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Mossa-Basha M, Yuan C, Wasserman BA, Mikulis DJ, Hatsukami TS, Balu N, Gupta A, Zhu C, Saba L, Li D, DeMarco JK, Lehman VT, Qiao Y, Jager HR, Wintermark M, Brinjikji W, Hess CP, Saloner DA. Survey of the American Society of Neuroradiology Membership on the Use and Value of Extracranial Carotid Vessel Wall MRI. AJNR Am J Neuroradiol 2022; 43:1756-1761. [PMID: 36423951 DOI: 10.3174/ajnr.a7720] [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] [Received: 06/22/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE Extracranial vessel wall MRI (EC-VWI) contributes to vasculopathy characterization. This survey study investigated EC-VWI adoption by American Society of Neuroradiology (ASNR) members and indications and barriers to implementation. MATERIALS AND METHODS The ASNR Vessel Wall Imaging Study Group survey on EC-VWI use, frequency, applications, MR imaging systems and field strength used, protocol development approaches, vendor engagement, reasons for not using EC-VWI, ordering provider interest, and impact on clinical care was distributed to the ASNR membership between April 2, 2019, to August 30, 2019. RESULTS There were 532 responses; 79 were excluded due to minimal, incomplete response and 42 due to redundant institutional responses, leaving 411 responses. Twenty-six percent indicated that their institution performed EC-VWI, with 66.3% performing it ≤1-2 times per month, most frequently on 3T MR imaging, with most using combined 3D and 2D protocols. Protocols most commonly included pre- and postcontrast T1-weighted imaging, TOF-MRA, and contrast-enhanced MRA. Inflammatory vasculopathy (63.3%), plaque vulnerability assessments (61.1%), intraplaque hemorrhage (61.1%), and dissection-detection/characterization (51.1%) were the most frequent applications. For those not performing EC-VWI, the reasons were a lack of ordering provider interest (63.9%), lack of radiologist time/interest (47.5%) or technical support (41.4%) for protocol development, and limited interpretation experience (44.9%) and knowledge of clinical applications (43.7%). Reasons given by 46.9% were that no providers approached radiology with interest in EC-VWI. If barriers were overcome, 51.1% of those not performing EC-VWI indicated they would perform it, and 40.6% were unsure; 48.6% did not think that EC-VWI had impacted patient management at their institution. CONCLUSIONS Only 26% of neuroradiology groups performed EC-VWI, most commonly due to limited clinician interest. Improved provider and radiologist education, protocols, processing techniques, technical support, and validation trials could increase adoption.
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Affiliation(s)
- M Mossa-Basha
- From the Department of Radiology (M.M.-B.), University of North Carolina, Chapel Hill, North Carolina .,Departments of Radiology (M.M.-B., N.B., C.Z.)
| | - C Yuan
- Department of Radiology (C.Y.), University of Utah, Salt Lake City, Utah
| | - B A Wasserman
- Department of Radiology (B.A.W.), University of Maryland, Baltimore, Maryland.,Department of Radiology (B.A.W., Y.Q.), Johns Hopkins University, Baltimore, Maryland
| | - D J Mikulis
- Joint Department of Medical Imaging (D.J.M.), The University Health Network and the University of Toronto, Toronto, Ontario, Canada
| | - T S Hatsukami
- Surgery (T.S.H.), University of Washington, Seattle, Washington
| | - N Balu
- Departments of Radiology (M.M.-B., N.B., C.Z.)
| | - A Gupta
- Department of Radiology (A.G.), Weill Cornell Medicine, New York, New York
| | - C Zhu
- Departments of Radiology (M.M.-B., N.B., C.Z.)
| | - L Saba
- Department of Radiology (L.S.), University of Cagliari, Cagliari, Sardinia, Italy
| | - D Li
- Biomedical Imaging Research Institute (D.L.), Cedars-Sinai Medical Center, Los Angeles, California
| | - J K DeMarco
- Department of Radiology (J.K.D.), Walter Reed National Military Medical Center, Bethesda, Maryland and Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - V T Lehman
- Department of Radiology (V.T.L., W.B.), Mayo Clinic, Rochester, Minnesota
| | - Y Qiao
- Department of Radiology (B.A.W., Y.Q.), Johns Hopkins University, Baltimore, Maryland
| | - H R Jager
- Neuroradiological Academic Unit (H.R.J.), Department of Brain Repair and Rehabilitation, University College London, Queen Square Institute of Neurology, London, UK
| | - M Wintermark
- Department of Neuroradiology (M.W.), MD Anderson Cancer Institute, Houston, Texas
| | - W Brinjikji
- Department of Radiology (V.T.L., W.B.), Mayo Clinic, Rochester, Minnesota
| | - C P Hess
- Department of Radiology and Biomedical Imaging (C.P.H., D.A.S.), University of California, San Francisco, San Francisco, California
| | - D A Saloner
- Department of Radiology and Biomedical Imaging (C.P.H., D.A.S.), University of California, San Francisco, San Francisco, California
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Mossa-Basha M, Zhu C, Yuan C, Saba L, Saloner DA, Edjlali M, Stence NV, Mandell DM, Romero JM, Qiao Y, Mikulis DJ, Wasserman BA. Survey of the American Society of Neuroradiology Membership on the Use and Value of Intracranial Vessel Wall MRI. AJNR Am J Neuroradiol 2022; 43:951-957. [PMID: 35710122 DOI: 10.3174/ajnr.a7541] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/22/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE Intracranial vessel wall MR imaging is an emerging technique for intracranial vasculopathy assessment. Our aim was to investigate intracranial vessel wall MR imaging use by the American Society of Neuroradiology (ASNR) members at their home institutions, including indications and barriers to implementation. MATERIALS AND METHODS The ASNR Vessel Wall Imaging Study Group survey on vessel wall MR imaging use, frequency, applications, MR imaging systems and field strength used, protocol development approaches, vendor engagement, reasons for not using vessel wall MR imaging, ordering-provider interest, and impact on clinical care, was distributed to the ASNR membership between April 2 and August 30, 2019. RESULTS There were 532 responses; 79 were excluded due to nonresponse and 42 due to redundant institutional responses, leaving 411 responses. Fifty-two percent indicated that their institution performs vessel wall MR imaging, with 71.5% performed at least 1-2 times/month, most frequently on 3T MR imaging, and 87.7% using 3D sequences. Protocols most commonly included were T1-weighted pre- and postcontrast and TOF-MRA; 60.6% had limited contributions from vendors or were still in protocol development. Vasculopathy differentiation (94.4%), cryptogenic stroke (41.3%), aneurysm (38.0%), and atherosclerosis (37.6%) evaluation were the most common indications. For those not performing vessel wall MR imaging, interpretation (53.1%) or technical (46.4%) expertise, knowledge of applications (50.5%), or limitations of clinician (56.7%) or radiologist (49.0%) interest were the most common reasons. If technical/expertise obstacles were overcome, 56.4% of those not performing vessel wall MR imaging indicated that they would perform it. Ordering providers most frequently inquiring about vessel wall MR imaging were from stroke neurology (56.5%) and neurosurgery (25.1%), while 34.3% indicated that no providers had inquired. CONCLUSIONS More than 50% of neuroradiology groups use vessel wall MR imaging for intracranial vasculopathy characterization and differentiation, emphasizing the need for additional technical and educational support, especially as clinical vessel wall MR imaging implementation continues to grow.
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Affiliation(s)
- M Mossa-Basha
- From the Department of Radiology (M.M.-B.), University of North Carolina, Chapel Hill, North Carolina .,Department of Radiology (M.M.-B., C.Z.), University of Washington, Seattle, Washington
| | - C Zhu
- Department of Radiology (M.M.-B., C.Z.), University of Washington, Seattle, Washington
| | - C Yuan
- Department of Radiology (C.Y.), University of Utah, Salt Lake City, Utah
| | - L Saba
- University of Cagliari (L.S.), Cagliari, Sardinia, Italy
| | - D A Saloner
- Department of Radiology and Biomedical Imaging (D.A.S.), University of California San Francisco, San Francisco, California
| | - M Edjlali
- Department of Radiology (M.E.), AP-HP, Laboratoire d'imagerie Biomédicale Multimodale (BioMaps), Paris-Saclay University, Paris, France
| | - N V Stence
- Department of Radiology (N.V.S.), Children's Hospital of Colorado, Aurora, Colorado
| | - D M Mandell
- Joint Department of Medical Imaging (D.M.M., D.J.M.), University Health Network, Toronto, Ontario, Canada
| | - J M Romero
- Department of Radiology (J.M.R.), Massachusetts General Hospital, Boston, Massachusetts
| | - Y Qiao
- Department of Radiology (Y.Q., B.A.W.), Johns Hopkins University, Baltimore, Maryland
| | - D J Mikulis
- Joint Department of Medical Imaging (D.M.M., D.J.M.), University Health Network, Toronto, Ontario, Canada
| | - B A Wasserman
- Department of Radiology (Y.Q., B.A.W.), Johns Hopkins University, Baltimore, Maryland.,Department of Radiology (B.A.W.), University of Maryland, Baltimore, Maryland
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Halawani AM, Tohyama S, Hung PSP, Behan B, Bernstein M, Kalia S, Zadeh G, Cusimano M, Schwartz M, Gentili F, Mikulis DJ, Laperriere NJ, Hodaie M. Correlation between Cranial Nerve Microstructural Characteristics and Vestibular Schwannoma Tumor Volume. AJNR Am J Neuroradiol 2021; 42:1853-1858. [PMID: 34615646 DOI: 10.3174/ajnr.a7257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 05/28/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Vestibular schwannomas are common cerebellopontine angle tumors arising from the vestibulocochlear nerve and can result in cranial nerve dysfunction. Conventional MR imaging does not provide information that could correlate with cranial nerve compression symptoms of hearing loss or imbalance. We used multitensor tractography to evaluate the relationship between the WM microstructural properties of cranial nerves and tumor volume in a cohort of patients with vestibular schwannomas. MATERIALS AND METHODS A retrospective study was performed in 258 patients with vestibular schwannomas treated at the Gamma Knife clinic at Toronto Western Hospital between 2014 and 2018. 3T MR images were analyzed in 160 surgically naïve patients with unilateral vestibular schwannomas. Multitensor tractography was used to extract DTI-derived metrics (fractional anisotropy and radial, axial, and mean diffusivities of the bilateral facial and vestibulocochlear nerves [cranial nerves VII/VIII]). ROIs were placed in the transition between cisternal and intracanalicular segments, and images were analyzed using the eXtended Streamline Tractography reconstruction method. Diffusion metrics were correlated with 3D tumor volume derived from the Gamma Knife clinic. RESULTS DTI analyses revealed significantly higher fractional anisotropy values and a reduction in axial diffusivity, radial diffusivity, and mean diffusivity (all P < .001) within the affected cranial nerves VII and VIII compared with unaffected side. All specific diffusivities (axial, radial, and mean diffusivity) demonstrated an inverse correlation with tumor volume (axial, radial, and mean diffusivity, P < .01). CONCLUSIONS Multitensor tractography allows the quantification of cranial nerve VII and VIII WM microstructural alterations in patients with vestibular schwannomas. Our findings support the hypothesis that tumor volume may cause microstructural alterations of the affected cranial nerves VII and VIII. This type of advanced imaging may represent a possible avenue to correlate diffusivities with cranial nerve function.
