroradiology, ISSN 0195-6108, E-ISSN 1936-959X, Vol. 39, no 8, p. 1432-1438Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND PURPOSE: Multidelay arterial spin-labeling is a promising emerging method in clinical practice. The effect of imaging parameters in multidelay arterial spin-labeling on estimated cerebral blood flow measurements remains unknown. We directly compared 3-delay versus 7-delay sequences, assessing the difference in the estimated transit time and blood flow.

MATERIALS AND METHODS: This study included 87 cognitively healthy controls (78.7 ± 3.8 years of age; 49 women). We assessed delay and transit time-uncorrected and transit time-corrected CBF maps. Data analysis included voxelwise permutation-based between-sequence comparisons of 3-delay versus 7-delay, within-sequence comparison of transit time-uncorrected versus transit time-corrected maps, and average CBF calculations in regions that have been shown to differ.

RESULTS: The 7-delay sequence estimated a higher CBF value than the 3-delay for the transit time-uncorrected and transit time-corrected maps in regions corresponding to the watershed areas (transit time-uncorrected = 27.62 ± 12.23 versus 24.58 ± 11.70 mL/min/100 g, Cohen's d = 0.25; transit time-corrected = 33.48 ± 14.92 versus 30.16 ± 14.32 mL/min/100 g, Cohen's d = 0.23). In the peripheral regions of the brain, the estimated delay was found to be longer for the 3-delay sequence (1.52408 ± 0.25236 seconds versus 1.47755 ± 0.24242 seconds, Cohen's d = 0.19), while the inverse was found in the center of the brain (1.39388 ± 0.22056 seconds versus 1.42565 ± 0.21872 seconds, Cohen's d = 0.14). Moreover, 7-delay had lower hemispheric asymmetry.

CONCLUSIONS: The results of this study support the necessity of standardizing acquisition parameters in multidelay arterial spin-labeling and identifying basic parameters as a confounding factor in CBF quantification studies. Our findings conclude that multidelay arterial spin-labeling sequences with a high number of delays estimate higher CBF values than those with a lower number of delays.

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-357433 (URN)10.3174/ajnr.A5717 (DOI)29976831 (PubMedID)
Available from: 2018-08-16 Created: 2018-08-16 Last updated: 2018-11-08Bibliographically approved
Haller, S., Vernooij, M. W., Kuijer, J. P., Larsson, E.-M., Jäger, H. R. & Barkhof, F. (2018). Cerebral Microbleeds: Imaging and Clinical Significance. Radiology, 287(1), 11-28
Open this publication in new window or tab >>Cerebral Microbleeds: Imaging and Clinical Significance
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2018 (English)In: Radiology, ISSN 0033-8419, E-ISSN 1527-1315, Vol. 287, no 1, p. 11-28Article, review/survey (Refereed) Published
Abstract [en]

Cerebral microbleeds (CMBs), also referred to as microhemorrhages, appear on magnetic resonance (MR) images as hypointense foci notably at T2*-weighted or susceptibility-weighted (SW) imaging. CMBs are detected with increasing frequency because of the more widespread use of high magnetic field strength and of newer dedicated MR imaging techniques such as three-dimensional gradient-echo T2*-weighted and SW imaging. The imaging appearance of CMBs is mainly because of changes in local magnetic susceptibility and reflects the pathologic iron accumulation, most often in perivascular macrophages, because of vasculopathy. CMBs are depicted with a true-positive rate of 48%–89% at 1.5 T or 3.0 T and T2*-weighted or SW imaging across a wide range of diseases. False-positive “mimics” of CMBs occur at a rate of 11%–24% and include microdissections, microaneurysms, and microcalcifications; the latter can be differentiated by using phase images. Compared with postmortem histopathologic analysis, at least half of CMBs are missed with premortem clinical MR imaging. In general, CMB detection rate increases with field strength, with the use of three-dimensional sequences, and with postprocessing methods that use local perturbations of the MR phase to enhance T2* contrast. Because of the more widespread availability of high-field-strength MR imaging systems and growing use of SW imaging, CMBs are increasingly recognized in normal aging, and are even more common in various disorders such as Alzheimer dementia, cerebral amyloid angiopathy, stroke, and trauma. Rare causes include endocarditis, cerebral autosomal dominant arteriopathy with subcortical infarcts, leukoencephalopathy, and radiation therapy. The presence of CMBs in patients with stroke is increasingly recognized as a marker of worse outcome. Finally, guidelines for adjustment of anticoagulant therapy in patients with CMBs are under development.

