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Kiernan MJ, Al Mukaddim R, Mitchell CC, Maybock J, Wilbrand SM, Dempsey RJ, Varghese T. Lumen segmentation using a Mask R-CNN in carotid arteries with stenotic atherosclerotic plaque. Ultrasonics 2024; 137:107193. [PMID: 37952384 PMCID: PMC10841729 DOI: 10.1016/j.ultras.2023.107193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/19/2023] [Accepted: 10/29/2023] [Indexed: 11/14/2023]
Abstract
In patients at high risk for ischemic stroke, clinical carotid ultrasound is often used to grade stenosis, determine plaque burden and assess stroke risk. Analysis currently requires a trained sonographer to manually identify vessel and plaque regions, which is time and labor intensive. We present a method for automatically determining bounding boxes and lumen segmentation using a Mask R-CNN network trained on sonographer assisted ground-truth carotid lumen segmentations. Automatic lumen segmentation also lays the groundwork for developing methods for accurate plaque segmentation, and wall thickness measurements in cases with no plaque. Different training schemes are used to identify the Mask R-CNN model with the highest accuracy. Utilizing a single-channel B-mode training input, our model produces a mean bounding box intersection over union (IoU) of 0.81 and a mean lumen segmentation IoU of 0.75. However, we encountered errors in prediction when the jugular vein is the most prominently visualized vessel in the B-mode image. This was due to the fact that our dataset has limited instances of B-mode images with both the jugular vein and carotid artery where the vein is dominantly visualized. Additional training datasets are anticipated to mitigate this issue.
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Affiliation(s)
- Maxwell J Kiernan
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health (UW-SMPH), United States.
| | - Rashid Al Mukaddim
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health (UW-SMPH), United States
| | | | - Jenna Maybock
- Department of Neurological Surgery, UW-SMPH. Madison, WI, United States
| | | | - Robert J Dempsey
- Department of Neurological Surgery, UW-SMPH. Madison, WI, United States
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health (UW-SMPH), United States.
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2
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Thomas KV, Wilbrand SM, Hess T, Maybock J, Lee Y, Kerwin B, Metoxen M, Danforth D, Riesenberg A, Dempsey RJ, Mitchell C. Abstract P470: Total Plaque Area and Association With Stroke Risk Factors in a Native American Population. Circulation 2023. [DOI: 10.1161/circ.147.suppl_1.p470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Abstract
Objective:
Total plaque area (TPA) has been associated with stroke risk factors; however, it has not been well studied in a Native American population. The objective of this study is to examine the relationship of TPA with stroke risk factors (RF).
Methods:
Participants enrolled in the “Stroke Prevention in the Wisconsin Native American Population” (n=119) underwent a health history risk assessment, cognitive testing, carotid ultrasound to measure TPA, and a meeting with a health wellness coach. TPA for each participant was measured using the LifeQ Medical Plaque Analysis Software (Nicosia, Cyprus). Statistical analyses were performed using SPSS (SPSS, IBM Corporation, Armonk, NY, USA) and SAS (SAS Institute Inc., Cary, NC, USA). Descriptive statistics for continuous variables are reported as the median and interquartile range (IQR). Spearman rho correlation was used to examine relationships between total plaque area and stroke risk factors. Robust M—estimation was used to examine which risk factors predicted TPA after adjustment for other covariates.
Results:
Of the 119 participants, 22 (18.5%) had no plaque and 97 (81.5%) had plaque, 100 (83.3%) were identified as high-risk (≥55 years with three risk factors for stroke) and 19 (15.8%) low-risk (≥55 years with fewer than three risk factors for stroke). Median participant age was 65 (IQR=11.0) years of age, 78.3% female. In univariate analyses, TPA was significantly associated with age (r
s
=.259;p=.005) and body mass index (BMI) (r
s
=-.300;p<.001). In a multivariable robust M-estimation model (including age, sex, BMI, systolic and diastolic blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, hemoglobin A1c, physical activity, and categorical variables (yes/no) current smoker, history of high cholesterol, coronary artery disease, diabetes, hypertension, and transient ischemic attack), only age (p=.03), sex (p=.012), and hemoglobin A1c (p=.028) remained significant for predicting total plaque area (r
2
=16.5%).
Conclusion:
Multivariate analysis demonstrated that age, sex, and hemoglobin A1c predicted TPA. Further work is needed to understand how both traditional and non-traditional stroke RFs may affect the risk of stroke in Native Americans.
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Affiliation(s)
| | | | | | | | - Yurim Lee
- Univ of Wisconsin Madison, Madison, WI
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3
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Mitchell C, Gaitán JM, Pewowaruk RJ, Gepner AD, Hess T, Wilbrand SM, Dempsey RJ, Dougherty RJ, Cook DB, Okonkwo O. Transcranial Color-Coded Doppler Cerebral Hemodynamics Following Aerobic Exercise Training: Outcomes From a Pilot Randomized Clinical Trial. J Vasc Ultrasound 2022; 46:110-117. [PMID: 36714789 PMCID: PMC9881430 DOI: 10.1177/15443167221099274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Introduction An active lifestyle with regular exercise is thought to decrease or delay the onset of Alzheimer dementia through increasing blood flow to the brain. We examined the mean flow velocity (MFV) and pulsatility index (PI) in the middle cerebral arteries of individuals randomized into two groups-a Usual Physical Activity (UPA) group and an Enhanced Physical Activity (EPA) exercise intervention group-to determine if exercise training is related to changes in cerebral blood flow. Methods We examined 23 participants, randomized into a UPA group (n=12) and an EPA group (n=11), with transcranial color-coded Doppler (TCCD) and cardiorespiratory fitness (VO2peak, mL/kg/min) testing at baseline and following a 26-week intervention. TCCD was used to measure MFV and PI. Participants in the EPA group completed supervised aerobic exercise training for 26 weeks. Kendall's tau b correlation was used to examine relationships between variables. The Wilcoxon Rank Sum tests were used to examine changes between the UPA and EPA groups. Results There was no significant change in MFV or PI in the UPA group or the EPA group (p-values >0.05) between baseline and 26 weeks; the change between the UPA and EPA groups was also not significant (p=0.603). There was no evidence of an association between change in VO2peak and change in MFV or PI (all p-values >0.05). Participants in the EPA group significantly increased their VO2peak compared to the UPA group (p=0.027). Conclusion This study did not demonstrate evidence of a significant change in the MFV in the middle cerebral arteries or evidence of a significant change in the PI between UPA and EPA groups. Future studies should be performed in larger cohorts and should consider use of personalized exercise programs to maximize understanding of how cerebrovascular hemodynamics change in structure and function with exercise for adults at risk for Alzheimer dementia.