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Affiliation(s)
- A M Halawani
- From the Division of Brain Imaging, and Behaviour-Systems Neuroscience (A.M.H., S.T., P.S.-P.H., D.J.M., M.H.), Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.,Department of Medical Imaging (A.M.H., D.J.M.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neuroradiology (A.M.H., D.J.M.), Joint Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - S Tohyama
- From the Division of Brain Imaging, and Behaviour-Systems Neuroscience (A.M.H., S.T., P.S.-P.H., D.J.M., M.H.), Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, (S.T., P.S.-P.H., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - P S-P Hung
- From the Division of Brain Imaging, and Behaviour-Systems Neuroscience (A.M.H., S.T., P.S.-P.H., D.J.M., M.H.), Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, (S.T., P.S.-P.H., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - B Behan
- Ontario Brain Institute (B.B.), Toronto, Ontario, Canada
| | - M Bernstein
- Department of Surgery (M.B., S.K., G.Z., M.C., F.G., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery (M.B., S.K., F.G., M.H.), Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - S Kalia
- Department of Surgery (M.B., S.K., G.Z., M.C., F.G., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery (M.B., S.K., F.G., M.H.), Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - G Zadeh
- Department of Surgery (M.B., S.K., G.Z., M.C., F.G., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,The Arthur and Sonia Labatt Brain Tumor Research Centre (G.Z.), Hospital for Sick Children, Toronto, Ontario, Canada
| | - M Cusimano
- Department of Surgery (M.B., S.K., G.Z., M.C., F.G., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery (M.C.), Saint Michael's Hospital, Toronto, Ontario, Canada
| | - M Schwartz
- Division of Neurosurgery (M.S.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - F Gentili
- Department of Surgery (M.B., S.K., G.Z., M.C., F.G., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery (M.B., S.K., F.G., M.H.), Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - D J Mikulis
- From the Division of Brain Imaging, and Behaviour-Systems Neuroscience (A.M.H., S.T., P.S.-P.H., D.J.M., M.H.), Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.,Department of Medical Imaging (A.M.H., D.J.M.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neuroradiology (A.M.H., D.J.M.), Joint Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - N J Laperriere
- Department of Radiation Oncology (N.J.L.), University of Toronto, Toronto, Ontario, Canada.,Division of Radiation Oncology (N.J.L.), Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
| | - M Hodaie
- From the Division of Brain Imaging, and Behaviour-Systems Neuroscience (A.M.H., S.T., P.S.-P.H., D.J.M., M.H.), Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada .,Institute of Medical Science, (S.T., P.S.-P.H., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery (M.B., S.K., G.Z., M.C., F.G., M.H.), Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery (M.B., S.K., F.G., M.H.), Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
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Schaafsma JD, Rawal S, Coutinho JM, Rasheedi J, Mikulis DJ, Jaigobin C, Silver FL, Mandell DM. Diagnostic Impact of Intracranial Vessel Wall MRI in 205 Patients with Ischemic Stroke or TIA. AJNR Am J Neuroradiol 2019; 40:1701-1706. [PMID: 31488500 DOI: 10.3174/ajnr.a6202] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/24/2019] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND PURPOSE Secondary prevention of ischemic stroke depends on determining the cause of the initial ischemic event, but standard investigations often fail to identify a cause or identify multiple potential causes. The purpose of this study was to characterize the impact of intracranial vessel wall MR imaging on the etiologic classification of ischemic stroke. MATERIALS AND METHODS This was a single-center, retrospective study of 205 consecutive patients who were referred for vessel wall MR imaging to clarify the etiology of an ischemic stroke or TIA. An expert panel classified stroke etiology before and after incorporating vessel wall MR imaging results using a modified Trial of Org 10172 in Acute Stroke Treatment system. We measured the proportion of patients with an altered etiologic classification after vessel wall MR imaging. RESULTS The median age was 56 years (interquartile range = 44-67 years), and 51% (106/205) of patients were men. Vessel wall MR imaging altered the etiologic classification in 55% (112/205) of patients. The proportion of patients classified as having intracranial arteriopathy not otherwise specified decreased from 31% to 4% (64/205 versus 9/205; P < .001) and the proportion classified as having intracranial atherosclerotic disease increased from 23% to 57% (48/205 versus 116/205; P < .001). Conventional work-up classification as intracranial arteriopathy not otherwise specified was an independent predictor of vessel wall MR imaging impact (OR = 8.9; 95% CI, 3.0-27.2). The time between symptom onset and vessel wall MR imaging was not a predictor of impact. CONCLUSIONS When vessel wall MR imaging is performed to clarify the etiology of a stroke or TIA, it frequently alters the etiologic classification. This is important because the etiologic classification is the basis for therapeutic decision-making.
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Affiliation(s)
- J D Schaafsma
- From the Division of Neurology, Department of Medicine (J.D.S., J.R., C.J., F.L.S.)
| | - S Rawal
- Division of Neuroradiology, Department of Medical Imaging (S.R., J.M.C., D.J.M., D.M.M.), University Health Network, Toronto, Ontario, Canada
| | - J M Coutinho
- Division of Neuroradiology, Department of Medical Imaging (S.R., J.M.C., D.J.M., D.M.M.), University Health Network, Toronto, Ontario, Canada.,Department of Neurology (J.M.C.), Academic Medical Center, Amsterdam, the Netherlands
| | - J Rasheedi
- From the Division of Neurology, Department of Medicine (J.D.S., J.R., C.J., F.L.S.)
| | - D J Mikulis
- Division of Neuroradiology, Department of Medical Imaging (S.R., J.M.C., D.J.M., D.M.M.), University Health Network, Toronto, Ontario, Canada
| | - C Jaigobin
- From the Division of Neurology, Department of Medicine (J.D.S., J.R., C.J., F.L.S.)
| | - F L Silver
- From the Division of Neurology, Department of Medicine (J.D.S., J.R., C.J., F.L.S.)
| | - D M Mandell
- Division of Neuroradiology, Department of Medical Imaging (S.R., J.M.C., D.J.M., D.M.M.), University Health Network, Toronto, Ontario, Canada
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5
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McKetton L, Venkatraghavan L, Rosen C, Mandell DM, Sam K, Sobczyk O, Poublanc J, Gray E, Crawley A, Duffin J, Fisher JA, Mikulis DJ. Improved White Matter Cerebrovascular Reactivity after Revascularization in Patients with Steno-Occlusive Disease. AJNR Am J Neuroradiol 2018; 40:45-50. [PMID: 30573457 DOI: 10.3174/ajnr.a5912] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/08/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE One feature that patients with steno-occlusive cerebrovascular disease have in common is the presence of white matter (WM) lesions on MRI. The purpose of this study was to evaluate the effect of direct surgical revascularization on impaired WM cerebrovascular reactivity in patients with steno-occlusive disease. MATERIALS AND METHODS We recruited 35 patients with steno-occlusive disease, Moyamoya disease (n = 24), Moyamoya syndrome (n = 3), atherosclerosis (n = 6), vasculitis (n = 1), and idiopathic stenosis (n = 1), who underwent unilateral brain revascularization using a direct superficial temporal artery-to-MCA bypass (19 women; mean age, 45.8 ± 16.5 years). WM cerebrovascular reactivity was measured preoperatively and postoperatively using blood oxygen level-dependent (BOLD) MR imaging during iso-oxic hypercapnic changes in end-tidal carbon dioxide and was expressed as %Δ BOLD MR signal intensity per millimeter end-tidal partial pressure of CO2. RESULTS WM cerebrovascular reactivity significantly improved after direct unilateral superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass in the revascularized hemisphere in the MCA territory (mean ± SD, -0.0005 ± 0.053 to 0.053 ± 0.046 %BOLD/mm Hg; P < .0001) and in the anterior cerebral artery territory (mean, 0.0015 ± 0.059 to 0.021 ± 0.052 %BOLD/mm Hg; P = .005). There was no difference in WM cerebrovascular reactivity in the ipsilateral posterior cerebral artery territory nor in the vascular territories of the nonrevascularized hemisphere (P < .05). CONCLUSIONS Cerebral revascularization surgery is an effective treatment for reversing preoperative cerebrovascular reactivity deficits in WM. In addition, direct-STA-MCA bypass may prevent recurrence of preoperative symptoms.
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Affiliation(s)
- L McKetton
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - L Venkatraghavan
- Department of Anesthesia and Pain Management (L.V., J.A.F.), University Health Network, Toronto, Ontario, Canada
| | - C Rosen
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - D M Mandell
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - K Sam
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.).,Russell H. Morgan Department of Radiology and Radiological Science (K.S.), John Hopkins School of Medicine, Baltimore, Maryland
| | - O Sobczyk
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - J Poublanc
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - E Gray
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - A Crawley
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.)
| | - J Duffin
- Department of Physiology (J.D., J.A.F.).,Institute of Medical Sciences (J.D., J.A.F., D.J.M.), University of Toronto, Toronto, Ontario, Canada
| | - J A Fisher
- Department of Anesthesia and Pain Management (L.V., J.A.F.), University Health Network, Toronto, Ontario, Canada.,Department of Physiology (J.D., J.A.F.).,Institute of Medical Sciences (J.D., J.A.F., D.J.M.), University of Toronto, Toronto, Ontario, Canada
| | - D J Mikulis
- From the Division of Neuroradiology, Joint Department of Medical Imaging (L.M., C.R., D.M.M., K.S., O.S., J.P., E.G., A.C., D.J.M.) .,Institute of Medical Sciences (J.D., J.A.F., D.J.M.), University of Toronto, Toronto, Ontario, Canada
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6
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Saba L, Yuan C, Hatsukami TS, Balu N, Qiao Y, DeMarco JK, Saam T, Moody AR, Li D, Matouk CC, Johnson MH, Jäger HR, Mossa-Basha M, Kooi ME, Fan Z, Saloner D, Wintermark M, Mikulis DJ, Wasserman BA. Carotid Artery Wall Imaging: Perspective and Guidelines from the ASNR Vessel Wall Imaging Study Group and Expert Consensus Recommendations of the American Society of Neuroradiology. AJNR Am J Neuroradiol 2018; 39:E9-E31. [PMID: 29326139 DOI: 10.3174/ajnr.a5488] [Citation(s) in RCA: 176] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis and surface irregularities using in vivo imaging techniques including sonography, CT and MR angiography, and digital subtraction angiography. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. The ability to look beyond the lumen using highly developed vessel wall imaging methods to identify plaque vulnerable to disruption has prompted an active debate as to whether a paradigm shift is needed to move away from relying on measurements of luminal stenosis for gauging the risk of ischemic injury. Further evaluation in randomized clinical trials will help to better define the exact role of plaque imaging in clinical decision-making. However, current carotid vessel wall imaging techniques can be informative. The goal of this article is to present the perspective of the ASNR Vessel Wall Imaging Study Group as it relates to the current status of arterial wall imaging in carotid artery disease.
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Affiliation(s)
- L Saba
- From the Department of Medical Imaging (L.S.), University of Cagliari, Cagliari, Italy
| | - C Yuan
- Departments of Radiology (C.Y., N.B., M.M.-B.)
| | - T S Hatsukami
- Surgery (T.S.H.), University of Washington, Seattle, Washington
| | - N Balu
- Departments of Radiology (C.Y., N.B., M.M.-B.)
| | - Y Qiao
- The Russell H. Morgan Department of Radiology and Radiological Sciences (Y.Q., B.A.W.), Johns Hopkins Hospital, Baltimore, Maryland
| | - J K DeMarco
- Department of Radiology (J.K.D.), Walter Reed National Military Medical Center, Bethesda, Maryland
| | - T Saam
- Department of Radiology (T.S.), Ludwig-Maximilian University Hospital, Munich, Germany
| | - A R Moody
- Department of Medical Imaging (A.R.M.), Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - D Li
- Biomedical Imaging Research Institute (D.L., Z.F.), Cedars-Sinai Medical Center, Los Angeles, California
| | - C C Matouk
- Departments of Neurosurgery, Neurovascular and Stroke Programs (C.C.M., M.H.J.).,Radiology and Biomedical Imaging (C.C.M., M.H.J.)
