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Groeschel S, Hagberg GE, Schultz T, Balla DZ, Klose U, Hauser TK, Nägele T, Bieri O, Prasloski T, MacKay AL, Krägeloh-Mann I, Scheffler K. Assessing White Matter Microstructure in Brain Regions with Different Myelin Architecture Using MRI. PLoS One 2016; 11:e0167274. [PMID: 27898701 PMCID: PMC5127571 DOI: 10.1371/journal.pone.0167274] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 11/13/2016] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE We investigate how known differences in myelin architecture between regions along the cortico-spinal tract and frontal white matter (WM) in 19 healthy adolescents are reflected in several quantitative MRI parameters that have been proposed to non-invasively probe WM microstructure. In a clinically feasible scan time, both conventional imaging sequences as well as microstructural MRI parameters were assessed in order to quantitatively characterise WM regions that are known to differ in the thickness of their myelin sheaths, and in the presence of crossing or parallel fibre organisation. RESULTS We found that diffusion imaging, MR spectroscopy (MRS), myelin water fraction (MWF), Magnetization Transfer Imaging, and Quantitative Susceptibility Mapping were myelin-sensitive in different ways, giving complementary information for characterising WM microstructure with different underlying fibre architecture. From the diffusion parameters, neurite density (NODDI) was found to be more sensitive than fractional anisotropy (FA), underlining the limitation of FA in WM crossing fibre regions. In terms of sensitivity to different myelin content, we found that MWF, the mean diffusivity and chemical-shift imaging based MRS yielded the best discrimination between areas. CONCLUSION Multimodal assessment of WM microstructure was possible within clinically feasible scan times using a broad combination of quantitative microstructural MRI sequences. By assessing new microstructural WM parameters we were able to provide normative data and discuss their interpretation in regions with different myelin architecture, as well as their possible application as biomarker for WM disorders.
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Affiliation(s)
| | - Gisela E. Hagberg
- High Field Magnetic Resonance, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany
- Biomedical Magnetic Resonance, University Hospital Tübingen, Germany
| | - Thomas Schultz
- Institute of Computer Science, University of Bonn, Germany
| | - Dávid Z. Balla
- Department Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Uwe Klose
- Department of Diagnostic and Interventional Neuroradiology, University Hospital, Tübingen, Germany
| | - Till-Karsten Hauser
- Department of Diagnostic and Interventional Neuroradiology, University Hospital, Tübingen, Germany
| | - Thomas Nägele
- Department of Diagnostic and Interventional Neuroradiology, University Hospital, Tübingen, Germany
| | - Oliver Bieri
- Radiological Physics, University of Basel, Basel, Switzerland
| | | | | | | | - Klaus Scheffler
- High Field Magnetic Resonance, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany
- Biomedical Magnetic Resonance, University Hospital Tübingen, Germany
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102
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Local texture descriptors for the assessment of differences in diffusion magnetic resonance imaging of the brain. Int J Comput Assist Radiol Surg 2016; 12:389-398. [DOI: 10.1007/s11548-016-1505-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/11/2016] [Indexed: 10/20/2022]
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103
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Sapkota N, Yoon S, Thapa B, Lee Y, Bisson EF, Bowman BM, Miller SC, Shah LM, Rose JW, Jeong EK. Characterization of spinal cord white matter by suppressing signal from hindered space. A Monte Carlo simulation and an ex vivo ultrahigh-b diffusion-weighted imaging study. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 272:53-59. [PMID: 27635467 DOI: 10.1016/j.jmr.2016.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/24/2016] [Accepted: 09/02/2016] [Indexed: 06/06/2023]
Abstract
Signal measured from white matter in diffusion-weighted imaging is difficult to interpret because of the heterogeneous structure of white matter. Characterization of the white matter will be straightforward if the signal contributed from the hindered space is suppressed and purely restricted signal is analyzed. In this study, a Monte Carlo simulation (MCS) of water diffusion in white matter was performed to understand the behavior of the diffusion-weighted signal in white matter. The signal originating from the hindered space of an excised pig cervical spinal cord white matter was suppressed using the ultrahigh-b radial diffusion-weighted imaging. A light microscopy image of a section of white matter was obtained from the excised pig cervical spinal cord for the MCS. The radial diffusion-weighted signals originating from each of the intra-axonal, extra-axonal, and total spaces were studied using the MCS. The MCS predicted that the radial diffusion-weighted signal remains almost constant in the intra-axonal space and decreases gradually to about 2% of its initial value in the extra-axonal space when the b-value is increased to 30,000s/mm2. The MCS also revealed that the diffusion-weighted signal for a b-value greater than 20,000s/mm2 is mostly from the intra-axonal space. The decaying behavior of the signal-b curve obtained from ultrahigh-b diffusion-weighted imaging (bmax∼30,000s/mm2) of the excised pig cord was very similar to the decaying behavior of the total signal-b curve synthesized in the MCS. A mono-exponential plus constant fitting of the signal-b curve obtained from a white matter pixel estimated the values of constant fraction and apparent diffusion coefficient of decaying fraction as 0.32±0.05 and (0.16±0.01)×10-3mm2/s, respectively, which agreed well with the results of the MCS. The signal measured in the ultrahigh-b region (b>20,000s/mm2) is mostly from the restricted (intra-axonal) space. Integrity and intactness of the axons can be evaluated by assessing the remaining signal in the ultrahigh-b region.
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Affiliation(s)
- Nabraj Sapkota
- Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, USA; Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - Sook Yoon
- Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, USA
| | - Bijaya Thapa
- Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, USA; Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - YouJung Lee
- Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, USA; Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Erica F Bisson
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - Beth M Bowman
- Department of Radiobiology, University of Utah, Salt Lake City, UT, USA
| | - Scott C Miller
- Department of Radiobiology, University of Utah, Salt Lake City, UT, USA
| | - Lubdha M Shah
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - John W Rose
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Eun-Kee Jeong
- Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, USA; Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA.
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104
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Zhang Z, Zhang B, Li M, Liang X, Chen X, Liu R, Zhang X, Guo H. Multishot cartesian turbo spin-echo diffusion imaging using iterative POCSMUSE Reconstruction. J Magn Reson Imaging 2016; 46:167-174. [PMID: 27766699 DOI: 10.1002/jmri.25522] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 10/07/2016] [Indexed: 11/08/2022] Open
Affiliation(s)
- Zhe Zhang
- Center for Biomedical Imaging Research, Department of Biomedical Engineering; Tsinghua University; Beijing China
| | - Bing Zhang
- Department of Radiology; Affiliated Drum Tower Hospital of Nanjing University Medical School; Nanjing China
| | - Ming Li
- Department of Radiology; Affiliated Drum Tower Hospital of Nanjing University Medical School; Nanjing China
| | - Xue Liang
- Department of Radiology; Affiliated Drum Tower Hospital of Nanjing University Medical School; Nanjing China
| | - Xiaodong Chen
- Center for Biomedical Imaging Research, Department of Biomedical Engineering; Tsinghua University; Beijing China
- Department of Radiology; Affiliated Hospital of Guangdong Medical College; Guangdong China
| | - Renyuan Liu
- Department of Radiology; Affiliated Drum Tower Hospital of Nanjing University Medical School; Nanjing China
| | - Xin Zhang
- Department of Radiology; Affiliated Drum Tower Hospital of Nanjing University Medical School; Nanjing China
| | - Hua Guo
- Center for Biomedical Imaging Research, Department of Biomedical Engineering; Tsinghua University; Beijing China
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105
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Lee Masson H, Wallraven C, Petit L. "Can touch this": Cross-modal shape categorization performance is associated with microstructural characteristics of white matter association pathways. Hum Brain Mapp 2016; 38:842-854. [PMID: 27696592 DOI: 10.1002/hbm.23422] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 09/23/2016] [Accepted: 09/25/2016] [Indexed: 11/07/2022] Open
Abstract
Previous studies on visuo-haptic shape processing provide evidence that visually learned shape information can transfer to the haptic domain. In particular, recent neuroimaging studies have shown that visually learned novel objects that were haptically tested recruited parts of the ventral pathway from early visual cortex to the temporal lobe. Interestingly, in such tasks considerable individual variation in cross-modal transfer performance was observed. Here, we investigate whether this individual variation may be reflected in microstructural characteristics of white-matter (WM) pathways. We first trained participants on a fine-grained categorization task of novel shapes in the visual domain, followed by a haptic categorization test. We then correlated visual training-performance and haptic test-performance, as well as performance on a symbol-coding task requiring visuo-motor dexterity with microstructural properties of WM bundles potentially involved in visuo-haptic processing (the inferior longitudinal fasciculus [ILF], the fronto-temporal part of the superior longitudinal fasciculus [SLFft ] and the vertical occipital fasciculus [VOF]). Behavioral results showed that haptic categorization performance was good on average but exhibited large inter-individual variability. Haptic performance also was correlated with performance in the symbol-coding task. WM analyses showed that fast visual learners exhibited higher fractional anisotropy (FA) in left SLFft and left VOF. Importantly, haptic test-performance (and symbol-coding performance) correlated with FA in ILF and with axial diffusivity in SLFft . These findings provide clear evidence that individual variation in visuo-haptic performance can be linked to microstructural characteristics of WM pathways. Hum Brain Mapp 38:842-854, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Haemy Lee Masson
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 136-713, Korea
| | - Christian Wallraven
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 136-713, Korea
| | - Laurent Petit
- Groupe d'Imagerie Neurofonctionnelle, Institut Des Maladies Neurodégénératives - UMR 5293, CNRS, CEA University of Bordeaux, Bordeaux, France
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106
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Allen B, Muldoon MF, Gianaros PJ, Jennings JR. Higher Blood Pressure Partially Links Greater Adiposity to Reduced Brain White Matter Integrity. Am J Hypertens 2016; 29:1029-37. [PMID: 26970287 DOI: 10.1093/ajh/hpw026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/18/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Adiposity and elevated blood pressure (BP) are associated with brain structure abnormalities, but whether these effects are independent is unknown. We tested whether associations between adiposity and white matter integrity were explained by elevated BP. METHODS A sample of 209 middle-aged adults underwent diffusion tensor imaging to quantify indirect metrics of white matter structural integrity. These included putative markers of global white matter integrity (fractional anisotropy (FA)), axonal integrity (axial diffusivity), and myelin integrity (radial diffusivity). Participants were either normotensive or prehypertensive. RESULTS After adjusting for age and sex, regression analyses showed that waist circumference was associated with FA (β = -0.15, P < 0.05) and axial diffusivity (β = -0.24, P < 0.001), and mean arterial pressure (MAP) was associated with FA (β = -0.21, P < 0.05). Direct and indirect effect analyses showed that waist circumference was indirectly associated with whole brain FA through MAP (β = -0.06), and directly related to whole brain axial diffusivity, independent of MAP (β = -0.24). Examination of specific white matter tracts yielded similar results; waist circumference was indirectly related to FA through MAP and radial diffusivity, and directly related to axial diffusivity, independent of MAP. Supplemental analyses using body mass index, systolic BP, and diastolic BP also yielded similar results. CONCLUSION These findings suggest at least 2 mechanisms explain the adiposity and white matter association: one pathway through elevated BP impacting global white matter integrity and reducing integrity of the myelin sheath, and at least one other adiposity-specific pathway decreasing axonal integrity.
