1
|
Yi JS, Ki HJ, Jeon YS, Park JJ, Lee TJ, Kwak JT, Lee SB, Lee HJ, Kim IS, Kim JH, Lee JS, Roh HG, Kim HJ. The collateral map: prediction of lesion growth and penumbra after acute anterior circulation ischemic stroke. Eur Radiol 2024; 34:1411-1421. [PMID: 37646808 PMCID: PMC10873223 DOI: 10.1007/s00330-023-10084-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 07/03/2023] [Accepted: 07/15/2023] [Indexed: 09/01/2023]
Abstract
OBJECTIVES This study evaluated the collateral map's ability to predict lesion growth and penumbra after acute anterior circulation ischemic strokes. METHODS This was a retrospective analysis of selected data from a prospectively collected database. The lesion growth ratio was the ratio of the follow-up lesion volume to the baseline lesion volume on diffusion-weighted imaging (DWI). The time-to-maximum (Tmax)/DWI ratio was the ratio of the baseline Tmax > 6 s volume to the baseline lesion volume. The collateral ratio was the ratio of the hypoperfused lesion volume of the phase_FU (phase with the hypoperfused lesions most approximate to the follow-up DWI lesion) to the hypoperfused lesion volume of the phase_baseline of the collateral map. Multiple logistic regression analyses were conducted to identify independent predictors of lesion growth. The concordance correlation coefficients of Tmax/DWI ratio and collateral ratio for lesion growth ratio were analyzed. RESULTS Fifty-two patients, including twenty-six males (mean age, 74 years), were included. Intermediate (OR, 1234.5; p < 0.001) and poor collateral perfusion grades (OR, 664.7; p = 0.006) were independently associated with lesion growth. Phase_FUs were immediately preceded phases of the phase_baselines in intermediate or poor collateral perfusion grades. The concordance correlation coefficients of the Tmax/DWI ratio and collateral ratio for the lesion growth ratio were 0.28 (95% CI, 0.17-0.38) and 0.88 (95% CI, 0.82-0.92), respectively. CONCLUSION Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. Further studies are needed to generalize the findings of this study. CLINICAL RELEVANCE STATEMENT Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. KEY POINTS • Cell viability in cerebral ischemia due to proximal arterial steno-occlusion mainly depends on the collateral circulation. • The collateral map shows salvageable brain extent, which can survive by recanalization treatments after acute anterior circulation ischemic stroke. • Precise estimation of salvageable brain makes it possible to make patient-specific treatment decision.
Collapse
Affiliation(s)
- Jin Seok Yi
- Department of Neurosurgery, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Hee Jong Ki
- Department of Neurosurgery, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Yoo Sung Jeon
- Department of Neurosurgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Jeong Jin Park
- Department of Neurology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
- Department of Neurosurgery, Kangwon National University College of Medicine, Chuncheon, Republic of Korea
| | - Taek-Jun Lee
- Department of Neurology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Jin Tae Kwak
- School of Electrical Engineering, Korea University, Seoul, Republic of Korea
| | - Sang Bong Lee
- Department of Neurology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Hyung Jin Lee
- Department of Neurosurgery, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - In Seong Kim
- Siemens Healthineers Ltd., Seoul, Republic of Korea
| | - Joo Hyun Kim
- Philips Healthcare Korea, Seoul, Republic of Korea
| | - Ji Sung Lee
- Clinical Research Center, Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hong Gee Roh
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, 120-1 Neungdong-Ro, Kwangjin-Gu, Seoul, 05030, Republic of Korea.
| | - Hyun Jeong Kim
- Department of Radiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 64 Daeheung-Ro, Jung-Gu, Daejeon, 34943, Republic of Korea.