| | - M H Johnson
- Departments of Neurosurgery, Neurovascular and Stroke Programs (C.C.M., M.H.J.).,Radiology and Biomedical Imaging (C.C.M., M.H.J.).,Surgery (M.H.J.), Yale University School of Medicine, New Haven, Connecticut
| | - H R Jäger
- Neuroradiological Academic Unit (H.R.J.), Department of Brain Repair and Rehabilitation, University College London Institute of Neurology, London, UK
| | | | - M E Kooi
- Department of Radiology (M.E.K.), CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Z Fan
- Biomedical Imaging Research Institute (D.L., Z.F.), Cedars-Sinai Medical Center, Los Angeles, California
| | - D Saloner
- Department of Radiology and Biomedical Imaging (D.S.), University of California, San Francisco, California
| | - M Wintermark
- Department of Radiology (M.W.), Neuroradiology Division, Stanford University, Stanford, California
| | - D J Mikulis
- Division of Neuroradiology (D.J.M.), Department of Medical Imaging, University Health Network
| | - B A Wasserman
- The Russell H. Morgan Department of Radiology and Radiological Sciences (Y.Q., B.A.W.), Johns Hopkins Hospital, Baltimore, Maryland
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7
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Martin AR, De Leener B, Cohen-Adad J, Cadotte DW, Kalsi-Ryan S, Lange SF, Tetreault L, Nouri A, Crawley A, Mikulis DJ, Ginsberg H, Fehlings MG. Clinically Feasible Microstructural MRI to Quantify Cervical Spinal Cord Tissue Injury Using DTI, MT, and T2*-Weighted Imaging: Assessment of Normative Data and Reliability. AJNR Am J Neuroradiol 2017; 38:1257-1265. [PMID: 28428213 DOI: 10.3174/ajnr.a5163] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/28/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE DTI, magnetization transfer, T2*-weighted imaging, and cross-sectional area can quantify aspects of spinal cord microstructure. However, clinical adoption remains elusive due to complex acquisitions, cumbersome analysis, limited reliability, and wide ranges of normal values. We propose a simple multiparametric protocol with automated analysis and report normative data, analysis of confounding variables, and reliability. MATERIALS AND METHODS Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences. Cross-sectional area, fractional anisotropy, magnetization transfer ratio, and T2*WI WM/GM signal intensity ratio were calculated. Relationships between MR imaging metrics and age, sex, height, weight, cervical cord length, and rostrocaudal level were analyzed. Test-retest coefficient of variation measured reliability in 24 DTI, 17 magnetization transfer, and 16 T2*WI datasets. DTI with and without cardiac triggering was compared in 10 subjects. RESULTS T2*WI WM/GM showed lower intersubject coefficient of variation (3.5%) compared with magnetization transfer ratio (5.8%), fractional anisotropy (6.0%), and cross-sectional area (12.2%). Linear correction of cross-sectional area with cervical cord length, fractional anisotropy with age, and magnetization transfer ratio with age and height led to decreased coefficients of variation (4.8%, 5.4%, and 10.2%, respectively). Acceptable reliability was achieved for all metrics/levels (test-retest coefficient of variation < 5%), with T2*WI WM/GM comparing favorably with fractional anisotropy and magnetization transfer ratio. DTI with and without cardiac triggering showed no significant differences for fractional anisotropy and test-retest coefficient of variation. CONCLUSIONS Reliable multiparametric assessment of spinal cord microstructure is possible by using clinically suitable methods. These results establish normalization procedures and pave the way for clinical studies, with the potential for improving diagnostics, objectively monitoring disease progression, and predicting outcomes in spinal pathologies.
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Affiliation(s)
- A R Martin
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - B De Leener
- Polytechnique Montreal (B.D.L., J.C.-A.), Montréal, Quebec, Canada
| | - J Cohen-Adad
- Polytechnique Montreal (B.D.L., J.C.-A.), Montréal, Quebec, Canada
- Functional Neuroimaging Unit (J.C.-A.), Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Université de Montréal, Montréal, Quebec, Canada
| | - D W Cadotte
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S Kalsi-Ryan
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S F Lange
- University of Groningen (S.F.L.), Groningen, the Netherlands
| | - L Tetreault
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Nouri
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Crawley
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - D J Mikulis
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - H Ginsberg
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - M G Fehlings
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
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8
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Cantor JM, Lafaille SJ, Hannah J, Kucyi A, Soh DW, Girard TA, Mikulis DJ. Independent Component Analysis of Resting-State Functional Magnetic Resonance Imaging in Pedophiles. J Sex Med 2017; 13:1546-54. [PMID: 27641922 DOI: 10.1016/j.jsxm.2016.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 06/01/2016] [Revised: 08/01/2016] [Accepted: 08/03/2016] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Neuroimaging and other studies have changed the common view that pedophilia is a result of childhood sexual abuse and instead is a neurologic phenomenon with prenatal origins. Previous research has identified differences in the structural connectivity of the brain in pedophilia. AIM To identify analogous differences in functional connectivity. METHODS Functional magnetic resonance images were recorded from three groups of participants while they were at rest: pedophilic men with a history of sexual offenses against children (n = 37) and two control groups: non-pedophilic men who committed non-sexual offenses (n = 28) and non-pedophilic men with no criminal history (n = 39). MAIN OUTCOME MEASURE Functional magnetic resonance imaging data were subjected to independent component analysis to identify known functional networks of the brain, and groups were compared to identify differences in connectivity with those networks (or "components"). RESULTS The pedophilic group demonstrated wide-ranging increases in functional connectivity with the default mode network compared with controls and regional differences (increases and decreases) with the frontoparietal network. Of these brain regions (total = 23), 20 have been identified by meta-analytic studies to respond to sexually relevant stimuli. Conversely, of the brain areas known to be those that respond to sexual stimuli, nearly all emerged in the present data as significantly different in pedophiles. CONCLUSION This study confirms the presence of significant differences in the functional connectivity of the brain in pedophilia consistent with previously reported differences in structural connectivity. The connectivity differences detected here and elsewhere are opposite in direction from those associated with anti-sociality, arguing against anti-sociality and for pedophilia as the source of the neuroanatomic differences detected.
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Affiliation(s)
- J M Cantor
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Complex Mental Illness Program, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto Faculty of Medicine, Toronto, ON, Canada.
| | - S J Lafaille
- Complex Mental Illness Program, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - J Hannah
- Complex Mental Illness Program, Centre for Addiction and Mental Health, Toronto, ON, Canada; University of Rochester, Rochester, NY, USA
| | - A Kucyi
- Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - D W Soh
- Department of Psychology, York University, Toronto, ON, Canada
| | - T A Girard
- Department of Psychology, Ryerson University, Toronto, ON, Canada
| | - D J Mikulis
- Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
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9
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Martin AR, De Leener B, Cohen-Adad J, Cadotte DW, Kalsi-Ryan S, Lange SF, Tetreault L, Nouri A, Crawley A, Mikulis DJ, Ginsberg H, Fehlings MG. A Novel MRI Biomarker of Spinal Cord White Matter Injury: T2*-Weighted White Matter to Gray Matter Signal Intensity Ratio. AJNR Am J Neuroradiol 2017; 38:1266-1273. [PMID: 28428212 DOI: 10.3174/ajnr.a5162] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/29/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE T2*-weighted imaging provides sharp contrast between spinal cord GM and WM, allowing their segmentation and cross-sectional area measurement. Injured WM demonstrates T2*WI hyperintensity but requires normalization for quantitative use. We introduce T2*WI WM/GM signal-intensity ratio and compare it against cross-sectional area, the DTI metric fractional anisotropy, and magnetization transfer ratio in degenerative cervical myelopathy. MATERIALS AND METHODS Fifty-eight patients with degenerative cervical myelopathy and 40 healthy subjects underwent 3T MR imaging, covering C1-C7. Metrics were automatically extracted at maximally compressed and uncompressed rostral/caudal levels. Normalized metrics were compared with t tests, area under the curve, and logistic regression. Relationships with clinical measures were analyzed by using Pearson correlation and multiple linear regression. RESULTS The maximally compressed level cross-sectional area demonstrated superior differences (P = 1 × 10-13), diagnostic accuracy (area under the curve = 0.890), and univariate correlation with the modified Japanese Orthopedic Association score (0.66). T2*WI WM/GM showed strong differences (rostral: P = 8 × 10-7; maximally compressed level: P = 1 × 10-11; caudal: P = 1 × 10-4), correlations (modified Japanese Orthopedic Association score; rostral: -0.52; maximally compressed level: -0.59; caudal: -0.36), and diagnostic accuracy (rostral: 0.775; maximally compressed level: 0.860; caudal: 0.721), outperforming fractional anisotropy and magnetization transfer ratio in most comparisons and cross-sectional area at rostral/caudal levels. Rostral T2*WI WM/GM showed the strongest correlations with focal motor (-0.45) and sensory (-0.49) deficits and was the strongest independent predictor of the modified Japanese Orthopedic Association score (P = .01) and diagnosis (P = .02) in multivariate models (R2 = 0.59, P = 8 × 10-13; area under the curve = 0.954, respectively). CONCLUSIONS T2*WI WM/GM shows promise as a novel biomarker of WM injury. It detects damage in compressed and uncompressed regions and contributes substantially to multivariate models for diagnosis and correlation with impairment. Our multiparametric approach overcomes limitations of individual measures, having the potential to improve diagnostics, monitor progression, and predict outcomes.
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Affiliation(s)
- A R Martin
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - B De Leener
- Polytechnique Montreal (B.D.L., J.C.-A.), Montreal, Quebec, Canada
| | - J Cohen-Adad
- Polytechnique Montreal (B.D.L., J.C.-A.), Montreal, Quebec, Canada.,Functional Neuroimaging Unit (J.C.-A.), Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Université de Montréal, Montreal, Quebec, Canada
| | - D W Cadotte
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S Kalsi-Ryan
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - S F Lange
- University of Groningen (S.F.L.), Groningen, the Netherlands
| | - L Tetreault
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Nouri
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - A Crawley
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto, Ontario, Canada
| | - D J Mikulis
- Department of Medical Imaging (A.C., D.J.M.), University of Toronto and the University Health Network, Toronto, Ontario, Canada
| | - H Ginsberg
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
| | - M G Fehlings
- From the Division of Neurosurgery, Department of Surgery (A.R.M., D.W.C., S.K.-R., L.T., A.N., H.G., M.G.F.)
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10
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Sam K, Crawley AP, Poublanc J, Conklin J, Sobczyk O, Mandell DM, Duffin J, Venkatraghavan L, Fisher JA, Black SE, Mikulis DJ. Vascular Dysfunction in Leukoaraiosis. AJNR Am J Neuroradiol 2016; 37:2258-2264. [PMID: 27492072 DOI: 10.3174/ajnr.a4888] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 06/07/2016] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND PURPOSE The pathogenesis of leukoaraiosis has long been debated. This work addresses a less well-studied mechanism, cerebrovascular reactivity, which could play a leading role in the pathogenesis of this disease. Our aim was to evaluate blood flow dysregulation and its relation to leukoaraiosis. MATERIALS AND METHODS Cerebrovascular reactivity, the change in the blood oxygen level-dependent 3T MR imaging signal in response to a consistently applied step change in the arterial partial pressure of carbon dioxide, was measured in white matter hyperintensities and their contralateral spatially homologous normal-appearing white matter in 75 older subjects (age range, 50-91 years; 40 men) with leukoaraiosis. Additional quantitative evaluation of regions of leukoaraiosis was performed by using diffusion (n = 75), quantitative T2 (n = 54), and DSC perfusion MRI metrics (n = 25). RESULTS When we compared white matter hyperintensities with contralateral normal-appearing white matter, cerebrovascular reactivity was lower by a mean of 61.2% ± 22.6%, fractional anisotropy was lower by 44.9 % ± 6.9%, and CBF was lower by 10.9% ± 11.9%. T2 was higher by 61.7% ± 13.5%, mean diffusivity was higher by 59.0% ± 11.7%, time-to-maximum was higher by 44.4% ± 30.4%, and TTP was higher by 6.8% ± 5.8% (all P < .01). Cerebral blood volume was lower in white matter hyperintensities compared with contralateral normal-appearing white matter by 10.2% ± 15.0% (P = .03). CONCLUSIONS Not only were resting blood flow metrics abnormal in leukoaraiosis but there is also evidence of reduced cerebrovascular reactivity in these areas. Studies have shown that reduced cerebrovascular reactivity is more sensitive than resting blood flow parameters for assessing vascular insufficiency. Future work is needed to examine the sensitivity of resting-versus-dynamic blood flow measures for investigating the pathogenesis of leukoaraiosis.
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Affiliation(s)
- K Sam
- From the Departments of Physiology (K.S., J.D., J.A.F.).,Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - A P Crawley
- Medical Imaging (A.P.C., D.J.M.), University of Toronto, Toronto, Ontario, Canada.,Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - J Poublanc
- Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - J Conklin
- Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - O Sobczyk
- Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - D M Mandell
- Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - J Duffin
- From the Departments of Physiology (K.S., J.D., J.A.F.).,Department of Anesthesiology (J.D., L.V., J.A.F.), University Health Network and The University of Toronto, Toronto, Ontario, Canada
| | - L Venkatraghavan
- Department of Anesthesiology (J.D., L.V., J.A.F.), University Health Network and The University of Toronto, Toronto, Ontario, Canada
| | - J A Fisher
- From the Departments of Physiology (K.S., J.D., J.A.F.).,Department of Anesthesiology (J.D., L.V., J.A.F.), University Health Network and The University of Toronto, Toronto, Ontario, Canada
| | - S E Black
- L.C. Campbell Cognitive Neurology Research Unit (S.E.B.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - D J Mikulis
- Medical Imaging (A.P.C., D.J.M.), University of Toronto, Toronto, Ontario, Canada .,Division of Neuroradiology (K.S., A.P.C., J.P., J.C., O.S., D.M.M., D.J.M.), Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
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11
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Mandell DM, Mossa-Basha M, Qiao Y, Hess CP, Hui F, Matouk C, Johnson MH, Daemen MJAP, Vossough A, Edjlali M, Saloner D, Ansari SA, Wasserman BA, Mikulis DJ. Intracranial Vessel Wall MRI: Principles and Expert Consensus Recommendations of the American Society of Neuroradiology. AJNR Am J Neuroradiol 2016; 38:218-229. [PMID: 27469212 DOI: 10.3174/ajnr.a4893] [Citation(s) in RCA: 397] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Intracranial vessel wall MR imaging is an adjunct to conventional angiographic imaging with CTA, MRA, or DSA. The technique has multiple potential uses in the context of ischemic stroke and intracranial hemorrhage. There remain gaps in our understanding of intracranial vessel wall MR imaging findings and research is ongoing, but the technique is already used on a clinical basis at many centers. This article, on behalf of the Vessel Wall Imaging Study Group of the American Society of Neuroradiology, provides expert consensus recommendations for current clinical practice.