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Affiliation(s)
- Ben Allen
- University of Pittsburgh, Pittsburgh, Pennsylvania, USA. (
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107
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Brambilla L, Rossi Sebastiano D, Aquino D, Torri Clerici V, Brenna G, Moscatelli M, Frangiamore R, Giovannetti AM, Antozzi C, Mantegazza R, Franceschetti S, Bruzzone MG, Erbetta A, Confalonieri P. Early effect of dalfampridine in patients with MS: A multi-instrumental approach to better investigate responsiveness. J Neurol Sci 2016; 368:402-7. [PMID: 27538672 DOI: 10.1016/j.jns.2016.06.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 06/06/2016] [Accepted: 06/08/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND 4-aminopyridine (4-AP) is a potassium-channel blocker able to enhance walking speed in MS improving the action potentials of demyelinated axons on which internodal potassium channels are exposed. OBJECTIVE to study early 4-AP effect with clinical, subjective, neurophysiological and neuroradiological tools. METHODS Clinical (Timed 25-Foot Walk - T25FW, Timed Up-And-Go - TUG), subjective (MS Walking Scale-12 - MSWS-12), neurophysiological (Motor Evoked Potentials - MEPs) and imaging (Diffusion Tensor Imaging - DTI) evaluations were performed before (T0) and after (T1) 14days of 4-AP treatment. MEPs were recorded from Abductor Hallucis of both legs. A Tract-Based-Spatial-Statistics (TBSS) was performed on DTI. RESULTS We found a significant difference between T0 and T1 for T25FW, TUG, MSWS-12 (p≤0.001) in the whole patients' sample (23 subjects, median EDSS 6.0) and decrease of Central Motor Conduction Time and increase of mean Amplitude (Amp) at T1 (p=0.008 and p=0.006). We also recorded a significant difference of T25FW, TUG, MSWS-12 and Amp in clinical responder (CR) patients (CR: amelioration >20% at T25FW). TBSS showed a significant Mean and Radial Diffusivity reduction in the corticospinal tracts (p<0.05) of the whole group of patients; this reduction was also found in the CR subgroup. CONCLUSION Neurophysiological and neuroradiological parameters were modified in MS patients treated with 4-AP, and most of them reported a subjective improvement of their motor performances after treatment. The use of clinical, subjective, neurophysiological and neuroradiological tools could help to better explore MS patients responsiveness to 4-AP.
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Affiliation(s)
- L Brambilla
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy.
| | - D Rossi Sebastiano
- Department of Neurophysiology, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - D Aquino
- Department of Neuroradiology, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - V Torri Clerici
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - G Brenna
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - M Moscatelli
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy; University of Milan, Via Festa del Perdono 7, 20122 Milan, Italy
| | - R Frangiamore
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - A M Giovannetti
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - C Antozzi
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - R Mantegazza
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - S Franceschetti
- Department of Neurophysiology, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - M G Bruzzone
- Department of Neuroradiology, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - A Erbetta
- Department of Neuroradiology, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
| | - P Confalonieri
- Department of Neuroimmunology and Neuromuscular Diseases, Neurological Institute C. Besta IRCCS Foundation, Milan, Italy
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108
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Sapkota N, Shi X, Shah LM, Bisson EF, Rose JW, Jeong EK. Two-dimensional single-shot diffusion-weighted stimulated EPI with reduced FOV for ultrahigh-b radial diffusion-weighted imaging of spinal cord. Magn Reson Med 2016; 77:2167-2173. [DOI: 10.1002/mrm.26302] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 05/19/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Nabraj Sapkota
- Utah Center for Advanced Imaging Research; University of Utah; Salt Lake City Utah USA
- Department of Physics and Astronomy; University of Utah; Salt Lake City Utah USA
| | - Xianfeng Shi
- Department of Psychiatry; University of Utah; Salt Lake City Utah USA
| | - Lubdha M. Shah
- Department of Radiology and Imaging Sciences; University of Utah; Salt Lake City Utah USA
| | - Erica F. Bisson
- Department of Neurosurgery; University of Utah; Salt Lake City Utah USA
| | - John W. Rose
- Department of Neurology; University of Utah; Salt Lake City Utah USA
| | - Eun-Kee Jeong
- Utah Center for Advanced Imaging Research; University of Utah; Salt Lake City Utah USA
- Department of Radiology and Imaging Sciences; University of Utah; Salt Lake City Utah USA
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109
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Harkins KD, Does MD. Simulations on the influence of myelin water in diffusion-weighted imaging. Phys Med Biol 2016; 61:4729-45. [PMID: 27271991 DOI: 10.1088/0031-9155/61/13/4729] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
While myelinated axons present an important barrier to water diffusion, many models used to interpret DWI signal neglect other potential influences of myelin. In this work, Monte Carlo simulations were used to test the sensitivity of DWI results to the diffusive properties of water within myelin. Within these simulations, the apparent diffusion coefficient (D app) varied slowly over several orders of magnitude of the coefficient of myelin water diffusion (D m), but exhibited important differences compared to D app values simulated that neglect D m (=0). Compared to D app, the apparent diffusion kurtosis (K app) was generally more sensitive to D m. Simulations also tested the sensitivity of D app and K app to the amount of myelin present. Unique variations in D app and K app caused by differences in the myelin volume fraction were diminished when myelin water diffusion was included. Also, expected trends in D app and K app with experimental echo time were reduced or inverted when accounting for myelin water diffusion, and these reduced/inverted trends were seen experimentally in ex vivo rat brain DWI experiments. In general, myelin water has the potential to subtly influence DWI results and bias models of DWI that neglect these components of white matter.
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Affiliation(s)
- K D Harkins
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA. Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
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110
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Rathee R, Rallabandi VPS, Roy PK. Age-Related Differences in White Matter Integrity in Healthy Human Brain: Evidence from Structural MRI and Diffusion Tensor Imaging. MAGNETIC RESONANCE INSIGHTS 2016; 9:9-20. [PMID: 27279747 PMCID: PMC4898444 DOI: 10.4137/mri.s39666] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/19/2016] [Accepted: 04/26/2016] [Indexed: 12/12/2022]
Abstract
The aim is to investigate the relationship between microstructural white matter (WM) diffusivity indices and macrostructural WM volume (WMV) among healthy individuals (20–85 years). Whole-brain diffusion measures were calculated from diffusion tensor imaging using FMRIB software library while WMV was estimated through voxel-based morphometry, and voxel-based analysis was carried out using tract-based spatial statistics. Our results revealed that mean diffusivity, axial diffusivity, and radial diffusivity had shown good correlation with WMV but not for fractional anisotropy (FA). Voxel-wise tract-based spatial statistics analysis for FA showed a significant decrease in four regions for middle-aged group compared to young-aged group, in 22 regions for old-aged group compared to middle-aged group, and in 26 regions for old-aged group compared to young-aged group (P < 0.05). We found significantly lower WMV, FA, and mean diffusivity values in females than males and inverted-U trend for FA in males. We conclude differential age- and gender-related changes for structural WMV and WM diffusion indices.
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Affiliation(s)
- Rishu Rathee
- Computational Neuroscience and Neuroimaging Division, National Brain Research Center, Manesar, Gurgaon, Haryana, India
| | - V P Subramanyam Rallabandi
- Computational Neuroscience and Neuroimaging Division, National Brain Research Center, Manesar, Gurgaon, Haryana, India
| | - Prasun K Roy
- Computational Neuroscience and Neuroimaging Division, National Brain Research Center, Manesar, Gurgaon, Haryana, India
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111
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Sarkar S, Dell’Acqua F, Froudist Walsh S, Blackwood N, Scott S, Craig MC, Deeley Q, Murphy DGM. A Whole-Brain Investigation of White Matter Microstructure in Adolescents with Conduct Disorder. PLoS One 2016; 11:e0155475. [PMID: 27271503 PMCID: PMC4894575 DOI: 10.1371/journal.pone.0155475] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 04/29/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The biological basis of severe antisocial behaviour in adolescents is poorly understood. We recently reported that adolescents with conduct disorder (CD) have significantly increased fractional anisotropy (FA) of the uncinate fasciculus (a white matter (WM) tract that connects the amygdala to the frontal lobe) compared to their non-CD peers. However, the extent of WM abnormality in other brain regions is currently unclear. METHODS We used tract-based spatial statistics to investigate whole brain WM microstructural organisation in 27 adolescent males with CD, and 21 non-CD controls. We also examined relationships between FA and behavioural measures. Groups did not differ significantly in age, ethnicity, or substance use history. RESULTS The CD group, compared to controls, had clusters of significantly greater FA in 7 brain regions corresponding to: 1) the bilateral inferior and superior cerebellar peduncles, corticopontocerebellar tract, posterior limb of internal capsule, and corticospinal tract; 2) right superior longitudinal fasciculus; and 3) left cerebellar WM. Severity of antisocial behavior and callous-unemotional symptoms were significantly correlated with FA in several of these regions across the total sample, but not in the CD or control groups alone. CONCLUSIONS Adolescents with CD have significantly greater FA than controls in WM regions corresponding predominantly to the fronto-cerebellar circuit. There is preliminary evidence that variation in WM microstructure may be dimensionally related to behaviour problems in youngsters. These findings are consistent with the hypothesis that antisocial behaviour in some young people is associated with abnormalities in WM 'connectivity'.
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Affiliation(s)
- Sagari Sarkar
- King’s College London, Sackler Institute for Translational Neurodevelopment and the Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
- King’s College London, Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Flavio Dell’Acqua
- King’s College London, Sackler Institute for Translational Neurodevelopment and the Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
- King’s College London, Natbrainlab, Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Seán Froudist Walsh
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Nigel Blackwood
- King’s College London, Sackler Institute for Translational Neurodevelopment and the Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
- King’s College London, NIHR Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Stephen Scott
- King’s College London, Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Michael C. Craig
- King’s College London, Sackler Institute for Translational Neurodevelopment and the Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
- King’s College London, NIHR Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Quinton Deeley
- King’s College London, Sackler Institute for Translational Neurodevelopment and the Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
- King’s College London, NIHR Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Declan G. M. Murphy
- King’s College London, Sackler Institute for Translational Neurodevelopment and the Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
- King’s College London, NIHR Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
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112
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Samson RS, Lévy S, Schneider T, Smith AK, Smith SA, Cohen-Adad J, Gandini Wheeler-Kingshott CAM. ZOOM or Non-ZOOM? Assessing Spinal Cord Diffusion Tensor Imaging Protocols for Multi-Centre Studies. PLoS One 2016; 11:e0155557. [PMID: 27171194 PMCID: PMC4865165 DOI: 10.1371/journal.pone.0155557] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/29/2016] [Indexed: 12/02/2022] Open
Abstract
The purpose of this study was to develop and evaluate two spinal cord (SC) diffusion tensor imaging (DTI) protocols, implemented at multiple sites (using scanners from two different manufacturers), one available on any clinical scanner, and one using more advanced options currently available in the research setting, and to use an automated processing method for unbiased quantification. DTI parameters are sensitive to changes in the diseased SC. However, imaging the cord can be technically challenging due to various factors including its small size, patient-related and physiological motion, and field inhomogeneities. Rapid acquisition sequences such as Echo Planar Imaging (EPI) are desirable but may suffer from image distortions. We present a multi-centre comparison of two acquisition protocols implemented on scanners from two different vendors (Siemens and Philips), one using a reduced field-of-view (rFOV) EPI sequence, and one only using options available on standard clinical scanners such as outer volume suppression (OVS). Automatic analysis was performed with the Spinal Cord Toolbox for unbiased and reproducible quantification of DTI metrics in the white matter. Images acquired using the rFOV sequence appear less distorted than those acquired using OVS alone. SC DTI parameter values obtained using both sequences at all sites were consistent with previous measurements made at 3T. For the same scanner manufacturer, DTI parameter inter-site SDs were smaller for the rFOV sequence compared to the OVS sequence. The higher inter-site reproducibility (for the same manufacturer and acquisition details, i.e. ZOOM data acquired at the two Philips sites) of rFOV compared to the OVS sequence supports the idea that making research options such as rFOV more widely available would improve accuracy of measurements obtained in multi-centre clinical trials. Future multi-centre studies should also aim to match the rFOV technique and signal-to-noise ratios in all sequences from different manufacturers/sites in order to avoid any bias in measured DTI parameters and ensure similar sensitivity to pathological changes.
