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Wang KY, Carlton J, Guffey D, Hutton GJ, Moron FE. Histogram analysis of apparent diffusion coefficient and fluid-attenuated inversion recovery in discriminating between enhancing and nonenhancing lesions in multiple sclerosis. Clin Imaging 2019; 59:13-20. [PMID: 31715512 DOI: 10.1016/j.clinimag.2019.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 08/12/2019] [Accepted: 08/19/2019] [Indexed: 01/08/2023]
Abstract
PURPOSE This study evaluates the diagnostic performance of apparent diffusion coefficient (ADC) and T2 fluid-attenuation inversion recovery (T2 FLAIR) in discriminating between new white matter (WM) enhancing lesions (ELs) and non-enhancing lesions (NELs) in multiple sclerosis (MS) patients. METHODS Thirty MS patients with a new solitary WM lesion on brain MRI were analyzed. A region-of-interest was drawn on all lesions and the contralateral normal-appearing WM (NAWM) on T2 FLAIR and ADC maps. Normalized ratios of T2 FLAIR and ADC were calculated by dividing lesion value by the contralateral NAWM. Histogram analysis was performed on the T2 FLAIR, ADC values, and their normalized ratios. Mann-Whitney U test was used to compare histogram parameters and receiver operating characteristic (ROC) analysis determined the area under the curve (AUC). RESULTS T2 FLAIR histogram parameters were not significantly different between ELs and NELs. Several EL ADC histogram parameters, including maximum and mean, were significantly higher than NELs (p = 0.006 to p = 0.031). There was a trend toward significantly higher maximum ADC in ELs after adjusting for multiple comparisons (p = 0.054). The standard deviation of T2 FLAIR (AUC 0.70), maximum ADC (AUC 0.79), and normalized maximum ADC ratio (AUC 0.75) were among histogram parameters with the highest diagnostic performance. A maximum ADC cutoff of 1274 × 10-6 mm2/s provided a 0.86 sensitivity and 0.75 specificity. CONCLUSION In patients with contraindications to gadolinium or concerns with gadolinium brain deposition, consideration may be given to ADC and T2 FLAIR as potential noncontrast methods for the evaluation of active MS lesions.
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Affiliation(s)
- Kevin Yuqi Wang
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA.
| | - Joshua Carlton
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
| | - Danielle Guffey
- Dan L Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, TX, USA
| | - George J Hutton
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Fanny E Moron
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
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Sheng H, Zhao B, Ge Y. Blood Perfusion and Cellular Microstructural Changes Associated With Iron Deposition in Multiple Sclerosis Lesions. Front Neurol 2019; 10:747. [PMID: 31354613 PMCID: PMC6637756 DOI: 10.3389/fneur.2019.00747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/26/2019] [Indexed: 12/18/2022] Open
Abstract
Background and Purpose: Susceptibility-weighted imaging (SWI) has emerged as a useful clinical tool in many neurological diseases including multiple sclerosis (MS). This study aims to investigate the relationship between SWI signal changes due to iron deposition in MS lesions and tissue blood perfusion and microstructural abnormalities to better understand their underlying histopathologies. Methods: Forty-six patients with relapsing remitting MS were recruited for this study. Conventional FLAIR, pre- and post-contrast T1-weighted imaging, SWI, diffusion tensor imaging (DTI), and dynamic susceptibility contrast (DSC) perfusion MRI were performed in these patients at 3T. The SWI was processed using both magnitude and phase information with one slice minimal intensity projection (mIP) and phase multiplication factor of 4. MS lesions were classified into 3 types based on their lesional signal appearance on SWI mIP relative to perilesional normal appearing white matter (peri-NAWM): Type-1: hypointense, Type-2: isointense, and Type-3: hyperintense lesions. The DTI and DSC MRI data were processed offline to generate DTI-derived mean diffusivity (MD) and fractional anisotropy (FA) maps, as well as DSC-derived cerebral blood flow (CBF) and cerebral blood volume (CBV) maps. Comparisons of diffusion and perfusion measurements between lesions and peri-NAWM, as well between different types of lesions, were performed. Results: A total of 137 lesions were identified on FLAIR in these patients that include 40 Type-1, 46 Type-2, and 51 Type-3 lesions according to their SWI intensity relative to peri-NAWM. All lesion types showed significant higher MD and lower FA compared to their peri-NAWM (P < 0.0001). Compared to Type-1 lesions (likely represent iron deposition), Type-2 lesions had significantly higher MD and lower FA (P < 0.001) as well as lower perfusion measurements (P < 0.05), while Type 3 lesions had significantly higher perfusion (P < 0.001) and lower FA (P < 0.05). Compared to Type-2, Type-3 lesions had higher perfusion (P < 0.0001) and marginally higher MD and lower FA (P < 0.05). Conclusion: The significant differences in diffusion and perfusion MRI metrics associated with MS lesions, that appear with different signal appearance on SWI, may help to identify the underlying destructive pathways of myelin and axons and their evolution related to inflammatory activities.