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-346992 (URN)10.1148/radiol.2018170803 (DOI)000427992600003 ()29558307 (PubMedID)
Available from: 2018-03-23 Created: 2018-03-23 Last updated: 2018-07-19Bibliographically approved
Haller, S., Montandon, M.-L., Rodriguez, C., Herrmann, F. R. & Giannakopoulos, P. (2018). Impact of Coffee, Wine, and Chocolate Consumption on Cognitive Outcome and MRI Parameters in Old Age.. Nutrients, 10(10), Article ID E1391.
Open this publication in new window or tab >>Impact of Coffee, Wine, and Chocolate Consumption on Cognitive Outcome and MRI Parameters in Old Age.
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2018 (English)In: Nutrients, ISSN 2072-6643, E-ISSN 2072-6643, Vol. 10, no 10, article id E1391Article in journal (Refereed) Published
Abstract [en]

Coffee, wine and chocolate are three frequently consumed substances with a significant impact on cognition. In order to define the structural and cerebral blood flow correlates of self-reported consumption of coffee, wine and chocolate in old age, we assessed cognition and brain MRI measures in 145 community-based elderly individuals with preserved cognition (69 to 86 years). Based on two neuropsychological assessments during a 3-year follow-up, individuals were classified into stable-stable (52 sCON), intermediate (61 iCON) and deteriorating-deteriorating (32 dCON). MR imaging included voxel-based morphometry (VBM), tract-based spatial statistics (TBSS) and arterial spin labelling (ASL). Concerning behavior, moderate consumption of caffeine was related to better cognitive outcome. In contrast, increased consumption of wine was related to an unfavorable cognitive evolution. Concerning MRI, we observed a negative correlation of wine and VBM in bilateral deep white matter (WM) regions across all individuals, indicating less WM lesions. Only in sCON individuals, we observed a similar yet weaker association with caffeine. Moreover, again only in sCON individuals, we observed a significant positive correlation between ASL and wine in overlapping left parietal WM indicating better baseline brain perfusion. In conclusion, the present observations demonstrate an inverse association of wine and coffee consumption with cognitive performances. Moreover, low consumption of wine but also moderate to heavy coffee drinking was associated with better WM preservation and cerebral blood-flow notably in cognitively stable elders.

Keywords
aging, caffeine, chocolate, cognition, wine
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-362620 (URN)10.3390/nu10101391 (DOI)30275380 (PubMedID)
Available from: 2018-10-08 Created: 2018-10-08 Last updated: 2018-11-28Bibliographically approved
Haller, S., Burke, M. & Mueller, T. L. (2018). MR skin signal loss effect/artifact. Neuroradiology, 60(6), 661-662
Open this publication in new window or tab >>MR skin signal loss effect/artifact
2018 (English)In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 60, no 6, p. 661-662Article in journal, Editorial material (Refereed) Published
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-349496 (URN)10.1007/s00234-018-2025-1 (DOI)000432292400010 ()29682697 (PubMedID)
Available from: 2018-04-27 Created: 2018-04-27 Last updated: 2018-08-28Bibliographically approved
Garibotto, V., Wissmeyer, M., Giavri, Z., Goldstein, R., Seimbille, Y., Seeck, M., . . . Picard, F. (2018). Nicotinic receptor abnormalities as a biomarker in idiopathic generalized epilepsy.. European Journal of Nuclear Medicine and Molecular Imaging
Open this publication in new window or tab >>Nicotinic receptor abnormalities as a biomarker in idiopathic generalized epilepsy.
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2018 (English)In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089Article in journal (Refereed) Epub ahead of print
Abstract [en]

PURPOSE: Mutations of cholinergic neuronal nicotinic receptors have been identified in the autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), associated with changes on PET images using [18F]-F-85380-A (F-A-85380), an α4β2 nicotinic receptor ligand. The aim of the present study was to evaluate potential changes in nicotinic receptor availability in other types of epilepsy.