| |
Collapse
|
2
|
Ivanova MV, Pappas I, Inglis B, Pracar AL, Herron TJ, Baldo JV, Kayser AS, D’Esposito M, Dronkers NF. Cerebral perfusion in post-stroke aphasia and its relationship to residual language abilities. Brain Commun 2023; 6:fcad252. [PMID: 38162898 PMCID: PMC10757451 DOI: 10.1093/braincomms/fcad252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/26/2023] [Accepted: 09/28/2023] [Indexed: 01/03/2024] Open
Abstract
Stroke alters blood flow to the brain resulting in damaged tissue and cell death. Moreover, the disruption of cerebral blood flow (perfusion) can be observed in areas surrounding and distal to the lesion. These structurally preserved but suboptimally perfused regions may also affect recovery. Thus, to better understand aphasia recovery, the relationship between cerebral perfusion and language needs to be systematically examined. In the current study, we aimed to evaluate (i) how stroke affects perfusion outside of lesioned areas in chronic aphasia and (ii) how perfusion in specific cortical areas and perilesional tissue relates to language outcomes in aphasia. We analysed perfusion data from a large sample of participants with chronic aphasia due to left hemisphere stroke (n = 43) and age-matched healthy controls (n = 25). We used anatomically defined regions of interest that covered the frontal, parietal, and temporal areas of the perisylvian cortex in both hemispheres, areas typically known to support language, along with several control regions not implicated in language processing. For the aphasia group, we also looked at three regions of interest in the perilesional tissue. We compared perfusion levels between the two groups and investigated the relationship between perfusion levels and language subtest scores while controlling for demographic and lesion variables. First, we observed that perfusion levels outside the lesioned areas were significantly reduced in frontal and parietal regions in the left hemisphere in people with aphasia compared to the control group, while no differences were observed for the right hemisphere regions. Second, we found that perfusion in the left temporal lobe (and most strongly in the posterior part of both superior and middle temporal gyri) and inferior parietal areas (supramarginal gyrus) was significantly related to residual expressive and receptive language abilities. In contrast, perfusion in the frontal regions did not show such a relationship; no relationship with language was also observed for perfusion levels in control areas and all right hemisphere regions. Third, perilesional perfusion was only marginally related to language production abilities. Cumulatively, the current findings demonstrate that blood flow is reduced beyond the lesion site in chronic aphasia and that hypoperfused neural tissue in critical temporoparietal language areas has a negative impact on behavioural outcomes. These results, using perfusion imaging, underscore the critical and general role that left hemisphere posterior temporal regions play in various expressive and receptive language abilities. Overall, the study highlights the importance of exploring perfusion measures in stroke.
Collapse
Affiliation(s)
- Maria V Ivanova
- Department of Psychology, University of California, Berkeley, CA 94720, USA
- Research Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Ioannis Pappas
- Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - Ben Inglis
- Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, CA 94720, USA
| | - Alexis L Pracar
- Department of Psychology, University of California, Berkeley, CA 94720, USA
| | - Timothy J Herron
- Research Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Juliana V Baldo
- Research Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Andrew S Kayser
- Division of Neurology, San Francisco VA Health Care System, San Francisco, CA 94121, USA
- Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Mark D’Esposito
- Department of Psychology, University of California, Berkeley, CA 94720, USA
- Neurology Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Nina F Dronkers
- Department of Psychology, University of California, Berkeley, CA 94720, USA
- Depertment of Neurology, University of California, Davis, CA 95817, USA
| |
Collapse
|
3
|
Marshall RS, Liebeskind DS, III JH, Edwards LJ, Howard G, Meschia JF, Brott TG, Lal BK, Heck D, Lanzino G, Sangha N, Kashyap VS, Morales CD, Cotton-Samuel D, Rivera AM, Brickman AM, Lazar RM. Cortical Thinning in High-Grade Asymptomatic Carotid Stenosis. J Stroke 2023; 25:92-100. [PMID: 36592969 PMCID: PMC9911846 DOI: 10.5853/jos.2022.02285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/17/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE High-grade carotid artery stenosis may alter hemodynamics in the ipsilateral hemisphere, but consequences of this effect are poorly understood. Cortical thinning is associated with cognitive impairment in dementia, head trauma, demyelination, and stroke. We hypothesized that hemodynamic impairment, as represented by a relative time-to-peak (TTP) delay on MRI in the hemisphere ipsilateral to the stenosis, would be associated with relative cortical thinning in that hemisphere. METHODS We used baseline MRI data from the NINDS-funded Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis-Hemodynamics (CREST-H) study. Dynamic contrast susceptibility MR perfusion-weighted images were post-processed with quantitative perfusion maps using deconvolution of tissue and arterial signals. The protocol derived a hemispheric TTP delay, calculated by subtraction of voxel values in the hemisphere ipsilateral minus those contralateral to the stenosis. RESULTS Among 110 consecutive patients enrolled in CREST-H to date, 45 (41%) had TTP delay of at least 0.5 seconds and 9 (8.3%) subjects had TTP delay of at least 2.0 seconds, the maximum delay measured. For every 0.25-second increase in TTP delay above 0.5 seconds, there was a 0.006-mm (6 micron) increase in cortical thickness asymmetry. Across the range of hemodynamic impairment, TTP delay independently predicted relative cortical thinning on the side of stenosis, adjusting for age, sex, hypertension, hemisphere, smoking history, low-density lipoprotein cholesterol, and preexisting infarction (P=0.032). CONCLUSIONS Our findings suggest that hemodynamic impairment from high-grade asymptomatic carotid stenosis may structurally alter the cortex supplied by the stenotic carotid artery.
