1
|
Nägele FL, Petersen M, Mayer C, Bönstrup M, Schulz R, Gerloff C, Thomalla G, Cheng B. Longitudinal microstructural alterations surrounding subcortical ischemic stroke lesions detected by free-water imaging. Hum Brain Mapp 2024; 45:e26722. [PMID: 38780442 PMCID: PMC11114091 DOI: 10.1002/hbm.26722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 03/20/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
In this study we explore the spatio-temporal trajectory and clinical relevance of microstructural white matter changes within and beyond subcortical stroke lesions detected by free-water imaging. Twenty-seven patients with subcortical infarct with mean age of 66.73 (SD 11.57) and median initial NIHSS score of 4 (IQR 3-7) received diffusion MRI 3-5 days, 1 month, 3 months, and 12 months after symptom-onset. Extracellular free-water and fractional anisotropy of the tissue (FAT) were averaged within stroke lesions and the surrounding tissue. Linear models showed increased free-water and decreased FAT in the white matter of patients with subcortical stroke (lesion [free-water/FAT, mean relative difference in %, ipsilesional vs. contralesional hemisphere at 3-5 days, 1 month, 3 months, and 12 months after symptom-onset]: +41/-34, +111/-37, +208/-26, +251/-18; perilesional tissue [range in %]: +[5-24]/-[0.2-7], +[2-20]/-[3-16], +[5-43]/-[2-16], +[10-110]/-[2-12]). Microstructural changes were most prominent within the lesion and gradually became less pronounced with increasing distance from the lesion. While free-water elevations continuously increased over time and peaked after 12 months, FAT decreases were most evident 1 month post-stroke, gradually returning to baseline values thereafter. Higher perilesional free-water and higher lesional FAT at baseline were correlated with greater reductions in lesion size (rho = -0.51, p = .03) in unadjusted analyses only, while there were no associations with clinical measures. In summary, we find a characteristic spatio-temporal pattern of extracellular and cellular alterations beyond subcortical stroke lesions, indicating a dynamic parenchymal response to ischemia characterized by vasogenic edema, cellular damage, and white matter atrophy.
Collapse
Affiliation(s)
- Felix L. Nägele
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Marvin Petersen
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Carola Mayer
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Marlene Bönstrup
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
- Department of NeurologyUniversity of Leipzig Medical CenterLeipzigGermany
| | - Robert Schulz
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Christian Gerloff
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Götz Thomalla
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Bastian Cheng
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| |
Collapse
|
2
|
Li CX, Meng Y, Yan Y, Kempf D, Howell L, Tong F, Zhang X. Investigation of white matter and grey matter alteration in the monkey brain following ischemic stroke by using diffusion tensor imaging. INVESTIGATIVE MAGNETIC RESONANCE IMAGING 2022; 26:275-283. [PMID: 36698483 PMCID: PMC9873195 DOI: 10.13104/imri.2022.26.4.275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Background Investigation of stroke lesion has mostly focused on grey matter (GM) in previous studies and white matter (WM) degeneration during acute stroke is understudied. In the present study, monkeys were utilized to investigate the alterations of GM and WM in the brain following ischemic occlusion using diffusion tensor imaging (DTI). Methods Permanent middle cerebral artery occlusion (pMCAO) was induced in rhesus monkeys (n=6) with an interventional approach. Serial DTI was conducted on a clinical 3T in the hyperacute phase (2-6 hours), 48, and 96 hours post occlusion. Regions of interest in GM and WM of lesion areas were selected for data analysis. Results Mean diffusivity (MD), radial diffusivity (RD), and axial Diffusivity (AD) in WM decreased substantially during hyperacute stroke, as similar as those seen in GM. No obvious fractional anasotropy (FA) changes were seen in GM and WM during hyper acute phase. until 48 hours post stroke when significant fiber losses were oberved also. Pseudo-normalization of MD, AD, and RD was seen at 96 hours. Pathological changes of WM and GM were observed in ischemic areas at 8, 48, and 96 hours post stroke. Relative changes of MD, AD and RD of WM were correlated negatively with infarction volumes at 6 hours post stroke. Conclusion The present study revealed the microstructural changes in gray matter and white matter of monkey brains during acute stroke by using DTI. The preliminary results suggest axial and radial diffusivity (AD and RD) may be sensitive surrogate markers to assess specific microstructural changes in white matter during hyper-acute stroke.