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Affiliation(s)
- Huaqiang Sheng
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan, China.,Department of Radiology, New York University School of Medicine, New York, NY, United States
| | - Bin Zhao
- Department of Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Yulin Ge
- Department of Radiology, New York University School of Medicine, New York, NY, United States
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Melendez-Torres GJ, Auguste P, Armoiry X, Maheswaran H, Court R, Madan J, Kan A, Lin S, Counsell C, Patterson J, Rodrigues J, Ciccarelli O, Fraser H, Clarke A. Clinical effectiveness and cost-effectiveness of beta-interferon and glatiramer acetate for treating multiple sclerosis: systematic review and economic evaluation. Health Technol Assess 2018; 21:1-352. [PMID: 28914229 DOI: 10.3310/hta21520] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND At the time of publication of the most recent National Institute for Health and Care Excellence (NICE) guidance [technology appraisal (TA) 32] in 2002 on beta-interferon (IFN-β) and glatiramer acetate (GA) for multiple sclerosis, there was insufficient evidence of their clinical effectiveness and cost-effectiveness. OBJECTIVES To undertake (1) systematic reviews of the clinical effectiveness and cost-effectiveness of IFN-β and GA in relapsing-remitting multiple sclerosis (RRMS), secondary progressive multiple sclerosis (SPMS) and clinically isolated syndrome (CIS) compared with best supportive care (BSC) and each other, investigating annualised relapse rate (ARR) and time to disability progression confirmed at 3 months and 6 months and (2) cost-effectiveness assessments of disease-modifying therapies (DMTs) for CIS and RRMS compared with BSC and each other. REVIEW METHODS Searches were undertaken in January and February 2016 in databases including The Cochrane Library, MEDLINE and the Science Citation Index. We limited some database searches to specific start dates based on previous, relevant systematic reviews. Two reviewers screened titles and abstracts with recourse to a third when needed. The Cochrane tool and the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and Philips checklists were used for appraisal. Narrative synthesis and, when possible, random-effects meta-analysis and network meta-analysis (NMA) were performed. Cost-effectiveness analysis used published literature, findings from the Department of Health's risk-sharing scheme (RSS) and expert opinion. A de novo economic model was built for CIS. The base case used updated RSS data, a NHS and Personal Social Services perspective, a 50-year time horizon, 2014/15 prices and a discount rate of 3.5%. Outcomes are reported as incremental cost-effectiveness ratios (ICERs). We undertook probabilistic sensitivity analysis. RESULTS In total, 6420 publications were identified, of which 63 relating to 35 randomised controlled trials (RCTs) were included. In total, 86% had a high risk of bias. There was very little difference between drugs in reducing moderate or severe relapse rates in RRMS. All were beneficial compared with BSC, giving a pooled rate ratio of 0.65 [95% confidence interval (CI) 0.56 to 0.76] for ARR and a hazard ratio of 0.70 (95% CI, 0.55 to 0.87) for time to disability progression confirmed at 3 months. NMA suggested that 20 mg of GA given subcutaneously had the highest probability of being the best at reducing ARR. Three separate cost-effectiveness searches identified > 2500 publications, with 26 included studies informing the narrative synthesis and model inputs. In the base case using a modified RSS the mean incremental cost was £31,900 for pooled DMTs compared with BSC and the mean incremental quality-adjusted life-years (QALYs) were 0.943, giving an ICER of £33,800 per QALY gained for people with RRMS. In probabilistic sensitivity analysis the ICER was £34,000 per QALY gained. In sensitivity analysis, using the assessment group inputs gave an ICER of £12,800 per QALY gained for pooled DMTs compared with BSC. Pegylated IFN-β-1 (125 µg) was the most cost-effective option of the individual DMTs compared with BSC (ICER £7000 per QALY gained); GA (20 mg) was the most cost-effective treatment for CIS (ICER £16,500 per QALY gained). LIMITATIONS Although we built a de novo model for CIS that incorporated evidence from our systematic review of clinical effectiveness, our findings relied on a population diagnosed with CIS before implementation of the revised 2010 McDonald criteria. CONCLUSIONS DMTs were clinically effective for RRMS and CIS but cost-effective only for CIS. Both RCT evidence and RSS data are at high risk of bias. Research priorities include comparative studies with longer follow-up and systematic review and meta-synthesis of qualitative studies. STUDY REGISTRATION This study is registered as PROSPERO CRD42016043278. FUNDING The National Institute for Health Research Health Technology Assessment programme.
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Affiliation(s)
- G J Melendez-Torres
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Peter Auguste
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Xavier Armoiry
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Hendramoorthy Maheswaran
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Rachel Court
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Jason Madan
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Alan Kan
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Stephanie Lin
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Carl Counsell
- Divison of Applied Health Sciences, University of Aberdeen, Aberdeen, UK
| | | | - Jeremy Rodrigues
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Olga Ciccarelli
- Department of Neuroinflammation, Institute of Neurology, University College London, London, UK
| | - Hannah Fraser
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Aileen Clarke
- Warwick Evidence, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
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Gupta A, Al-Dasuqi K, Xia F, Askin G, Zhao Y, Delgado D, Wang Y. The Use of Noncontrast Quantitative MRI to Detect Gadolinium-Enhancing Multiple Sclerosis Brain Lesions: A Systematic Review and Meta-Analysis. AJNR Am J Neuroradiol 2017; 38:1317-1322. [PMID: 28522663 DOI: 10.3174/ajnr.a5209] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/22/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND Concerns have arisen about the long-term health effects of repeat gadolinium injections in patients with multiple sclerosis and the incomplete characterization of MS lesion pathophysiology that results from relying on enhancement characteristics alone. PURPOSE Our aim was to perform a systematic review and meta-analysis analyzing whether noncontrast MR imaging biomarkers can distinguish enhancing and nonenhancing brain MS lesions. DATA SOURCES Our sources were Ovid MEDLINE, Ovid Embase, and the Cochrane data base from inception to August 2016. STUDY SELECTION We included 37 journal articles on 985 patients with MS who had MR imaging in which T1-weighted postcontrast sequences were compared with noncontrast sequences obtained during the same MR imaging examination by using ROI analysis of individual MS lesions. DATA ANALYSIS We performed random-effects meta-analyses comparing the standard mean difference of each MR imaging metric taken from enhancing-versus-nonenhancing lesions. DATA SYNTHESIS DTI-based fractional anisotropy values are significantly different between enhancing and nonenhancing lesions (P = .02), with enhancing lesions showing decreased fractional anisotropy compared with nonenhancing lesions. Of the other most frequently studied MR imaging biomarkers (mean diffusivity, magnetization transfer ratio, or ADC), none were significantly different (P values of 0.30, 0.47, and 0.19. respectively) between enhancing and nonenhancing lesions. Of the limited studies providing diagnostic accuracy measures, gradient-echo-based quantitative susceptibility mapping had the best performance in discriminating enhancing and nonenhancing MS lesions. LIMITATIONS MR imaging techniques and patient characteristics were variable across studies. Most studies did not provide diagnostic accuracy measures. All imaging metrics were not studied in all 37 studies. CONCLUSIONS Noncontrast MR imaging techniques, such as DTI-based FA, can assess MS lesion acuity without gadolinium.
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Affiliation(s)
- A Gupta
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.) .,Clinical and Translational Neuroscience Unit (A.G.), Feil Family Brain and Mind Research Institute
| | - K Al-Dasuqi
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.)
| | - F Xia
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.).,Department of Biomedical Engineering (F.X., Y.W.), Cornell University, Ithaca, New York
| | - G Askin
- Department of Healthcare Policy and Research (G.A., Y.Z.)
| | - Y Zhao
- Department of Healthcare Policy and Research (G.A., Y.Z.)