Collapse
Affiliation(s)
- Randolph S. Marshall
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA,Correspondence: Randolph S. Marshall Department of Neurology, Columbia University Irving Medical Center, 710 W 168th St, New York, NY 10032, USA Tel: +1-212-305-8389 Fax: +1-212-305-3741 E-mail:
| | - David S. Liebeskind
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Lloyd J. Edwards
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - George Howard
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | | | - Brajesh K. Lal
- Department of Surgery, University of Maryland, Baltimore, MD, USA
| | - Donald Heck
- Department of Radiology, Novant Health Clinical Research, Winston-Salem, NC, USA
| | - Giuseppe Lanzino
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Navdeep Sangha
- Department of Neurology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA, USA
| | - Vikram S. Kashyap
- Department of Surgery, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH, USA
| | - Clarissa D. Morales
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Dejania Cotton-Samuel
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Andres M. Rivera
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Adam M. Brickman
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Ronald M. Lazar
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
4
|
Saber H, Liebeskind DS. Infarct Progression in the Early and Late Phases of Acute Ischemic Stroke. Neurology 2021; 97:S60-S67. [PMID: 34785605 DOI: 10.1212/wnl.0000000000012795] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE OF REVIEW To explore factors associated with infarct progression in the early and late phase of acute ischemic stroke in patients undergoing endovascular therapy. RECENT FINDINGS Following ischemic stroke, brain injury can progress at a variable rate, at the expense of "penumbral tissue," which is the ischemic tissue at risk of infarction. Despite dramatic advances in endovascular stroke therapies with early revascularization in more than 80% of cases, nearly half of patients do not achieve functional independence despite successful recanalization. This is largely attributed to the irreversible damage that is already extensive at the time of revascularization. SUMMARY The underlying pathophysiology and determinants of the core infarct progression are complex and multifactorial, depending on a balance between brain energy consumption and collateral perfusion supply. It is crucial to develop creative and individualized theranostics to predict infarct progression and to "freeze" the tissue at risk prior to recanalization.
Collapse
Affiliation(s)
- Hamidreza Saber
- From the Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA
| | - David S Liebeskind
- From the Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA.
| |
Collapse
|
5
|
Girnar GA, Mahajan HS. Cerebral ischemic stroke and different approaches for treatment of stroke. FUTURE JOURNAL OF PHARMACEUTICAL SCIENCES 2021. [DOI: 10.1186/s43094-021-00289-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Cerebral ischemia can be considered a lethal disease as it is a leading cause of death worldwide with no prompt line of treatment. The factors which make this disease more fatal are failure of drugs while crossing BBB, very low availability of the drug in the brain, inefficiency of drug molecule in the clinical studies, limited availability of clinical data, lack of awareness about this disease, and many more.
Main body
This review focuses on reasons and mechanisms of stroke, classification of brain ischemia; it also reveals the current scenario of stroke in India. Very few drugs are effective for the treatment of stroke. This compilation furnishes conventional and recent treatments of stroke along with their hurdles like the gap between preclinical and clinical studies. This review also suggests effective routes of administration of drugs for the treatment of brain ischemia specifically nose-to-brain route and effectiveness of different dosage forms precisely nanoformulations, as the most effective dosage form.
Conclusion
By following different guidelines and treatments, the risk of brain ischemia can be minimized as well as some advanced techniques for the treatment of this disease proving their efficiency. One of the important aspects in the success of the treatment for this disease is the route of administration of the drug. Among all routes, intranasal drug delivery presents a potential approach and is supposed to be the next-generation therapy for brain disorders. The nose-to-brain route is very effective, and it shows some promising results in case of stroke treatment. The strategy is still under investigation despite various successful lab-scale studies; there are numerous challenges to reach the product in the market. Research is going on to get a better understanding of this strategy. We believe that detailed studies to resolve pitfalls will lead to the successful development of an intranasal formulation for the management of ischemic brain injury such as stroke.
Collapse
|
6
|
Winder A, d’Esterre CD, Menon BK, Fiehler J, Forkert ND. Automatic arterial input function selection in CT and MR perfusion datasets using deep convolutional neural networks. Med Phys 2020; 47:4199-4211. [DOI: 10.1002/mp.14351] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 05/27/2020] [Accepted: 06/18/2020] [Indexed: 11/06/2022] Open
Affiliation(s)
- Anthony Winder
- Department of Radiology University of Calgary Calgary Canada
- Hotchkiss Brain Institute University of Calgary Calgary Canada
| | - Christopher D. d’Esterre
- Hotchkiss Brain Institute University of Calgary Calgary Canada
- Department of Clinical Neuroscience University of Calgary Calgary Canada
| | - Bijoy K. Menon
- Department of Radiology University of Calgary Calgary Canada
- Hotchkiss Brain Institute University of Calgary Calgary Canada
- Department of Clinical Neuroscience University of Calgary Calgary Canada
| | - Jens Fiehler
- Department of Diagnostic and Interventional Neuroradiology University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Nils D. Forkert
- Department of Radiology University of Calgary Calgary Canada
- Hotchkiss Brain Institute University of Calgary Calgary Canada
- Department of Clinical Neuroscience University of Calgary Calgary Canada
- Alberta Children's Hospital Research InstituteUniversity of Calgary Calgary Canada
| |
Collapse
|
7
|
Moshayedi P, Saber H, Liebeskind DS. Is there Still a Time Window in the Treatment of Acute Stroke? Curr Treat Options Neurol 2020. [DOI: 10.1007/s11940-020-00628-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
8
|
Shazeeb MS, King RM, Brooks OW, Puri AS, Henninger N, Boltze J, Gounis MJ. Infarct Evolution in a Large Animal Model of Middle Cerebral Artery Occlusion. Transl Stroke Res 2019; 11:468-480. [PMID: 31478129 DOI: 10.1007/s12975-019-00732-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 11/26/2022]
Abstract
Mechanical thrombectomy for the treatment of ischemic stroke shows high rates of recanalization; however, some patients still have a poor clinical outcome. A proposed reason for this relates to the fact that the ischemic infarct growth differs significantly between patients. While some patients demonstrate rapid evolution of their infarct core (fast evolvers), others have substantial potentially salvageable penumbral tissue even hours after initial vessel occlusion (slow evolvers). We show that the dog middle cerebral artery occlusion model recapitulates this key aspect of human stroke rendering it a highly desirable model to develop novel multimodal treatments to improve clinical outcomes. Moreover, this model is well suited to develop novel image analysis techniques that allow for improved lesion evolution prediction; we provide proof-of-concept that MRI perfusion-based time-to-peak maps can be utilized to predict the rate of infarct growth as validated by apparent diffusion coefficient-derived lesion maps allowing reliable classification of dogs into fast versus slow evolvers enabling more robust study design for interventional research.