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Affiliation(s)
- Rebecca S. Samson
- NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom
- * E-mail:
| | - Simon Lévy
- Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada
- Functional Neuroimaging Unit, University of Montreal, Montreal, QC, Canada
| | - Torben Schneider
- NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom
- Philips Healthcare, Guilford, Surrey, United Kingdom
| | - Alex K. Smith
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Seth A. Smith
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Julien Cohen-Adad
- Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada
- Functional Neuroimaging Unit, University of Montreal, Montreal, QC, Canada
| | - Claudia A. M. Gandini Wheeler-Kingshott
- NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom
- Brain MRI 3T Center, C. Mondino National Neurological Institute, Pavia, Italy
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
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113
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Fu Y, Dong Y, Zhang C, Sun Y, Zhang S, Mu X, Wang H, Xu W, Wu S. Diffusion tensor imaging study in Duchenne muscular dystrophy. ANNALS OF TRANSLATIONAL MEDICINE 2016; 4:109. [PMID: 27127762 DOI: 10.21037/atm.2016.03.19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is a progressive muscle disorder associated with an intellectual deficit which is non-progressive. The aim of this study was to investigate brain microstructural changes in DMD and to explore the relationship between such changes and cognitive impairment. METHODS All participants (12 DMD patients, 14 age-matched healthy boys), intelligence quotients (IQs) [both full (FIQ) and verbal (VIQ)] were evaluated using the Wechsler intelligence scale for children China revised (WISC-CR) edition, and brain gray matter (GM) and white matter (WM) changes were mapped using diffusion tensor imaging (DTI) with fractional anisotropy (FA). The differences between groups were analyzed using the t-test and the association of cognition with neuroimaging parameters was evaluated using Pearson's correlation coefficient. RESULTS Compared to the normal controls, the DMD group had lower FIQ (82.0±15.39 vs. 120.21±16.06) and significantly lower splenium of corpus callosum (CC) FA values (P<0.05). Splenium of CC FA was positively correlated with VIQ (r=0.588, P=0.044). CONCLUSIONS There were microstructural changes of splenium of CC in DMD patients, which was associated with cognitive impairment.
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Affiliation(s)
- Ya Fu
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Yuru Dong
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Chao Zhang
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Yu Sun
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Shu Zhang
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Xuetao Mu
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Hong Wang
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Weihai Xu
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
| | - Shiwen Wu
- 1 Department of Neurology, 2 Department of MRI, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China ; 3 Department of Neurology, Peking Union Medical College Hospital and Chinese Academy of Medical Science, Beijing 100005, China
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114
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Su CH, Tsai CY, Chang AY, Chan JY, Chan SH. MRI/DTI of the Brain Stem Reveals Reversible and Irreversible Disruption of the Baroreflex Neural Circuits: Clinical Implications. Theranostics 2016; 6:837-48. [PMID: 27162554 PMCID: PMC4860892 DOI: 10.7150/thno.14837] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/06/2016] [Indexed: 01/29/2023] Open
Abstract
Baroreflex is the physiological mechanism for the maintenance of blood pressure and heart rate. Impairment of baroreflex is not a disease per se. However, depending on severity, the eventuality of baroreflex dysfunction varies from inconvenience in daily existence to curtailment of mobility to death. Despite universal acceptance, neuronal traffic within the contemporary neural circuits during the execution of baroreflex has never been visualized. By enhancing signal detection and fine-tuning the scanning parameters, we have successfully implemented tractographic analysis of the medulla oblongata in mice that allowed for visualization of connectivity between key brain stem nuclei in the baroreflex circuits. When viewed in conjunction with radiotelemetric analysis of the baroreflex, we found that under pathophysiological conditions when the disrupted connectivity between key nuclei in the baroreflex circuits was reversible, the associated disease condition (e.g. neurogenic hypertension) was amenable to remedial measures. Nevertheless, fatality ensues under pathological conditions (e.g. hepatic encephalopathy) when the connectivity between key substrates in the baroreflex circuits was irreversibly severed. MRI/DTI also prompted partial re-wiring of the contemporary circuit for baroreflex-mediated sympathetic vasomotor tone, and unearthed an explanation for the time lapse between brain death and the inevitable asystole signifying cardiac death that follows.
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Affiliation(s)
- Chia-Hao Su
- 1. Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, Republic of China
| | - Ching-Yi Tsai
- 1. Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, Republic of China
| | - Alice Y.W. Chang
- 2. Institute of Physiology, National Cheng Kung University, Tainan, Taiwan, Republic of China
| | - Julie Y.H. Chan
- 1. Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, Republic of China
| | - Samuel H.H. Chan
- 1. Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, Republic of China
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115
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Dhital B, Labadie C, Stallmach F, Möller HE, Turner R. Temperature dependence of water diffusion pools in brain white matter. Neuroimage 2016; 127:135-143. [DOI: 10.1016/j.neuroimage.2015.11.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 11/15/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022] Open
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116
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Yin Z, Kearney SP, Magin RL, Klatt D. Concurrent
3D
acquisition of diffusion tensor imaging and magnetic resonance elastography displacement data (
DTI‐MRE
): Theory and in vivo application. Magn Reson Med 2016; 77:273-284. [DOI: 10.1002/mrm.26121] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 12/15/2015] [Accepted: 12/17/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Ziying Yin
- Richard and Loan Hill Department of BioengineeringUniversity of Illinois at ChicagoChicago IL USA
| | - Steven P. Kearney
- Department of Mechanical and Industrial EngineeringUniversity of Illinois at ChicagoChicago IL USA
| | - Richard L. Magin
- Richard and Loan Hill Department of BioengineeringUniversity of Illinois at ChicagoChicago IL USA
| | - Dieter Klatt
- Richard and Loan Hill Department of BioengineeringUniversity of Illinois at ChicagoChicago IL USA
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117
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Landi A, Palmarini V, D’Elia A, Marotta N, Salvati M, Santoro A, Delfini R. Magnetic resonance diffusion tensor imaging and fiber-tracking diffusion tensor tractography in the management of spinal astrocytomas. World J Clin Cases 2016; 4:1-4. [PMID: 26798625 PMCID: PMC4714290 DOI: 10.12998/wjcc.v4.i1.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/05/2015] [Accepted: 12/02/2015] [Indexed: 02/05/2023] Open
Abstract
Some specially imaging of magnetic resonance imaging, the diffusion-weighted imaging (DWI), the diffusion tensor imaging and fractional anisotropy (FA), are useful to described, detect, and map the extent of spinal cord lesions. FA measurements may are used to predicting the outcome of patients who have spinal cord lesions. Fiber tracking enable to visualizing the integrity of white matter tracts surrounding some lesions, and this information could be used to formulating a differential diagnosis and planning biopsies or resection. In this article, we will describe the current uses for DWI and fiber tracking and speculate on others in which we believe these techniques will be useful in the future.
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118
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SUZUKI Y, HORI M, KAMIYA K, FUKUNAGA I, AOKI S, VAN CAUTEREN M. Estimation of the Mean Axon Diameter and Intra-axonal Space Volume Fraction of the Human Corpus Callosum: Diffusion q-space Imaging with Low q-values. Magn Reson Med Sci 2016; 15:83-93. [DOI: 10.2463/mrms.2014-0141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Yuriko SUZUKI
- Philips Electronics Japan, Ltd., Healthcare
- Department of Radiology, Graduate School of Medicine, Juntendo University
| | - Masaaki HORI
- Department of Radiology, Graduate School of Medicine, Juntendo University
| | - Kouhei KAMIYA
- Department of Radiology, Graduate School of Medicine, The University of Tokyo
| | - Issei FUKUNAGA
- Department of Radiology, Graduate School of Medicine, Juntendo University
| | - Shigeki AOKI
- Department of Radiology, Graduate School of Medicine, Juntendo University
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119
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Mueller L, Wetscherek A, Kuder TA, Laun FB. Eddy current compensated double diffusion encoded (DDE) MRI. Magn Reson Med 2015; 77:328-335. [PMID: 26715361 DOI: 10.1002/mrm.26092] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 11/06/2015] [Accepted: 11/24/2015] [Indexed: 11/07/2022]
Abstract
PURPOSE Eddy currents might lead to image distortions in diffusion-weighted echo planar imaging. A method is proposed to reduce their effects on double diffusion encoding (DDE) MRI experiments and the thereby derived microscopic fractional anisotropy (μFA). METHODS The twice-refocused spin echo scheme was adapted for DDE measurements. To assess the effect of individual diffusion encodings on the image distortions, measurements of a grid of plastic rods in water were performed. The effect of eddy current compensation on μFA measurements was evaluated in the brains of six healthy volunteers. RESULTS The use of an eddy current compensation reduced the signal variation. As expected, the distortions caused by the second encoding were larger than those of the first encoding, entailing a stronger need to compensate for them. For an optimal result, however, both encodings had to be compensated. The artifact reduction strongly improved the measurement of the μFA in ventricles and gray matter by reducing the overestimation. An effect of the compensation on absolute μFA values in white matter was not observed. CONCLUSION It is advisable to compensate both encodings in DDE measurements for eddy currents. Magn Reson Med 77:328-335, 2017. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Lars Mueller
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andreas Wetscherek
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Tristan Anselm Kuder
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frederik Bernd Laun
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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120
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Yang J, Poot DHJ, van Vliet LJ, Vos FM. Estimation of diffusion properties in three-way fiber crossings without overfitting. Phys Med Biol 2015; 60:9123-44. [PMID: 26562005 DOI: 10.1088/0031-9155/60/23/9123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Diffusion-weighted magnetic resonance imaging permits assessment of the structural integrity of the brain's white matter. This requires unbiased and precise quantification of diffusion properties. We aim to estimate such properties in simple and complex fiber geometries up to three-way fiber crossings using rank-2 tensor model selection. A maximum a-posteriori (MAP) estimator is employed to determine the parameters of a constrained triple tensor model. A prior is imposed on the parameters to avoid the degeneracy of the model estimation. This prior maximizes the divergence between the three tensor's principal orientations. A new model selection approach quantifies the extent to which the candidate models are appropriate, i.e. a single-, dual- or triple-tensor model. The model selection precludes overfitting to the data. It is based on the goodness of fit and information complexity measured by the total Kullback-Leibler divergence (ICOMP-TKLD). The proposed framework is compared to maximum likelihood estimation on phantom data of three-way fiber crossings. It is also compared to the ball-and-stick approach from the FMRIB Software Library (FSL) on experimental data. The spread in the estimated parameters reduces significantly due to the prior. The fractional anisotropy (FA) could be precisely estimated with MAP down to an angle of approximately 40° between the three fibers. Furthermore, volume fractions between 0.2 and 0.8 could be reliably estimated. The configurations inferred by our method corresponded to the anticipated neuro-anatomy both in single fibers and in three-way fiber crossings. The main difference with FSL was in single fiber regions. Here, ICOMP-TKLD predominantly inferred a single fiber configuration, as preferred, whereas FSL mostly selected dual or triple order ball-and-stick models. The prior of our MAP estimator enhances the precision of the parameter estimation, without introducing a bias. Additionally, our model selection effectively balances the trade-off between the goodness of fit and information complexity. The proposed framework can enhance the sensitivity of statistical analysis of diffusion tensor MRI.