| | - D Delgado
- Samuel J. Wood Library and C.V. Starr Biomedical Information Center (D.D.), Weill Cornell Medicine, New York, New York
| | - Y Wang
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.).,Department of Biomedical Engineering (F.X., Y.W.), Cornell University, Ithaca, New York
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Pakpoor J, Saylor D, Izbudak I, Liu L, Mowry EM, Yousem DM. Emergency Department MRI Scanning of Patients with Multiple Sclerosis: Worthwhile or Wasteful? AJNR Am J Neuroradiol 2017; 38:12-17. [PMID: 27758773 DOI: 10.3174/ajnr.a4953] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/11/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The increasing use of the emergency department MR imaging scanner at our institution raises questions about its added value to certain patient groups. We hypothesized that the use of emergency department MR imaging for identifying active demyelination in MS patients presenting with new neurologic symptoms would be of low yield. MATERIALS AND METHODS Electronic medical records were reviewed for patients with MS who had emergency department MR imaging scans for a suspected MS exacerbation between March 1, 2014, and March 1, 2016. Details surrounding patient disposition, imaging, diagnosis, and management were determined. RESULTS Of 115 patients in our study, 48 (41.7%) were ultimately diagnosed with an MS exacerbation. Nearly all patients with MS exacerbations (87.5%, 42/48) had active demyelination on their emergency department MR imaging, identified on 30.6% (33/108) of brain MRIs and 20.4% (19/93) of spinal MRIs. The presence of active demyelination at MRI was significantly associated with the ultimate diagnosis of an MS exacerbation (P < .001). MR imaging activity isolated to the spinal cord (ie, not found on concurrent brain MR imaging) was present in only 9 of 93 (9.7%) cases. Pseudoexacerbations accounted for 18 of the alternative diagnoses. CONCLUSIONS Emergency department MR imaging is a worthwhile endeavor from a diagnostic standpoint for MS exacerbations despite not being part of the diagnostic criteria. This finding has corresponding downstream impact on management decisions to admit and/or administer intravenous steroids. However, we raise the question of whether clinicians over-rely on emergency department imaging for making exacerbation diagnoses. Additionally, spinal MR imaging is of questionable value as an addition to brain MR imaging due to a low yield of isolated spinal disease.
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Affiliation(s)
- J Pakpoor
- From the Division of Neuroradiology (J.P., I.I., L.L., D.M.Y.), Russell H. Morgan Department of Radiology and Radiological Science
| | - D Saylor
- Department of Neurology (D.S., E.M.M.), Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - I Izbudak
- From the Division of Neuroradiology (J.P., I.I., L.L., D.M.Y.), Russell H. Morgan Department of Radiology and Radiological Science
| | - L Liu
- From the Division of Neuroradiology (J.P., I.I., L.L., D.M.Y.), Russell H. Morgan Department of Radiology and Radiological Science
| | - E M Mowry
- Department of Neurology (D.S., E.M.M.), Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - D M Yousem
- From the Division of Neuroradiology (J.P., I.I., L.L., D.M.Y.), Russell H. Morgan Department of Radiology and Radiological Science
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Karami V, Khayati RM, Nabavi SM. ASSOCIATION ASSESSMENT BETWEEN DIFFUSION TENSOR MAGNETIC RESONANCE IMAGING INDICES AND CLINICAL DISABILITIES IN MS PATIENTS. BIOMEDICAL ENGINEERING: APPLICATIONS, BASIS AND COMMUNICATIONS 2016. [DOI: 10.4015/s1016237216500344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Purpose: Diffusion tensor magnetic resonance imaging (DT-MRI) has the ability to gather information on tissue microstructure by using the indices that quantify the anisotropy of water diffusion in tissues. This study was designed to find out the impact of patient clinical disability on diffusion tensor (DT) indices. Method: In this paper, images were generated from the data acquired at 3T among 25 MS patients (mean age [Formula: see text] years old). DT indices including fractional anisotropy (FA), mean diffusivity (MD), relative anisotropy (RA), and volume ratio (VR) of multiple sclerosis (MS) lesions are calculated and the correlation between Kurtzke expanded disability status scale (EDSS) score and the values of DT indices of 25 MS patients lesions are obtained. The correlation comparison procedure is done between the EDSS scores and DT indices in MS lesions attained, respectively, from fluid attenuated inversion recovery (FLAIR) images and black holes of T1-weighted (T1-w) images. Results: EDSS scores and DT indices of MS lesions extracted from the black holes present in T1-w images are more correlated in comparison with those extracted from FLAIR images. It is found that MD has a significant correlation with EDSS in both types of images. The results of FLAIR image processing indicates that any increase in EDSS leads to decreasing FA and RA on one hand and increasing MD and VR on the other hand. The correlation between the identical size of lesions in different parts of brain with EDSS shows that the location of lesion in brain also has a correlation with EDSS. Conclusion: The results showed, MD is the best biomarker of clinical disability between these four DT indices. It is also concluded that the correlation between DT indices of frontal brain lesions and EDSS is higher than the other selected brain parts.
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Affiliation(s)
- Vania Karami
- Biomedical Engineering Department, Shahed University, Tehran, Iran
| | | | - S. Massood Nabavi
- Neurology Department, Medical Faculty, Shahed University, Tehran, Iran
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Ontaneda D, Sakaie K, Lin J, Wang XF, Lowe MJ, Phillips MD, Fox RJ. Measuring Brain Tissue Integrity during 4 Years Using Diffusion Tensor Imaging. AJNR Am J Neuroradiol 2016; 38:31-38. [PMID: 27659189 DOI: 10.3174/ajnr.a4946] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/26/2016] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND PURPOSE DTI is an MR imaging measure of brain tissue integrity. Little is known regarding the long-term longitudinal evolution of lesional and nonlesional tissue DTI parameters in multiple sclerosis and the present study examines DTI evolution over 4 years. MATERIALS AND METHODS Twenty-one patients with multiple sclerosis were imaged for up to 48 months after starting natalizumab therapy. Gadolinium-enhancing lesions at baseline, chronic T2 lesions, and normal-appearing white matter were followed longitudinally. T2 lesions were subclassified as black holes and non-black holes. Within each ROI, the average values of DTI metrics were derived by using Analysis of Functional Neuro Images software. The longitudinal trend in DTI metrics was estimated by using a mixed-model regression analysis. RESULTS A significant increase was observed for axial diffusivity (P < .001) in gadolinium-enhancing lesions and chronic T2 lesions during 4 years. No significant change in radial diffusivity either in normal-appearing white matter or lesional tissue was observed. The evolution of axial diffusivity was different in gadolinium-enhancing lesions (P < .001) and chronic T2 lesions (P = .02) compared with normal-appearing white matter. CONCLUSIONS An increase in axial diffusion in both gadolinium-enhancing lesions and T2 lesions may relate to the complex evolution of chronically demyelinated brain tissue. Pathologic changes in normal-appearing white matter are likely more subtle than in lesional tissue and may explain the stability of these measures with DTI.