Collapse
Affiliation(s)
- Mohammed Salman Shazeeb
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA.
- Image Processing and Analysis Core, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA.
| | - Robert M King
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Olivia W Brooks
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
- St. George's University School of Medicine, St. George's, West Indies, Grenada
| | - Ajit S Puri
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Nils Henninger
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Johannes Boltze
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Matthew J Gounis
- New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
- Image Processing and Analysis Core, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| |
Collapse
|
9
|
|
10
|
Zaro-Weber O, Fleischer H, Reiblich L, Schuster A, Moeller-Hartmann W, Heiss WD. Penumbra detection in acute stroke with perfusion magnetic resonance imaging: Validation with 15 O-positron emission tomography. Ann Neurol 2019; 85:875-886. [PMID: 30937950 PMCID: PMC6593670 DOI: 10.1002/ana.25479] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/20/2019] [Accepted: 03/31/2019] [Indexed: 12/17/2022]
Abstract
Objective Accurate identification of the ischemic penumbra, the therapeutic target in acute clinical stroke, is of critical importance to identify patients who might benefit from reperfusion therapies beyond the established time windows. Therefore, we aimed to validate magnetic resonance imaging (MRI) mismatch–based penumbra detection against full quantitative positron emission tomography (15O‐PET), the gold standard for penumbra detection in acute ischemic stroke. Methods Ten patients (group A) with acute and subacute ischemic stroke underwent perfusion‐weighted (PW)/diffusion‐weighted MRI and consecutive full quantitative 15O‐PET within 48 hours of stroke onset. Penumbra as defined by 15O‐PET cerebral blood flow (CBF), oxygen extraction fraction, and oxygen metabolism was used to validate a wide range of established PW measures (eg, time‐to‐maximum [Tmax]) to optimize penumbral tissue detection. Validation was carried out using a voxel‐based receiver‐operating‐characteristic curve analysis. The same validation based on penumbra as defined by quantitative 15O‐PET CBF was performed for comparative reasons in 23 patients measured within 48 hours of stroke onset (group B). Results The PW map Tmax (area‐under‐the‐curve = 0.88) performed best in detecting penumbral tissue up to 48 hours after stroke onset. The optimal threshold to discriminate penumbra from oligemia was Tmax >5.6 seconds with a sensitivity and specificity of >80%. Interpretation The performance of the best PW measure Tmax to detect the upper penumbral flow threshold in ischemic stroke is excellent. Tmax >5.6 seconds–based penumbra detection is reliable to guide treatment decisions up to 48 hours after stroke onset and might help to expand reperfusion treatment beyond the current time windows. ANN NEUROL 2019;85:875–886.