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Affiliation(s)
- Jianfei Yang
- Quantitative Imaging Group, Department of Imaging Physics, Delft University of Technology, The Netherlands. Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands
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121
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Abdelsalam EM, Ashamallah GA, Lateef MA, Fathy K. Proton MR Spectroscopy in leukodystrophies. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2015. [DOI: 10.1016/j.ejrnm.2015.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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122
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Occupation and the risk of chronic toxic leukoencephalopathy. HANDBOOK OF CLINICAL NEUROLOGY 2015; 131:73-91. [PMID: 26563784 DOI: 10.1016/b978-0-444-62627-1.00006-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Among the hundreds of environmental insults capable of inducing nervous system injury, a small number can produce clinically significant damage to the brain white matter. The use of magnetic resonance imaging (MRI) in affected individuals has greatly illuminated this previously obscure area of neurotoxicology. Toxic leukoencephalopathy has acute and chronic forms, in both of which cognitive dysfunction is the major clinical manifestation. Chronic toxic leukoencephalopathy (CTL) has been most thoroughly described in individuals with intense and prolonged exposure to leukotoxins, but the consequences of lesser degrees of exposure are not well understood. Rare cases of CTL have been reported in workers exposed to culpable leukotoxins, but study of this syndrome is hindered by many confounds such as uncertain level of toxin exposure, the presence of multiple toxins, vague dose-response relationship, comorbid medical or neurologic disorders, psychiatric illness, and legal issues. The risk of CTL in workers is low, although it is not possible to determine quantitative risk estimates. More knowledge can be expected with the application of advanced MRI techniques to the assessment of workers who may have been exposed to known or potential leukotoxins. Preventive measures for avoiding workplace CTL will be informed by clinical assessment involving the use of advanced neuroimaging and neuropsychologic evaluation in combination with accurate measurement of leukotoxin exposure.
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123
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Guglielmetti C, Veraart J, Roelant E, Mai Z, Daans J, Van Audekerke J, Naeyaert M, Vanhoutte G, Delgado Y Palacios R, Praet J, Fieremans E, Ponsaerts P, Sijbers J, Van der Linden A, Verhoye M. Diffusion kurtosis imaging probes cortical alterations and white matter pathology following cuprizone induced demyelination and spontaneous remyelination. Neuroimage 2015; 125:363-377. [PMID: 26525654 DOI: 10.1016/j.neuroimage.2015.10.052] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 10/15/2015] [Accepted: 10/19/2015] [Indexed: 12/21/2022] Open
Abstract
Although MRI is the gold standard for the diagnosis and monitoring of multiple sclerosis (MS), current conventional MRI techniques often fail to detect cortical alterations and provide little information about gliosis, axonal damage and myelin status of lesioned areas. Diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) provide sensitive and complementary measures of the neural tissue microstructure. Additionally, specific white matter tract integrity (WMTI) metrics modelling the diffusion in white matter were recently derived. In the current study we used the well-characterized cuprizone mouse model of central nervous system demyelination to assess the temporal evolution of diffusion tensor (DT), diffusion kurtosis tensor (DK) and WMTI-derived metrics following acute inflammatory demyelination and spontaneous remyelination. While DT-derived metrics were unable to detect cuprizone induced cortical alterations, the mean kurtosis (MK) and radial kurtosis (RK) were found decreased under cuprizone administration, as compared to age-matched controls, in both the motor and somatosensory cortices. The MK remained decreased in the motor cortices at the end of the recovery period, reflecting long lasting impairment of myelination. In white matter, DT, DK and WMTI-derived metrics enabled the detection of cuprizone induced changes differentially according to the stage and the severity of the lesion. More specifically, the MK, the RK and the axonal water fraction (AWF) were the most sensitive for the detection of cuprizone induced changes in the genu of the corpus callosum, a region less affected by cuprizone administration. Additionally, microgliosis was associated with an increase of MK and RK during the acute inflammatory demyelination phase. In regions undergoing severe demyelination, namely the body and splenium of the corpus callosum, DT-derived metrics, notably the mean diffusion (MD) and radial diffusion (RD), were among the best discriminators between cuprizone and control groups, hence highlighting their ability to detect both acute and long lasting changes. Interestingly, WMTI-derived metrics showed the aptitude to distinguish between the different stages of the disease. Both the intra-axonal diffusivity (Da) and the AWF were found to be decreased in the cuprizone treated group, Da specifically decreased during the acute inflammatory demyelinating phase whereas the AWF decrease was associated to the spontaneous remyelination and the recovery period. Altogether our results demonstrate that DKI is sensitive to alterations of cortical areas and provides, along with WMTI metrics, information that is complementary to DT-derived metrics for the characterization of demyelination in both white and grey matter and subsequent inflammatory processes associated with a demyelinating event.
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Affiliation(s)
- C Guglielmetti
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - J Veraart
- iMinds - Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium; Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - E Roelant
- StatUa Center for Statistics, University of Antwerp, Antwerp, Belgium
| | - Z Mai
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - J Daans
- Experimental Cell Transplantation Group, Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | | | - M Naeyaert
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - G Vanhoutte
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | | | - J Praet
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - E Fieremans
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - P Ponsaerts
- Experimental Cell Transplantation Group, Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - J Sijbers
- iMinds - Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
| | | | - M Verhoye
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
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Colgan N, Siow B, O'Callaghan JM, Harrison IF, Wells JA, Holmes HE, Ismail O, Richardson S, Alexander DC, Collins EC, Fisher EM, Johnson R, Schwarz AJ, Ahmed Z, O'Neill MJ, Murray TK, Zhang H, Lythgoe MF. Application of neurite orientation dispersion and density imaging (NODDI) to a tau pathology model of Alzheimer's disease. Neuroimage 2015; 125:739-744. [PMID: 26505297 PMCID: PMC4692518 DOI: 10.1016/j.neuroimage.2015.10.043] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 09/30/2015] [Accepted: 10/17/2015] [Indexed: 11/21/2022] Open
Abstract
Increased hyperphosphorylated tau and the formation of intracellular neurofibrillary tangles are associated with the loss of neurons and cognitive decline in Alzheimer's disease, and related neurodegenerative conditions. We applied two diffusion models, diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI), to in vivo diffusion magnetic resonance images (dMRI) of a mouse model of human tauopathy (rTg4510) at 8.5 months of age. In grey matter regions with the highest degree of tau burden, microstructural indices provided by both NODDI and DTI discriminated the rTg4510 (TG) animals from wild type (WT) controls; however only the neurite density index (NDI) (the volume fraction that comprises axons or dendrites) from the NODDI model correlated with the histological measurements of the levels of hyperphosphorylated tau protein. Reductions in diffusion directionality were observed when implementing both models in the white matter region of the corpus callosum, with lower fractional anisotropy (DTI) and higher orientation dispersion (NODDI) observed in the TG animals. In comparison to DTI, histological measures of tau pathology were more closely correlated with NODDI parameters in this region. This in vivo dMRI study demonstrates that NODDI identifies potential tissue sources contributing to DTI indices and NODDI may provide greater specificity to pathology in Alzheimer's disease. We analyzed the microstructural changes in rTg4510 and wild type mice at 8.5 months. We correlated microstructural findings with histological measures of tau burden We compare two diffusion MR models: DTI and NODDI. Both models revealed changes in tissue microstructure due to tau pathology. The NODDI metrics demonstrated a good correlation with histological measures of tau burden.
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Affiliation(s)
- N Colgan
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK; Department of Medical Physics and Bioengineering, Saolta University Health Care Group, University Hospital Galway, Newcastle Road, Galway, H91 YR71, Ireland.
| | - B Siow
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK; Department of Computer Science & Centre for Medical Image Computing, University College London, UK
| | - J M O'Callaghan
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK
| | - I F Harrison
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK
| | - J A Wells
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK
| | - H E Holmes
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK
| | - O Ismail
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK
| | - S Richardson
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK; Department of Computer Science & Centre for Medical Image Computing, University College London, UK
| | - D C Alexander
- Department of Computer Science & Centre for Medical Image Computing, University College London, UK
| | - E C Collins
- Eli Lilly & Co. Ltd, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - E M Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square London, UK
| | - R Johnson
- Eli Lilly & Co. Ltd, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - A J Schwarz
- Eli Lilly & Co. Ltd, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Z Ahmed
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey GU20 6PH, UK
| | - M J O'Neill
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey GU20 6PH, UK
| | - T K Murray
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey GU20 6PH, UK
| | - H Zhang
- Department of Computer Science & Centre for Medical Image Computing, University College London, UK
| | - M F Lythgoe
- UCL Centre for Advanced Biomedical Imaging , Division of Medicine, University College London, UK
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125
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Barrio-Arranz G, de Luis-García R, Tristán-Vega A, Martín-Fernández M, Aja-Fernández S. Impact of MR Acquisition Parameters on DTI Scalar Indexes: A Tractography Based Approach. PLoS One 2015; 10:e0137905. [PMID: 26457415 PMCID: PMC4601730 DOI: 10.1371/journal.pone.0137905] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/23/2015] [Indexed: 11/19/2022] Open
Abstract
Acquisition parameters play a crucial role in Diffusion Tensor Imaging (DTI), as they have a major impact on the values of scalar measures such as Fractional Anisotropy (FA) or Mean Diffusivity (MD) that are usually the focus of clinical studies based on white matter analysis. This paper presents an analysis on the impact of the variation of several acquisition parameters on these scalar measures with a novel double focus. First, a tractography-based approach is employed, motivated by the significant number of clinical studies that are carried out using this technique. Second, the consequences of simultaneous changes in multiple parameters are analyzed: number of gradient directions, b-value and voxel resolution. Results indicate that the FA is most affected by changes in the number of gradients and voxel resolution, while MD is specially influenced by variations in the b-value. Even if the choice of a tractography algorithm has an effect on the numerical values of the final scalar measures, the evolution of these measures when acquisition parameters are modified is parallel.
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Affiliation(s)
- Gonzalo Barrio-Arranz
- Laboratorio de Procesado de Imagen, Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática/ETSI Telecomunicación, Universidad de Valladolid, Valladolid, España
| | - Rodrigo de Luis-García
- Laboratorio de Procesado de Imagen, Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática/ETSI Telecomunicación, Universidad de Valladolid, Valladolid, España
| | - Antonio Tristán-Vega
- Laboratorio de Procesado de Imagen, Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática/ETSI Telecomunicación, Universidad de Valladolid, Valladolid, España
| | - Marcos Martín-Fernández
- Laboratorio de Procesado de Imagen, Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática/ETSI Telecomunicación, Universidad de Valladolid, Valladolid, España
| | - Santiago Aja-Fernández
- Laboratorio de Procesado de Imagen, Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática/ETSI Telecomunicación, Universidad de Valladolid, Valladolid, España
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126
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Santis S, Assaf Y, Evans CJ, Jones DK. Improved precision in CHARMED assessment of white matter through sampling scheme optimization and model parsimony testing. Magn Reson Med 2015; 71:661-71. [PMID: 23475834 DOI: 10.1002/mrm.24717] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE The composite hindered and restricted model of diffusion provides microstructural indices that are potentially more specific than those from diffusion tensor imaging. However, in comparison to diffusion tensor imaging, the acquisition time is longer, limiting clinical applications. Moreover, the model requires several parameters to be estimated whose confidence intervals can be large. Here, the composite hindered and restricted model of diffusion acquisition and data processing pipelines are optimized to extend the utility of this approach. METHODS A multishell sampling scheme was optimized using the electrostatic repulsion algorithm, combined with optimal ordering. The optimal protocol, using as few measurements as possible, was determined through leave-n-out analyses. Parsimonious model selection criteria were used to select between nested models, comprising up to three restricted compartments. The schemes were evaluated using both through Monte-Carlo simulations and in vivo data. RESULTS The optimization/model selection procedure resulted in increased accuracy and precision on the estimated parameters, allowing for a reduction in acquisition time and marked improvements in data quality. The final protocol provided whole brain coverage data in only 12 min. CONCLUSION Through careful optimization of the acquisition and analysis pipeline for the composite hindered and restricted model of diffusion, it is possible to reduce acquisition time for whole brain datasets to a time that is clinically applicable.