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Affiliation(s)
- D M Mandell
- From the Division of Neuroradiology (D.M.M., D.J.M.), Department of Medical Imaging, University Health Network and the University of Toronto, Toronto, Ontario, Canada
| | - M Mossa-Basha
- Department of Radiology (M.M.-B.), University of Washington, Seattle, Washington
| | - Y Qiao
- The Russell H. Morgan Department of Radiology and Radiological Sciences (Y.Q., F.H., B.A.W.), Johns Hopkins Hospital, Baltimore, Maryland
| | - C P Hess
- Department of Radiology and Biomedical Imaging (C.P.H., D.S.), University of California, San Francisco, San Francisco, California
| | - F Hui
- The Russell H. Morgan Department of Radiology and Radiological Sciences (Y.Q., F.H., B.A.W.), Johns Hopkins Hospital, Baltimore, Maryland
| | - C Matouk
- Departments of Neurosurgery (C.M., M.H.J.).,Radiology and Biomedical Imaging (C.M., M.H.J.)
| | - M H Johnson
- Departments of Neurosurgery (C.M., M.H.J.).,Radiology and Biomedical Imaging (C.M., M.H.J.).,Surgery (M.H.J.), Yale University School of Medicine, New Haven, Connecticut
| | - M J A P Daemen
- Department of Pathology (M.J.A.P.D.), Academic Medical Center, Amsterdam, the Netherlands
| | - A Vossough
- Departments of Surgery (A.V.).,Radiology (A.V.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - M Edjlali
- Department of Radiology (M.E.), Université Paris Descartes Sorbonne Paris Cité, Institut National de la Santé et de la Recherche Médicale S894, Centre Hospitalier Sainte-Anne, Paris, France
| | - D Saloner
- Department of Radiology and Biomedical Imaging (C.P.H., D.S.), University of California, San Francisco, San Francisco, California
| | - S A Ansari
- Departments of Radiology (S.A.A.).,Neurology (S.A.A.).,Neurological Surgery (S.A.A.), Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - B A Wasserman
- The Russell H. Morgan Department of Radiology and Radiological Sciences (Y.Q., F.H., B.A.W.), Johns Hopkins Hospital, Baltimore, Maryland
| | - D J Mikulis
- From the Division of Neuroradiology (D.M.M., D.J.M.), Department of Medical Imaging, University Health Network and the University of Toronto, Toronto, Ontario, Canada
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12
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Sobczyk O, Crawley AP, Poublanc J, Sam K, Mandell DM, Mikulis DJ, Duffin J, Fisher JA. Identifying Significant Changes in Cerebrovascular Reactivity to Carbon Dioxide. AJNR Am J Neuroradiol 2016; 37:818-24. [PMID: 26846924 DOI: 10.3174/ajnr.a4679] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/23/2015] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND PURPOSE Changes in cerebrovascular reactivity can be used to assess disease progression and response to therapy but require discrimination of pathology from normal test-to-test variability. Such variability is due to variations in methodology, technology, and physiology with time. With uniform test conditions, our aim was to determine the test-to-test variability of cerebrovascular reactivity in healthy subjects and in patients with known cerebrovascular disease. MATERIALS AND METHODS Cerebrovascular reactivity was the ratio of the blood oxygen level-dependent MR imaging response divided by the change in carbon dioxide stimulus. Two standardized cerebrovascular reactivity tests were conducted at 3T in 15 healthy men (36.7 ± 16.1 years of age) within a 4-month period and were coregistered into standard space to yield voxelwise mean cerebrovascular reactivity interval difference measures, composing a reference interval difference atlas. Cerebrovascular reactivity interval difference maps were prepared for 11 male patients. For each patient, the test-retest difference of each voxel was scored statistically as z-values of the corresponding voxel mean difference in the reference atlas and then color-coded and superimposed on the anatomic images to create cerebrovascular reactivity interval difference z-maps. RESULTS There were no significant test-to-test differences in cerebrovascular reactivity in either gray or white matter (mean gray matter, P = .431; mean white matter, P = .857; paired t test) in the healthy cohort. The patient cerebrovascular reactivity interval difference z-maps indicated regions where cerebrovascular reactivity increased or decreased and the probability that the changes were significant. CONCLUSIONS Accounting for normal test-to-test differences in cerebrovascular reactivity enables the assessment of significant changes in disease status (stability, progression, or regression) in patients with time.
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Affiliation(s)
- O Sobczyk
- From the Institute of Medical Science (O.S., D.J.M., J.A.F.)
| | - A P Crawley
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory (A.P.C., J.P., K.S., D.M.M., D.J.M.)
| | - J Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory (A.P.C., J.P., K.S., D.M.M., D.J.M.)
| | - K Sam
- Department of Physiology (K.S., J.D., J.A.F.), University of Toronto, Toronto, Canada Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory (A.P.C., J.P., K.S., D.M.M., D.J.M.)
| | - D M Mandell
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory (A.P.C., J.P., K.S., D.M.M., D.J.M.)
| | - D J Mikulis
- From the Institute of Medical Science (O.S., D.J.M., J.A.F.) Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory (A.P.C., J.P., K.S., D.M.M., D.J.M.)
| | - J Duffin
- Department of Physiology (K.S., J.D., J.A.F.), University of Toronto, Toronto, Canada Department of Anaesthesia and Pain Management (J.D., J.A.F.), University Health Network, Toronto, Canada
| | - J A Fisher
- From the Institute of Medical Science (O.S., D.J.M., J.A.F.) Department of Physiology (K.S., J.D., J.A.F.), University of Toronto, Toronto, Canada Department of Anaesthesia and Pain Management (J.D., J.A.F.), University Health Network, Toronto, Canada
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13
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Coutinho JM, Sacho RH, Schaafsma JD, Agid R, Krings T, Radovanovic I, Matouk CC, Mikulis DJ, Mandell DM. High-Resolution Vessel Wall Magnetic Resonance Imaging in Angiogram-Negative Non-Perimesencephalic Subarachnoid Hemorrhage. Clin Neuroradiol 2015; 27:175-183. [PMID: 26608742 DOI: 10.1007/s00062-015-0484-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/05/2015] [Indexed: 11/30/2022]
Abstract
PURPOSE Standard magnetic resonance imaging (MRI) rarely identifies the cause of hemorrhage in patients with an angiogram-negative, non-perimesencephalic subarachnoid hemorrhage (SAH). Yet up to 10 % of these patients have recurrent hemorrhage. The aim of the study was to explore the potential role of high-resolution contrast-enhanced 3-Tesla vessel wall-MRI in patients with angiogram-negative SAH. METHODS We performed intracranial vessel wall-MRI of the circle of Willis using a 3-Tesla scanner in consecutive patients presenting with a spontaneous, angiogram-negative, non-perimesencephalic SAH. Vessel wall-MRI included T1-, T2-, and gadolinium-enhanced T1-weighted two-dimensional black-blood sequences in multiple planes (voxel size 0.4 × 0.4 × 2.0 mm). Two neuroradiologists independently scored abnormalities of the arterial wall. RESULTS In all, 11 patients (mean age 59 years) underwent vessel wall-MRI. A total of seven patients had vessel wall abnormalities despite normal catheter angiography. Two patients had focal abnormalities contiguous with the outer margin of the basilar artery wall for which we considered a differential of ruptured blood blister aneurysm, thrombosed aneurysm, and loculated extramural blood from elsewhere. Two patients had arterial wall enhancement involving multiple arteries, possibly secondary to SAH. Three patients had arterial wall enhancement at sites of dural penetration, remote from the SAH, likely related to age and atherosclerotic risk factors. Vessel wall-MRI did not alter patient management in this cohort. CONCLUSION Vessel wall-MRI showed abnormalities in seven patients with angiogram-negative SAH. These findings did not alter patient management, but the findings may be useful for other physicians who choose to perform vessel wall-MRI in this patient population.
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Affiliation(s)
- J M Coutinho
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network and the University of Toronto, 399 Bathurst St, M5T 2S8, Toronto, ON, Canada
| | - R H Sacho
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network and the University of Toronto, 399 Bathurst St, M5T 2S8, Toronto, ON, Canada
| | - J D Schaafsma
- Division of Neurology, Department of Medicine, University Health Network and the University of Toronto, Toronto, ON, Canada
| | - R Agid
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network and the University of Toronto, 399 Bathurst St, M5T 2S8, Toronto, ON, Canada
| | - T Krings
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network and the University of Toronto, 399 Bathurst St, M5T 2S8, Toronto, ON, Canada
| | - I Radovanovic
- Division of Neurosurgery, Department of Surgery, University Health Network and the University of Toronto, Toronto, ON, Canada
| | - C C Matouk
- Departments of Diagnostic Radiology and Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - D J Mikulis
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network and the University of Toronto, 399 Bathurst St, M5T 2S8, Toronto, ON, Canada
| | - D M Mandell
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network and the University of Toronto, 399 Bathurst St, M5T 2S8, Toronto, ON, Canada.
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14
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Goswami R, Dufort P, Tartaglia MC, Green RE, Crawley A, Tator CH, Wennberg R, Mikulis DJ, Keightley M, Davis KD. Frontotemporal correlates of impulsivity and machine learning in retired professional athletes with a history of multiple concussions. Brain Struct Funct 2015; 221:1911-25. [PMID: 25721800 PMCID: PMC4853456 DOI: 10.1007/s00429-015-1012-0] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 02/11/2015] [Indexed: 12/15/2022]
Abstract
The frontotemporal cortical network is associated with behaviours such as impulsivity and aggression. The health of the uncinate fasciculus (UF) that connects the orbitofrontal cortex (OFC) with the anterior temporal lobe (ATL) may be a crucial determinant of behavioural regulation. Behavioural changes can emerge after repeated concussion and thus we used MRI to examine the UF and connected gray matter as it relates to impulsivity and aggression in retired professional football players who had sustained multiple concussions. Behaviourally, athletes had faster reaction times and an increased error rate on a go/no-go task, and increased aggression and mania compared to controls. MRI revealed that the athletes had (1) cortical thinning of the ATL, (2) negative correlations of OFC thickness with aggression and task errors, indicative of impulsivity, (3) negative correlations of UF axial diffusivity with error rates and aggression, and (4) elevated resting-state functional connectivity between the ATL and OFC. Using machine learning, we found that UF diffusion imaging differentiates athletes from healthy controls with significant classifiers based on UF mean and radial diffusivity showing 79–84 % sensitivity and specificity, and 0.8 areas under the ROC curves. The spatial pattern of classifier weights revealed hot spots at the orbitofrontal and temporal ends of the UF. These data implicate the UF system in the pathological outcomes of repeated concussion as they relate to impulsive behaviour. Furthermore, a support vector machine has potential utility in the general assessment and diagnosis of brain abnormalities following concussion.