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Affiliation(s)
- Carol Mitchell
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - J. Max Gaitán
- Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Ryan J. Pewowaruk
- Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Adam D. Gepner
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
- William S. Middleton Memorial Veteran’s Hospital, Madison, WI, USA
| | - Timothy Hess
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Stephanie M. Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Robert J. Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Ryan J. Dougherty
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 2024 E. Monument St., Suite 2-207, Baltimore, MD
| | - Dane B. Cook
- Department of Kinesiology, University of Wisconsin School of Education, Madison, WI, United States
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, United States
| | - Ozioma Okonkwo
- Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, United States
- Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
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Mitchell C, Wilbrand SM, Salamat M, Eickhoff J, Meshram NH, Steffel C, Varghese T, Liu Y, Eliceiri K, Dempsey RJ. Abstract P351: Grayscale Texture Feature Angular Second Moment Correlates With Collagen Alignment in Carotid Artery Plaques. Stroke 2021. [DOI: 10.1161/str.52.suppl_1.p351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Grayscale (GS) texture features that examine homogeneity and echogenicity have been used to identify vulnerable plaques with
in vivo
ultrasound imaging have been shown to correlate with plaque tissue composition. However, the relationship of collagen fiber organization to GS texture features extracted from
in vivo
images is a novel idea to provide additional information about plaque structure. We hypothesize that collagen fiber alignment is clinically relevant to identify vulnerable plaques. The objective of this feasibility study was to use multiscale imaging (in vivo ultrasound and high resolution optical microscopy) to determine how GS texture features are related to plaque collagen structure.
Methods:
Participants (n=6) scheduled for clinically indicated carotid endarterectomy underwent
in vivo
carotid ultrasound imaging with texture feature extraction (spatial gray level dependence matrices method for calculating angular second moment [SGLDM-ASM] and grayscale median value [GSM]). Plaque specimens were sent to histopathology and stained with H&E. The collagen fibers in the fibrous cap of the plaque histopathology slides were imaged with liquid crystal based polarization microscopy and quantified using an established software tool (CurveAlign). Correlations between collagen alignment coefficient (range 0-1, 1 represents perfectly aligned fibers) and the texture feature SGLDM-ASM (a measure of homogeneity, higher values are more homogenous) and GSM (a measure of echogenicity higher values are more echogenic) were examined.
Results:
Participants were mean (SD) 72.5 (6.1) years of age, had 71.67 (8.16) percent stenosis. The mean SGLDM-ASM was 0.0017 (0.0023), the mean SD GSM was 73.13 (30.98). SGLDM-ASM was significantly correlated to collagen alignment (r=0.83; p=0.028). There was no significant correlation detected between GSM and collagen alignment (r=-0.43;p=0.38).
Conclusion:
Results of this study indicate the potential role for using high resolution optical microscopy with ultrasound to characterize collagen fiber alignment in plaques with measures of homogeneity. Future studies are needed to see how multiscale imaging can be used to inform
in vivo
imaging for identification of vulnerable plaque features.
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5
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Meshram NH, Jackson D, Mitchell CC, Wilbrand SM, Dempsey RJ, Hermann BP, Varghese T. Study of the Relationship Between Ultrasound Strain Indices and Cognitive Decline for Vulnerable Carotid Plaque. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2020:2088-2091. [PMID: 33018417 DOI: 10.1109/embc44109.2020.9175911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A relationship between ultrasound strain indices in carotid plaque to cognitive domains of executive and language function are studied in 42 symptomatic and 34 asymptomatic patients. The mean and standard deviation of the percentage stenosis were 72.10 ± 15.19 and 77.41 ± 11.20 for symptomatic and asymptomatic patients respectively. Pearson's correlation between axial, lateral and shear strain indices versus executive and language composite scores was performed.. A significant inverse correlation for both executive and language function for symptomatic patients to strain indices was found. On the other hand, for asymptomatic patients only executive function was inversely correlated with the corresponding strain indices. Our hypothesis that microemboli from vulnerable plaque and possible 'silent strokes' may be responsible for decline in executive function for both symptomatic and asymptomatic patients'. Strokes and transient ischemic attacks may be responsible for further cognitive decline in language function for symptomatic patients.
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6
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Mitchell CC, Wilbrand SM, Cook TD, Meshram NH, Steffel CN, Nye R, Varghese T, Hermann BP, Dempsey RJ. Carotid Plaque Strain Indices Were Correlated With Cognitive Performance in a Cohort With Advanced Atherosclerosis, and Traditional Doppler Measures Showed no Association. J Ultrasound Med 2020; 39:2033-2042. [PMID: 32395885 PMCID: PMC7531894 DOI: 10.1002/jum.15311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/20/2020] [Accepted: 04/06/2020] [Indexed: 05/17/2023]
Abstract
OBJECTIVES Traditional Doppler measures have been used to predict cognitive performance in patients with carotid atherosclerosis. Novel measures, such as carotid plaque strain indices (CPSIs), have shown associations with cognitive performance. We hypothesized that lower mean middle cerebral artery (MCA) velocities, higher bulb-internal carotid artery (ICA) velocities, the MCA pulsatility index (PI), and CPSIs would be associated with poorer cognitive performance in individuals with advanced atherosclerosis. METHODS Neurocognitive testing, carotid ultrasound imaging, transcranial Doppler imaging, and carotid strain imaging were performed on 40 patients scheduled for carotid endarterectomy. Kendall tau correlations were used to examine relationships between cognitive tests and the surgical-side maximum peak systolic velocity (PSV; from the bulb, proximal, mid, or distal ICA), mean MCA velocity and PI, and maximum CPSIs (axial, lateral, and shear strain indices used to characterize plaque deformations with arterial pulsation). Cognitive measures included age-adjusted indices of verbal fluency, verbal and visual learning/memory, psychomotor speed, auditory attention/working memory, visuospatial construction, and mental flexibility. RESULTS Participants had a median age of 71.0 (interquartile range, 9.75) years; 26 were male (65%), and 14 were female (35%). Traditional Doppler parameters, PSV, mean MCA velocity, and MCA PI did not predict cognitive performance (all P > .05). Maximum CPSIs were significantly associated with cognitive performance (P < .05). CONCLUSIONS Traditional velocity measurements of the maximum bulb-ICA PSV, mean MCA velocity, and PI were not associated with cognitive performance in patients with advanced atherosclerotic disease; however, maximum CPSIs were associated with cognitive performance. These findings suggest that cognition may be associated with unstable plaque rather than blood flow.