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Affiliation(s)
- S Santis
- CUBRIC School of Psychology, Cardiff University, Cardiff, UK; Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, UK
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127
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Ho LC, Wang B, Conner IP, van der Merwe Y, Bilonick RA, Kim SG, Wu EX, Sigal IA, Wollstein G, Schuman JS, Chan KC. In Vivo Evaluation of White Matter Integrity and Anterograde Transport in Visual System After Excitotoxic Retinal Injury With Multimodal MRI and OCT. Invest Ophthalmol Vis Sci 2015; 56:3788-800. [PMID: 26066747 DOI: 10.1167/iovs.14-15552] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
PURPOSE Excitotoxicity has been linked to the pathogenesis of ocular diseases and injuries and may involve early degeneration of both anterior and posterior visual pathways. However, their spatiotemporal relationships remain unclear. We hypothesized that the effects of excitotoxic retinal injury (ERI) on the visual system can be revealed in vivo by diffusion tensor magnetic resonance imagining (DTI), manganese-enhanced magnetic resonance imagining (MRI), and optical coherence tomography (OCT). METHODS Diffusion tensor MRI was performed at 9.4 Tesla to monitor white matter integrity changes after unilateral N-methyl-D-aspartate (NMDA)-induced ERI in six Sprague-Dawley rats and six C57BL/6J mice. Additionally, four rats and four mice were intravitreally injected with saline to compare with NMDA-injected animals. Optical coherence tomography of the retina and manganese-enhanced MRI of anterograde transport were evaluated and correlated with DTI parameters. RESULTS In the rat optic nerve, the largest axial diffusivity decrease and radial diffusivity increase occurred within the first 3 and 7 days post ERI, respectively, suggestive of early axonal degeneration and delayed demyelination. The optic tract showed smaller directional diffusivity changes and weaker DTI correlations with retinal thickness compared with optic nerve, indicative of anterograde degeneration. The splenium of corpus callosum was also reorganized at 4 weeks post ERI. The DTI profiles appeared comparable between rat and mouse models. Furthermore, the NMDA-injured visual pathway showed reduced anterograde manganese transport, which correlated with diffusivity changes along but not perpendicular to optic nerve. CONCLUSIONS Diffusion tensor MRI, manganese-enhanced MRI, and OCT provided an in vivo model system for characterizing the spatiotemporal changes in white matter integrity, the eye-brain relationships and structural-physiological relationships in the visual system after ERI.
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Affiliation(s)
- Leon C Ho
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 2UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylva
| | - Bo Wang
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Bioengineering, Swanson School of Engineering, University
| | - Ian P Conner
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Bioengineering, Swanson School of Engineering, University
| | - Yolandi van der Merwe
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 2UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylva
| | - Richard A Bilonick
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Bioengineering, Swanson School of Engineering, University
| | - Seong-Gi Kim
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 6McGowan Institute for Regenerative
| | - Ed X Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Ian A Sigal
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Bioengineering, Swanson School of Engineering, University
| | - Gadi Wollstein
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 5Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pi
| | - Joel S Schuman
- UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Bioengineering, Swanson School of Engineering, University
| | - Kevin C Chan
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 2UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylva
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128
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Grossman EJ, Kirov II, Gonen O, Novikov DS, Davitz MS, Lui YW, Grossman RI, Inglese M, Fieremans E. N-acetyl-aspartate levels correlate with intra-axonal compartment parameters from diffusion MRI. Neuroimage 2015; 118:334-43. [PMID: 26037050 PMCID: PMC4651014 DOI: 10.1016/j.neuroimage.2015.05.061] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 04/19/2015] [Accepted: 05/22/2015] [Indexed: 11/27/2022] Open
Abstract
Diffusion MRI combined with biophysical modeling allows for the description of a white matter (WM) fiber bundle in terms of compartment specific white matter tract integrity (WMTI) metrics, which include intra-axonal diffusivity (Daxon), extra-axonal axial diffusivity (De||), extra-axonal radial diffusivity (De┴), axonal water fraction (AWF), and tortuosity (α) of extra-axonal space. Here we derive these parameters from diffusion kurtosis imaging to examine their relationship to concentrations of global WM N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho) and myo-Inositol (mI), as measured with proton MR spectroscopy ((1)H-MRS), in a cohort of 25 patients with mild traumatic brain injury (MTBI). We found statistically significant (p<0.05) positive correlations between NAA and Daxon, AWF, α, and fractional anisotropy; negative correlations between NAA and De,┴ and the overall radial diffusivity (D┴). These correlations were supported by similar findings in regional analysis of the genu and splenium of the corpus callosum. Furthermore, a positive correlation in global WM was noted between Daxon and Cr, as well as a positive correlation between De|| and Cho, and a positive trend between De|| and mI. The specific correlations between NAA, an endogenous probe of the neuronal intracellular space, and WMTI metrics related to the intra-axonal space, combined with the specific correlations of De|| with mI and Cho, both predominantly present extra-axonally, corroborate the overarching assumption of many advanced modeling approaches that diffusion imaging can disentangle between the intra- and extra-axonal compartments in WM fiber bundles. Our findings are also generally consistent with what is known about the pathophysiology of MTBI, which appears to involve both intra-axonal injury (as reflected by a positive trend between NAA and Daxon) as well as axonal shrinkage, demyelination, degeneration, and/or loss (as reflected by correlations between NAA and De┴, AWF, and α).
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Affiliation(s)
- Elan J Grossman
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Department of Physiology and Neuroscience, New York University School of Medicine, New York, NY, USA.
| | - Ivan I Kirov
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Oded Gonen
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Department of Physiology and Neuroscience, New York University School of Medicine, New York, NY, USA.
| | - Dmitry S Novikov
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Matthew S Davitz
- College of Arts and Sciences, New York University, New York, NY, USA.
| | - Yvonne W Lui
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Robert I Grossman
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Matilde Inglese
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Department of Neurology, Radiology, and Neuroscience, Mount Sinai School of Medicine, New York, NY, USA; Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy.
| | - Els Fieremans
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
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129
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Wright SN, Hong LE, Winkler AM, Chiappelli J, Nugent K, Muellerklein F, Du X, Rowland LM, Wang DJJ, Kochunov P. Perfusion shift from white to gray matter may account for processing speed deficits in schizophrenia. Hum Brain Mapp 2015; 36:3793-804. [PMID: 26108347 DOI: 10.1002/hbm.22878] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 05/23/2015] [Accepted: 06/04/2015] [Indexed: 12/16/2022] Open
Abstract
Reduced speed of cerebral information processing is a cognitive deficit associated with schizophrenia. Normal information processing speed (PS) requires intact white matter (WM) physiology to support information transfer. In a cohort of 107 subjects (47/60 patients/controls), we demonstrate that PS deficits in schizophrenia patients are explained by reduced WM integrity, which is measured using diffusion tensor imaging, mediated by the mismatch in WM/gray matter blood perfusion, and measured using arterial spin labeling. Our findings are specific to PS, and testing this hypothesis for patient-control differences in working memory produces no explanation. We demonstrate that PS deficits in schizophrenia can be explained by neurophysiological alterations in cerebral WM. Whether the disproportionately low WM integrity in schizophrenia is due to illness or secondary due to this disorder deserves further examination.
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Affiliation(s)
- Susan N Wright
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - L Elliot Hong
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Anderson M Winkler
- Oxford Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, Oxford, United Kingdom
| | - Joshua Chiappelli
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Katie Nugent
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Florian Muellerklein
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Xioming Du
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Laura M Rowland
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland.,Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Psychology, University of Maryland, Baltimore County, Maryland
| | - Danny J J Wang
- Department of Neurology, University of California, Los Angeles, California
| | - Peter Kochunov
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland.,Department of Physics, University of Maryland, Baltimore County, Maryland
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130
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Gholami A, Mang A, Biros G. An inverse problem formulation for parameter estimation of a reaction-diffusion model of low grade gliomas. J Math Biol 2015; 72:409-33. [PMID: 25963601 DOI: 10.1007/s00285-015-0888-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 03/04/2015] [Indexed: 11/26/2022]
Abstract
We present a numerical scheme for solving a parameter estimation problem for a model of low-grade glioma growth. Our goal is to estimate the spatial distribution of tumor concentration, as well as the magnitude of anisotropic tumor diffusion. We use a constrained optimization formulation with a reaction-diffusion model that results in a system of nonlinear partial differential equations. In our formulation, we estimate the parameters using partially observed, noisy tumor concentration data at two different time instances, along with white matter fiber directions derived from diffusion tensor imaging. The optimization problem is solved with a Gauss-Newton reduced space algorithm. We present the formulation and outline the numerical algorithms for solving the resulting equations. We test the method using a synthetic dataset and compute the reconstruction error for different noise levels and detection thresholds for monofocal and multifocal test cases.
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Affiliation(s)
- Amir Gholami
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA.
| | - Andreas Mang
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA.
| | - George Biros
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA.
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131
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Pires P, Santos A, Vives-Gilabert Y, Webb SM, Sainz-Ruiz A, Resmini E, Crespo I, de Juan-Delago M, Gómez-Anson B. White matter alterations in the brains of patients with active, remitted, and cured cushing syndrome: a DTI study. AJNR Am J Neuroradiol 2015; 36:1043-8. [PMID: 25929879 DOI: 10.3174/ajnr.a4322] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 12/14/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Cushing syndrome appears after chronic exposure to elevated glucocorticoid levels. Cortisol excess may alter white matter microstructure. Our purpose was to study WM changes in patients with Cushing syndrome compared with controls by using DTI and the influence of hypercortisolism. MATERIALS AND METHODS Thirty-five patients with Cushing syndrome and 35 healthy controls, matched for age, education, and sex, were analyzed through DTI (tract-based spatial statistics) for fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity (general linear model, family-wise error, and threshold-free cluster enhancement corrections, P < .05). Furthermore, the influence of hypercortisolism on WM DTI changes was studied by comparing 4 subgroups: 8 patients with Cushing syndrome with active hypercortisolism, 7 with Cushing syndrome with medication-remitted cortisol, 20 surgically cured, and 35 controls. Cardiovascular risk factors were used as covariates. In addition, correlations were analyzed among DTI values, concomitant 24-hour urinary free cortisol levels, and disease duration. RESULTS There were widespread alterations (reduced fractional anisotropy, and increased mean diffusivity, axial diffusivity, and radial diffusivity values; P < .05) in patients with Cushing syndrome compared with controls, independent of the cardiovascular risk factors present. Both active and cured Cushing syndrome subgroups showed similar changes compared with controls. Patients with medically remitted Cushing syndrome also had reduced fractional anisotropy and increased mean diffusivity and radial diffusivity values, compared with controls. No correlations were found between DTI maps and 24-hour urinary free cortisol levels or with disease duration. CONCLUSIONS Diffuse WM alterations in patients with Cushing syndrome suggest underlying loss of WM integrity and demyelination. Once present, they seem to be independent of concomitant hypercortisolism, persisting after remission/cure.