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Affiliation(s)
- R Goswami
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Division of Brain, Imaging and Behaviour-Systems Neuroscience, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Room MP14-306, Toronto, ON, M5T 2S8, Canada
| | - P Dufort
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Department of Medical Imaging, Toronto Western Hospital and University of Toronto, Toronto, Canada
| | - M C Tartaglia
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada.,Division of Neurology, Krembil Neuroscience Centre, Toronto, Canada
| | - R E Green
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Toronto Rehabilitation Institute, University Health Network, Toronto, Canada
| | - A Crawley
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Division of Brain, Imaging and Behaviour-Systems Neuroscience, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Room MP14-306, Toronto, ON, M5T 2S8, Canada.,Department of Medical Imaging, Toronto Western Hospital and University of Toronto, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - C H Tator
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Division of Brain, Imaging and Behaviour-Systems Neuroscience, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Room MP14-306, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada.,Division of Neurosurgery, Krembil Neuroscience Centre, Toronto Western Hospital, Toronto, Canada.,Department of Surgery, University of Toronto, Toronto, Canada
| | - R Wennberg
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Division of Neurology, Krembil Neuroscience Centre, Toronto, Canada
| | - D J Mikulis
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Division of Brain, Imaging and Behaviour-Systems Neuroscience, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Room MP14-306, Toronto, ON, M5T 2S8, Canada.,Department of Medical Imaging, Toronto Western Hospital and University of Toronto, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - M Keightley
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada.,Department of Occupational Science and Occupational Therapy, University of Toronto and Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada
| | - Karen D Davis
- Canadian Sports Concussion Project, Toronto Western Hospital, Toronto, Canada. .,Division of Brain, Imaging and Behaviour-Systems Neuroscience, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Room MP14-306, Toronto, ON, M5T 2S8, Canada. .,Institute of Medical Science, University of Toronto, Toronto, Canada. .,Department of Surgery, University of Toronto, Toronto, Canada.
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15
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Abstract
SUMMARY This review article explains the methodology of breath-hold cerebrovascular reactivity mapping, both in terms of acquisition and analysis, and reviews applications of this method to presurgical mapping, particularly with respect to blood oxygen level-dependent fMRI. Its main application in clinical fMRI is for the assessment of neurovascular uncoupling potential. Neurovascular uncoupling is potentially a major limitation of clinical fMRI, particularly in the setting of mass lesions in the brain such as brain tumors and intracranial vascular malformations that are associated with alterations in regional hemodynamics on either an acquired or congenital basis. As such, breath-hold cerebrovascular reactivity mapping constitutes an essential component of quality control analysis in clinical fMRI, particularly when performed for presurgical mapping of eloquent cortex. Exogenous carbon dioxide challenges used for cerebrovascular reactivity mapping will also be discussed, and their applications to the evaluation of cerebrovascular reserve and cerebrovascular disease will be described.
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Affiliation(s)
- J J Pillai
- From the Division of Neuroradiology (J.J.P.), Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - D J Mikulis
- Department of Medical Imaging (D.J.M.), The University of Toronto, The University Health Network, The Toronto Western Hospital, Toronto, Ontario, Canada
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16
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Faro SH, Mohamed FB, Helpern JA, Jensen JH, Thulborn KR, Atkinson IC, Sair HI, Mikulis DJ. Hot topics in functional neuroradiology. AJNR Am J Neuroradiol 2013; 34:2241-9. [PMID: 24136644 DOI: 10.3174/ajnr.a3721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Functional neuroradiology represents a relatively new and ever-growing subspecialty in the field of neuroradiology. Neuroradiology has evolved beyond anatomy and basic tissue signal characteristics and strives to understand the underlying physiologic processes of central nervous system disease. The American Society of Functional Neuroradiology sponsors a yearly educational and scientific meeting, and the educational committee was asked to suggest a few cutting-edge functional neuroradiology techniques (hot topics). The following is a review of several of these topics and includes "Diffusion Tensor Imaging of the Pediatric Spinal Cord"; "Diffusional Kurtosis Imaging"; "From Standardization to Quantification: Beyond Biomarkers toward Bioscales as Neuro MR Imaging Surrogates of Clinical End Points"; Resting-State Functional MR Imaging"; and "Current Use of Cerebrovascular Reserve Imaging."
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17
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Fierstra J, Sobczyk O, Battisti-Charbonney A, Mandell DM, Poublanc J, Crawley AP, Mikulis DJ, Duffin J, Fisher JA. Measuring cerebrovascular reactivity: what stimulus to use? J Physiol 2013; 591:5809-21. [PMID: 24081155 DOI: 10.1113/jphysiol.2013.259150] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cerebrovascular reactivity is the change in cerebral blood flow in response to a vasodilatory or vasoconstrictive stimulus. Measuring variations of cerebrovascular reactivity between different regions of the brain has the potential to not only advance understanding of how the cerebral vasculature controls the distribution of blood flow but also to detect cerebrovascular pathophysiology. While there are standardized and repeatable methods for estimating the changes in cerebral blood flow in response to a vasoactive stimulus, the same cannot be said for the stimulus itself. Indeed, the wide variety of vasoactive challenges currently employed in these studies impedes comparisons between them. This review therefore critically examines the vasoactive stimuli in current use for their ability to provide a standard repeatable challenge and for the practicality of their implementation. Such challenges include induced reductions in systemic blood pressure, and the administration of vasoactive substances such as acetazolamide and carbon dioxide. We conclude that many of the stimuli in current use do not provide a standard stimulus comparable between individuals and in the same individual over time. We suggest that carbon dioxide is the most suitable vasoactive stimulus. We describe recently developed computer-controlled MRI compatible gas delivery systems which are capable of administering reliable and repeatable vasoactive CO2 stimuli.
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Affiliation(s)
- J Fierstra
- J. Duffin: Department of Physiology, Medical Sciences Building, 1 King's College Circle, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.
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18
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Skarpathiotakis M, Mandell DM, Swartz RH, Tomlinson G, Mikulis DJ. Intracranial atherosclerotic plaque enhancement in patients with ischemic stroke. AJNR Am J Neuroradiol 2012; 34:299-304. [PMID: 22859280 DOI: 10.3174/ajnr.a3209] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND PURPOSE Inflammation of an atherosclerotic plaque is a well-known risk factor in the development of ischemic stroke and myocardial infarction. MR imaging is capable of characterizing inflammation by assessing plaque enhancement in both extracranial carotid arteries and coronary arteries. Our goal was to determine whether enhancing intracranial atherosclerotic plaque was present in the vessel supplying the territory of infarction by using high-resolution vessel wall MR imaging. MATERIALS AND METHODS High-resolution vessel wall 3T MR imaging studies performed in 29 patients with ischemic stroke and intracranial vascular stenoses were reviewed for presence and strength of plaque enhancement. RESULTS Sixteen patients were studied during the acute phase (<4 weeks from acute stroke), 5 patients in the subacute phase (4-12 weeks), and 8 patients in the chronic phase (>12 weeks) of the ischemic injury. In all of the acute phase patients, atherosclerotic plaque in the vessel supplying the stroke territory demonstrated strong enhancement. There was a trend of decreasing enhancement as the time of imaging relative to the ischemic event increased. CONCLUSIONS Strong pathologic enhancement of intracranial atherosclerotic plaque was seen in all patients imaged within 4 weeks of ischemic stroke in the vessel supplying the stroke territory. The strength and presence of enhancement of the atherosclerotic plaque decreased with increasing time after the ischemic event. These findings suggest a relationship between enhancing intracranial atherosclerotic plaque and acute ischemic stroke.
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Affiliation(s)
- M Skarpathiotakis
- Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, M5T Canada
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19
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Conklin J, Fierstra J, Crawley AP, Han JS, Poublanc J, Silver FL, Tymianski M, Fisher JA, Mandell DM, Mikulis DJ. Mapping white matter diffusion and cerebrovascular reactivity in carotid occlusive disease. Neurology 2011; 77:431-8. [PMID: 21775744 DOI: 10.1212/wnl.0b013e318227b1e7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To characterize the relationship between cerebrovascular reactivity (CVR) and white matter (WM) diffusion in patients with internal carotid artery (ICA) occlusive disease. METHODS In this exploratory observational study, 41 patients with severe stenosis or occlusion of the extracranial ICA and 12 healthy control subjects underwent CVR mapping using the fMRI response to hypercapnia. Conventional anatomic and diffusion-weighted MRI sequences were used to calculate maps of the apparent diffusion coefficient (ADC) and to exclude areas of previous ischemic injury. In all subjects, ADC was compared between WM with positive and negative CVR. In 27 patients with unilateral ICA involvement, ADC and CVR were compared between ipsilateral and contralateral WM while covarying for relevant clinical risk factors. RESULTS In patients with bilateral disease and in the ipsilateral hemisphere of patients with unilateral disease, negative CVR was associated with increased WM ADC (p < 0.01 and p < 0.005, respectively). In patients with unilateral disease, the ipsilateral CVR deficit was correlated with the degree of hemispheric WM ADC elevation (p < 0.005). ADC elevation remained significant after correction for potential confounding risk factors. CONCLUSIONS CVR impairment is associated with ADC elevation in normal-appearing WM of patients with severe stenosis or occlusion of the extracranial ICA. This finding is consistent with the presence of early, low-grade ischemic injury.
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Affiliation(s)
- J Conklin
- Department of Medical Imaging, Toronto Western Hospital, Toronto, ON, Canada
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20
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Fierstra J, Conklin J, Krings T, Slessarev M, Han JS, Fisher JA, TerBrugge K, Wallace MC, Tymianski M, Mikulis DJ. Reply: A comment on impaired peri-nidal cerebrovascular reserve in seizure patients with brain arteriovenous malformations. Brain 2011. [DOI: 10.1093/brain/awr106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Mandell DM, Han JS, Poublanc J, Crawley AP, Fierstra J, Tymianski M, Fisher JA, Mikulis DJ. Quantitative measurement of cerebrovascular reactivity by blood oxygen level-dependent MR imaging in patients with intracranial stenosis: preoperative cerebrovascular reactivity predicts the effect of extracranial-intracranial bypass surgery. AJNR Am J Neuroradiol 2011; 32:721-7. [PMID: 21436343 DOI: 10.3174/ajnr.a2365] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND PURPOSE CVR is a measure of cerebral hemodynamic impairment. A recently validated technique quantifies CVR by using a precise CO(2) vasodilatory stimulus and BOLD MR imaging. Our aim was to determine whether preoperative CO(2) BOLD CVR predicts the hemodynamic effect of ECIC bypass surgery in patients with intracranial steno-occlusive disease. MATERIALS AND METHODS Twenty-five patients undergoing ECIC bypass surgery for treatment of intracranial stenosis or occlusion were recruited. CVR was measured preoperatively and postoperatively and expressed as %ΔBOLD MR signal intensity per mm Hg ΔPetCO(2). Using normative data from healthy subjects, we stratified patients on the basis of preoperative CVR into 3 groups: normal CVR, reduced CVR, and negative (paradoxical) CVR. Wilcoxon 2-sample tests (2-sided, α = 0.05) were used to determine whether the 3 groups differed with respect to change in CVR following bypass surgery. RESULTS The group with normal preoperative CVR demonstrated no significant change in CVR following bypass surgery (mean, 0.22% ± 0.05% to 0.22% ± 0.01%; P = .881). The group with reduced preoperative CVR demonstrated a significant improvement following bypass surgery (mean, 0.08% ± 0.05% to 0.21 ± 0.08%; P < .001), and the group with paradoxical preoperative CVR demonstrated the greatest improvement (mean change, -0.04% ± 0.03% to 0.27% ± 0.03%; P = .028). CONCLUSIONS Preoperative measurement of CVR by using CO(2) BOLD MR imaging predicts the hemodynamic effect of ECIC bypass in patients with intracranial steno-occlusive disease. The technique is potentially useful for selecting patients for surgical revascularization.
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Affiliation(s)
- D M Mandell
- Division of Neuroradiology, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
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22
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Thornhill RE, Chen S, Rammo W, Mikulis DJ, Kassner A. Contrast-enhanced MR imaging in acute ischemic stroke: T2* measures of blood-brain barrier permeability and their relationship to T1 estimates and hemorrhagic transformation. AJNR Am J Neuroradiol 2010; 31:1015-22. [PMID: 20190209 DOI: 10.3174/ajnr.a2003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE rtPA is an effective treatment for AIS, yet it is substantially underused due to the increased risk of HT. Recent work suggests that permeability-related information can be extracted from routine T2*-based perfusion images by measuring the rR of the contrast agent. Given that other T2*-based measures have recently been proposed, the purpose of this study was to evaluate 4 such permeability measures in identifying patients with AIS who will proceed to HT. MATERIALS AND METHODS Eighteen patients with AIS were examined within a mean of 3.3 +/- 1.4 hours postonset. Dynamic T2*-weighted imaging consisted of a single-shot EPI following a bolus of gadodiamide. HT was determined on follow-up CT or MR imaging at 24-72 hours. Mean values of rR, Peak Height, Recovery, as well as Slope were calculated and analyzed on the basis of follow-up HT status. RESULTS Eight patients proceeded to HT. The mean rR for patients with HT was significantly greater than that for patients without HT (0.22 +/- 0.06 versus 0.14 +/- 0.06, P = .006), while there was a trend toward decreased %Recovery in patients with HT (76 +/- 6 versus 82 +/- 11%, P = .092). There was a significant negative correlation between %Recovery and rR (r = -0.88, P < .001). No significant differences or trends were detected with respect to Peak Height or Slope. CONCLUSIONS Both rR and %Recovery can be readily extracted from a routine perfusion MR imaging dataset and show potential for identifying HT during the acute phase poststroke.