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Affiliation(s)
- Carol C. Mitchell
- Department of Medicine, Division of Cardiovascular
Medicine, University of Wisconsin School of Medicine and Public Health, 600 Highland
Avenue, Madison, WI, USA 53792
| | - Stephanie M. Wilbrand
- Department of Neurological Surgery, University of Wisconsin
School of Medicine and Public Health, 600 Highland Avenue, Madison, WI, USA
53792
| | - Thomas D. Cook
- Department of Biostatistics and Medical Informatics,
University of Wisconsin School of Medicine and Public Health, 610 Walnut Street,
Madison WI, USA 53726
| | - Nirvedh H. Meshram
- Department of Medical Physics, University of Wisconsin
School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland
Avenue, Madison, WI, USA 53705
- Department of Electrical and Computer Engineering,
University of Wisconsin-Madison, University of Wisconsin-Madison, 1415 Engineering
Drive, Madison, WI, USA 53706
- Corresponding Author: Carol C. Mitchell,
PhD, 600 Highland Avenue, Madison, WI, USA 53792, 608-262-0680,
| | - Catherine N. Steffel
- Department of Medical Physics, University of Wisconsin
School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland
Avenue, Madison, WI, USA 53705
| | - Rebecca Nye
- Department of Medicine, Division of Cardiovascular
Medicine, University of Wisconsin School of Medicine and Public Health, 600 Highland
Avenue, Madison, WI, USA 53792
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin
School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland
Avenue, Madison, WI, USA 53705
- Department of Electrical and Computer Engineering,
University of Wisconsin-Madison, University of Wisconsin-Madison, 1415 Engineering
Drive, Madison, WI, USA 53706
| | - Bruce P. Hermann
- Department of Neurology, University of Wisconsin School of
Medicine and Public Health, 600 Highland Avenue, Madison, WI USA 53792
| | - Robert J. Dempsey
- Department of Neurological Surgery, University of Wisconsin
School of Medicine and Public Health, 600 Highland Avenue, Madison, WI, USA
53792
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7
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Steffel CN, Salamat S, Cook TD, Wilbrand SM, Dempsey RJ, Mitchell CC, Varghese T. Attenuation Coefficient Parameter Computations for Tissue Composition Assessment of Carotid Atherosclerotic Plaque in Vivo. Ultrasound Med Biol 2020; 46:1513-1532. [PMID: 32291105 PMCID: PMC7216316 DOI: 10.1016/j.ultrasmedbio.2020.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 01/17/2020] [Accepted: 02/26/2020] [Indexed: 06/11/2023]
Abstract
Quantitative ultrasound has been used to assess carotid plaque tissue composition. Here, we compute the attenuation coefficient (AC) in vivo with the optimum power spectral shift estimator (OPSSE) and reference phantom method (RPM), extract AC parameters and form parametric maps. Differences between OPSSE and RPM AC parameters are computed. Relationships between AC parameters, surgical scores and histopathology assessments are examined. Kendall's τ correlations between OPSSE AC and surgical scores are significant, including those between cholesterol and Standard Deviation (adjusted p = 0.038); thrombus and Minimum (adjusted p = 0.002), Maximum (adjusted p = 0.021) and Standard Deviation (adjusted p = 0.001); ulceration and Average (adjusted p = 0.033), Median (unadjusted p = 0.013), Maximum (unadjusted p = 0.039) and Mode (adjusted p = 0.009). The strongest correlations with histopathology are percentage cholesterol and Median OPSSE (unadjusted p = 0.007); percentage hemorrhage and Minimum OPSSE (adjusted p < 0.001); hemosiderin score and Median OPSSE (adjusted p = 0.010); and percentage calcium and Percentage Non-physical RPM Pixels (unadjusted p = 0.014). Kruskal-Wallis H and Dunn's post hoc tests have the ability to distinguish between groups (p < 0.05). Results suggest AC parameters may assist in vivo evaluation of carotid plaque vulnerability.
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Affiliation(s)
- Catherine N Steffel
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
| | - Shahriar Salamat
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Thomas D Cook
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Carol C Mitchell
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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8
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Vahidy FS, Sozener CB, Meeks JR, Chhatbar PY, Ramos-Estebanez C, Ayodele M, Richards RJ, Sharma R, Wilbrand SM, Prabhakaran S, Bregman BS, Adams HP, Jordan LC, Liebeskind DS, Tirschwell D, Janis LS, Marshall RS, Kleindorfer D. National Institutes of Health StrokeNet Training Core. Stroke 2019; 51:347-352. [PMID: 31795907 DOI: 10.1161/strokeaha.119.027946] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose- The National Institutes of Health (NIH) StrokeNet provides a nationwide infrastructure to advance stroke research. Capitalizing on this unique opportunity, the NIH StrokeNet Training Core (NSTC) was established with the overarching goal of enhancing the professional development of a diverse spectrum of professionals who are embedded in the stroke clinical trials network of the NIH StrokeNet. Methods- This special report provides a descriptive account of the rationale, organization, and activities of the NSTC since its inception in 2013. Current processes and their evolution over time for facilitating training of NIH StrokeNet trainees have been highlighted. Data collected for monitoring training are summarized. Outcomes data (publications and grants) collected by NSTC was supplemented by publicly available resources. Results- The NSTC comprises of cross-network faculty, trainees, and education coordinators. It helps in the development and monitoring of training programs and organizes educational and career development activities. Trainees are provided directed guidance towards their mandated research projects, including opportunities to present at the International Stroke Conference. The committee has focused on developing sustainable models of peer-to-peer interaction and cross-institutional mentorships. A total of 124 professionals (43.7% female, 10.5% underrepresented minorities) have completed training between 2013 and 2018, of whom 55% were clinical vascular neurologists. Of the total, 85% transitioned to a formal academic position and 95% were involved in stroke research post-training. Altogether, 1659 indexed publications have been authored or co-authored by NIH StrokeNet Trainees, of which 58% were published during or after their training years. Based on data from 109 trainees, 33% had submitted 72 grant proposals as principal or co-principal investigators of which 22.2% proposals have been funded. Conclusions- NSTC has provided a foundation to foster nationwide training in stroke research. Our data demonstrate strong contribution of trainees towards academic scholarship. Continued innovation in educational methodologies is required to adapt to unique training opportunities such as the NIH StrokeNet.