Collapse
Affiliation(s)
- Chun-Xia Li
- Emory National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Yuguang Meng
- Emory National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Yumei Yan
- Emory National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Doty Kempf
- Emory National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Leonard Howell
- Emory National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Frank Tong
- Department of Radiology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Xiaodong Zhang
- Emory National Primate Research Center, Emory University, Atlanta, Georgia 30329
| |
Collapse
|
3
|
Mostafa M, Abdel Naseer M, Edward R, Edrees M, Labib DM. Can diffusion tensor imaging lesion patterns predict the outcome of ischemic stroke? THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2020. [DOI: 10.1186/s41983-020-00176-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Stroke can affect any portion of the central nervous system leading to a wide variety of symptoms depending on the part that is involved. Diffusion tensor imaging (DTI) is an emerging neuroimaging technique that allows measuring the integrity of white matter tracts.
Objectives
The objective of this study is to find out if the diffusion tensor tractography technique can provide prognostic information regarding clinical outcome following ischemic stroke.
Subjects and methods
Forty patients with acute ischemic stroke were studied with DTI. Size of infraction, degree of reduction of fractional anisotropy (FA), and pattern of corticospinal tract (CST) affection were identified. We assessed our patients according to the National Institute of Health Stroke Scale (NIHSS) and Medical Research Council (MRC) scale at onset of stroke and 3 months later.
Results
FA reduction was correlated with MRC and NIHSS on admission (P < 0.001, 0.004 respectively) and after 3 months (P < 0.001, 0.013 respectively). The pattern of CST affection was associated with NIHSS and MRC after 3 months (P = 0.035, 0.001 respectively).
Conclusion
DTI may be an indirect indicator of the ischemic stroke outcome.
Collapse
|
4
|
Zhang X, Yan Y, Tong F, Li CX, Jones B, Wang S, Meng Y, Muly EC, Kempf D, Howell L. Progressive Assessment of Ischemic Injury to White Matter Using Diffusion Tensor Imaging: A Preliminary Study of a Macaque Model of Stroke. Open Neuroimag J 2018; 12:30-41. [PMID: 29785226 PMCID: PMC5897992 DOI: 10.2174/1874440001812010030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 02/10/2018] [Accepted: 03/05/2018] [Indexed: 01/20/2023] Open
Abstract
Background: Previous Diffusion Tensor Imaging (DTI) studies have demonstrated the temporal evolution of stroke injury in grey matter and white matter can be characterized by DTI indices. However, it still remains not fully understood how the DTI indices of white matter are altered progressively during the hyperacute (first 6 hours) and acute stage of stroke (≤ 1 week). In the present study, DTI was employed to characterize the temporal evolution of infarction and white matter injury after stroke insult using a macaque model with permanent ischemic occlusion. Methods and materials: Permanent middle cerebral artery (MCA) occlusion was induced in rhesus monkeys (n=4, 10-21 years old). The brain lesion was examined longitudinally with DTI during the hyperacute phase (2-6 hours, n=4), 48 hours (n=4) and 96 hours (n=3) post-occlusion. Results: Cortical infarction was seen in all animals. The Mean Diffusivity (MD) in lesion regions decreased substantially at the first time point (2 hours post stroke) (35%, p <0.05, compared to the contralateral side) and became pseudo-normalized at 96 hours. In contrast, evident FA reduction was seen at 48 hours (39%, p <0.10) post-stroke. MD reduction in white matter bundles of the lesion area was much less than that in the grey matter during the hyper-acute phase but significant change was observed 4 hours (4.2%, p < 0.05) post stroke . Also, MD pseudonormalisation was seen at 96 hours post stroke. There was a significant correlation between the temporal changes of MD in white matter bundles and those in whole lesion areas during the entire study period. Meanwhile, no obvious fractional anisotropy (FA) changes were seen during the hyper-acute phase in either the entire infarct region or white matter bundles. Significant FA alteration was observed in entire lesion areas and injured white matter bundles 48 and 96 hours post stroke. The stroke lesion in grey matter and white matter was validated by pathological findings. Conclusion:
The temporal evolution of ischemic injury to the grey matter and white matter from 2 to 96 hours after stroke onset was characterized using a macaque model and DTI. Progressive MD changes in white matter bundles are seen from hyperacute phase to acute phase after permanent MCA occlusion and temporally correlated with the MD changes in entire infarction regions. MD reduction in white matter bundles is mild in comparison with that in the grey matter but significant and progressive, indicating it may be useful to detect early white matter degeneration after stroke.