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Affiliation(s)
- R E Thornhill
- Department of Medical Imaging, University of Toronto, 150 College Street, Toronto, Ontario, Canada
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23
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Heyn C, Poublanc J, Crawley A, Mandell D, Han JS, Tymianski M, terBrugge K, Fisher JA, Mikulis DJ. Quantification of cerebrovascular reactivity by blood oxygen level-dependent MR imaging and correlation with conventional angiography in patients with Moyamoya disease. AJNR Am J Neuroradiol 2010; 31:862-7. [PMID: 20075092 DOI: 10.3174/ajnr.a1922] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND AND PURPOSE BOLD MR imaging combined with a technique for precision control of end-tidal pCO(2) was used to produce quantitative maps of CVR in patients with Moyamoya disease. The technique was validated against measures of disease severity by using conventional angiography; it then was used to study the relationship between CVR, vascular steal, and disease severity. MATERIALS AND METHODS A retrospective analysis comparing conventional angiography with BOLD MR imaging was performed on 11 patients with Moyamoya disease. Iso-oxic cycling of end-tidal pCO(2) between 2 target values was performed during BOLD MR imaging. CVR was calculated as the BOLD signal difference per Delta pCO(2). CVR was correlated with the presence of Moyamoya or pial collaterals and the degree of Moyamoya disease as graded by using a modified Suzuki score. RESULTS A good correlation between mean CVR and Suzuki score was found for the MCA and ACA territories (Pearson correlation coefficient, -0.7560 and -0.6140, respectively; P < .0001). A similar correlation was found between mean CVR and the presence of pial and Moyamoya collateral vessels for combined MCA and ACA territories (Pearson correlation coefficient, -0.7466; P < .0001). On a voxel-for-voxel basis, there was a greater extent of steal within vascular territories with increasing disease severity (higher modified Suzuki score). Mean CVR was found to scale nonlinearly with the extent of vascular steal. CONCLUSIONS Quantitative measures of CVR show direct correlation with impaired vascular supply as measured by the modified Suzuki score and enable direct investigation of the physiology of autoregulatory reserve, including steal phenomenon, within a given vascular territory.
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Affiliation(s)
- C Heyn
- Departments of Medical Imaging, Toronto Western Hospital of the University Health Network, Toronto, Ontario, Canada
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24
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Kassner A, Roberts TPL, Moran B, Silver FL, Mikulis DJ. Recombinant tissue plasminogen activator increases blood-brain barrier disruption in acute ischemic stroke: an MR imaging permeability study. AJNR Am J Neuroradiol 2009; 30:1864-9. [PMID: 19661169 DOI: 10.3174/ajnr.a1774] [Citation(s) in RCA: 60] [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] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Although thrombolytic therapy (recombinant tissue plasminogen activator [rtPA]) represents an important step forward in acute ischemic stroke (AIS) management, there is a clear need to identify high-risk patients. The purpose of this study was to investigate the role of quantitative permeability (KPS) MR imaging in patients with AIS treated with and without rtPA. We hypothesized that rtPA would increase KPS and that KPS MR imaging can be used to predict the risk of hemorrhagic transformation (HT). MATERIALS AND METHODS Thirty-six patients with AIS were examined within a mean of 3.6 hours of documented symptom onset. KPS MR imaging was performed as part of our AIS protocol. KPS coefficients in the stroke lesion were estimated for all patients, and the relationship between KPS and both HT and rtPA was investigated by using Student t tests. Receiver operating characteristic (ROC) curves were computed for predicting HT from KPS. RESULTS The occurrence rate of HT for patients who received rtPA and those who did not was 43% and 37%, respectively. Assessment of KPS in the lesion revealed significant differences between those who hemorrhaged and those who did not (P < .0001) as well as between rtPA-treated and untreated patients (P = .008). ROC analysis indicated a KPS threshold of 0.67 mL/100 g/min, with a sensitivity of 92% and a specificity of 78%. CONCLUSIONS The results of this study indicate that KPS is able to identify patients at higher risk of HT and may allow use of physiologic imaging rather than time from onset of symptoms to guide treatment decision.
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Affiliation(s)
- A Kassner
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
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25
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Swartz RH, Bhuta SS, Farb RI, Agid R, Willinsky RA, Terbrugge KG, Butany J, Wasserman BA, Johnstone DM, Silver FL, Mikulis DJ. Intracranial arterial wall imaging using high-resolution 3-tesla contrast-enhanced MRI. Neurology 2009; 72:627-34. [PMID: 19221296 DOI: 10.1212/01.wnl.0000342470.69739.b3] [Citation(s) in RCA: 299] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- R H Swartz
- Division of Neuroradiology, Department of Medical Imaging, New East Wing, Toronto Western Hospital, University Health Network, 399 Bathurst St., Toronto, Ontario M5T2S8, Canada
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26
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Kiehl TR, Chow EWC, Mikulis DJ, George SR, Bassett AS. Neuropathologic Features in Adults with 22q11.2 Deletion Syndrome. Cereb Cortex 2008; 19:153-64. [DOI: 10.1093/cercor/bhn066] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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27
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Guo G, Wu RH, Zhang YP, Mikulis DJ, terBrugger K. Prediction of hemorrhagic transformation after acute ischemic stroke using hyperintense MCA sign. Conf Proc IEEE Eng Med Biol Soc 2007; 2006:1881-4. [PMID: 17946485 DOI: 10.1109/iembs.2006.260171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
PURPOSE The hyperintense appearance of the middle cerebral artery (HMCA) sign consists of a thickened MCA stem with a blurred intense signal on contrast enhanced T1-weighted magnetic resonance imaging (T1W MRI). In this article, we define it and determine its incidence, diagnostic value, and reliability by comparison with magnetic resonance angiography and digital subtraction angiography. MATERIALS AND METHIODS: Non-contrast CT and immediately subsequent MRI were performed on 30 consecutive patients with acute ischemic stroke within 6 hours after symptom onset. Ml patients underwent at least one follow-up MRI or non-contrast CT within 2-7 days. Initial studies were analyzed for HMCA sign on post-Gd T1WI. Vascular findings on both MRI and CT were compared with findings at MRA and DSA. RESULTS Eleven patients were developed subsequent HT at follow-up studies. The HMCA sign on MRI was found in 6 hemorrhagic patients (P=0.00), and all of them had M1 occlusion on angiography. None of the patients in nonhemorrhagic group had HMCA sign on MRI. CONCLUSION HMCA sign on post-Gd T1WI is highly specific and moderately sensitive indicator of acute thrombus with M1 MCA segment, as validated by angiography. Additionally, HMCA sign may be a useful marker of subsequent HT in acute ischemic stroke.
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Affiliation(s)
- G Guo
- Dept. of Med. Imaging, Shantou Univ. Med. Coll. ,China
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28
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Farb RI, Forghani R, Lee SK, Mikulis DJ, Agid R. The venous distension sign: a diagnostic sign of intracranial hypotension at MR imaging of the brain. AJNR Am J Neuroradiol 2007; 28:1489-93. [PMID: 17846197 PMCID: PMC8134393 DOI: 10.3174/ajnr.a0621] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Patients with intracranial hypotension (IH) demonstrate intracranial venous enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from the normal appearance of this segment, which usually has a slightly concave or straight lower margin. This sign is introduced, and its performance as a test for the presence of this disease is evaluated. MATERIALS AND METHODS The transverse sinuses on T1-weighted sagittal imaging of 15 patients with IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for the presence of a VDS. A present or absent VDS was determined for each patient by each reader, and a consensus result for each patient was determined by unanimity or majority rule. RESULTS Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients and similarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readers for the interpretation of the VDS (multirater kappa = 0.82). The overall sensitivity of the VDS for the diagnosis of intracranial hypotension was 94%. Specificity was also 94%. CONCLUSION The VDS appears to be an accurate test for the presence or absence of IH and may be helpful in the evaluation of these patients.
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Affiliation(s)
- R I Farb
- Department of Medical Imaging, Division of Neuroradiology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
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29
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Wu RH, Ducreux D, Crawley A, Lin R, Kong KM, Guo G, Luo XT, Lang ZJ, terBrugge K, Mikulis DJ. Improving spatial signal homogeneity in MR 2D chemical shift imaging using outer volume saturation bands. Conf Proc IEEE Eng Med Biol Soc 2007; 2004:1084-7. [PMID: 17271871 DOI: 10.1109/iembs.2004.1403352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Many endeavors of improving chemical shift imaging (CSI) techniques have been made during last two decades. Good examples of two-dimensional CSI and three-dimensional CSI can be found in the literature. However, clinical CSI using available sequences is still not satisfactory. The purpose of this study was to assess the effect of outer volume saturation bands on signal homogeneity in MR 2D chemical shift imaging. The 2D CSI scans were acquired using a point resolved spectroscopy (PRESS) CSI sequence on a phantom filled with brain metabolites. A single PRESS volume of interest was prescribed graphically. The acquisition matrix was 18x18 phase encodings over a 24-cm FOV. Identical acquisitions were obtained with and without outer-volume saturation bands. After initial acquisition was obtained, four more acquisitions were repeated for both studies with and without saturation bands. Identical five groups of voxels were compared for both studies. Standard deviations of metabolite ratios were calculated in each group for both studies. Spectra obtained without outer-volume saturation bands showed signal to noise gradient with higher concentration of signal within voxels at the center of the volume of interest. Outer volume saturation bands reduced this gradient. In general, standard deviations of metabolite ratios with saturation bands were smaller than those without saturation bands. Improved spatial homogeneity of spectra in voxels of CSI with saturation bands was obtained. Outer-volume saturation bands improve spatial signal homogeneity of chemical shift imaging.
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Affiliation(s)
- R H Wu
- Dept. of Med. Imaging, Shantou Univ. Med. Coll., China
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Guo G, Wu R, Ter Brugge K, Mikulis DJ. Focal Lesion in Splenium of Corpus Callosum on FLAIR MRI: Common Findings in Aged Patients. Neuroradiol J 2006; 19:301-5. [PMID: 24351214 DOI: 10.1177/197140090601900305] [Citation(s) in RCA: 3] [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] [Received: 04/03/2006] [Accepted: 05/11/2006] [Indexed: 02/05/2023] Open
Abstract
Focal high signal intensity in the splenium of the corpus callosum on fluid-attenuated inversion-recovery (FLAIR) images is generally considered an abnormal MR finding. The aim of this study was to determine the frequency of this finding in elderly patients and review the differentiation from other diseases with the similar findings. FLAIR images of 132 patients with suspect CNS disease were retrospectively reviewed. The changes in the splenium of corpus callosum, deep white matter lesions, periventricular matter lesions, infarcts, atrophy and age were analyzed, as well as history. Among the initial 132 patients, focal high signal intensity in the splenium was associated with aging, white matter changes, atrophy, and cognitive disorders. Focal high signal intensity in the splenium of the corpus callosum on FLAIR image is a common finding in elderly patients, especially in aged patients with cognitive disorders. The pathologic alterations were commonly described by the term of "leukoaraiosis". Knowledge of this finding and differentiation from other lesions focusing on the splenium of corpus callosum may help avoid unnecessary invasive diagnostic and therapeutic intervention.