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Affiliation(s)
- Farhaan S Vahidy
- From the Department of Neurology, Institute for Stroke and Cerebrovascular Diseases, The University of Texas Health Science Center, Houston (F.S.V., J.R.M.)
| | - Cemal B Sozener
- Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor (C.B.S.)
| | - Jennifer R Meeks
- From the Department of Neurology, Institute for Stroke and Cerebrovascular Diseases, The University of Texas Health Science Center, Houston (F.S.V., J.R.M.)
| | - Pratik Y Chhatbar
- Department of Neurology, Duke University Medical Center, Durham, NC (P.Y.C.)
| | - Ciro Ramos-Estebanez
- Department of Neurology, Case Western Reserve University, Cleveland, OH (C.R.-E.)
| | - Maranatha Ayodele
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA (M.A.)
| | - Rebekah J Richards
- Department of Emergency Medicine, The Ohio State University Wexner Medical Center, Columbus (R.J.R.)
| | - Richa Sharma
- Department of Neurology, Yale School of Medicine, New Haven, CT (R.S.)
| | | | - Shyam Prabhakaran
- Department of Neurology, Pritzker School of Medicine, University of Chicago, IL (S.P.)
| | - Barbara S Bregman
- Department of Neuroscience, Georgetown University Medical Center, Washington DC (B.S.B.)
| | - Harold P Adams
- Department of Neurology, University of Iowa Carver College of Medicine (H.P.A.)
| | - Lori C Jordan
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN (L.C.J.)
| | - David S Liebeskind
- Neurovascular Imaging Research Core and UCLA Stroke Center, University of California, Los Angeles (D.S.L.)
| | | | - L Scott Janis
- Division of Clinical Research, National Institute of Neurological Diseases and Stroke, National Institutes of Health (L.S.J.)
| | - Randolph S Marshall
- Department of Neurology, New York Presbyterian and Columbia University Medical Center, New York, NY (R.S.M.)
| | - Dawn Kleindorfer
- Department of Neurology and Rehabilitation Medicine, University of Cincinnati, OH (D.K.)
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9
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Varghese T, Meshram NH, Mitchell CC, Wilbrand SM, Hermann BP, Dempsey RJ. Lagrangian carotid strain imaging indices normalized to blood pressure for vulnerable plaque. J Clin Ultrasound 2019; 47:477-485. [PMID: 31168787 PMCID: PMC6760247 DOI: 10.1002/jcu.22739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/10/2019] [Accepted: 05/22/2019] [Indexed: 05/14/2023]
Abstract
OBJECTIVE Ultrasound Lagrangian carotid strain imaging (LCSI) utilizes physiological deformation caused by arterial pressure variations to generate strain tensor maps of the vessel walls and plaques. LCSI has been criticized for the lack of normalization of magnitude-based strain indices to physiological stimuli, namely blood pressure. We evaluated the impact of normalization of magnitude-based strain indices to blood pressure measured immediately after the acquisition of radiofrequency (RF) data loops for LCSI. MATERIALS AND METHODS A complete clinical ultrasound examination along with RF data loops for LCSI was performed on 50 patients (30 males and 20 females) who presented with >60% carotid stenosis and were scheduled for carotid endarterectomy. Cognition was assessed using the 60-minute neuropsychological test protocol. RESULTS For axial strains correlation of maximum accumulated strain indices (MASI), cognition scores were -0.46 for non-normalized and -0.45, -0.49, -0.37, and -0.48 for systolic, diastolic, pulse pressure, and mean arterial pressure normalized data, respectively. The corresponding area under the curve (AUC) values for classifiers designed using maximum likelihood estimation of a binormal distribution with a median-split of the executive function cognition scores were 0.73, 0.70, 0.71, 0.70, and 0.71, respectively. CONCLUSIONS No significant differences in the AUC estimates were obtained between normalized and non-normalized magnitude-based strain indices.
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Affiliation(s)
- Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nirvedh H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin
| | - Carol C Mitchell
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Bruce P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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10
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Dempsey RJ, Jackson DC, Wilbrand SM, Mitchell CC, Berman SE, Johnson SC, Meshram NH, Varghese T, Hermann BP. The Preservation of Cognition 1 Year After Carotid Endarterectomy in Patients With Prior Cognitive Decline. Neurosurgery 2019; 82:322-328. [PMID: 28575478 DOI: 10.1093/neuros/nyx173] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/13/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Vascular cognitive decline is critically important in the course of atherosclerosis and stroke. OBJECTIVE To explore the hypothesis that carotid endarterectomy (CEA) by removing an unstable plaque may slow the course of vascular cognitive decline in both symptomatic and asymptomatic patients. METHODS Patients with clinically significant (>60%) carotid stenosis were studied preop and 1 yr post-CEA for clinical symptoms, vascular cognitive decline, instability of carotid plaque-presence of microemboli, brain white matter changes, and medical risk factors. RESULTS Forty-six percent were classically symptomatic. All patients showed vascular cognitive decline at presentation which correlated with degree of plaque instability. Significant white matter hyperintensity changes (48.7%) and cerebral emboli (25%) were also seen at baseline in both classically symptomatic and asymptomatic. One year after CEA, both groups showed no decline in cognitive function and significant improvement in 2 tests (P = .028 and P = .013). Brain white matter hyperintensities were unchanged. Microemboli were reduced but remained present (17.86%). Improvement was predicted by the presence of hypertension (P = .001), or less advanced cognitive decline preoperatively (P = .009). CONCLUSION This study demonstrates the importance of vascular cognitive decline in atherosclerotic disease. This is a function of the degree of instability of the atherosclerotic plaque more than the presence of stroke symptoms. It further suggests that atherosclerotic vascular cognitive decline need not be inevitable, and may be modified by treating hypertension and removal of the unstable plaque. This highlights the need for continued research on the cognitive effects of cerebrovascular disease and the synergistic benefits of intensive medical and surgical therapy.
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Affiliation(s)
- Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Daren C Jackson
- Wisconsin Surgical Outcomes Center Research Program, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Carol C Mitchell
- Department of Medicine, Cardiovascular Medicine Division, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Sara E Berman
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Sterling C Johnson
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Nirvedh H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.,Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Bruce P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Centennial Building, Madison, Wisconsin
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11
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Abstract
Carotid plaque rupture can result in stroke or transient ischemic attack that can be devastating for patients. Ultrasound strain imaging provides a noninvasive method to identify unstable plaque likely to rupture. Axial, lateral and shear strains in carotid plaque have been shown to be linked to carotid plaque instability. Recently, there has been interest in using principal strains, which do not depend on angle of insonification of the carotid artery for quantifying instability in plaque along the longitudinal view. In this work relationships between angle dependent axial, lateral and shear strain along with axis independent principal strains are compared. Three strain indices were defined, 1) Average Mean Strain (AMS), 2) Maximum Mean Strain (MMS) and 3) Mean Standard Deviation (MSD) to identify relationships between these five strain image types in a group of 76 in vivo patients. The maximum principal strain demonstrated the highest strain values when compared to axial strain for all patients with a linear regression slope of 1.6 and a y intercept of 2.4 percent strain for AMS. The maximum shear strain when compared to shear strain had a slope of 1.15 and a y intercept of 0.21 percent for AMS. Next, the effect of insonification angle, which is the angle subtended by the artery at the location of plaque was studied. Patients were divided into three sub groups, i.e. less than 5 degrees (n = 31), between 5 and 10 degrees (n = 24) and above 10 degrees (n = 21). The angle of insonification did not make a significant difference between the three angle groups when comparing the relationship between the angle dependent and independent strain values.