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Affiliation(s)
- D Ontaneda
- From the Department of Neurology (D.O., R.J.F.), Neurological Institute, Mellen Center for Multiple Sclerosis Treatment and Research
| | - K Sakaie
- Imaging Institute (K.S., J.L., M.J.L., M.D.P.)
| | - J Lin
- Imaging Institute (K.S., J.L., M.J.L., M.D.P.)
| | - X-F Wang
- Department of Quantitative Health Sciences (X.-F.W.), Cleveland Clinic Foundation, Cleveland, Ohio
| | - M J Lowe
- Imaging Institute (K.S., J.L., M.J.L., M.D.P.)
| | | | - R J Fox
- From the Department of Neurology (D.O., R.J.F.), Neurological Institute, Mellen Center for Multiple Sclerosis Treatment and Research
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Klistorner A, Wang C, Fofanova V, Barnett MH, Yiannikas C, Parratt J, You Y, Graham SL. Diffusivity in multiple sclerosis lesions: At the cutting edge? NEUROIMAGE-CLINICAL 2016; 12:219-26. [PMID: 27489769 PMCID: PMC4950592 DOI: 10.1016/j.nicl.2016.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/04/2016] [Accepted: 07/04/2016] [Indexed: 12/22/2022]
Abstract
Background Radial Diffusivity (RD) has been suggested as a promising biomarker associated with the level of myelination in MS lesions. However, the level of RD within the lesion is affected not only by loss of myelin sheaths, but also by the degree of tissue destruction. This may lead to exaggeration of diffusivity measures, potentially masking the effect of remyelination. Objective To test the hypothesis that the T2 hyperintense lesion edge that extends beyond the T1 hypointense lesion core is less affected by tissue loss, and therefore a more appropriate target for imaging biomarker development targeting de- and re-myelination. Method Pre- and post-gadolinium (Gd) enhanced T1, T2 and DTI images were acquired from 75 consecutive RRMS patients. The optic radiation (OR) was identified in individual patients using a template-based method. T2 lesions were segmented into T1-hypointense and T1-isointense areas and lesion masks intersected with the OR. Average Radial, Axial and Mean diffusivity (RD, AD and MD) and fractional anisotropy (FA) were calculated for lesions of the entire brain and the OR. In addition, Gd enhancing lesions were excluded from the analysis. Results 86% of chronic T2 lesions demonstrated hypointense areas on T1-weighted images, which typically occupied the central part of each T2 lesion, taking about 40% of lesional volume. The T1-isointense component of the T2 lesion was most commonly seen as a peripheral ring of relatively constant thickness (“T2-rim”). While changes of diffusivity between adjacent normal appearing white matter and the “T2-rim” demonstrated a disproportionally high elevation of RD compare to AD, the increase of water diffusion was largely isointense between the “T2-rim” and T1-hypointense parts of the lesion. Conclusion Distinct patterns of diffusivity within the central and peripheral components of MS lesions suggest that axonal loss dominates in the T1 hypointense core. The effects of de/remyelination may be more readily detected in the “T2-rim”, where there is relative preservation of structural integrity. Identifying and separating those patterns has an important implication for clinical trials of both neuroprotective and, in particular, remyelinating agents. Distinct patterns of diffusivity within the central and peripheral components of MS lesions were identified. Axonal loss is likely to dominate the T1 hypointense core. The effects of de/remyelination may be more readily detected in the “T2-rim”.
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Affiliation(s)
- Alexander Klistorner
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
- Corresponding author at: Save Sight Institute, University of Sydney, 8 Macquarie St. Sydney, NSW 2000, Australia.Save Sight InstituteUniversity of Sydney8 Macquarie St. SydneyNSW2000Australia
| | - Chenyu Wang
- Brain and Mind Research Institute, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Vera Fofanova
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Michael H. Barnett
- Brain and Mind Research Institute, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | | | - John Parratt
- Royal North Shore Hospital, Sydney, NSW, Australia
| | - Yuyi You
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Stuart L. Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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9
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Inal M, Unal B, Kala I, Turkel Y, Bilgili YK. ADC evaluation of the corticospinal tract in multiple sclerosis. Acta Neurol Belg 2015; 115:105-9. [PMID: 24878661 DOI: 10.1007/s13760-014-0311-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/13/2014] [Indexed: 10/25/2022]
Abstract
Apparent diffusion coefficient (ADC) values derived from diffusion-weighted MR imaging (DWI) provide important information about tissues. The goal of this study was to evaluate the ADC values in the corticospinal tract regions in multiple sclerosis (MS). The ADC values of 42 patients with multiple sclerosis and 46 healthy people were measured. The ADC values in the corticospinal tract at the capsula interna posterior crus from six points and mesencephalon from three points bilaterally in MS patients were compared with those of controls. An ANOVA post hoc test was used to analyse the differences in mean ADC values between the MS and control groups. The mean ADC values of the right (p = 0.008) and left internal capsules (p = 0.000) and right (p = 0.002) and left mesencephalons (p = 0.044) in MS patients were significantly lower than in the control group. There was no significant difference between the right and left side ADC values in MS (p = 0.313 vs. p = 0.223) and control groups (p = 0.756 vs. p = 0.105), respectively. The mean ADC values of the corticospinal tract in MS patients were significantly lower than in the control group. This decreased diffusion may be the result of cellular infiltration due to inflammation, cytotoxic oedema, demyelination or remyelination processes.
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10
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Balashov KE, Lindzen E. Acute demyelinating lesions with restricted diffusion in multiple sclerosis. Mult Scler 2012; 18:1745-53. [PMID: 22523157 DOI: 10.1177/1352458512445407] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND OBJECTIVES It is widely accepted that typical acute demyelinating lesions in relapsing-remitting multiple sclerosis (RRMS) exhibit vasogenic edema with increased diffusion, as demonstrated by an increased apparent diffusion coefficient on MRI. In contrast, acute ischemic lesions demonstrate cytotoxic edema with restricted diffusion. Recent reports have documented selected cases of acute demyelinating lesions exhibiting restricted diffusion (ADLRD) in MS. We aimed to assess the morphologies, distributions, signal characteristics and changes over time of nine ADLRD. An additional goal was to obtain clinical correlations and relate our findings to all previously published case reports describing ADLRD. METHODS A retrospective case series study was performed at two academic centers. MRI characteristics of nine ADLRD found in six RRMS patients were compared with typical active symptomatic contrast-enhancing lesions with increased or normal diffusion in control RRMS patients. RESULTS The average size of ADLRD was not significantly different from typical lesions. A periventricular location and faint signal on T2-weighted images were significantly more common for ADLRD compared with typical lesions. Two patients with ADLRD on initial MRI exhibited new ADLRD on their follow up scans. CONCLUSION Our results and review of prior published cases suggest that ADLRD represent a new variant of MS lesion. The restricted diffusion that is a characteristic of ADLRD on MRI is a new challenge in the differential diagnosis of stroke in young adults. The pathogenesis of ADLRD remains to be understood.
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Affiliation(s)
- Konstantin E Balashov
- Department of Neurology, UMDNJ, Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA.