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Affiliation(s)
- G Guo
- Dapartment of Medical Imaging, The Second Hospital, Shantou University Medical College; Shantou, China -
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Agid R, Farb RI, Willinsky RA, Mikulis DJ, Tomlinson G. Idiopathic intracranial hypertension: the validity of cross-sectional neuroimaging signs. Neuroradiology 2006; 48:521-7. [PMID: 16703359 DOI: 10.1007/s00234-006-0095-y] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2005] [Accepted: 02/10/2006] [Indexed: 12/20/2022]
Abstract
The aim of this study was to evaluate the accuracy of previously reported neuroimaging signs in establishing or excluding the diagnosis of idiopathic intracranial hypertension (IIH). In a retrospective study, 30 patients with confirmed IIH and 56 controls were evaluated with brain magnetic resonance imaging. All examinations were evaluated in a blinded fashion by three neuroradiologists for the presence or absence of the 'traditional' signs of IIH: empty sella turcica, deformation of the pituitary, slit-like ventricles, 'tight' subarachnoid spaces, flattening of the posterior globe, protrusion of the optic nerve, enhancement of the optic nerve head, distension of the optic nerve sheath and vertical tortuosity of the optic nerve. Optic nerve protrusion and enhancement, slit-like ventricles and tight cerebrospinal fluid spaces were not significantly associated with IIH (P>0.05). Posterior globe flattening, optic nerve sheath distension, optic nerve tortuosity, pituitary deformity and empty sella turcica were significantly associated with IIH (P<0.05). However, most of these are not helpful in a clinical setting, with the exception of posterior globe flattening. This is the only sign that, if present, strongly suggests the diagnosis of IIH (specificity 100%, 95% CI 93.6% to 100%; sensitivity 43.5%, 95% CI 27.3% to 60.8%; positive likelihood ratio 49.7). The majority of the reported signs for IIH on cross-sectional imaging are not helpful in establishing or excluding the diagnosis of IIH, and are of no value in the clinical setting. Flattening of the posterior aspect of the globe is the only sign that, if present, is suggestive of the diagnosis of IIH.
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Affiliation(s)
- R Agid
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, McLaughlin Wing 3-425, 399 Bathurst Street, Toronto, ON, M5T 2S8, Canada.
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Abstract
The authors used voxel-based morphometry to compare sensorimotor cortical gray and white matter volume on structural MR images of a group of 17 individuals with cervical spinal cord injury (SCI) and a group of 17 healthy subjects. SCI subjects had reduced gray matter volume bilaterally in primary somatosensory cortex (p < 0.001). These findings suggest that the somatosensory cortex of the human brain atrophies after SCI.
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Affiliation(s)
- M T Jurkiewicz
- Department of Physiology, University of Toronto, Toronto, Canada
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33
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Abstract
BACKGROUND Abnormal cortical pain responses in patients with fibromyalgia and conversion disorder raise the possibility of a neurobiologic basis underlying so-called "functional" chronic pain. OBJECTIVE To use percept-related fMRI to test the hypothesis that patients with a painful functional bowel disorder do not process visceral input or sensations normally or effectively at the cortical level. METHODS Eleven healthy subjects and nine patients with irritable bowel syndrome (IBS) underwent fMRI during rectal distensions that elicited either a moderate level of urge to defecate or pain. Subjects continuously rated their rectal stimulus-evoked urge or pain sensations during fMRI acquisition. fMRI data were interrogated for activity related to stimulus presence and to specific sensations. RESULTS In IBS, abnormal responses associated with rectal-evoked sensations were identified in five brain regions. In primary sensory cortex, there were urge-related responses in the IBS but not control group. In the medial thalamus and hippocampus, there were pain-related responses in the IBS but not control group. However, pronounced urge- and pain-related activations were present in the right anterior insula and the right anterior cingulate cortex in the control group but not the IBS group. CONCLUSIONS Percept-related fMRI revealed abnormal urge- and pain-related forebrain activity during rectal distension in patients with irritable bowel syndrome (IBS). As visceral stimulation evokes pain and triggers unconscious processes related to homeostasis and reflexes, abnormal brain responses in IBS may reflect the sensory symptoms of rectal pain and hypersensitivity, visceromotor dysfunction, and abnormal interoceptive processing.
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Affiliation(s)
- C L Kwan
- Institute of Medical Science, University of Toronto, Ontario, Canada
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34
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Al-Shafai LS, Mikulis DJ. Diffusion MR imaging in a case of acute ischemic optic neuropathy. AJNR Am J Neuroradiol 2006; 27:255-7. [PMID: 16484386 PMCID: PMC8148791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The purpose of this case report is to show the diagnostic potential of diffusion-weighted MR imaging in establishing the presence of ischemic optic neuropathy (ION). We report the MR imaging findings in a patient presenting with acute ION in whom diffusion imaging showed decreased water mobility as seen in patients with acute brain ischemia.
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Affiliation(s)
- L S Al-Shafai
- Department of Radiology, National Guard Hospital, Al-Ahsa, Saudi Arabia
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35
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Guo G, Wu RH, Zhang YP, Guan JT, Guo YL, Cheng Y, terBrugge K, Mikulis DJ. Combination 3D TOP with 2D PC MRA Techique for cerebral blood flow volume measurement. Conf Proc IEEE Eng Med Biol Soc 2006; 2006:489-92. [PMID: 17946401 DOI: 10.1109/iembs.2006.259362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To demonstrate the discrepancy of cerebral blood flow volume (BFV) estimation with 2D phase-contrast (2D PC) MRA guided with 3D time-of-flight (3D TOF) MR localization by using an "internal" standard. 20 groups of the common (CCA), internal (ICA), and external (ECA) carotid arteries in 10 healthy subjects were examined with 2D PC MRA guided by 3D TOF MR angiograms. The sum BFV of the internal and external carotid arteries was then compared with the ipsilateral common carotid artery flow. An accurate technique would demonstrate no difference. The difference was therefore a measure of accuracy of the method. 3D TOF MRA localization is presented to allow the determination of a slice orientation to improve the accuracy of 2D PC MRA in estimate the BFV. By using the combined protocols, there was better correlation in BFV estimate between the sum of ICA+ECA with the ipsilateral CCA (R2=0.729, P=0.000). The inconsistency (mean +/- SD) was found to be 6.95 +/- 5.95% for estimate the BFV in ICA+ECA and ipsilateral CCA. The main inconsistency was contributed to the ECA and its branches. Guided with 3D TOF MRA localization, 2D PC MRA is more accurate in the determination of blood flow volume in the carotid arteries.
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Affiliation(s)
- G Guo
- Medical Imaging & Central Laboratory, Shantou University Medical College, Guangdong, China
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36
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Abstract
UNLABELLED Spongiform leukoencephalopathy is a rare complication from inhalation of heated heroin vapour, a practice called "chasing the dragon". The MRI findings are considered pathognomonic, making MRI important for diagnosis. This is especially true in busy urban emergency departments where a variety of patients may present obtunded, unable or unwilling to provide a useful history. Even though the MR pattern of "chasing" toxicity is considered pathognomonic, there are mimickers. We compare the MRI findings of two classic cases of chasing leukoencephalopathy with one case of mimickery from cocaine exposure only. All three cases had diffuse symmetrical white matter changes. MR spectroscopy (MRS) in chasing patients showed increased lactic acid and myo-inositol, decreased N-acetyl aspartate and creatine, normal to slightly decreased choline, and normal lipid peak. MRS in the cocaine exposure patient showed marked increase in lactic acid and lipids. MR perfusion in one chasing patient was normal. IN CONCLUSION (1) All three cases have MR findings suggestive of spongiform leukoencephalopathy. MRS may help differentiate toxicity due to inhaled heroin from other non-heroin related toxicities. (2) Discordance between perfusion and spectroscopy in one chasing patient adds evidence that the disease is due to impaired energy metabolism at the cellular level. (3) MR findings of spongiform leukoencephalopathy secondary to chasing heroin can progress despite apparent abstinence of the drug and during clinical improvement, suggesting the MR changes may represent an evolving injury.
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Affiliation(s)
- E Bartlett
- Neuroradiology, Toronto Western Hospital, University Health Network, 3 Fell Pavilion, Room 210, 399 Bathurst Street, Toronto, Ontario M5T 2S8, Canada
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37
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Guo G, Wu RH, Mikulis DJ. Construction of Optimal Velocity Encoding for Cerebral Blood Flow Volume Measurement with Phase-Contrast MRA. Conf Proc IEEE Eng Med Biol Soc 2005; 2005:1404-7. [PMID: 17282461 DOI: 10.1109/iembs.2005.1616692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE Accurate velocity encoding is crucial for quantification of arterial inflow and venous outflow in intracranial diseases. The purpose of this study was to optimize the velocity encoding of phase-contrast (PC) MRA and quantify cerebral blood flow in normal volunteers. METHODS Ten healthy volunteers were examined on a GE 1.5T MR system with 2D PCMRA sequence. The parameters of the sequence were as follows: TR 40ms, TE 6.6ms, flip angle 20°, slice thickness 4mm, matrix 256x256, field of view 140 mm. In each cardiac cycle, 40 images were obtained. Velocity encoding was set from 30 to 90 cm/sec at 10cm/sec interval for total of 7 scans per volunteer. The scan level was chosen at C2 perpendicular to the vessels of interest. Data were analyzed using CV Flow software on a GE Advantage Windows Workstation.
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Affiliation(s)
- G Guo
- Department of Medical Imaging, Shantou University Medical College, Shantou 515041, China; Department of Neuroradiology, Toronto Western Hospital, University of Toronto, Toronto, ON M5T 2S8, Canada
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Seminowicz DA, Mikulis DJ, Davis KD. Cognitive modulation of pain-related brain responses depends on behavioral strategy. Pain 2004; 112:48-58. [PMID: 15494184 DOI: 10.1016/j.pain.2004.07.027] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Revised: 07/06/2004] [Accepted: 07/26/2004] [Indexed: 11/29/2022]
Abstract
Interactions of pain and cognition have been studied in humans and animals previously, but the relationship between such behavioral interactions and brain activity is unknown. We aimed to show using functional MRI (fMRI) how a cognitively demanding task (Stroop) modulates pain-related brain activations and conversely, how pain modulates attention-related activity. Reaction time data indicated two types of pain responders: subjects in the A group had a faster Stroop reaction time when pain was concomitant to the attention task, while those in the P group had a slower Stroop performance during painful stimulation. fMRI data obtained during Stroop performance with and without noxious stimulation were subjected to region of interest analyses. We first tested whether brain activity during painful median nerve stimulation was modulated by cognitive load. We next tested whether brain activity during the high conflict cognitive task was modulated by pain. Pain-related activity in three regions, primary (S1), and secondary (S2) somatosensory cortices, and anterior insula, was attenuated by cognitive engagement, but this effect was specific to the A group. Pain-related activations in the caudal and rostral anterior cingulate cortex (ACC) and ventroposterior thalamus were not modulated by cognitive load. None of the areas showing attention-related responses, including bilateral dorsolateral prefrontal and posterior parietal cortices, were modulated by pain. These findings suggest that cortical regions associated with pain can be modulated by cognitive strategies. Furthermore, the distinction of behavioral subgroups may relate to cognitive coping strategies taken by patients with chronic pain.
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Affiliation(s)
- D A Seminowicz
- Toronto Western Research Institute, Toronto Western Hospital, University Health Network, MP14-306, 399 Bathurst Street, Toronto, Ont., Canada M5T 2S8
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Abstract
Paradoxical heat (PH), the illusion of skin heat, accompanies many neurological disorders. Using the technique of percept-related functional MRI, we found a region of the right insular cortex specifically activated when subjects perceive a heat sensation in their right hand even though their skin temperature is cool or at neutral. This region was suppressed during mild skin cooling. We propose that this differential response is a manifestation of the role of the insula in signaling temperature perceptions regardless of the actual temperature of the skin. These findings suggest that a region within the insula has a complex role in heat perception, perhaps contributing to a specific, rather than general, thermosensory perception. These data provide insight to our basic understanding of normal and pathological thermosensory perceptions.
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Affiliation(s)
- K D Davis
- Toronto Western Hospital, MP14-306, 399 Bathurst Street, Toronto, Ontario M5T 2S8, Canada.
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40
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Affiliation(s)
- R Agid
- Department of Medical Imaging, Division of Neuroradiology, Toronto Western Hospital of the University Health Network and the University of Toronto, ON, Canada
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41
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Sarma D, Farb RI, Mikulis DJ, terBrugge KG. Reversal of restricted diffusion in cerebral venous thrombosis: case report. Neuroradiology 2004; 46:118-21. [PMID: 14726984 DOI: 10.1007/s00234-003-1121-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2003] [Accepted: 07/29/2003] [Indexed: 11/28/2022]
Abstract
We report a patient with extensive cerebral venous thrombosis who showed complete reversal of restricted diffusion on MRI, accompanied by excellent clinical recovery. The implications of these findings in relation to interpretation of diffusion changes in cerebral venous thrombosis are discussed, and differences with arterial stroke are highlighted.