Collapse
Affiliation(s)
- Xiaodong Zhang
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Yumei Yan
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Frank Tong
- Department of Radiology, School of Medicine, Emory University, Atlanta, Georgia 30322
| | - Chun-Xia Li
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Benjamin Jones
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Silun Wang
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Yuguang Meng
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - E Chris Muly
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, Georgia 30322
| | - Doty Kempf
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329
| | - Leonard Howell
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329.,Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, Georgia 30322
| |
Collapse
|
5
|
Aojula A, Botfield H, McAllister JP, Gonzalez AM, Abdullah O, Logan A, Sinclair A. Diffusion tensor imaging with direct cytopathological validation: characterisation of decorin treatment in experimental juvenile communicating hydrocephalus. Fluids Barriers CNS 2016; 13:9. [PMID: 27246837 PMCID: PMC4888658 DOI: 10.1186/s12987-016-0033-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/20/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND In an effort to develop novel treatments for communicating hydrocephalus, we have shown previously that the transforming growth factor-β antagonist, decorin, inhibits subarachnoid fibrosis mediated ventriculomegaly; however decorin's ability to prevent cerebral cytopathology in communicating hydrocephalus has not been fully examined. Furthermore, the capacity for diffusion tensor imaging to act as a proxy measure of cerebral pathology in multiple sclerosis and spinal cord injury has recently been demonstrated. However, the use of diffusion tensor imaging to investigate cytopathological changes in communicating hydrocephalus is yet to occur. Hence, this study aimed to determine whether decorin treatment influences alterations in diffusion tensor imaging parameters and cytopathology in experimental communicating hydrocephalus. Moreover, the study also explored whether diffusion tensor imaging parameters correlate with cellular pathology in communicating hydrocephalus. METHODS Accordingly, communicating hydrocephalus was induced by injecting kaolin into the basal cisterns in 3-week old rats followed immediately by 14 days of continuous intraventricular delivery of either human recombinant decorin (n = 5) or vehicle (n = 6). Four rats remained as intact controls and a further four rats served as kaolin only controls. At 14-days post-kaolin, just prior to sacrifice, routine magnetic resonance imaging and magnetic resonance diffusion tensor imaging was conducted and the mean diffusivity, fractional anisotropy, radial and axial diffusivity of seven cerebral regions were assessed by voxel-based analysis in the corpus callosum, periventricular white matter, caudal internal capsule, CA1 hippocampus, and outer and inner parietal cortex. Myelin integrity, gliosis and aquaporin-4 levels were evaluated by post-mortem immunohistochemistry in the CA3 hippocampus and in the caudal brain of the same cerebral structures analysed by diffusion tensor imaging. RESULTS Decorin significantly decreased myelin damage in the caudal internal capsule and prevented caudal periventricular white matter oedema and astrogliosis. Furthermore, decorin treatment prevented the increase in caudal periventricular white matter mean diffusivity (p = 0.032) as well as caudal corpus callosum axial diffusivity (p = 0.004) and radial diffusivity (p = 0.034). Furthermore, diffusion tensor imaging parameters correlated primarily with periventricular white matter astrocyte and aquaporin-4 levels. CONCLUSIONS Overall, these findings suggest that decorin has the therapeutic potential to reduce white matter cytopathology in hydrocephalus. Moreover, diffusion tensor imaging is a useful tool to provide surrogate measures of periventricular white matter pathology in communicating hydrocephalus.