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Sämann PG, Knop M, Golgor E, Messler S, Czisch M, Weber F. Brain volume and diffusion markers as predictors of disability and short-term disease evolution in multiple sclerosis. AJNR Am J Neuroradiol 2012; 33:1356-62. [PMID: 22383242 DOI: 10.3174/ajnr.a2972] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE MRI markers of neuroaxonal damage in MS have emerged as critical long-term predictors of MS-related disability. Here we investigated the potential of whole-brain diffusivity and brain volume for the prediction of cross-sectional disability and short- to medium-term clinical evolution. MATERIALS AND METHODS In this multimodal prospective longitudinal MRI study of 54 patients with MS (87% under immunomodulatory therapy, baseline and follow-up at a median of 12 months), ADC histogram analysis, WM lesion load, BPF, whole-brain atrophy rate, MSFC score, and EDSS score were obtained. A total of 44 patients with no relapse at both time points were included. RESULTS At both time points, ADC histogram analysis provided robust predictors of the MSFC scores (maximal R(2) = 0.576, P < .001), incorporated cognition and fine-motor skill subscores, and EDSS scores. Significant changes beyond physiologic age-related changes at follow-up were noted for ADC histogram markers and BPF. Stronger diffusivity alterations and brain volume at baseline predicted MSFC decline, as demonstrated by multiple linear regression analysis (mean ADC, R(2) = 0.203; P = .003) and lower baseline BPF in patients with declined compared with stable MSFC scores (P = .001). Results were independent of intercurrent relapses. CONCLUSIONS Diffusion histogram analysis provided stable surrogates of disability in MS and proved sensitive for monitoring disease progression during a median of 12 months. Advanced neuroaxonal pathology at baseline was indicative of an increased risk for sustained progression during a median of 12 months, independent of intercurrent relapses.
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Affiliation(s)
- P G Sämann
- Neuroimaging Research Group, Max Planck Institute of Psychiatry, Munich, Germany.
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12
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Inglese M, Bester M. Diffusion imaging in multiple sclerosis: research and clinical implications. NMR IN BIOMEDICINE 2010; 23:865-72. [PMID: 20882528 PMCID: PMC3071990 DOI: 10.1002/nbm.1515] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Multiple sclerosis (MS) is an inflammatory-demyelinating and neurodegenerative disease of the central nervous system (CNS) and the most frequent cause of non-traumatic disability in young and middle-age adults. Although conventional MRI (including T2-weighted, pre- and post-contrast T1-weighted scans) has had a huge impact on MS by enabling an earlier diagnosis, and by providing surrogate markers for monitoring treatment response, it is limited by the low pathological specificity and the low sensitivity to diffuse damage in normal-appearing white matter and gray matter. Diffusion weighted MRI is a quantitative technique able to overcome these limitations by providing markers more specific to the underlying pathologic substrates and more sensitive to the full extent of 'occult' brain tissue damage. This review describes diffusion studies in MS, discusses their pathophysiological implications and emphasizes their clinical relevance.
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Affiliation(s)
- M Inglese
- Department of Radiology, New York University School of Medicine, New York 10016, USA.
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13
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Naismith RT, Xu J, Tutlam NT, Scully PT, Trinkaus K, Snyder AZ, Song SK, Cross AH. Increased diffusivity in acute multiple sclerosis lesions predicts risk of black hole. Neurology 2010; 74:1694-701. [PMID: 20498437 DOI: 10.1212/wnl.0b013e3181e042c4] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Diffusion tensor imaging (DTI) quantifies Brownian motion of water within tissue. Inflammation leads to tissue injury, resulting in increased diffusivity and decreased directionality. We hypothesize that DTI can quantify the damage within acute multiple sclerosis (MS) white matter lesions to predict gadolinium (Gd)-enhancing lesions that will persist 12 months later as T1 hypointensities. METHODS A cohort of 22 individuals underwent 7 brain MRI scans over 15 months. DTI parameters were temporally quantified within regions of Gd enhancement. Comparison to the homologous region in the hemisphere contralateral to the Gd-enhancing lesion was also performed to standardize individual lesion DTI parameters. RESULTS After classifying each Gd-enhancing region as to black hole outcome, radial diffusivity, mean diffusivity, and fractional anisotropy, along with their standardized values, were significantly altered for persistent black holes (PBHs), and remained elevated throughout the study. A Gd-enhancing region with a 40% elevation in radial diffusivity had a 5.4-fold (95% confidence interval [CI]: 2.1, 13.8) increased risk of becoming a PBH, with 70% (95% CI: 51%, 85%) sensitivity and 69% (95% CI: 57%, 80%) specificity. A model of radial diffusivity, with volume and length of Gd enhancement, was associated with a risk of becoming a PBH of 5.0 (95% CI: 2.6, 9.9). Altered DTI parameters displayed a dose relationship to duration of black hole persistence. CONCLUSIONS Elevated radial diffusivity during gadolinium enhancement was associated with increased risk for development of a persistent black hole, a surrogate of severe demyelination and axonal injury. An elevated radial diffusivity within active multiple sclerosis lesions may be indicative of more severe tissue injury.
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Affiliation(s)
- R T Naismith
- Neurology, Washington University, St. Louis, MO 63110, USA.
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14
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Kim DS, Na DG, Kim KH, Kim JH, Kim E, Yun BL, Chang KH. Distinguishing Tumefactive Demyelinating Lesions from Glioma or Central Nervous System Lymphoma: Added Value of Unenhanced CT Compared with Conventional Contrast-enhanced MR Imaging. Radiology 2009; 251:467-75. [DOI: 10.1148/radiol.2512072071] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Paavilainen T, Kurki T, Korhonen K, Airas L. Apparent Diffusion Coefficient Histograms in the Follow-up of Relapsing-Remitting Multiple Sclerosis. Neuroradiol J 2009; 22:22-8. [PMID: 24206949 DOI: 10.1177/197140090902200104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 02/08/2009] [Indexed: 11/17/2022] Open
Abstract
Diffusion-weighted (DW) magnetic resonance (MR) imaging in addition to conventional magnetic resonance MR images provide valuable information in multiple sclerosis (MS). Increased diffusivity measured with diffusion-weighted imaging (DWI) has been demonstrated in normal appearing brain tissue in MS. So far, longitudinal changes taking place in whole-brain histograms in patients with active relapsing-remitting MS have not been evaluated. The aim of this study was to evaluate how apparent diffusion coefficient (ADC) histograms are altered during the follow-up of active relapsing-remitting MS patients. Nine patients were studied twice by MRI with a three-month interval. All patients had active newly diagnosed MS with two to three relapses during the year preceding the first MRI, and interferon-beta treatment was initiated after obtaining the first image. ADC histograms were produced after removing extracranial tissues and cerebrospinal fluid from the images. Additionally, brain volume index (BVI) and lesion volume on FLAIR images were measured. Five patients had signs of disease activity in the follow-up MRI. In the four patients without signs of disease activity the change in ADC histogram parameters was less than 2%. In patients with disease activity both increase (one case) and decrease (four cases) in histogram parameters were detected. Changes in BVI or lesion volume did not significantly correlate with histogram changes. The number of new T2-lesions showed a positive correlation with mean (r=0.79, P=0.014) and upper quartile (r=0.77, P=0.021) value change. Alterations in disease activity lead to histogram changes; both shifts to lower values and shifts to higher values are possible. The histogram changes are mostly related to subtle inflammatory changes in normal appearing brain tissue during inflammatory activity and their resolution during less active inflammatory conditions.