METHODS: We included 34 male participants, 12 patients with idiopathic generalized epilepsy (IGE), 10 with non-lesional diurnal focal epilepsy, and 12 age-matched healthy controls. All patients underwent PET/CT using F-A-85380 and [18F]-fluorodeoxyglucose (FDG), 3D T1 MRI and diffusion tensor imaging (DTI). F-A-85380 and FDG images were compared with the control group using a voxel-wise (SPM12) and a volumes of interest (VOI) analysis.

RESULTS: In the group of patients with IGE, the voxel-wise and VOI analyses showed a significant increase of F-A-85380 ratio index of binding potential (BPRI, corresponding to the receptor availability) in the anterior cingulate cortex (ACC), without structural changes on MRI. At an individual level, F-A-85380 BPRI increase in the ACC could distinguish IGE patients from controls and from patients with focal epilepsy with good accuracy.

CONCLUSIONS: We observed focal changes of density/availability of nicotinic receptors in IGE, namely an increase in the ACC. These data suggest that the modulation of α4β2 nicotinic receptors plays a role not only in ADNFLE, but also in other genetic epileptic syndromes such as IGE and could serve as a biomarker of epilepsy syndromes with a genetic background.

Keywords
F-A-85380, Focal epilepsy, Idiopathic generalized epilepsy, Nicotinic receptors, PET
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-362194 (URN)10.1007/s00259-018-4175-0 (DOI)30269157 (PubMedID)
Available from: 2018-10-02 Created: 2018-10-02 Last updated: 2018-11-29Bibliographically approved
Georgiopoulos, C., Witt, S. T., Haller, S., Dizdar, N., Zachrisson, H., Engström, M. & Larsson, E.-M. (2018). Olfactory fMRI: implications of stimulation length and repetition time. Chemical Senses, 43(6), 389-398
Open this publication in new window or tab >>Olfactory fMRI: implications of stimulation length and repetition time
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2018 (English)In: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 43, no 6, p. 389-398Article in journal (Refereed) Published
Abstract [en]

Studying olfaction with functional Magnetic Resonance imaging (fMRI) poses various methodological challenges. This study aimed to investigate the effects of stimulation length and repetition time (TR) on the activation pattern of four olfactory brain regions: the anterior and the posterior piriform cortex, the orbitofrontal cortex and the insula. 22 healthy participants with normal olfaction were examined with fMRI, with two stimulation lengths (6 seconds and 15 seconds) and two TRs (0.901 seconds and 1.34 seconds). Data were analyzed using General Linear Model (GLM), Tensorial Independent Component Analysis (TICA) and by plotting the event related time course of brain activation in the four olfactory regions of interest. The statistical analysis of the time courses revealed that short TR was associated with more pronounced signal increase and short stimulation was associated with shorter time to peak signal. Additionally, both long stimulation and short TR were associated with oscillatory time courses, whereas both short stimulation and short TR resulted in more typical time courses. GLM analysis showed that the combination of short stimulation and short TR could result in visually larger activation within these olfactory areas. TICA validated that the tested paradigm was spatially and temporally associated with a functionally connected network that included all four olfactory regions. In conclusion, the combination of short stimulation and short TR is associated with higher signal increase and shorter time to peak, making it more amenable to standard GLM-type analyses than long stimulation and long TR, and it should, thus, be preferable for olfactory fMRI.