Collapse
Affiliation(s)
- Anuriti Aojula
- />Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
- />Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TH UK
- />Neurotrauma, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Hannah Botfield
- />Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
- />Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TH UK
- />Neurotrauma, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - James Patterson McAllister
- />Department of Neurosurgery, Division of Pediatric Neurosurgery at the Washington University School of Medicine and the Saint Louis Children’s Hospital, St. Louis, MO 63110 USA
| | - Ana Maria Gonzalez
- />Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
- />Neurotrauma, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Osama Abdullah
- />Department of Bioengineering, University of Utah, Salt Lake City, UT 84112 USA
| | - Ann Logan
- />Department of Bioengineering, University of Utah, Salt Lake City, UT 84112 USA
- />Neurotrauma, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Alexandra Sinclair
- />Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
- />Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TH UK
- />Neurotrauma, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
- />Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, B15 2TH UK
| |
Collapse
|
6
|
Song Z, Dang L, Zhou Y, Dong Y, Liang H, Zhu Z, Pan S. Why do stroke patients with negative motor evoked potential show poor limb motor function recovery? Neural Regen Res 2013; 8:2713-24. [PMID: 25206582 PMCID: PMC4145996 DOI: 10.3969/j.issn.1673-5374.2013.29.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 06/09/2013] [Indexed: 11/18/2022] Open
Abstract
Negative motor evoked potentials after cerebral infarction, indicative of poor recovery of limb motor function, tend to be accompanied by changes in fractional anisotropy values and the cerebral peduncle area on the affected side, but the characteristics of these changes have not been reported. This study included 57 cases of cerebral infarction whose motor evoked potentials were tested in the 24 hours after the first inspection for diffusion tensor imaging, in which 29 cases were in the negative group and 28 cases in the positive group. Twenty-nine patients with negative motor evoked potentials were divided into two groups according to fractional anisotropy on the affected side of the cerebral peduncle: a fractional anisotropy < 0.36 group and a fractional anisotropy ≥ 0.36 group. All patients underwent a regular magnetic resonance imaging and a diffusion tensor imaging examination at 1 week, 1, 3, 6 and 12 months after cerebral infarction. The Fugl-Meyer scores of their hemiplegic limbs were tested before the magnetic resonance and diffusion tensor imaging tions. In the negative motor evoked potential group, fractional anisotropy in the affected cerebral peduncle declined progressively, which was most obvious in the first 1-3 months after the onset of cerebral infarction. The areas and area asymmetries of the cerebral peduncle on the affected side were significantly decreased at 6 and 12 months after onset. At 12 months after onset, the area asymmetries of the cerebral peduncle on the affected side were lower than the normal lower limit value of 0.83. Fugl-Meyer scores in the fractional anisotropy ≥ 0.36 group were significantly higher than in the fractional anisotropy < 0.36 group at 3-12 months after onset. The fractional anisotropy of the cerebral peduncle in the positive motor evoked potential group decreased in the first 1 month after onset, and stayed unchanged from 3-12 months; there was no change in the area of the cerebral peduncle in the first 1-12 months after cerebral infarction. These findings confirmed that if the fractional anisotropy of the cerebral peduncle on the affected side is < 0.36 and the area asymmetries < 0.83 in patients with negative motor evoked potential after cerebral infarction, then poor hemiplegic limb motor function recovery may occur.