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Affiliation(s)
- T Paavilainen
- Medical Imaging Centre of Southwest Finland, Turku University Hospital; Turku, Finland -
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16
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MacKay AL, Vavasour IM, Rauscher A, Kolind SH, Mädler B, Moore GRW, Traboulsee AL, Li DKB, Laule C. MR relaxation in multiple sclerosis. Neuroimaging Clin N Am 2009; 19:1-26. [PMID: 19064196 DOI: 10.1016/j.nic.2008.09.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This article provides an overview of relaxation times and their application to normal brain and brain and cord affected by multiple sclerosis. The goal is to provide readers with an intuitive understanding of what influences relaxation times, how relaxation times can be accurately measured, and how they provide specific information about the pathology of MS. The article summarizes significant results from relaxation time studies in the normal human brain and cord and from people who have multiple sclerosis. It also reports on studies that have compared relaxation time results with results from other MR techniques.
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Affiliation(s)
- A L MacKay
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada.
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17
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Chung SH, Cerussi AE, Klifa C, Baek HM, Birgul O, Gulsen G, Merritt SI, Hsiang D, Tromberg BJ. In vivo water state measurements in breast cancer using broadband diffuse optical spectroscopy. Phys Med Biol 2008; 53:6713-27. [PMID: 18997265 DOI: 10.1088/0031-9155/53/23/005] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Structural changes in water molecules are related to physiological, anatomical and pathological properties of tissues. Near infrared (NIR) optical absorption methods are sensitive to water; however, detailed characterization of water in thick tissues is difficult to achieve because subtle spectral shifts can be obscured by multiple light scattering. In the NIR, a water absorption peak is observed around 975 nm. The precise NIR peak's shape and position are highly sensitive to water molecular disposition. We introduce a bound water index (BWI) that quantifies shifts observed in tissue water absorption spectra measured by broadband diffuse optical spectroscopy (DOS). DOS quantitatively measures light absorption and scattering spectra and therefore reveals bound water spectral shifts. BWI as a water state index was validated by comparing broadband DOS to magnetic resonance spectroscopy, diffusion-weighted MRI and conductivity in bound water tissue phantoms. Non-invasive DOS measurements of malignant and normal breast tissues performed in 18 subjects showed a significantly higher fraction of free water in malignant tissues (p < 0.0001) compared to normal tissues. BWI of breast cancer tissues inversely correlated with Nottingham-Bloom-Richardson histopathology scores. These results highlight broadband DOS sensitivity to molecular disposition of water and demonstrate the potential of BWI as a non-invasive in vivo index that correlates with tissue pathology.
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Affiliation(s)
- S H Chung
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road, Irvine, CA 92612, USA
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18
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Lowe MJ, Beall EB, Sakaie KE, Koenig KA, Stone L, Marrie RA, Phillips MD. Resting state sensorimotor functional connectivity in multiple sclerosis inversely correlates with transcallosal motor pathway transverse diffusivity. Hum Brain Mapp 2008; 29:818-27. [PMID: 18438889 DOI: 10.1002/hbm.20576] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Recent studies indicate that functional connectivity using low-frequency BOLD fluctuations (LFBFs) is reduced between the bilateral primary sensorimotor regions in multiple sclerosis. In addition, it has been shown that pathway-dependent measures of the transverse diffusivity of water in white matter correlate with related clinical measures of functional deficit in multiple sclerosis. Taken together, these methods suggest that MRI methods can be used to probe both functional connectivity and anatomic connectivity in subjects with known white matter impairment. We report the results of a study comparing anatomic connectivity of the transcallosal motor pathway, as measured with diffusion tensor imaging (DTI) and functional connectivity of the bilateral primary sensorimotor cortices (SMC), as measured with LFBFs in the resting state. High angular resolution diffusion imaging was combined with functional MRI to define the transcallosal white matter pathway connecting the bilateral primary SMC. Maps were generated from the probabilistic tracking employed and these maps were used to calculate the mean pathway diffusion measures fractional anisotropy FA, mean diffusivity MD, longitudinal diffusivity lambda(1), and transverse diffusivity lambda(2). These were compared with LFBF-based functional connectivity measures (F(c)) obtained at rest in a cohort of 11 multiple sclerosis patients and approximately 10 age- and gender-matched control subjects. The correlation between FA and F(c) for MS patients was r = -0.63, P < 0.04. The correlation between all subjects lambda(2) and F(c) was r = 0.42, P < 0.05. The correlation between all subjects lambda(2) and F(c) was r = -0.50, P < 0.02. None of the control subject correlations were significant, nor were FA, lambda(1), or MD significantly correlated with F(c) for MS patients. This constitutes the first in vivo observation of a correlation between measures of anatomic connectivity and functional connectivity using spontaneous LFBFs.
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Affiliation(s)
- Mark J Lowe
- Imaging Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
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19
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Bosnell R, Giorgio A, Johansen-Berg H. Imaging white matter diffusion changes with development and recovery from brain injury. Dev Neurorehabil 2008; 11:174-86. [PMID: 18781502 DOI: 10.1080/17518420802289065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE This study reviews the application of diffusion tensor imaging (DTI) to the study of developmental and pathological changes in brain white matter. The ability to measure and monitor such changes in vivo would provide important opportunities for charting disease progression and monitoring response to therapeutic intervention. This study first reviews the use of DTI in studying normal human brain development. It goes on to illustrate how DTI has been used to provide insights into recovery from damage in selected brain disorders. CONCLUSIONS It is concluded that potential clinical applications of DTI include: (i) monitoring pathological change, (ii) providing markers that predict recovery and allow for individual targeting of therapy, (iii) providing outcome measures, (iv) providing measures of potentially compensatory structural changes and (v) improving understanding of normal brain anatomy to aid in interpretation of the consequences of localized damage.