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Affiliation(s)
- N H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706.,Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - C C Mitchell
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706
| | - S M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706
| | - R J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706
| | - T Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706.,Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin, 53706
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12
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Mitchell C, Wilbrand SM, Cook TD, Meshram NH, Steffel CN, Nye R, Varghese T, Hermann BP, Dempsey RJ. Abstract WMP47: Traditional Doppler Measures Do Not predict Cognition in a Cohort With Advanced Atherosclerosis. Stroke 2019. [DOI: 10.1161/str.50.suppl_1.wmp47] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Traditional Doppler measures have been used to predict cognitive performance in patients with carotid atherosclerosis. Novel measures, such as carotid strain indices (CSI) have shown associations with cognitive performance. We hypothesized that lower mean middle cerebral artery (MCA) velocities, higher bulb-internal carotid artery (ICA) velocities, MCA pulsatility index (PI) and CSI would be associated with poorer cognitive performance in individuals with advanced atherosclerosis.
Methods:
Neurocognitive testing, carotid ultrasound, transcranial Doppler and CSI were performed on 40 subjects scheduled for carotid endarterectomy. Kendall tau correlations were used to examine relationships between cognitive tests and the maximum peak systolic velocity (PSV) (from bulb, proximal, mid or distal ICA), mean MCA velocity and PI (on surgical side) and CSI (maximum axial, lateral and shear strain indices used to characterize plaque deformations with arterial pulsation). Cognitive measures included age adjusted indices of verbal fluency, verbal and visual learning/memory, psychomotor speed, auditory attention/working memory, visuoconstruction, and mental flexibility.
Results:
Participants were median age 71.0 (IQR 9.75) years, 26 male (65%) and 14 female (35%). Median stenosis was 70.00 (IQR 10.00) percent. Traditional Doppler parameters, PSV, mean MCA velocity and MCA PI did not predict cognitive performance (p values all >0.05). Maximum strain values were significantly associated with cognitive performance (p<0.05).
Table
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Conclusions:
Traditional velocity measurements of maximum bulb-ICA PSV, mean MCA velocity and PI were not associated with cognitive performance in patients with advanced atherosclerotic disease, however maximum strain indices were associated with cognitive performance. Findings suggest that cognition may be associated with unstable plaque (plaques at greater risk for rupture) rather than blood flow.
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Affiliation(s)
| | | | - Thomas D Cook
- Biostatistics and Med Informatics, Univ of Wisconsin Madison, Madison, WI
| | | | | | - Rebecca Nye
- Medicine, Cadiovascular division, Univ of Wisconsin Madison, Madison, WI
| | - Tomy Varghese
- Med Physics and Electrical and Computer Engineering, Univ of Wisconsin Madison, Madison, WI
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13
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Steffel CN, Brown R, Korcarz CE, Varghese T, Stein JH, Wilbrand SM, Dempsey RJ, Mitchell CC. Influence of Ultrasound System and Gain on Grayscale Median Values. J Ultrasound Med 2019; 38:307-319. [PMID: 30027550 PMCID: PMC6339613 DOI: 10.1002/jum.14690] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 03/22/2018] [Accepted: 04/21/2018] [Indexed: 06/08/2023]
Abstract
OBJECTIVES The purpose of this study was to determine the reliability of grayscale median (GSM) measurements across different ultrasound (US) systems and effects of gain on GSM values. METHODS Two vessels in a grayscale vascular phantom were imaged with 7 US systems at 3 gain settings. Two human participants were imaged at 3 gain settings. Each image was normalized, standardized, and segmented by expert and novice readers using grayscale analysis software. The concordance correlation coefficient (CCC) assessed agreement of GSM values for each system across gain settings and vessels and between readers. The intraclass correlation coefficient (ICC) assessed system-level reader concordance across gain settings and vessels. A general linear mixed model for repeated measures was used to assess within- and between-system mean GSM values. RESULTS Grayscale median measurements performed on images from the same US system yielded excellent (CCC) (95% confidence intervals): 0.85 (0.75, 0.92) to 0.96 (0.92, 0.98). ICC per system were 0.94 to 0.98 for the expert reader and 0.85 to 0.95 for the novice reader. Gain adjustments above and below an optimal setting contributed to significantly different intrasystem GSM values on 4 of 7 systems in the near zone and 5 of 7 systems in the far zone (P < .05). Intersystem GSM values differed on 5 of 7 systems (P < .05). Images from the human participants showed differences in GSM values at optimum gain values ± 10 dB/%. CONCLUSIONS Grayscale median measurements are highly reproducible when obtained from the same US system with similar gain settings. Grayscale median values differ significantly across gain values and between systems. Researchers should consider the impact of US system and gain settings on GSM values when working to minimize system- and operator-dependent factors.
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Affiliation(s)
- Catherine N Steffel
- Department of Medical Physics, University of Wisconsin Atherosclerosis Imaging Research Program, Madison, Wisconsin USA
| | - Roger Brown
- Research Design and Statistics Unit, University of Wisconsin Schools of Nursing, Medicine, and Public Health, Madison, Wisconsin USA
| | - Claudia E Korcarz
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin Atherosclerosis Imaging Research Program, Madison, Wisconsin USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin Atherosclerosis Imaging Research Program, Madison, Wisconsin USA
| | - James H Stein
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin Atherosclerosis Imaging Research Program, Madison, Wisconsin USA
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin USA
| | - Carol C Mitchell
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin Atherosclerosis Imaging Research Program, Madison, Wisconsin USA
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14
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Meshram NH, Jackson D, Varghese T, Mitchell CC, Wilbrand SM, Dempsey RJ, Hermann BP. A Cross-Sectional Investigation of Cognition and Ultrasound-Based Vascular Strain Indices. Arch Clin Neuropsychol 2019; 35:46-55. [PMID: 30805597 PMCID: PMC7014973 DOI: 10.1093/arclin/acz006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/19/2018] [Accepted: 01/30/2019] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE We examine the relationship between variability in the plaque strain distribution estimated using ultrasound with multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. METHOD Asymptomatic (n = 42) and symptomatic (n = 34) patients with significant (>60%) carotid artery stenosis were studied for plaque instability using ultrasound strain imaging and multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. Correlation and ROC analyses were performed between ultrasound strain indices and cognitive function. Strain indices and cognition scores were also compared between symptomatic and asymptomatic patients to determine whether there are significant group differences. RESULTS Association of high-strain distributions with dysexecutive function was observed in both asymptomatic and symptomatic patients. For memory, visuospatial, and language functions, the correlations between strain and cognition were weaker for the asymptomatic compared to symptomatic group. CONCLUSIONS Both asymptomatic and symptomatic patients demonstrate a relationship between vessel strain indices and executive function indicating that silent strokes and micro-emboli could initially contribute to a decline in executive function, whereas strokes and transient ischemic attacks may cause the further decline in other cognitive functions.