Collapse
Affiliation(s)
- Olivier Zaro-Weber
- Max Planck Institute for Neurological Research, Cologne, Germany.,Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Hermann Fleischer
- Max Planck Institute for Neurological Research, Cologne, Germany.,Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lucas Reiblich
- Max Planck Institute for Neurological Research, Cologne, Germany.,Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | |
Collapse
|
11
|
Evaluation of cerebrovascular reserve in patients with cerebrovascular diseases using resting-state MRI: A feasibility study. Magn Reson Imaging 2019; 59:46-52. [PMID: 30849484 DOI: 10.1016/j.mri.2019.03.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 11/22/2022]
Abstract
PURPOSE To demonstrate the feasibility of mapping cerebrovascular reactivity (CVR) using resting-state functional MRI (fMRI) data without gas or other challenges in patients with cerebrovascular diseases and to show that brain regions affected by the diseases have diminished vascular reactivity. MATERIALS AND METHODS Two sub-studies were performed on patients with stroke and Moyamoya disease. In Study 1, 20 stroke patients (56.3 ± 9.7 years, 7 females) were enrolled and resting-state blood‑oxygenation-level-dependent (rs-BOLD) fMRI data were collected, from which CVR maps were computed. CVR values were compared across lesion, perilesional and control ROIs defined on anatomic images. Reproducibility of the CVR measurement was tested in 6 patients with follow-up scans. In Study 2, rs-BOLD fMRI and dynamic susceptibility contrast (DSC) MRI scans were collected in 5 patients with Moyamoya disease (32.4 ± 8.2 years, 4 females). Cerebral blood flow (CBF), cerebral blood volume (CBV), and time-to-peak (TTP) maps were obtained from the DSC MRI data. CVR values were compared between stenotic brain regions and control regions perfused by non-stenotic arteries. RESULTS In stroke patients, lesion CVR (0.250 ± 0.055 relative unit (r.u.)) was lower than control CVR (0.731 ± 0.088 r.u., p = 0.0002). CVR was also lower in the perilesional regions in a graded manner (perilesion 1 CVR = 0.422 ± 0.051 r.u., perilesion 2 CVR = 0.492 ± 0.046 r.u.), relative to that in the control regions (p = 0.005 and 0.036, respectively). In the repeatability analysis, a strong correlation was observed between lesion CVR (r2 = 0.91, p = 0.006) measured at two time points, as well as between control CVR (r2 = 0.79, p = 0.036) at two time points. In Moyamoya patients, CVR in the perfusion deficit regions delineated by DSC TTP maps (0.178 ± 0.189 r.u.) was lower than that in the control regions (0.868 ± 0.214 r.u., p = 0.013). Furthermore, the extent of reduction in CVR was significantly correlated with the extent of lengthening in TTP (r2 = 0.91, p = 0.033). CONCLUSION Our findings suggested that rs-BOLD data can be used to reproducibly evaluate CVR in patients with cerebrovascular diseases without the use of any vasoactive challenges.
Collapse
|
12
|
Quarles CC, Bell LC, Stokes AM. Imaging vascular and hemodynamic features of the brain using dynamic susceptibility contrast and dynamic contrast enhanced MRI. Neuroimage 2018; 187:32-55. [PMID: 29729392 DOI: 10.1016/j.neuroimage.2018.04.069] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 04/27/2018] [Accepted: 04/29/2018] [Indexed: 12/22/2022] Open
Abstract
In the context of neurologic disorders, dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) MRI provide valuable insights into cerebral vascular function, integrity, and architecture. Even after two decades of use, these modalities continue to evolve as their biophysical and kinetic basis is better understood, with improvements in pulse sequences and accelerated imaging techniques and through application of more robust and automated data analysis strategies. Here, we systematically review each of these elements, with a focus on how their integration improves kinetic parameter accuracy and the development of new hemodynamic biomarkers that provide sub-voxel sensitivity (e.g., capillary transit time and flow heterogeneity). Regarding contrast mechanisms, we discuss the dipole-dipole interactions and susceptibility effects that give rise to simultaneous T1, T2 and T2∗ relaxation effects, including their quantification, influence on pulse sequence parameter optimization, and use in methods such as vessel size and vessel architectural imaging. The application of technologic advancements, such as parallel imaging, simultaneous multi-slice, undersampled k-space acquisitions, and sliding window strategies, enables improved spatial and/or temporal resolution of DSC and DCE acquisitions. Such acceleration techniques have also enabled the implementation of, clinically feasible, simultaneous multi-echo spin- and gradient echo acquisitions, providing more comprehensive and quantitative interrogation of T1, T2 and T2∗ changes. Characterizing these relaxation rate changes through different post-processing options allows for the quantification of hemodynamics and vascular permeability. The application of different biophysical models provides insight into traditional hemodynamic parameters (e.g., cerebral blood volume) and more advanced parameters (e.g., capillary transit time heterogeneity). We provide insight into the appropriate selection of biophysical models and the necessary post-processing steps to ensure reliable measurements while minimizing potential sources of error. We show representative examples of advanced DSC- and DCE-MRI methods applied to pathologic conditions affecting the cerebral microcirculation, including brain tumors, stroke, aging, and multiple sclerosis. The maturation and standardization of conventional DSC- and DCE-MRI techniques has enabled their increased integration into clinical practice and use in clinical trials, which has, in turn, spurred renewed interest in their technological and biophysical development, paving the way towards a more comprehensive assessment of cerebral hemodynamics.