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Affiliation(s)
- Rose Bosnell
- Oxford Centre for Functional MRI of the Brain, John Radcliffe Hospital, Headington, Oxford, UK
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20
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Vavasour IM, Li DKB, Laule C, Traboulsee AL, Moore GRW, MacKay AL. Multi-parametric MR assessment of T1 black holes in multiple sclerosis. J Neurol 2007; 254:1653-9. [DOI: 10.1007/s00415-007-0604-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 01/31/2007] [Accepted: 02/27/2007] [Indexed: 12/19/2022]
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21
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Paavilainen T, Kurki T, Parkkola R, Färkkilä M, Salonen O, Dastidar P, Elovaara I, Airas L. Magnetic resonance imaging of the brain used to detect early post-partum activation of multiple sclerosis. Eur J Neurol 2007; 14:1216-21. [PMID: 17727663 DOI: 10.1111/j.1468-1331.2007.01927.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Post-partum relapses are a frequent phenomenon in multiple sclerosis (MS). The purpose of this study was to evaluate the timing and extent of new or growing T2-lesions after delivery in a cohort of Finnish MS patients. In addition to serial magnetic resonance imaging (MRI), the patients were followed up clinically with determination of relapse rate and expanded disability status scale. The annualized relapse rate was decreased during the last trimester of pregnancy [mean 0.14, standard deviation (SD) 0.14] when compared with the time before pregnancy (mean 0.64, SD 0.14; P = 0.04) and to time post-partum (mean 1.50, SD 0.45; P = 0.0002). New or enlarging lesions were detected in the post-partum images in 14 of 28 patients. Gadolinium-enhancing lesions in post-partum MRI were present in eight of 13 patients. There was a significant increase in the number of T2-lesions (P = 0.0009), in the total volume of MS-lesions measured from fluid-attenuated inversion recovery images (P = 0.0126) and in the number of diffusion weighted imaging hyperintense lesions (P = 0.0098) in the post-partum images. The clinical results support the earlier findings of decreased disease activity in late pregnancy. The clinical and MRI findings indicate that post-partum activation is an early and common phenomenon amongst mothers with MS.
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Affiliation(s)
- T Paavilainen
- Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku, Finland
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22
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Yurtsever I, Hakyemez B, Taskapilioglu O, Erdogan C, Turan OF, Parlak M. The contribution of diffusion-weighted MR imaging in multiple sclerosis during acute attack. Eur J Radiol 2007; 65:421-6. [PMID: 17587524 DOI: 10.1016/j.ejrad.2007.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 04/27/2007] [Accepted: 05/02/2007] [Indexed: 10/23/2022]
Abstract
PURPOSE The aims of the study are firstly, to determine the difference in diffusion-weighted imaging (DWI) in normal appearing white matter (NAWM) between patients with acute multiple sclerosis (MS) and controls; secondly, to determine whether there is a correlation between EDSS scores and DWI in acute plaques and also NAWM. MATERIALS AND METHOD Out of 50 patients with acute MS attack, 35 patients had active plaques with diffuse or ring enhancement on postcontrast images. Eighteen healthy volunteers constituted the control group. While 26 of 35 had relapsing-remitting, 9 had secondary progressive MS. Apparent diffusion coefficients (ADC) of the active plaques, NAWM at the level of centrum semiovale and occipital horn of lateral ventricle in the patients and NAWM in control group were measured. ADC values of active plaques were compared with WM of the patients and the control group. The relationship of ADC value of active plaques and WM in MS with expanded disability status scale (EDSS) was investigated by using Mann-Whitney U-test. RESULTS Of 63 plaques totally, 26 and 37 of the active plaques had diffuse and ring enhancement, respectively. There was no statistically significant difference between ADC value of active plaques and EDSS (p>0.05). However, there was a statistically significant difference between ADC value of WM occipital horn and EDSS (p<0.05). ADC value of active plaques were higher than WM in both groups (p<0.001). The difference between ADC value of WM at the centrum semiovale (p<0.05) and occipital horns (p<0.001) in patients and controls was statistically significant. There was no statistically significant difference between EDSS scores, ADC value at centrum semiovale and WM around occipital horn and active plaques in subgroups (p>0.05). CONCLUSION Apparently normal tissue in MS patients may show early abnormalities when investigated carefully enough, and there is an even though moderate correlation between EDSS and ADC values and early alterations of ADC value are starting in the occipital white matter along the ventricles. This has to be verified in larger series.
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Affiliation(s)
- Ismail Yurtsever
- Uludag University Medical School, Department of Radiology, Bursa, Turkey
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23
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Abstract
We have summarized the diffusion-weighed imaging (DWI) findings in a number of different cerebral disorders. In many cases, DWI with the accompanying apparent diffusion coefficient (ADC) map provides additional useful information to the standard imaging sequences. Pathophysiologic mechanisms resulting in baseline normal ADC values and changes with disease processes are not well understood; therefore, caution should be used when prognosticating the outcome of regions with abnormal ADCs. DWI should be used as an adjunct to routine imaging and interpreted in the context of the routine imaging findings and clinical scenario. As our understanding of ADC mechanisms increases and we begin to incorporate information about tissue organization from diffusion tensor imaging or diffusion spectrum imaging, the role of these methods in clinical diagnosis should continue to increase.
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Affiliation(s)
- Pallavi Sagar
- Division of Pediatric Radiology, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
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24
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Oh J, Henry RG, Genain C, Nelson SJ, Pelletier D. Mechanisms of normal appearing corpus callosum injury related to pericallosal T1 lesions in multiple sclerosis using directional diffusion tensor and 1H MRS imaging. J Neurol Neurosurg Psychiatry 2004; 75:1281-6. [PMID: 15314115 PMCID: PMC1739254 DOI: 10.1136/jnnp.2004.039032] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To investigate the extent of tissue damage in a region of normal appearing corpus callosum (NACC) for different forms of multiple sclerosis (MS) using diffusion tensor and proton magnetic resonance (MR) spectroscopic imaging. METHODS A total of 47 patients with MS and 15 controls were included. Regions of interest from the NACC were manually segmented using high resolution anatomical images. Diffusion tensor eigenvalues and metabolite ratio of N-acetyl-aspartate (NAA) to creatine/phosphocreatine (Cr) were calculated in the NACC region. RESULTS Increased apparent diffusion coefficients (ADCs) and decreased anisotropy were observed in the NACC for patients with MS relative to the control subjects. These resulted from increased diffusion tensor eigenvalues perpendicular to the maximum diffusion direction. The NAA:Cr ratio was decreased in the NACC for patients with MS relative to the control subjects. Significant correlations between pericallosal T1 lesion load and MR modalities in the NACC were observed for patients with relapsing remitting/secondary progressive MS (RR/SPMS), but not for patients with primary progressive MS (PPMS). CONCLUSION This study provides further insight into changes in the ADC and diffusion anisotropy based on the diffusion tensor eigenvalues for patients with MS. The changes in the diffusion tensor eigenvalues and NAA:Cr ratio in the NACC for patients with RR/SPMS suggest axonal injury and/or dysfunction induced by wallerian degeneration. The lack of correlation between these variables in the NACC and focal MS lesions for patients with PPMS further supports intrinsic differences related to tissue injury between these subtypes of MS.