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Affiliation(s)
- N H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - D Jackson
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - T Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - C C Mitchell
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - S M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - R J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - B P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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15
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Dempsey RJ, Jackson DC, Wilbrand SM, Mitchell CC, Berman SE, Johnson SC, Meshram NH, Varghese T, Hermann BP. In Reply: The Preservation of Cognition 1 Year After Carotid Endarterectomy in Patients With Prior Cognitive Decline. Neurosurgery 2018; 83:E181. [PMID: 31222269 DOI: 10.1093/neuros/nyy325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Robert J Dempsey
- Department of Neurological Surgery University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Daren C Jackson
- Wisconsin Surgical Outcomes Center Research Program Department of Surgery University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Stephanie M Wilbrand
- Department of Neurological Surgery University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Carol C Mitchell
- Department of Medicine Cardiovascular Medicine Division University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Sara E Berman
- Alzheimer's Disease Research Center University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Sterling C Johnson
- Alzheimer's Disease Research Center University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Nirvedh H Meshram
- Department of Medical Physics University of Wisconsin School of Medicine and Public Health Madison, Wisconsin.,Department of Electrical and Computer Engineering University of Wisconsin-Madison Madison, Wisconsin
| | - Tomy Varghese
- Department of Medical Physics University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
| | - Bruce P Hermann
- Department of Neurology University Wisconsin School of Medicine and Public Health Madison, Wisconsin
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16
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Mitchell CC, Wilbrand SM, Kundu B, Steffel CN, Varghese T, Meshram NH, Li G, Cook TD, Salamat MS, Dempsey RJ. Transcranial Doppler and Microemboli Detection: Relationships to Symptomatic Status and Histopathology Findings. Ultrasound Med Biol 2017. [PMID: 28645797 PMCID: PMC5532746 DOI: 10.1016/j.ultrasmedbio.2017.04.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The purpose of this study was to determine the relationship between symptomatic status, transcranial Doppler (TCD) microemboli presence and plaque histopathology findings. TCD was performed on 60 patients (37 symptomatic, 23 asymptomatic) before undergoing clinically indicated carotid endarterectomy. The frequency of microemboli signals was not significantly different between symptomatic and asymptomatic subject groups (p = 0.88) and there were no differences observed in the macroscopic or histopathology scoring of these plaques (p-values all > 0.05). The presence of microemboli was associated with an ulceration score (regardless of symptomatic or asymptomatic status, p = 0.034), with a one-level increase in ulceration rating associated with an odds ratio of 5.86 (95% [CI] 1.55, 43.4). These findings suggest that both symptomatic and asymptomatic patients may have plaque with similar features of instability and ability to create emboli. Thus, identifying new ways to measure plaque instability may provide important information for optimizing treatment to prevent future stroke.
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Affiliation(s)
- Carol C Mitchell
- Department of Medicine, Cardiovascular Medicine Division, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Bornali Kundu
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Catherine N Steffel
- Department of Medicine, Cardiovascular Medicine Division, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Nirvedh H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Geng Li
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Thomas D Cook
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - M Shahriar Salamat
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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17
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Meshram NH, Varghese T, Mitchell CC, Jackson DC, Wilbrand SM, Hermann BP, Dempsey RJ. Quantification of carotid artery plaque stability with multiple region of interest based ultrasound strain indices and relationship with cognition. Phys Med Biol 2017; 62:6341-6360. [PMID: 28594333 DOI: 10.1088/1361-6560/aa781f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vulnerability and instability in carotid artery plaque has been assessed based on strain variations using noninvasive ultrasound imaging. We previously demonstrated that carotid plaques with higher strain indices in a region of interest (ROI) correlated to patients with lower cognition, probably due to cerebrovascular emboli arising from these unstable plaques. This work attempts to characterize the strain distribution throughout the entire plaque region instead of being restricted to a single localized ROI. Multiple ROIs are selected within the entire plaque region, based on thresholds determined by the maximum and average strains in the entire plaque, enabling generation of additional relevant strain indices. Ultrasound strain imaging of carotid plaques, was performed on 60 human patients using an 18L6 transducer coupled to a Siemens Acuson S2000 system to acquire radiofrequency data over several cardiac cycles. Patients also underwent a battery of neuropsychological tests under a protocol based on National Institute of Neurological Disorders and Stroke and Canadian Stroke Network guidelines. Correlation of strain indices with composite cognitive index of executive function revealed a negative association relating high strain to poor cognition. Patients grouped into high and low cognition groups were then classified using these additional strain indices. One of our newer indices, namely the average L - 1 norm with plaque (AL1NWP) presented with significantly improved correlation with executive function when compared to our previously reported maximum accumulated strain indices. An optimal combination of three of the new indices generated classifiers of patient cognition with an area under the curve (AUC) of 0.880, 0.921 and 0.905 for all (n = 60), symptomatic (n = 33) and asymptomatic patients (n = 27) whereas classifiers using maximum accumulated strain indices alone provided AUC values of 0.817, 0.815 and 0.813 respectively.
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Affiliation(s)
- N H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI-53706, United States of America. Department of Electrical and Computer Engineering, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI-53706, United States of America
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18
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Dempsey RJ, Varghese T, Jackson DC, Wang X, Meshram NH, Mitchell CC, Hermann BP, Johnson SC, Berman SE, Wilbrand SM. Carotid atherosclerotic plaque instability and cognition determined by ultrasound-measured plaque strain in asymptomatic patients with significant stenosis. J Neurosurg 2017; 128:111-119. [PMID: 28298048 DOI: 10.3171/2016.10.jns161299] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE This article describes the use of ultrasound measurements of physical strain within carotid atherosclerotic plaques as a measure of instability and the potential for vascular cognitive decline, microemboli, and white matter changes. METHODS Asymptomatic patients with significant (> 60%) carotid artery stenosis were studied for dynamic measures of plaque instability, presence of microemboli, white matter changes, and vascular cognitive decline in comparison with normative controls and premorbid state. RESULTS Although classically asymptomatic, these patients showed vascular cognitive decline. The degree of strain instability measured within the atherosclerotic plaque directly predicted vascular cognitive decline in these patients thought previously to be asymptomatic according to classic criteria. Furthermore, 26% of patients showed microemboli, and patients had twice as much white matter hyperintensity as controls. CONCLUSIONS These data show that physical measures of plaque instability are possible through interpretation of ultrasound strain data during pulsation, which may be more clinically relevant than solely measuring degree of stenosis. The data also highlight the importance of understanding that the definition of symptoms should not be limited to motor, speech, and vision function but underscore the role of vascular cognitive decline in the pathophysiology of carotid atherosclerotic disease. Clinical trial registration no.: NCT02476396 (clinicaltrials.gov).