National Category
Radiology, Nuclear Medicine and Medical Imaging Neurosciences
Identifiers
urn:nbn:se:uu:diva-350749 (URN)10.1093/chemse/bjy025 (DOI)000438293600001 ()29726890 (PubMedID)
Funder
Region Östergötland
Available from: 2018-05-15 Created: 2018-05-15 Last updated: 2018-09-27Bibliographically approved
Haller, S. & Barkhof, F. (2018). Peri-hippocampal developmental venous anomalies and memory loss: more than a normal variant? [Letter to the editor]. Neuroradiology, 60(6), 579-582
Open this publication in new window or tab >>Peri-hippocampal developmental venous anomalies and memory loss: more than a normal variant?
2018 (English)In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 60, no 6, p. 579-582Article in journal, Letter (Refereed) Published
National Category
Radiology, Nuclear Medicine and Medical Imaging Neurology
Identifiers
urn:nbn:se:uu:diva-350040 (URN)10.1007/s00234-018-2026-0 (DOI)000432292400001 ()29700565 (PubMedID)
Available from: 2018-05-03 Created: 2018-05-03 Last updated: 2018-08-28Bibliographically approved
Haller, S. (2018). Use of MR Imaging-defined Connectome to Predict the Recovery of Patients after Cardiac Arrest.. Radiology, 287(1), 256-257
Open this publication in new window or tab >>Use of MR Imaging-defined Connectome to Predict the Recovery of Patients after Cardiac Arrest.
2018 (English)In: Radiology, ISSN 0033-8419, E-ISSN 1527-1315, Vol. 287, no 1, p. 256-257Article in journal (Refereed) Published
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-346991 (URN)10.1148/radiol.2017172372 (DOI)000427992600031 ()29558302 (PubMedID)
Available from: 2018-03-23 Created: 2018-03-23 Last updated: 2018-07-19Bibliographically approved
Emmert, K., Breimhorst, M., Bauermann, T., Birklein, F., Rebhorn, C., Van De Ville, D. & Haller, S. (2017). Active pain coping is associated with the response in real-time fMRI neurofeedback during pain. Brain Imaging and Behavior, 11(3), 712-721
Open this publication in new window or tab >>Active pain coping is associated with the response in real-time fMRI neurofeedback during pain
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2017 (English)In: Brain Imaging and Behavior, ISSN 1931-7557, E-ISSN 1931-7565, Vol. 11, no 3, p. 712-721Article in journal (Refereed) Published
Abstract [en]

Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback is used as a tool to gain voluntary control of activity in various brain regions. Little emphasis has been put on the influence of cognitive and personality traits on neurofeedback efficacy and baseline activity. Here, we assessed the effect of individual pain coping on rt-fMRI neurofeedback during heat-induced pain. Twenty-eight healthy subjects completed the Coping Strategies Questionnaire (CSQ) prior to scanning. The first part of the fMRI experiment identified target regions using painful heat stimulation. Then, subjects were asked to down-regulate the pain target brain region during four neurofeedback runs with painful heat stimulation. Functional MRI analysis included correlation analysis between fMRI activation and pain ratings as well as CSQ ratings. At the behavioral level, the active pain coping (first principal component of CSQ) was correlated with pain ratings during neurofeedback. Concerning neuroimaging, pain sensitive regions were negatively correlated with pain coping. During neurofeedback, the pain coping was positively correlated with activation in the anterior cingulate cortex, prefrontal cortex, hippocampus and visual cortex. Thermode temperature was negatively correlated with anterior insula and dorsolateral prefrontal cortex activation. In conclusion, self-reported pain coping mechanisms and pain sensitivity are a source of variance during rt-fMRI neurofeedback possibly explaining variations in regulation success. In particular, active coping seems to be associated with successful pain regulation.

Keywords
Real-time fMRI, Neurofeedback, fMRI, Pain, Pain coping, CSQ
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-312309 (URN)10.1007/s11682-016-9547-0 (DOI)000403676400010 ()27071949 (PubMedID)
Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-10-26Bibliographically approved
Haller, S. (2017). Advance MR imaging in sports-related concussion and mild traumatic brain injury: ready for clinical use? (Commentary on Tremblay et al. 2017). European Journal of Neuroscience, 46(4), 1954-1955
Open this publication in new window or tab >>Advance MR imaging in sports-related concussion and mild traumatic brain injury: ready for clinical use? (Commentary on Tremblay et al. 2017)
2017 (English)In: European Journal of Neuroscience, ISSN 0953-816X, E-ISSN 1460-9568, Vol. 46, no 4, p. 1954-1955Article in journal, Editorial material (Other academic) Published
National Category
Neurology
Identifiers
urn:nbn:se:uu:diva-336183 (URN)10.1111/ejn.13643 (DOI)000407639000002 ()28699247 (PubMedID)
Available from: 2017-12-12 Created: 2017-12-12 Last updated: 2018-03-13Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-7433-0203

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