Collapse
Affiliation(s)
- C Chad Quarles
- Division of Neuro imaging Research, Barrow Neurological Institute, 350 W. Thomas Rd, Phoenix, AZ, USA.
| | - Laura C Bell
- Division of Neuro imaging Research, Barrow Neurological Institute, 350 W. Thomas Rd, Phoenix, AZ, USA
| | - Ashley M Stokes
- Division of Neuro imaging Research, Barrow Neurological Institute, 350 W. Thomas Rd, Phoenix, AZ, USA
| |
Collapse
|
13
|
Ohmura T, Lee Y, Takahashi N, Toyoshima H. [Novel Perfusion Evaluation Method Using Phase-ratio Image Map in Head 4D-CT]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2017; 73:1125-1131. [PMID: 29151545 DOI: 10.6009/jjrt.2017_jsrt_73.11.1125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE CT perfusion (CTP) is a powerful tool for the assessment of cerebrovascular disease. However, CTP maps are significantly different depending on CTP software and algorithm, even when using identical image data. We developed a phase-ratio image map (PI map), which was a novel perfusion map, without using CTP software. The purpose of this study was to investigate the usefulness of the PI map by comparing it with a positron emission tomography (PET) image. METHODS Twenty patients (16 men, 4 women; mean age: 61.6 years) with unilateral cervical and intracranial steno-occlusive disease underwent CTP. CTP source images were obtained at 1-s intervals of 23 times and 5 intervals using dynamic multiphase imaging. An early-phase image was generated by computing the average of CT images for 5 s in the vicinity of the peak enhancement curve of a normal hemisphere. A delayed-phase image was generated by computing the average of CT images for 5 s immediately after the early phase. The PI map was created by dividing the delayed-phase image by the early-phase image. We investigated the validity of the PI map compared with PET-cerebral blood flow (CBF). Lesion-to-normal ratios between a PET-CBF and the PI map or two conventional CTP-CBFs were observed and compared, and the relative errors were also compared. RESULT There was a strong correlation between the PET-CBF and the PI map (R=0.82). Correlations between the PET-CBF and two CTP-CBFs were weak (R=0.30) and middle (R=0.62), respectively. The relative error between the PI map and the PET-CBF was within 10% in most cases. CONCLUSION The PI map was more similar to the PET-CBF on perfusion evaluation, and did not depend on CTP software. The robustness and simplicity of the PI mapping method would be advantageous compared with conventional CTP mapping methods.
Collapse
Affiliation(s)
- Tomomi Ohmura
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita.,Department of Radiological Technology, Graduate School of Health Sciences, Niigata University
| | - Yongbum Lee
- Department of Radiological Technology, Graduate School of Health Sciences, Niigata University
| | - Noriyuki Takahashi
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita
| | - Hideto Toyoshima
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita
| |
Collapse
|
14
|
Wouters A, Christensen S, Straka M, Mlynash M, Liggins J, Bammer R, Thijs V, Lemmens R, Albers GW, Lansberg MG. A Comparison of Relative Time to Peak and Tmax for Mismatch-Based Patient Selection. Front Neurol 2017; 8:539. [PMID: 29081762 PMCID: PMC5645507 DOI: 10.3389/fneur.2017.00539] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/26/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND AND PURPOSE The perfusion-weighted imaging (PWI)/diffusion-weighted imaging (DWI) mismatch profile is used to select patients for endovascular treatment. A PWI map of Tmax is commonly used to identify tissue with critical hypoperfusion. A time to peak (TTP) map reflects similar hemodynamic properties with the added benefit that it does not require arterial input function (AIF) selection and deconvolution. We aimed to determine if TTP could substitute Tmax for mismatch categorization. METHODS Imaging data of the DEFUSE 2 trial were reprocessed to generate relative TTP (rTTP) maps. We identified the rTTP threshold that yielded lesion volumes comparable to Tmax > 6 s and assessed the effect of reperfusion according to mismatch status, determined based on Tmax and rTTP volumes. RESULTS Among 102 included cases, the Tmax > 6 s lesion volumes corresponded most closely with rTTP > 4.5 s lesion volumes: median absolute difference 6.9 mL (IQR: 2.3-13.0). There was 94% agreement in mismatch classification between Tmax and rTTP-based criteria. When mismatch was assessed by Tmax criteria, the odds ratio (OR) for favorable clinical response associated with reperfusion was 7.4 (95% CI 2.3-24.1) in patients with mismatch vs. 0.4 (95% CI 0.1-2.6) in patients without mismatch. When mismatch was assessed with rTTP criteria, these ORs were 7.2 (95% CI 2.3-22.2) and 0.3 (95% CI 0.1-2.2), respectively. CONCLUSION rTTP yields lesion volumes that are comparable to Tmax and reliably identifies the PWI/DWI mismatch profile. Since rTTP is void of the problems associated with AIF selection, it is a suitable substitute for Tmax that could improve the robustness and reproducibility of mismatch classification in acute stroke.