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Affiliation(s)
| | - Tomy Varghese
- 2Medical Physics, University of Wisconsin School of Medicine and Public Health
| | - Daren C Jackson
- 3Wisconsin Surgical Outcomes Research Program, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Xiao Wang
- 4Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey
| | - Nirvedh H Meshram
- 2Medical Physics, University of Wisconsin School of Medicine and Public Health
| | | | - Bruce P Hermann
- 6Department of Neurology, University of Wisconsin School of Medicine and Public Health; and
| | - Sterling C Johnson
- 7Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Waisman Laboratory for Brain Injury and Behavior, University of Wisconsin-Madison & Geriatric Research Education & Clinical Center, William S. Middleton Veterans Hospital, Madison, Wisconsin
| | - Sara E Berman
- 7Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Waisman Laboratory for Brain Injury and Behavior, University of Wisconsin-Madison & Geriatric Research Education & Clinical Center, William S. Middleton Veterans Hospital, Madison, Wisconsin
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19
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Mitchell C, Wilbrand SM, Steffel CN, Varghese T, Meshram N, Li G, Cook TD, Salamat S, Dempsey RJ. Abstract WP126: Transcranial Doppler and Microemboli Detection. Relationships to Symptomatic Status and Histopathology Findings. Stroke 2017. [DOI: 10.1161/str.48.suppl_1.wp126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Microemboli, as detected by transcranial Doppler (TCD), are hypothesized to be associated with carotid plaque instability and symptomatic subject status associated with motor, sensory, visual and speech deficits of stroke and transient ischemic attack (TIA). However, the current clinical exam does not assess sequeli of small emboli and probable differences between symptomatic and asymptomatic plaques. The purpose of this study was to determine the relationship between symptomatic status, microemboli presence and histopathology findings.
Methods:
TCD examination was performed on 60 study subjects for an hour to assess the presence of microemboli, prior to undergoing clinically indicated carotid endarterectomy. Macroscopic scoring for cholesterol, thrombus, calcium and ulceration were performed with a dissecting microscope. Histopathological examination, with high power magnification on fixed plaque was scored for hemorrhage, hemosiderin, inflammation, percent cholesterol and calcium. Pearson’s chi-squared test was used to assess the frequency of microemboli between symptomatic and asymptomatic subjects. Logistic regression was used to analyze the relationship between operative and histopathology plaque findings and presence of microemboli.
Results:
The frequency of microemboli signals, as detected with TCD, was not significantly different between symptomatic and asymptomatic subject groups (p=0.88) nor was there any difference observed in the macroscopic or histopathology scoring of these plaques (p-values all > 0.05). The presence of microemboli was associated with an ulceration score (regardless of symptomatic or asymptomatic status, p=0.034), with a one level increase in ulceration rating associated with an odds ratio of 5.86 (95% [CI] 1.55, 4.34).
Conclusion:
These findings suggest that both symptomatic and asymptomatic subjects (with clinical indications for carotid endarterectomy) may have plaque with similar features of instability and ability to create emboli. Thus, identifying new ways to measure plaque instability may provide important information for optimizing treatment to prevent future stroke. It also suggests that present clinical exam does not detect the sequeli of small emboli.
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Affiliation(s)
| | | | | | - Tomy Varghese
- Med Physics / Electrical and Computer Engineering, Univ of Wisconsin Madison, Madison, WI
| | - Nirvedh Meshram
- Med Physics / Electrical and Computer Engineering, Univ of Wisconsin Madison, Madison, WI
| | - Geng Li
- Biostatistics and Med Informatics, Univ of Wisconsin Madison, Madison, WI
| | - Thomas D Cook
- Biostatistics and Med Informatics, Univ of Wisconsin Madison, Madison, WI
| | - Shahriar Salamat
- Pathology and Laboratory Medicine / Neurological Surgery, Univ of Wisconsin Madison, Madison, WI
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20
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Mitchell CC, Stein JH, Cook TD, Salamat S, Wang X, Varghese T, Jackson DC, Sandoval Garcia C, Wilbrand SM, Dempsey RJ. Histopathologic Validation of Grayscale Carotid Plaque Characteristics Related to Plaque Vulnerability. Ultrasound Med Biol 2017; 43:129-137. [PMID: 27720278 PMCID: PMC5327497 DOI: 10.1016/j.ultrasmedbio.2016.08.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 05/03/2023]
Abstract
Inflammation and angiogenesis play major roles in carotid plaque vulnerability. The purpose of this study was to determine whether gray-scale features of carotid plaques are associated with histologic markers for inflammation. Thirty-eight individuals completed a dedicated research carotid ultrasound exam before carotid endarterectomy. Gray-scale analysis was performed on plaque images to measure plaque echogenicity (gray-scale median [GSM] pixel brightness), plaque area, presence of discrete white areas (DWAs) and the percent of black area near the lumen on any one component of the plaque. Plaques with higher ultrasound GSM had greater percent calcification (p = 0.013) on histopathology. Presence of an ultrasound DWA was associated with more plaque hemosiderin (p = 0.0005) and inflammation (p = 0.019) on histopathology examination. The percent of plaque black area in any one component was associated with a higher score for macroscopic ulceration (p = 0.028). Ultrasound plaque characteristics (GSM, DWAs and black areas) represent histopathologic markers associated with plaque vulnerability. ClinicalTrials.gov identifier: NCT02476396.