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Affiliation(s)
- P Pires
- From the Asociación para la Innovación en Análisis, Gestión y Procesamiento de Datos Científicos y Tecnológicos (P.P., Y.V.-G.), Barcelona, Spain Departments of Endocrinology/Medicine (P.P., A.S., S.M.W., E.R., I.C.), Hospital Sant Pau, IIB-Sant Pau, Instituto de Salud Carlos III, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - A Santos
- Departments of Endocrinology/Medicine (P.P., A.S., S.M.W., E.R., I.C.), Hospital Sant Pau, IIB-Sant Pau, Instituto de Salud Carlos III, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Y Vives-Gilabert
- From the Asociación para la Innovación en Análisis, Gestión y Procesamiento de Datos Científicos y Tecnológicos (P.P., Y.V.-G.), Barcelona, Spain Port d'Informació Científica (Y.V.-G., A.S.-R.), Bellaterra, Barcelona, Spain
| | - S M Webb
- Departments of Endocrinology/Medicine (P.P., A.S., S.M.W., E.R., I.C.), Hospital Sant Pau, IIB-Sant Pau, Instituto de Salud Carlos III, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - A Sainz-Ruiz
- Port d'Informació Científica (Y.V.-G., A.S.-R.), Bellaterra, Barcelona, Spain Institut de Fisica d'Altes Energies (A.S.-R.), Barcelona, Spain
| | - E Resmini
- Departments of Endocrinology/Medicine (P.P., A.S., S.M.W., E.R., I.C.), Hospital Sant Pau, IIB-Sant Pau, Instituto de Salud Carlos III, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - I Crespo
- Departments of Endocrinology/Medicine (P.P., A.S., S.M.W., E.R., I.C.), Hospital Sant Pau, IIB-Sant Pau, Instituto de Salud Carlos III, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M de Juan-Delago
- Neuroradiology Unit (M.d.J.-D., B.G.-A.), Hospital Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - B Gómez-Anson
- Neuroradiology Unit (M.d.J.-D., B.G.-A.), Hospital Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain.
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132
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Chiappelli J, Hong LE, Wijtenburg SA, Du X, Gaston F, Kochunov P, Rowland LM. Alterations in frontal white matter neurochemistry and microstructure in schizophrenia: implications for neuroinflammation. Transl Psychiatry 2015; 5:e548. [PMID: 25871973 PMCID: PMC4462606 DOI: 10.1038/tp.2015.43] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 01/23/2015] [Accepted: 01/27/2015] [Indexed: 01/01/2023] Open
Abstract
We investigated in vivo neurochemical markers reflective of neuronal health and glial activation to determine if these could yield clues regarding the reduced fractional anisotropy (FA) of white matter and accelerated decline of FA with age in schizophrenia. Participants with schizophrenia and healthy controls completed diffusion tensor imaging to assess FA and proton magnetic resonance spectroscopy to assess neurochemical metabolites in the same frontal region. Frontal FA was significantly lower in the schizophrenia and declined more rapidly with age compared with the healthy control group. In both groups, N-acetylaspartate (NAA), a putative marker of neuronal integrity, and glutamate declined with age, and this decline was stronger in patients. Myo-inositol, a marker of glial cells, was negatively related to FA in both groups. The relationship between FA and age remained significant in schizophrenia even when controlling for all metabolites. The relationships of FA, NAA and myo-inositol to age appear to be independent of one another. The relationship between FA and myo-inositol was independently present in both patients and controls, even after controlling for age, indicating a potential general effect of neuroinflammation on white matter microstructure. Further studies are warranted to determine the underlying mechanism driving the accelerated FA decline with age in schizophrenia.
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Affiliation(s)
- J Chiappelli
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - L E Hong
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228, USA. E-mail: or
| | - S A Wijtenburg
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - X Du
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - F Gaston
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - P Kochunov
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - L M Rowland
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
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133
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Dodd AB, Epstein K, Ling JM, Mayer AR. Diffusion tensor imaging findings in semi-acute mild traumatic brain injury. J Neurotrauma 2015; 31:1235-48. [PMID: 24779720 DOI: 10.1089/neu.2014.3337] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The past 10 years have seen a rapid increase in the use of diffusion tensor imaging to identify biomarkers of traumatic brain injury (TBI). Although the literature generally indicates decreased anisotropic diffusion at more chronic injury periods and in more severe injuries, considerable debate remains regarding the direction (i.e., increased or decreased) of anisotropic diffusion in the acute to semi-acute phase (here defined as less than 3 months post-injury) of mild TBI (mTBI). A systematic review of the literature was therefore performed to (1) determine the prevalence of different anisotropic diffusion findings (increased, decreased, bidirectional, or null) during the semi-acute injury phase of mTBI and to (2) identify clinical (e.g., age of injury, post-injury scan time, etc.) and experimental factors (e.g., number of unique directions, field strength) that may influence these findings. Results from the literature review indicated 31 articles with independent samples of semi-acute mTBI patients, with 13 studies reporting decreased anisotropic diffusion, 11 reporting increased diffusion, 2 reporting bidirectional findings, and 5 reporting null findings. Chi-squared analyses indicated that the total number of diffusion-weighted (DW) images was significantly associated with findings of either increased (DW ≥ 30) versus decreased (DW ≤ 25) anisotropic diffusion. Other clinical and experimental factors were not statistically significant for direction of anisotropic diffusion, but these results may have been limited by the relatively small number of studies within each domain (e.g., pediatric studies). In summary, current results indicate roughly equivalent number of studies reporting increased versus decreased anisotropic diffusion during semi-acute mTBI, with the number of unique diffusion images being statistically associated with the direction of findings.
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Affiliation(s)
- Andrew B Dodd
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Albuquerque, New Mexico
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134
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Chen DQ, Strauss I, Hayes DJ, Davis KD, Hodaie M. Age-related changes in diffusion tensor imaging metrics of fornix subregions in healthy humans. Stereotact Funct Neurosurg 2015; 93:151-9. [PMID: 25790958 DOI: 10.1159/000368442] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/18/2014] [Indexed: 11/19/2022]
Abstract
OBJECTIVE White matter diffusivity measures of the fornix change with aging, which likely relates to changes in memory and cognition in older adults. Subregional variations in forniceal diffusivity may exist, given its heterogeneous anatomy and connectivity; however, these have not been closely examined in vivo. We examined diffusivity parameters (fractional anisotropy, FA; radial diffusivity, RD; axial diffusivity, AD) in forniceal subregions of healthy subjects and correlated them with age and hippocampal volume. METHODS Diffusion-weighted imaging and streamline tractography of the fornix were performed on 20 healthy, right-handed females (23-66 years). Six anatomical subregions were defined: midline (body, column, precommissural fornix) or lateral (fimbria, crura, postcommissural fornix). Regression analysis was performed comparing diffusivities against age. Hippocampal and ventricular volumes were also compared. RESULTS Diffusivity values revealed statistical changes with age in both midline and lateralized subregions. The fornix body and left crus showed age-related alterations in all metrics (FA, RD, AD), whereas only right crus FA was altered. There was no significant change in hippocampal volumes, suggesting that forniceal changes may precede hippocampal age-related changes. CONCLUSIONS Age-related changes in fornix diffusivity measures appear subregion dependent and asymmetrical. Specific subregion diffusivity measures may be a more sensitive aging marker than hippocampal volume change.
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Affiliation(s)
- David Qixiang Chen
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada
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135
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Focus on diffusion MR investigations of musculoskeletal tissue to improve osteoporosis diagnosis: a brief practical review. BIOMED RESEARCH INTERNATIONAL 2015; 2015:948610. [PMID: 25861652 PMCID: PMC4377366 DOI: 10.1155/2015/948610] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 02/18/2015] [Indexed: 01/13/2023]
Abstract
Nowadays, a huge number of papers have documented the ability of diffusion magnetic resonance imaging (D-MRI) to highlight normal and pathological conditions in a variety of cerebral, abdominal, and cardiovascular applications. To date, however, the role of D-MRI to investigate musculoskeletal tissue, specifically the cancellous bone, has not been extensively explored. In order to determine potentially useful applications of diffusion techniques in musculoskeletal investigation, D-MRI applications to detect osteoporosis disease were reviewed and further explained.
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136
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Jelescu IO, Veraart J, Adisetiyo V, Milla SS, Novikov DS, Fieremans E. One diffusion acquisition and different white matter models: how does microstructure change in human early development based on WMTI and NODDI? Neuroimage 2014; 107:242-256. [PMID: 25498427 DOI: 10.1016/j.neuroimage.2014.12.009] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/28/2014] [Accepted: 12/03/2014] [Indexed: 11/16/2022] Open
Abstract
White matter microstructural changes during the first three years of healthy brain development are characterized using two different models developed for limited clinical diffusion data: White Matter Tract Integrity (WMTI) metrics from Diffusional Kurtosis Imaging (DKI) and Neurite Orientation Dispersion and Density Imaging (NODDI). Both models reveal a non-linear increase in intra-axonal water fraction and in tortuosity of the extra-axonal space as a function of age, in the genu and splenium of the corpus callosum and the posterior limb of the internal capsule. The changes are consistent with expected behavior related to myelination and asynchrony of fiber development. The intra- and extracellular axial diffusivities as estimated with WMTI do not change appreciably in normal brain development. The quantitative differences in parameter estimates between models are examined and explained in the light of each model's assumptions and consequent biases, as highlighted in simulations. Finally, we discuss the feasibility of a model with fewer assumptions.
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Affiliation(s)
- Ileana O Jelescu
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA.
| | - Jelle Veraart
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
| | - Vitria Adisetiyo
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
| | - Sarah S Milla
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
| | - Dmitry S Novikov
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
| | - Els Fieremans
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
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137
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Krzyżak AT, Olejniczak Z. Improving the accuracy of PGSE DTI experiments using the spatial distribution of b matrix. Magn Reson Imaging 2014; 33:286-95. [PMID: 25460327 DOI: 10.1016/j.mri.2014.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 10/21/2014] [Indexed: 11/17/2022]
Abstract
A novel method for improving the accuracy of diffusion tensor imaging (DTI) is proposed. It takes into account the b matrix spatial variations, which can be easily determined using a simple anisotropic diffusion phantom. In opposite to standard numerical procedure of the b matrix calculation that requires the exact knowledge of amplitudes, shapes and time dependencies of diffusion gradients, the new method, which we call BSD-DTI (B-matrix spatial distribution in DTI), relies on direct measurements of its space-dependent components. The proposed technique was demonstrated on the Bruker Biospec 94/20USR system, using the spin echo diffusion sequence to image an isotropic water phantom and an anisotropic capillary phantom. The accuracy of the diffusion tensor determination was improved by an overall factor of about 8 for the isotropic water phantom.
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138
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Aghajani M, Veer IM, van Lang NDJ, Meens PHF, van den Bulk BG, Rombouts SARB, Vermeiren RRJM, van der Wee NJ. Altered white-matter architecture in treatment-naive adolescents with clinical depression. Psychol Med 2014; 44:2287-2298. [PMID: 24330845 DOI: 10.1017/s0033291713003000] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Depressive disorders are highly prevalent in adolescence and confer a heightened risk of recurrence in adulthood. Insight into the developmental neurocircuitry of depression could advance our understanding of depression and aid the development of effective treatment strategies. Whereas white-matter (WM) abnormalities are strongly implicated in adult depression, we still lack a firm understanding of WM architecture in adolescent depression. Using diffusion tensor imaging (DTI), we set out to investigate WM microstructure in a sample of clinically depressed adolescents relative to matched controls. METHOD We employed tract-based spatial statistics (TBSS) to examine WM microstructure in 25 treatment-naive adolescents with clinical depression relative to 21 matched controls. Using TBSS, we examined fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD). Threshold-free cluster enhancement (TFCE) with family-wise error (FWE) correction was used to control for multiple comparisons. RESULTS Our analysis revealed abnormal WM microstructure in clinically depressed adolescents. More specifically, whole-brain analysis revealed that patients had lower FA values in the body of the corpus callosum (CC), coupled with elevated RD and MD, and preserved AD. Conversely, region-of-interest analysis revealed that patients had higher FA values in the uncinate fasciculus (UF), coupled with elevated AD, reduced RD and preserved MD. CONCLUSIONS In line with neurocircuitry models of depression, our findings suggest that WM abnormalities within pathways facilitating cognitive and emotional functioning are involved in the pathophysiology of depression. Importantly, our findings show that these WM abnormalities are already present early in the course of the disorder.