Collapse
Affiliation(s)
- Anke Wouters
- Department of Neurosciences, Experimental Neurology, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium.,Laboratory of Neurobiology, Center for Brain and Disease Research, VIB, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Søren Christensen
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| | - Matus Straka
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| | - Michael Mlynash
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| | - John Liggins
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| | - Roland Bammer
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| | - Vincent Thijs
- Florey Institute of Neuroscience and Mental Health, Heidelberg, VIC, Australia
| | - Robin Lemmens
- Department of Neurosciences, Experimental Neurology, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium.,Laboratory of Neurobiology, Center for Brain and Disease Research, VIB, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Gregory W Albers
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| | - Maarten G Lansberg
- Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, United States
| |
Collapse
|
15
|
Zaro-Weber O, Moeller-Hartmann W, Siegmund D, Kandziora A, Schuster A, Heiss WD, Sobesky J. MRI-based mismatch detection in acute ischemic stroke: Optimal PWI maps and thresholds validated with PET. J Cereb Blood Flow Metab 2017; 37:3176-3183. [PMID: 28029273 PMCID: PMC5584696 DOI: 10.1177/0271678x16685574] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Perfusion-weighted (PW) magnetic resonance imaging (MRI) is used to detect penumbral tissue in acute stroke, but the selection of optimal PW-maps and thresholds for tissue at risk detection remains a matter of debate. We validated the performance of PW-maps with 15O-water-positron emission tomography (PET) in a large comparative PET-MR cohort of acute stroke patients. In acute and subacute stroke patients with back-to-back MRI and PET imaging, PW-maps were validated with 15O-water-PET. We pooled two different cerebral blood flow (CBF) PET-maps to define the critical flow (CF) threshold, (i) quantitative (q)CBF-PET with the CF threshold <20 ml/100 g/min and (ii) normalized non-quantitative (nq)CBF-PET with a CF threshold of <70% (corresponding to <20 ml/100 g/min according to a previously published normogram). A receiver operating characteristic (ROC) curve analysis was performed to specify the accuracy and the optimal critical flow threshold of each PW-map as defined by PET. In 53 patients, (stroke to imaging: 9.8 h; PET to MRI: 52 min) PW-time-to-maximum (Tmax) with a threshold >6.1 s (AUC = 0.94) and non-deconvolved PW-time-to-peak (TTP) >4.8 s (AUC = 0.93) showed the best performance to detect the CF threshold as defined by PET. PW-Tmax with a threshold >6.1 s and TTP with a threshold >4.8 s are the most predictive in detecting the CF threshold for MR-based mismatch definition.
Collapse
Affiliation(s)
- Olivier Zaro-Weber
- 1 Max-Planck-Institute for Neurological Research, Cologne, Germany.,3 Department of Neurology, Charité-Universitätsmedizin, Berlin, Germany.,4 Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin, Berlin, Germany
| | | | - Dora Siegmund
- 1 Max-Planck-Institute for Neurological Research, Cologne, Germany
| | | | | | | | - Jan Sobesky
- 3 Department of Neurology, Charité-Universitätsmedizin, Berlin, Germany.,4 Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin, Berlin, Germany
| |
Collapse
|
16
|
|
17
|
Reitmeir R, Eyding J, Oertel MF, Wiest R, Gralla J, Fischer U, Giquel PY, Weber S, Raabe A, Mattle HP, Z'Graggen WJ, Beck J. Is ultrasound perfusion imaging capable of detecting mismatch? A proof-of-concept study in acute stroke patients. J Cereb Blood Flow Metab 2017; 37:1517-1526. [PMID: 27389180 PMCID: PMC5453469 DOI: 10.1177/0271678x16657574] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In this study, we compared contrast-enhanced ultrasound perfusion imaging with magnetic resonance perfusion-weighted imaging or perfusion computed tomography for detecting normo-, hypo-, and nonperfused brain areas in acute middle cerebral artery stroke. We performed high mechanical index contrast-enhanced ultrasound perfusion imaging in 30 patients. Time-to-peak intensity of 10 ischemic regions of interests was compared to four standardized nonischemic regions of interests of the same patient. A time-to-peak >3 s (ultrasound perfusion imaging) or >4 s (perfusion computed tomography and magnetic resonance perfusion) defined hypoperfusion. In 16 patients, 98 of 160 ultrasound perfusion imaging regions of interests of the ischemic hemisphere were classified as normal, and 52 as hypoperfused or nonperfused. Ten regions of interests were excluded due to artifacts. There was a significant correlation of the ultrasound perfusion imaging and magnetic resonance perfusion or perfusion computed tomography (Pearson's chi-squared test 79.119, p < 0.001) (OR 0.1065, 95% CI 0.06-0.18). No perfusion in ultrasound perfusion imaging (18 regions of interests) correlated highly with diffusion restriction on magnetic resonance imaging (Pearson's chi-squared test 42.307, p < 0.001). Analysis of receiver operating characteristics proved a high sensitivity of ultrasound perfusion imaging in the diagnosis of hypoperfused area under the curve, (AUC = 0.917; p < 0.001) and nonperfused (AUC = 0.830; p < 0.001) tissue in comparison with perfusion computed tomography and magnetic resonance perfusion. We present a proof of concept in determining normo-, hypo-, and nonperfused tissue in acute stroke by advanced contrast-enhanced ultrasound perfusion imaging.