Collapse
Affiliation(s)
- Zhibin Song
- Department of Neurology, Xiaolan Hospital of Southern Medical University, Zhongshan 528415, Guangdong Province, China
| | - Lijuan Dang
- Department of Neurology, Xiaolan Hospital of Southern Medical University, Zhongshan 528415, Guangdong Province, China
| | - Yanling Zhou
- Department of Neurology, Xiaolan Hospital of Southern Medical University, Zhongshan 528415, Guangdong Province, China
| | - Yanjiang Dong
- Department of Neurology, Xiaolan Hospital of Southern Medical University, Zhongshan 528415, Guangdong Province, China
| | - Haimao Liang
- Department of Neurology, Xiaolan Hospital of Southern Medical University, Zhongshan 528415, Guangdong Province, China
| | - Zhengfeng Zhu
- Department of Neurology, Xiaolan Hospital of Southern Medical University, Zhongshan 528415, Guangdong Province, China
| | - Suyue Pan
- Department of Neurology, Nanfang Hospital of Southern Medical University, Guangzhou 510515, Guangdong Province, China
| |
Collapse
|
7
|
Vargas P, Gaudron M, Valabrègue R, Bertasi E, Humbert F, Lehéricy S, Samson Y, Rosso C. Assessment of corticospinal tract (CST) damage in acute stroke patients: comparison of tract-specific analysis versus segmentation of a CST template. J Magn Reson Imaging 2012; 37:836-45. [PMID: 23086724 DOI: 10.1002/jmri.23870] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 09/07/2012] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To compare two techniques to assess corticospinal tract (CST) damage in stroke patients: tract-specific analysis by probabilistic tractography and segmentation using a CST template. MATERIALS AND METHODS We extracted fractional anisotropy (FA) values, the FA ratio, and mean diffusivity (MD) in 18 stroke patients and 21 healthy volunteers matched for age and sex. We compared the two methods in order to determine their ability to detect 1) differences between diffusion tensor imaging (DTI) parameters of healthy volunteers and stroke patients, 2) the correlation between DTI parameters and clinical scores, and 3) the correlation between DTI parameters and blood oxygen level-dependent (BOLD) signals in a fist-closure task. RESULTS FA values were higher with the tractography approach than with the segmentation method, but differences between the ipsilesional CST and the homologous region in healthy subjects were detected using both methods. In patients, clinical scores were significantly correlated with FA values and FA ratios with both methods. The BOLD signal was positively correlated with FA values for CST with the segmentation but not with the tractography approach. CONCLUSION CST damage in stroke patients can be assessed by either probabilistic tractography or segmentation of a CST template. Although each method has advantages and limitations, both are sensitive enough to detect differences among stroke patients and identify specific correlations with clinical scores.
Collapse
|
8
|
Hakulinen U, Brander A, Ryymin P, Öhman J, Soimakallio S, Helminen M, Dastidar P, Eskola H. Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain. BMC Med Imaging 2012. [PMID: 23057584 DOI: 10.1186/1471-2342-12-30.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain's white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain's parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. METHODS Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. RESULTS The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10-3 mm2/s with the CM and 0.747 ×10-3 mm2/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM. CONCLUSIONS With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.
Collapse
Affiliation(s)
- Ullamari Hakulinen
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Teiskontie 35 PL 2000, 33521, Tampere, Finland.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Hakulinen U, Brander A, Ryymin P, Öhman J, Soimakallio S, Helminen M, Dastidar P, Eskola H. Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain. BMC Med Imaging 2012; 12:30. [PMID: 23057584 PMCID: PMC3533516 DOI: 10.1186/1471-2342-12-30] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 10/02/2012] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain's white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain's parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. METHODS Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. RESULTS The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10-3 mm2/s with the CM and 0.747 ×10-3 mm2/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM. CONCLUSIONS With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.
Collapse
Affiliation(s)
- Ullamari Hakulinen
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Teiskontie 35 PL 2000, 33521, Tampere, Finland.
| | | | | | | | | | | | | | | |
Collapse
|