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Affiliation(s)
- J Oh
- Magnetic Resonance Science Center, Department of Radiology, University of California, San Francisco 94107, USA.
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Abstract
Magnetic resonance imaging (MRI) is often divided into structural MRI and functional MRI (fMRI). The former is a widely used imaging technique in research as well as in clinical practice. This review describes the more important developments in structural MRI in recent years, including high resolution imaging, T2 relaxation measurement, T2*-weighted imaging, T1 relaxation measurement, magnetisation transfer imaging, and diffusion imaging. The principles underlying these techniques, as well as their use in research and in clinical practice, will be discussed.
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Affiliation(s)
- M Symms
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, London, UK
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26
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Sundgren PC, Dong Q, Gómez-Hassan D, Mukherji SK, Maly P, Welsh R. Diffusion tensor imaging of the brain: review of clinical applications. Neuroradiology 2004; 46:339-50. [PMID: 15103435 DOI: 10.1007/s00234-003-1114-x] [Citation(s) in RCA: 276] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Accepted: 09/02/2003] [Indexed: 01/21/2023]
Abstract
We review the theoretical background to diffusion tensor imaging (DTI) and some of its commoner clinical applications, such as cerebral ischemia, brain maturation and traumatic brain injury. We also review its potential use in diseases such as epilepsy, multiple sclerosis, and Alzheimer's disease. The value of DTI in the investigation of brain tumors and metabolic disorders is assessed.
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Affiliation(s)
- P C Sundgren
- Department of Radiology, University of Michigan Health System, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0030, USA.
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27
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Filippi M, Rocca MA, Comi G. The use of quantitative magnetic-resonance-based techniques to monitor the evolution of multiple sclerosis. Lancet Neurol 2003; 2:337-46. [PMID: 12849150 DOI: 10.1016/s1474-4422(03)00408-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conventional MRI can improve accuracy in the diagnosis of multiple sclerosis (MS) and monitor the efficacy of experimental treatments. However, conventional MRI provides only gross estimates of the extent and nature of tissue damage associated with this disease. Other quantitative magnetic-resonance-based techniques have the potential to overcome the limitations of conventional MRI and, as a consequence, to improve our understanding of the natural history of MS. Magnetisation-transfer, diffusion-weighted, and functional MRI--as well as proton magnetic-resonance spectroscopy--are helping us to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. These techniques are substantially changing our understanding of how MS causes irreversible disability and should be used more extensively in clinical trials and in studies of disease progression.
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Affiliation(s)
- Massimo Filippi
- Department of Neurology, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
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28
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Chan JHM, Peh WCG, Tsui EYK, Chau LF, Cheung KK, Chan KB, Yuen MK, Wong ETH, Wong KPC. Acute vertebral body compression fractures: discrimination between benign and malignant causes using apparent diffusion coefficients. Br J Radiol 2002; 75:207-14. [PMID: 11932212 DOI: 10.1259/bjr.75.891.750207] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Diffusion weighted MRI was performed on patients with acute vertebral body compression. The usefulness of the apparent diffusion coefficient (ADC) in differentiating between benign and malignant fractures was evaluated. A total of 49 acute vertebral body compression fractures were found in 32 patients. 25 fractures in 18 patients were due to osteoporosis, 18 fractures in 12 patients were histologically proven to be due to malignancy, and 6 fractures in 2 patients were due to tuberculosis. Signal intensities on T(1) weighted, short tau inversion recovery (STIR) and diffusion weighted images were compared. ADC values of normal and abnormal vertebral bodies were calculated. Except for two patients with sclerotic metastases, benign acute vertebral fractures were hypointense and malignant acute vertebral fractures were hyperintense with respect to normal bone marrow on diffusion weighted images. Mean combined ADCs (ADC(cmb); average of the combined ADCs in the x, y and z diffusion directions) were 0.23 x 10(-3) mm(2) s(-1) in normal vertebrae, 0.82 x 10(-3) mm(2) s(-1) in malignant acute vertebral fractures and 1.94 x 10(-3) mm(2) s(-1) in benign acute vertebral fractures. The differences between ADC(cmb) values were statistically significant (p<0.001). The ADC is useful in differentiating benign from malignant acute vertebral body compression fractures, but there may be overlapping ADC values between malignant fractures and tuberculous spondylitis.
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Affiliation(s)
- J H M Chan
- Department of Diagnostic Radiology, Tuen Mun Hospital, Hong Kong
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29
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Horsfield MA. Using diffusion-weighted MRI in multicenter clinical trials for multiple sclerosis. J Neurol Sci 2001; 186 Suppl 1:S51-4. [PMID: 11334990 DOI: 10.1016/s0022-510x(01)00492-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This paper reviews the current state of knowledge about the use of diffusion-weighted MRI in the field of multiple sclerosis (MS) research. The contribution that diffusion-weighted imaging has made to our understanding of MS is critically appraised, and pointers are given to the sort of work that needs to be done before diffusion-weighted MRI could be recommended for inclusion in a clinical trial. The types of procedures that would be needed for quality assurance of diffusion data, and the data collection schemes that would lead to reliable data, are then reviewed. The quantitative nature of diffusion MRI makes it an attractive proposition for inclusion in clinical trials for MS therapeutic agents, but without further validation work with clinical correlates cannot be recommended at present.
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Affiliation(s)
- M A Horsfield
- Division of Medical Physics, University of Leicester, Leicester Royal Infirmary, Leicester, LE1 5WW, UK.
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Filippi M, Inglese M. Overview of diffusion-weighted magnetic resonance studies in multiple sclerosis. J Neurol Sci 2001; 186 Suppl 1:S37-43. [PMID: 11334988 DOI: 10.1016/s0022-510x(01)00489-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Diffusion-weighted magnetic resonance imaging (DW-MRI) provides a unique form of MR contrast that enables the diffusional motion of water molecules to be quantitatively measured. As a consequence, DW-MRI provides information about the size, shape, integrity, and orientation of brain structures. Pathological processes able to alter tissue integrity by removing or modifying some of the structural barriers that normally restrict water molecular motion in biological tissues cause changes in water diffusion characteristics, which can be measured in-vivo using DW-MRI. Although DW-MRI has been shown to be of great clinical utility in the assessment of patients with cerebral ischemia, it is also increasingly being used to quantify in-vivo the extent and severity of multiple sclerosis (MS) pathology. The pathological elements of MS have the potential to alter the permeability or geometry of structural barriers to water molecular motion in the brain, optic nerve and spinal cord. The present review outlines the major contributions given by DW-MRI for the quantification of MS-related damage and for the understanding of MS pathophysiology.
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Affiliation(s)
- M Filippi
- Neuroimaging Research Unit, Department of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Via Olgettina, 60, 20132 Milan, Italy.
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