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Affiliation(s)
- Carol C Mitchell
- Cardiovascular Medicine Division, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - James H Stein
- Cardiovascular Medicine Division, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Thomas D Cook
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Shahriar Salamat
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Xiao Wang
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Daren C Jackson
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Carolina Sandoval Garcia
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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Wang X, Jackson DC, Mitchell CC, Varghese T, Wilbrand SM, Rocque BG, Hermann BP, Dempsey RJ. Classification of Symptomatic and Asymptomatic Patients with and without Cognitive Decline Using Non-invasive Carotid Plaque Strain Indices as Biomarkers. Ultrasound Med Biol 2016; 42:909-18. [PMID: 26778288 PMCID: PMC4775393 DOI: 10.1016/j.ultrasmedbio.2015.11.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/17/2015] [Accepted: 11/30/2015] [Indexed: 05/03/2023]
Abstract
Vascular cognitive decline may be caused by micro-emboli generated by carotid plaque instability. We previously found that maximum strain indices in carotid plaque were significantly correlated with cognitive function. In the work described here, we examined these associations with a larger sample size, as well as evaluated the performance of these maximum strain indices in predicting cognitive impairment. Ultrasound-based strain imaging and cognition assessment were conducted on 75 human patients. Patients underwent one of two standardized cognitive test batteries, either the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) or the National Institute of Neurologic Disorder and Stroke-Canadian Stroke Network (NINDS-CSN) Vascular Cognitive Impairment Harmonization Standards (60 min). Scores were standardized within each battery to allow these data to be combined across all participants. Radiofrequency signals for ultrasound strain imaging were acquired on the carotid arteries using either a Siemens Antares with a VFX 13-5 linear array transducer or a Siemens S2000 with an 18 L6 linear array transducer. The same hierarchical block-matching motion tracking algorithm developed in our laboratory was used to estimate accumulated axial, lateral, and shear strain indices in carotid plaque, with inclusion of adventitia regardless of the ultrasound system and transducer used. Associations between cognitive z-scores and maximum strain indices were examined using Pearson's correlation coefficients. Maximum strain indices were also employed to predict cognitive impairment using receiver operating characteristic analysis. All correlations between maximum strain indices and total cognition were statistically significant (p < 0.05), indicating that these indices have good utility in predicting cognitive impairment. Maximum lateral strain indices provided an area under the curve of 0.85 for symptomatic patients and 0.68 for asymptomatic patients. Our results indicate the important relationship of maximum strain indices to cognitive function and the feasibility of using maximum strain indices to predict cognitive decline with inclusion of the adventitia layer into the segmentation of plaque.
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Affiliation(s)
- Xiao Wang
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
| | - Daren C Jackson
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Carol C Mitchell
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Brandon G Rocque
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Bruce P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Jackson DC, Sandoval-Garcia C, Rocque BG, Wilbrand SM, Mitchell CC, Hermann BP, Dempsey RJ. Cognitive Deficits in Symptomatic and Asymptomatic Carotid Endarterectomy Surgical Candidates. Arch Clin Neuropsychol 2015; 31:1-7. [PMID: 26663810 DOI: 10.1093/arclin/acv082] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2015] [Indexed: 11/14/2022] Open
Abstract
The role played by vessel disease in stroke-related cognition dysfunction is unclear. We assessed the impact of significant atherosclerotic disease on cognition-even in patients asymptomatic for stroke. We hypothesized that patients would perform poorly relative to controls, but that symptomatic/asymptomatic status (history of stroke/transient ischemic attack) would have no effect. Fifty-two carotid endarterectomy candidates with >60% carotid stenosis and 17 controls underwent a 60-min neuropsychological test protocol. Symptomatic and asymptomatic patients showed deficits in executive function, delayed verbal recall, and general knowledge. Patients symptomatic for stroke also performed worse on tests of language and motor/visuomotor ability. Symptomatic and asymptomatic patients differed in working memory and language task performance. Although all patients showed deficits in executive function and memory, only symptomatic patients showed additional deficits in language and motor function. Cognitive abnormalities in patients viewed as "asymptomatic" for stroke underscore the need for early identification and treatment.
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Affiliation(s)
- Daren C Jackson
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Carolina Sandoval-Garcia
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Brandon G Rocque
- Department of Neurosurgery, University of Alabama, Birmingham, AL, USA
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Carol C Mitchell
- University of Wisconsin Atherosclerosis Imaging Research Program, Section of Cardiovascular Medicine, Madison, WI, USA
| | - Bruce P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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Berman SE, Wang X, Mitchell CC, Kundu B, Jackson DC, Wilbrand SM, Varghese T, Hermann BP, Rowley HA, Johnson SC, Dempsey RJ. The relationship between carotid artery plaque stability and white matter ischemic injury. Neuroimage Clin 2015; 9:216-22. [PMID: 26448914 PMCID: PMC4572385 DOI: 10.1016/j.nicl.2015.08.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/17/2015] [Accepted: 08/17/2015] [Indexed: 12/12/2022]
Abstract
Higher local carotid artery strain has previously been shown to be a characteristic of unstable carotid plaques. These plaques may be characterized by microvascular changes that predispose to intraplaque hemorrhage, increasing the likelihood of embolization. Little is known however, about how these strain indices correspond with imaging markers of brain health and metrics of brain structure. White matter hyperintensities (WMHs), which are bright regions seen on T2-weighted brain MRI imaging, are postulated to result from cumulative ischemic vascular injury. Consequently, we hypothesized that plaques that are more prone to microvascular changes and embolization, represented by higher strain indices on ultrasound, would be associated with an increased amount of WMH lesion volume. This relationship would suggest not only emboli as a cause for the brain degenerative changes, but more importantly, a common microvascular etiology for large and small vessel contributions to this process. Subjects scheduled to undergo a carotid endarterectomy were recruited from a neurosurgery clinic. Prior to surgery, participating subjects underwent both ultrasound strain imaging and brain MRI scans as part of a larger clinical study on vascular health and cognition. A linear regression found that maximum absolute strain and peak to peak strain in the surgical side carotid artery were predictive of WMH burden. Furthermore, the occurrence of microembolic signals monitored using transcranial Doppler (TCD) ultrasound examinations also correlated with increasing lesion burden. It is becoming increasingly recognized that cognitive decline is often multifactorial in nature. One contributing extra-brain factor may be changes in the microvasculature that produce unstable carotid artery plaques. In this study, we have shown that higher strain indices in carotid artery plaques are significantly associated with an increased WMH burden, a marker of vascular mediated brain damage. We examine how carotid artery plaque strain indices correspond with MRI metrics. Strain in the ICA predicts increased white matter hyperintensity lesion burden. Subjects with embolizing plaques have greater white matter lesion burden.
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Affiliation(s)
- Sara E Berman
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA ; Neuroscience Training Program, University of Wisconsin - Madison, Madison, WI 53705, USA ; Medical Scientist Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Xiao Wang
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Carol C Mitchell
- Department of Medicine, Cardiovascular Medicine Section, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Bornali Kundu
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Daren C Jackson
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Stephanie M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Bruce P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Howard A Rowley
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Sterling C Johnson
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Veterans Hospital, Madison, WI 53705, USA ; Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin - Madison, Madison, WI 53705, USA
| | - Robert J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
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