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Affiliation(s)
- D Sarma
- Fell Pavilion 3-210, Toronto Western Hospital, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada
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42
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Ducreux D, Wu RH, Mikulis DJ, terBrugge K. Diffusion-weighted imaging and single-voxel MR spectroscopy in a case of malignant cerebral lymphoma. Neuroradiology 2003; 45:865-8. [PMID: 14605786 DOI: 10.1007/s00234-003-1107-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2003] [Accepted: 08/15/2003] [Indexed: 11/25/2022]
Abstract
Since conventional MRI fails to distinguish between the common neoplasm involving the corpus callosum, we explored the utility of diffusion weighted imaging and single-voxel proton spectroscopy in a case of corpus callosum lymphoma.
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Affiliation(s)
- D Ducreux
- Department of Neuroradiology, CHU de Bicetre, Paris XI University, 78 rue du Gènèral Leclerc, 94270 Le Kremlin Bicetre, France.
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43
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Farb RI, Vanek I, Scott JN, Mikulis DJ, Willinsky RA, Tomlinson G, terBrugge KG. Idiopathic intracranial hypertension: the prevalence and morphology of sinovenous stenosis. Neurology 2003; 60:1418-24. [PMID: 12743224 DOI: 10.1212/01.wnl.0000066683.34093.e2] [Citation(s) in RCA: 417] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the prevalence and nature of sinovenous obstruction in idiopathic intracranial hypertension (IIH) using auto-triggered elliptic-centric-ordered three-dimensional gadolinium-enhanced MR venography (ATECO MRV). METHODS In a prospective controlled study, 29 patients with established IIH as well as 59 control patients underwent ATECO MRV. In a randomized blinded fashion, three readers evaluated the images. Using a novel scoring system, each reader graded the degree of stenosis seen in the transverse and sigmoid sinuses of each patient. RESULTS There was excellent agreement across the three readers for application of the grading system. Substantial bilateral sinovenous stenoses were seen in 27 of 29 patients with IIH and in only 4 of 59 control patients. CONCLUSION Using ATECO MRV and a novel grading system for quantifying sinovenous stenoses, the authors can identify IIH patients with sensitivity and specificity of 93%.
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Affiliation(s)
- R I Farb
- Department of Medical Imaging, Toronto Western Hospital, ON, Canada.
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44
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Mailis-Gagnon A, Giannoylis I, Downar J, Kwan CL, Mikulis DJ, Crawley AP, Nicholson K, Davis KD. Altered central somatosensory processing in chronic pain patients with "hysterical" anesthesia. Neurology 2003; 60:1501-7. [PMID: 12743239 DOI: 10.1212/wnl.60.9.1501] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The authors hypothesized that central factors may underlie sensory deficits in patients with nondermatomal somatosensory deficits (NDSD) and that functional brain imaging would reveal altered responses in supraspinal nuclei. BACKGROUND Patients with chronic pain frequently present with NDSD, ranging from hypoesthesia to complete anesthesia in the absence of substantial pathology and often in association with motor weakness and occasional paralysis. Patients with pain and such pseudoneurologic symptoms can be classified as having both a pain disorder and a conversion disorder (Diagnostic and Statistical Manual of Mental Disorders-IV classification). METHODS The authors tested their hypothesis with functional MRI (fMRI) of brush and noxious stimulation-evoked brain responses in four patients with chronic pain and NDSD. RESULTS The fMRI findings revealed altered somatosensory-evoked responses in specific forebrain areas. Unperceived stimuli failed to activate areas that were activated with perceived touch and pain: notably, the thalamus, posterior region of the anterior cingulate cortex (ACC), and Brodmann area 44/45. Furthermore, unperceived stimuli were associated with deactivations in primary and secondary somatosensory cortex (S1, S2), posterior parietal cortex, and prefrontal cortex. Finally, unperceived (but not perceived) stimuli activated the rostral ACC. CONCLUSIONS Diminished perception of innocuous and noxious stimuli is associated with altered activity in many parts of the somatosensory pathway or other supraspinal areas. The cortical findings indicate a neurobiological component for at least part of the symptoms in patients presenting with nondermatomal somatosensory deficits.
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Affiliation(s)
- A Mailis-Gagnon
- Comprehensive Pain Program, Toronto Western Hospital, Ontario, Canada
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45
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Davis KD, Pope GE, Crawley AP, Mikulis DJ. Neural correlates of prickle sensation: a percept-related fMRI study. Nat Neurosci 2002; 5:1121-2. [PMID: 12368810 DOI: 10.1038/nn955] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2002] [Accepted: 08/30/2002] [Indexed: 11/09/2022]
Abstract
The painful sensations produced by a laceration, freeze, burn, muscle strain or internal injury are readily distinguishable because each is characterized by a particular sensory quality such as sharp, aching, burning or prickling. We propose that there are specific neural correlates of each pain quality, and here we used a new functional magnetic resonance imaging (fMRI) method to identify time-locked responses to prickle sensations that were evoked by noxious cold stimuli. With percept-related fMRI, we identified prickle-related brain activations in the anterior cingulate cortex (ACC), insula, secondary somatosensory cortex (S2), prefrontal cortex (PFC), premotor cortex (PMC), caudate nucleus and dorsomedial thalamus, indicating that multiple pain, sensory and motor areas act together to produce the prickle sensation.
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Affiliation(s)
- K D Davis
- Department of Surgery, University of Toronto, Ontario, Canada.
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46
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Manduch M, Bezuhly M, Anastakis DJ, Crawley AP, Mikulis DJ. Serial fMRI of adaptive changes in primary sensorimotor cortex following thumb reconstruction. Neurology 2002; 59:1278-81. [PMID: 12391368 DOI: 10.1212/wnl.59.8.1278] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Serial fMRI was performed in a patient who underwent transfer of the left great toe to the hand following amputation of the right thumb. Motor activation within the primary sensorimotor cortex (SMC) of both hemispheres was quantified over 2 years, showing a transient increase in contralateral but not ipsilateral primary SMC. The temporal pattern of motor cortical activation observed in this patient may represent a "signature" of good functional recovery.
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Affiliation(s)
- M Manduch
- Faculty of Medicine, University of Toronto, Toronto, Canada
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47
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Mikulis DJ, Jurkiewicz MT, McIlroy WE, Staines WR, Rickards L, Kalsi-Ryan S, Crawley AP, Fehlings MG, Verrier MC. Adaptation in the motor cortex following cervical spinal cord injury. Neurology 2002; 58:794-801. [PMID: 11889245 DOI: 10.1212/wnl.58.5.794] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The nature of the adaptive changes that occur in the cerebral cortex following injury to the cervical spinal cord are largely unknown. OBJECTIVE To investigate these adaptive changes by examining the relationship between the motor cortical representation of the paretic right upper extremity compared with that of the tongue. The tongue was selected because the spinal cord injury (SCI) does not affect its movement and the cortical representation of the tongue is adjacent to that of the paretic upper extremity. METHODS FMRI was used to map cortical representations associated with simple motor tasks of the right upper extremity and tongue in 14 control subjects and 9 patients with remote (>5.5 months) cervical SCI. RESULTS The mean value for the site of maximum cortical activation during upper limb movement was identical between the two groups. The site of maximum left hemispheric cortical activation during tongue movement was 12.8 mm (p < 0.01) medial and superior to that of control subjects, indicating the presence of a shift in cortical activation. CONCLUSION The findings indicate that the adult motor cortex does indeed adapt following cervical SCI. The nature of the adaptation and the underlying biological mechanisms responsible for this change require further investigation.
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Affiliation(s)
- D J Mikulis
- Department of Medical Imaging, Toronto Western Hospital of the University Health Network, Ontario, Canada.
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Downar J, Crawley AP, Mikulis DJ, Davis KD. The effect of task relevance on the cortical response to changes in visual and auditory stimuli: an event-related fMRI study. Neuroimage 2001; 14:1256-67. [PMID: 11707082 DOI: 10.1006/nimg.2001.0946] [Citation(s) in RCA: 264] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Attention is, in part, a mechanism for identifying features of the sensory environment of potential relevance to behavior. The network of brain areas sensitive to the behavioral relevance of multimodal sensory events has not been fully characterized. We used event-related fMRI to identify brain regions responsive to changes in both visual and auditory stimuli when those changes were either behaviorally relevant or behaviorally irrelevant. A widespread network of "context-dependent" activations responded to both task-irrelevant and task-relevant events but responded more strongly to task-relevant events. The most extensive activations in this network were located in right and left temporoparietal junction (TPJ), with smaller activations in left precuneus, left anterior insula, left anterior cingulate cortex, and right thalamus. Another network of "context-independent" activations responded similarly to all events, regardless of task relevance. This network featured a large activation encompassing left supplementary and cingulate motor areas (SMA/CMA) as well as right IFG, right/left precuneus, and right anterior insula, with smaller activations in right/left inferior temporal gyrus and left posterior cingulate cortex. Distinct context-dependent and context-independent subregions of activation were also found within the left and right TPJ, left anterior insula, and left SMA/CMA. In the right TPJ, a subregion in the supramarginal gyrus showed sensitivity to the behavioral context (i.e., relevance) of stimulus changes, while two subregions in the superior temporal gyrus did not. The results indicate a role for the TPJ in detecting behaviorally relevant events in the sensory environment. The TPJ may serve to identify salient events in the sensory environment both within and independent of the current behavioral context.
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Affiliation(s)
- J Downar
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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Sheth TN, Winslow JL, Mikulis DJ. Rotational changes in the morphology of the vertebral artery at a common site of artery dissection. Can Assoc Radiol J 2001; 52:236-41. [PMID: 11512296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
OBJECTIVE Given that vertebral artery dissection and transient vertebrobasilar insufficiency occurs commonly at the C1-C2 junction, the objective was to study, in vivo, the normal rotational anatomy at C1-C2 using magnetic resonance angiography (MRA) with 3-dimensional (3D) reconstructions and to correlate these reconstructions with our experience of dissection location. METHODS 3D phase-contrast MRAs were obtained from the foramen magnum to C3 in 4 normal volunteers in neutral and rotated (45 degrees) positions. The magnitude images were used as source images for 3D reconstruction. The images from only 1 of the volunteers were completely motion free, and these were subjected to arterial length calculations using image analysis wire frame outline of the vessel. All angiograms of vertebral artery dissection obtained at our institution from 1993 to 1997 were also reviewed. RESULTS 3D reconstructions document elongation (approximately 7% in quantitatively analyzed case) and slight narrowing of the artery contralateral to the direction of head rotation from C2 to the dural entry point. The artery turns most sharply and is subject to the anterior force of the rotating C1 vertebra as it exits the C1 foramen. Of 14 cases of vertebral artery dissection, 50% occurred between the transverse foramen and the posterior lamina of C1. CONCLUSIONS With head rotation, the contralateral vertebral artery undergoes the greatest anatomical distortion as it exits the C1 transverse foramen. This increased stress may account for the higher frequency of dissections at this location.
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Affiliation(s)
- T N Sheth
- Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, 399 Bathurst St., Toronto, ON M5T 2S8
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Abstract
Phonological and semantic aspects of language were examined in patients with unilateral temporal lobe epilepsy (TLE) and healthy controls using functional MRI. We expected to replicate previous findings in healthy individuals showing relatively greater activation in frontal regions for phonological compared with semantic processing, and greater activation in temporal regions for semantic compared with phonological processing. We hypothesized that differences between patients with left TLE and healthy controls would be found in the pattern of left temporal cortical activation associated specifically with semantic processing. Patients with right TLE were included as a seizure control group. All TLE patients previously showed left hemisphere language dominance on intracarotid sodium amytal studies. Greater blood oxygen level dependent activation was found during phonological processing compared with semantic processing in frontal regions for healthy participants but, contrary to expectation, semantic processing did not lead to increased temporal lobe activity relative to phonological processing. Furthermore, no differences between left temporal patients and controls were found specifically in left temporal cortex. Rather, patients with left temporal seizure foci showed significantly greater left dorsolateral prefrontal activity compared with controls, as well as increased signal change in left inferior frontal and right middle temporal gyrus. Surprisingly, patients with right, but not left, TLE showed poorer performance on the linguistic tasks compared with controls, as well as a decrease in right superior temporal activation. The results converge with studies of dyslexic patients showing increased left frontal activity in the presence of left temporal dysfunction and are suggestive of both inter- and intra-hemispheric functional reorganization of language representation in left TLE.
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