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Affiliation(s)
- M Aghajani
- Department of Child and Adolescent Psychiatry, Curium,Leiden University Medical Center,The Netherlands
| | - I M Veer
- Leiden Institute for Brain and Cognition (LIBC),The Netherlands
| | - N D J van Lang
- Department of Child and Adolescent Psychiatry, Curium,Leiden University Medical Center,The Netherlands
| | - P H F Meens
- Department of Child and Adolescent Psychiatry, Curium,Leiden University Medical Center,The Netherlands
| | - B G van den Bulk
- Department of Child and Adolescent Psychiatry, Curium,Leiden University Medical Center,The Netherlands
| | | | - R R J M Vermeiren
- Department of Child and Adolescent Psychiatry, Curium,Leiden University Medical Center,The Netherlands
| | - N J van der Wee
- Leiden Institute for Brain and Cognition (LIBC),The Netherlands
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139
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Improvement of partial volume segmentation for brain tissue on diffusion tensor images using multiple-tensor estimation. J Digit Imaging 2014; 26:1131-40. [PMID: 23589185 DOI: 10.1007/s10278-013-9601-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
To improve evaluations of cortical and subcortical diffusivity in neurological diseases, it is necessary to improve the accuracy of brain diffusion tensor imaging (DTI) data segmentation. The conventional partial volume segmentation method fails to classify voxels with multiple white matter (WM) fiber orientations such as fiber-crossing regions. Our purpose was to improve the performance of segmentation by taking into account the partial volume effects due to both multiple tissue types and multiple WM fiber orientations. We quantitatively evaluated the overall performance of the proposed method using digital DTI phantom data. Moreover, we applied our method to human DTI data, and compared our results with those of a conventional method. In the phantom experiments, the conventional method and proposed method yielded almost the same root mean square error (RMSE) for gray matter (GM) and cerebrospinal fluid (CSF), while the RMSE in the proposed method was smaller than that in the conventional method for WM. The volume overlap measures between our segmentation results and the ground truth of the digital phantom were more than 0.8 in all three tissue types, and were greater than those in the conventional method. In visual comparisons for human data, the WM/GM/CSF regions obtained using our method were in better agreement with the corresponding regions depicted in the structural image than those obtained using the conventional method. The results of the digital phantom experiment and human data demonstrated that our method improved accuracy in the segmentation of brain tissue data on DTI compared to the conventional method.
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140
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Chiang CW, Wang Y, Sun P, Lin TH, Trinkaus K, Cross AH, Song SK. Quantifying white matter tract diffusion parameters in the presence of increased extra-fiber cellularity and vasogenic edema. Neuroimage 2014; 101:310-9. [PMID: 25017446 DOI: 10.1016/j.neuroimage.2014.06.064] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 06/12/2014] [Accepted: 06/27/2014] [Indexed: 12/01/2022] Open
Abstract
The effect of extra-fiber structural and pathological components confounding diffusion tensor imaging (DTI) computation was quantitatively investigated using data generated by both Monte-Carlo simulations and tissue phantoms. Increased extent of vasogenic edema, by addition of various amount of gel to fixed normal mouse trigeminal nerves or by increasing non-restricted isotropic diffusion tensor components in Monte-Carlo simulations, significantly decreased fractional anisotropy (FA) and increased radial diffusivity, while less significantly increased axial diffusivity derived by DTI. Increased cellularity, mimicked by graded increase of the restricted isotropic diffusion tensor component in Monte-Carlo simulations, significantly decreased FA and axial diffusivity with limited impact on radial diffusivity derived by DTI. The MC simulation and tissue phantom data were also analyzed by the recently developed diffusion basis spectrum imaging (DBSI) to simultaneously distinguish and quantify the axon/myelin integrity and extra-fiber diffusion components. Results showed that increased cellularity or vasogenic edema did not affect the DBSI-derived fiber FA, axial or radial diffusivity. Importantly, the extent of extra-fiber cellularity and edema estimated by DBSI correlated with experimentally added gel and Monte-Carlo simulations. We also examined the feasibility of applying 25-direction diffusion encoding scheme for DBSI analysis on coherent white matter tracts. Results from both phantom experiments and simulations suggested that the 25-direction diffusion scheme provided comparable DBSI estimation of both fiber diffusion parameters and extra-fiber cellularity/edema extent as those by 99-direction scheme. An in vivo 25-direction DBSI analysis was performed on experimental autoimmune encephalomyelitis (EAE, an animal model of human multiple sclerosis) optic nerve as an example to examine the validity of derived DBSI parameters with post-imaging immunohistochemistry verification. Results support that in vivo DBSI using 25-direction diffusion scheme correctly reflect the underlying axonal injury, demyelination, and inflammation of optic nerves in EAE mice.
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Affiliation(s)
- Chia-Wen Chiang
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Yong Wang
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Peng Sun
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tsen-Hsuan Lin
- Department of Physics, Washington University, St. Louis, MO 63130, USA
| | - Kathryn Trinkaus
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Anne H Cross
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sheng-Kwei Song
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA.
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141
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Kochunov P, Hong LE. Neurodevelopmental and neurodegenerative models of schizophrenia: white matter at the center stage. Schizophr Bull 2014; 40:721-8. [PMID: 24870447 PMCID: PMC4059450 DOI: 10.1093/schbul/sbu070] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Schizophrenia is a disorder of cerebral disconnectivity whose lifetime course is modeled as both neurodevelopmental and neurodegenerative. The neurodevelopmental models attribute schizophrenia to alterations in the prenatal-to-early adolescent development. The neurodegenerative models identify progressive neurodegeneration as its core attribute. Historically, the physiology, pharmacology, and treatment targets in schizophrenia were conceptualized in terms of neurons, neurotransmitter levels, and synaptic receptors. Much of the evidence for both models was derived from studies of cortical and subcortical gray matter. We argue that the dynamics of the lifetime trajectory of white matter, and the consistency of connectivity deficits in schizophrenia, support white matter integrity as a promising phenotype to evaluate the competing evidence for and against neurodevelopmental and neurodegenerative heuristics. We develop this perspective by reviewing normal lifetime trajectories of white and gray matter changes. We highlighted the overlap between the age of peak of white matter development and the age of onset of schizophrenia and reviewed findings of white matter abnormalities prior to, at the onset, and at chronic stages of schizophrenia. We emphasized the findings of reduced white matter integrity at the onset and findings of accelerated decline in chronic stages, but the developmental trajectory that precedes the onset is largely unknown. We propose 4 probable lifetime white matter trajectory models that can be used as the basis for separation between the neurodevelopmental and neurodegenerative etiologies. We argue that a combination of the cross-sectional and longitudinal studies of white matter integrity in patients may be used to bridge the neurodevelopment and degeneration heuristics to advance schizophrenia research.
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Affiliation(s)
- Peter Kochunov
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD.
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142
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Vakhtin AA, Calhoun VD, Jung RE, Prestopnik JL, Taylor PA, Ford CC. Changes in intrinsic functional brain networks following blast-induced mild traumatic brain injury. Brain Inj 2014; 27:1304-10. [PMID: 24020442 DOI: 10.3109/02699052.2013.823561] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Blast-induced mild traumatic brain injuries (mTBI) commonly go undetected by computed tomography and conventional magnetic resonance imaging (MRI). This study was used to investigate functional brain network abnormalities in a group of blast-induced mTBI subjects using independent component analysis (ICA) of resting state functional MRI (fMRI) data. METHODS Twenty-eight resting state networks of 13 veterans who sustained blast-induced mTBI were compared with healthy controls across three fMRI domains: blood oxygenation level-dependent spatial maps, time course spectra and functional connectivity. RESULTS The mTBI group exhibited hyperactivity in the temporo-parietal junctions and hypoactivity in the left inferior temporal gyrus. Abnormal frequencies in default-mode (DMN), sensorimotor, attentional and frontal networks were detected. In addition, functional connectivity was disrupted in six network pairs: DMN-basal ganglia, attention-sensorimotor, frontal-DMN, attention-sensorimotor, attention-frontal and sensorimotor-sensorimotor. CONCLUSIONS The results suggest white matter disruption across certain attentional networks. Additionally, given their elevated activity relative to controls', the temporo-parietal junctions of blast mTBI subjects may be compensating for diffuse axonal injury in other cortical regions.
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Affiliation(s)
- Andrei A Vakhtin
- Department of Neurology, Health Sciences Center, University of New Mexico , Albuquerque, NM , USA
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143
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Miller TR, Mohan S, Choudhri AF, Gandhi D, Jindal G. Advances in multiple sclerosis and its variants: conventional and newer imaging techniques. Radiol Clin North Am 2014; 52:321-36. [PMID: 24582342 DOI: 10.1016/j.rcl.2013.11.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Multiple sclerosis (MS) and its variants are inflammatory as well as neurodegenerative diseases that diffusely affect the central nervous system (CNS). There is a poor correlation between traditional imaging findings and symptoms in patients with MS. Current research in conventional magnetic resonance (MR) imaging of MS and related diseases includes optimization of hardware and pulse sequences and the development of automated and semiautomated techniques to measure and quantify disease burden. Advanced nonconventional MR techniques such as diffusion tensor and functional MR imaging probe the changes found in the CNS, and correlate these findings with clinical measures of disease.
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Affiliation(s)
- Timothy R Miller
- Neuroradiology Division, Department of Radiology, University of Maryland Medical Center, Baltimore, MD 21201, USA.
| | - Suyash Mohan
- Neuroradiology Division, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Asim F Choudhri
- Neuroradiology Division, Department of Radiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Dheeraj Gandhi
- Neuroradiology Division, Department of Radiology, University of Maryland Medical Center, Baltimore, MD 21201, USA
| | - Gaurav Jindal
- Neuroradiology Division, Department of Radiology, University of Maryland Medical Center, Baltimore, MD 21201, USA
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144
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The limbic degradation of aging brain: a quantitative analysis with diffusion tensor imaging. ScientificWorldJournal 2014; 2014:196513. [PMID: 24977184 PMCID: PMC4009154 DOI: 10.1155/2014/196513] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/02/2014] [Accepted: 03/03/2014] [Indexed: 11/17/2022] Open
Abstract
Introduction. The limbic system primarily responsible for our emotional life and memories is known to undergo degradation with aging and diffusion tensor imaging (DTI) is capable of revealing the white matter integrity. The aim of this study is to investigate age-related changes of quantitative diffusivity parameters and fiber characteristics on limbic system in healthy volunteers. Methods. 31 healthy subjects aged 25–70 years were examined at 1,5 TMR. Quantitative fiber tracking was performed of fornix, cingulum, and the parahippocampal gyrus. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) measurements of bilateral hippocampus, amygdala, fornix, cingulum, and parahippocampal gyrus were obtained as related components. Results. The FA values of left hippocampus, bilateral parahippocampal gyrus, and fornix showed negative correlations with aging. The ADC values of right amygdala and left cingulum interestingly showed negative relation and the left hippocampus represented positive relation with age. The cingulum showed no correlation. The significant relative changes per decade of age were found in the cingulum and parahippocampal gyrus FA measurements. Conclusion. Our approach shows that aging affects hippocampus, parahippocampus, and fornix significantly but not cingulum. These findings reveal age-related changes of limbic system in normal population that may contribute to future DTI studies.
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145
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Yin Z, Magin RL, Klatt D. Simultaneous MR elastography and diffusion acquisitions: Diffusion-MRE (dMRE). Magn Reson Med 2014; 71:1682-8. [DOI: 10.1002/mrm.25180] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/27/2013] [Accepted: 01/23/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Ziying Yin
- The Richard and Loan Hill Department of Bioengineering; University of Illinois at Chicago; Chicago Illinois USA
| | - Richard L. Magin
- The Richard and Loan Hill Department of Bioengineering; University of Illinois at Chicago; Chicago Illinois USA
| | - Dieter Klatt
- The Richard and Loan Hill Department of Bioengineering; University of Illinois at Chicago; Chicago Illinois USA
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146
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Racine AM, Adluru N, Alexander AL, Christian BT, Okonkwo OC, Oh J, Cleary CA, Birdsill A, Hillmer AT, Murali D, Barnhart TE, Gallagher CL, Carlsson CM, Rowley HA, Dowling NM, Asthana S, Sager MA, Bendlin BB, Johnson SC. Associations between white matter microstructure and amyloid burden in preclinical Alzheimer's disease: A multimodal imaging investigation. NEUROIMAGE-CLINICAL 2014; 4:604-14. [PMID: 24936411 PMCID: PMC4053642 DOI: 10.1016/j.nicl.2014.02.001] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/29/2014] [Accepted: 02/10/2014] [Indexed: 10/30/2022]
Abstract
Some cognitively healthy individuals develop brain amyloid accumulation, suggestive of incipient Alzheimer's disease (AD), but the effect of amyloid on other potentially informative imaging modalities, such as Diffusion Tensor Imaging (DTI), in characterizing brain changes in preclinical AD requires further exploration. In this study, a sample (N = 139, mean age 60.6, range 46 to 71) from the Wisconsin Registry for Alzheimer's Prevention (WRAP), a cohort enriched for AD risk factors, was recruited for a multimodal imaging investigation that included DTI and [C-11]Pittsburgh Compound B (PiB) positron emission tomography (PET). Participants were grouped as amyloid positive (Aβ+), amyloid indeterminate (Aβi), or amyloid negative (Aβ-) based on the amount and pattern of amyloid deposition. Regional voxel-wise analyses of four DTI metrics, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da), and radial diffusivity (Dr), were performed based on amyloid grouping. Three regions of interest (ROIs), the cingulum adjacent to the corpus callosum, hippocampal cingulum, and lateral fornix, were selected based on their involvement in the early stages of AD. Voxel-wise analysis revealed higher FA among Aβ+ compared to Aβ- in all three ROIs and in Aβi compared to Aβ- in the cingulum adjacent to the corpus callosum. Follow-up exploratory whole-brain analyses were consistent with the ROI findings, revealing multiple regions where higher FA was associated with greater amyloid. Lower fronto-lateral gray matter MD was associated with higher amyloid burden. Further investigation showed a negative correlation between MD and PiB signal, suggesting that Aβ accumulation impairs diffusion. Interestingly, these findings in a largely presymptomatic sample are in contradistinction to relationships reported in the literature in symptomatic disease stages of Mild Cognitive Impairment and AD, which usually show higher MD and lower FA. Together with analyses showing that cognitive function in these participants is not associated with any of the four DTI metrics, the present results suggest an early relationship between PiB and DTI, which may be a meaningful indicator of the initiating or compensatory mechanisms of AD prior to cognitive decline.
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Key Words
- AD risk
- ANCOVA, Analysis of Covariance
- ANTs, Advanced Normalization Tools
- APOE4, apolipoprotein E gene ε4
- Alzheimer's disease
- Amyloid imaging
- Aβ+, amyloid positive
- Aβi, amyloid indeterminate
- Aβ−, amyloid negative
- BET, Brain Extraction Tool
- Cingulum–CC, cingulum adjacent to corpus callosum
- Cingulum–HC, hippocampal cingulum (projecting to medial temporal lobe)
- DTI, Diffusion Tensor Imaging
- DTI-TK, Diffusion Tensor Imaging Toolkit
- DVR, distribution volume ratio
- Da, axial diffusivity
- Dr, radial diffusivity
- FA, fractional anisotropy
- FH, (parental) family history
- FSL, FMRIB Software Library
- FUGUE, FMRIB's utility for geometrically unwarping EPIs
- FWE, family wise error
- GM, gray matter
- HARDI, high angular resolution diffusion imaging
- ICBM, International Consortium for Brain Mapping
- MD, mean diffusivity
- PCC, posterior cingulate cortex
- PIB, Pittsburgh compound B
- PRELUDE, phase region expanding labeler for unwrapping discrete estimates
- RAVLT, Rey Auditory Verbal Learning Test
- SPM, Statistical Parametric Mapping
- TMT, Trail Making Test
- WASI, Wechsler Abbreviated Scale of Intelligence
- WM, white matter
- WRAP, Wisconsin Registry for Alzheimer's Prevention
- WRAT, Wide Range Achievement Test
- White matter
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Affiliation(s)
- Annie M Racine
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Nagesh Adluru
- Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Andrew L Alexander
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705, USA ; Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53719, USA
| | - Bradley T Christian
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Ozioma C Okonkwo
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Jennifer Oh
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Caitlin A Cleary
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Alex Birdsill
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Ansel T Hillmer
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53719, USA
| | - Dhanabalan Murali
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Catherine L Gallagher
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Cynthia M Carlsson
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Howard A Rowley
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - N Maritza Dowling
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Sanjay Asthana
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Mark A Sager
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Barbara B Bendlin
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Sterling C Johnson
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705, USA
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147
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Widespread reductions of white matter integrity in patients with long-term remission of Cushing's disease. NEUROIMAGE-CLINICAL 2014; 4:659-67. [PMID: 24936417 PMCID: PMC4053612 DOI: 10.1016/j.nicl.2014.01.017] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/09/2014] [Accepted: 01/31/2014] [Indexed: 11/23/2022]
Abstract
BACKGROUND Hypercortisolism leads to various physical, psychological and cognitive symptoms, which may partly persist after the treatment of Cushing's disease. The aim of the present study was to investigate abnormalities in white matter integrity in patients with long-term remission of Cushing's disease, and their relation with psychological symptoms, cognitive impairment and clinical characteristics. METHODS In patients with long-term remission of Cushing's disease (n = 22) and matched healthy controls (n = 22) we examined fractional anisotropy (FA) values of white matter in a region-of-interest (ROI; bilateral cingulate cingulum, bilateral hippocampal cingulum, bilateral uncinate fasciculus and corpus callosum) and the whole brain, using 3 T diffusion tensor imaging (DTI) and a tract-based spatial statistics (TBSS) approach. Psychological and cognitive functioning were assessed with validated questionnaires and clinical severity was assessed using the Cushing's syndrome Severity Index. RESULTS The ROI analysis showed FA reductions in all of the hypothesized regions, with the exception of the bilateral hippocampal cingulum, in patients when compared to controls. The exploratory whole brain analysis showed multiple regions with lower FA values throughout the brain. Patients reported more apathy (p = .003) and more depressive symptoms (p < .001), whereas depression symptom severity in the patient group was negatively associated with FA in the left uncinate fasciculus (p < 0.05). Post-hoc analyses showed increased radial and mean diffusivity in the patient group. CONCLUSION Patients with a history of endogenous hypercortisolism in present remission show widespread changes of white matter integrity in the brain, with abnormalities in the integrity of the uncinate fasciculus being related to the severity of depressive symptoms, suggesting persistent structural effects of hypercortisolism.
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Schmitz T, Krabbe G, Weikert G, Scheuer T, Matheus F, Wang Y, Mueller S, Kettenmann H, Matyash V, Bührer C, Endesfelder S. Minocycline protects the immature white matter against hyperoxia. Exp Neurol 2014; 254:153-65. [PMID: 24491957 DOI: 10.1016/j.expneurol.2014.01.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 12/21/2013] [Accepted: 01/23/2014] [Indexed: 01/06/2023]
Abstract
Poor neurological outcome in preterm infants is associated with periventricular white matter damage and hypomyelination, often caused by perinatal inflammation, hypoxia-ischemia, and hyperoxia. Minocycline has been demonstrated in animal models to protect the immature brain against inflammation and hypoxia-ischemia by microglial inhibition. Here we studied the effect of minocycline on white matter damage caused by hyperoxia. To mimic the 3- to 4-fold increase of oxygen tension caused by preterm birth, we have used the hyperoxia model in neonatal rats providing 24h exposure to 4-fold increased oxygen concentration (80% instead of 21% O2) from P6 to P7. We analyzed whether minocycline prevents activation of microglia and damage of oligodendroglial precursor cell development, and whether acute treatment of hyperoxia-exposed rats with minocycline improves long term white matter integrity. Minocycline administration during exposure to hyperoxia resulted in decreased apoptotic cell death and in improved proliferation and maturation of oligodendroglial precursor cells (OPC). Minocycline blocked changes in microglial morphology and IL-1β release induced by hyperoxia. In primary microglial cell cultures, minocycline inhibited cytokine release while in mono-cultures of OPCs, it improved survival and proliferation. Long term impairment of white matter diffusivity in MRI/DTI in P30 and P60 animals after neonatal hyperoxia was attenuated by minocycline. Minocycline protects white matter development against oxygen toxicity through direct protection of oligodendroglia and by microglial inhibition. This study moreover demonstrates long term benefits of minocycline on white matter integrity.
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Affiliation(s)
- Thomas Schmitz
- Department for Neonatology, Charité University Medical Center, Berlin, Germany.
| | - Grietje Krabbe
- Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Straße 10, Berlin, Germany
| | - Georg Weikert
- Department for Neonatology, Charité University Medical Center, Berlin, Germany
| | - Till Scheuer
- Department for Neonatology, Charité University Medical Center, Berlin, Germany
| | - Friederike Matheus
- Department for Neonatology, Charité University Medical Center, Berlin, Germany
| | - Yan Wang
- Department for Neonatology, Charité University Medical Center, Berlin, Germany
| | - Susanne Mueller
- Berlin Center for Stroke Research, Charité University Medical Center, Berlin, Germany
| | - Helmut Kettenmann
- Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Straße 10, Berlin, Germany
| | - Vitali Matyash
- Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Straße 10, Berlin, Germany
| | - Christoph Bührer
- Department for Neonatology, Charité University Medical Center, Berlin, Germany
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149
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Sierra A, Laitinen T, Gröhn O, Pitkänen A. Diffusion tensor imaging of hippocampal network plasticity. Brain Struct Funct 2013; 220:781-801. [PMID: 24363120 DOI: 10.1007/s00429-013-0683-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 11/29/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Alejandra Sierra
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, 70211, Kuopio, Finland
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Gupta PK, Garg RK, Gupta RK, Malhotra HS, Paliwal VK, Rathore RKS, Verma R, Singh MK, Rai Y, Pandey CM. Diffusion tensor tractography and neuropsychological assessment in patients with vitamin B12 deficiency. Neuroradiology 2013; 56:97-106. [DOI: 10.1007/s00234-013-1306-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 11/28/2013] [Indexed: 11/30/2022]
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