Collapse
Affiliation(s)
- Raluca Reitmeir
- 1 Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jens Eyding
- 2 Department of Neurology, University Hospital, Knappschaftskrankenhaus, Ruhr University Bochum, Bochum, Germany
| | - Markus F Oertel
- 1 Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Roland Wiest
- 3 Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jan Gralla
- 3 Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Urs Fischer
- 4 Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Pierre-Yves Giquel
- 5 ARTORG Center for Biomedical Engineering, University of Bern, Switzerland
| | - Stefan Weber
- 5 ARTORG Center for Biomedical Engineering, University of Bern, Switzerland
| | - Andreas Raabe
- 1 Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Heinrich P Mattle
- 4 Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Werner J Z'Graggen
- 1 Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jürgen Beck
- 1 Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| |
Collapse
|
18
|
Livne M, Madai VI, Brunecker P, Zaro-Weber O, Moeller-Hartmann W, Heiss WD, Mouridsen K, Sobesky J. A PET-Guided Framework Supports a Multiple Arterial Input Functions Approach in DSC-MRI in Acute Stroke. J Neuroimaging 2017; 27:486-492. [PMID: 28207200 DOI: 10.1111/jon.12428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 01/02/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE In acute stroke, arterial-input-function (AIF) determination is essential for obtaining perfusion estimates with dynamic susceptibility-weighted contrast-enhanced magnetic resonance imaging (DSC-MRI). Standard DSC-MRI postprocessing applies single AIF selection, ie, global AIF. Physiological considerations, however, suggest that a multiple AIFs selection method would improve perfusion estimates to detect penumbral flow. In this study, we developed a framework based on comparable DSC-MRI and positron emission tomography (PET) images to compare the two AIF selection approaches and assess their performance in penumbral flow detection in acute stroke. METHODS In a retrospective analysis of 17 sub(acute) stroke patients with consecutive MRI and PET scans, voxel-wise optimized AIFs were calculated based on the kinetic model as derived from both imaging modalities. Perfusion maps were calculated based on the optimized-AIF using two methodologies: (1) Global AIF and (2) multiple AIFs as identified by cluster analysis. Performance of penumbral-flow detection was tested by receiver-operating characteristics (ROC) curve analysis, ie, the area under the curve (AUC). RESULTS Large variation of optimized AIFs across brain voxels demonstrated that there is no optimal single AIF. Subsequently, the multiple-AIF method (AUC range over all maps: .82-.90) outperformed the global AIF methodology (AUC .72-.85) significantly. CONCLUSIONS We provide PET imaging-based evidence that a multiple AIF methodology is beneficial for penumbral flow detection in comparison with the standard global AIF methodology in acute stroke.
Collapse
Affiliation(s)
- Michelle Livne
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Vince I Madai
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Brunecker
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | | - Kim Mouridsen
- Center of Functionally Integrative Neuroscience, Aarhus University, Denmark
| | - Jan Sobesky
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
19
|
Heiss WD, Zaro Weber O. Validation of MRI Determination of the Penumbra by PET Measurements in Ischemic Stroke. J Nucl Med 2016; 58:187-193. [PMID: 27879370 DOI: 10.2967/jnumed.116.185975] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 11/16/2022] Open
Abstract
The concept of the ischemic penumbra was formulated on the basis of animal experiments showing functional impairment and electrophysiologic disturbances with decreasing flow to the brain below defined values (the threshold for function) and irreversible tissue damage with blood supply further decreased (the threshold for infarction). The perfusion range between these thresholds was termed the "penumbra," and restitution of flow above the functional threshold was able to reverse the deficits without permanent damage. In further experiments, the dependency of the development of irreversible lesions on the interaction of the severity and the duration of critically reduced blood flow was established, proving that the lower the flow, the shorter the time for efficient reperfusion. As a consequence, infarction develops from the core of ischemia to the areas of less severe hypoperfusion. The translation of this experimental concept as the basis for the efficient treatment of stroke requires noninvasive methods with which regional flow and energy metabolism can be repeatedly investigated to demonstrate penumbra tissue, which can benefit from therapeutic interventions. PET allows the quantification of regional cerebral blood flow, the regional oxygen extraction fraction, and the regional metabolic rate for oxygen. With these variables, clear definitions of irreversible tissue damage and of critically hypoperfused but potentially salvageable tissue (i.e., the penumbra) in stroke patients can be achieved. However, PET is a research tool, and its complex logistics limit clinical routine applications. Perfusion-weighted or diffusion-weighted MRI is a widely applicable clinical tool, and the "mismatch" between perfusion-weighted and diffusion-weighted abnormalities serves as an indicator of the penumbra. However, comparative studies of perfusion-weighted or diffusion-weighted MRI and PET have indicated overestimation of the core of irreversible infarction as well as of the penumbra by the MRI modalities. Some of these discrepancies can be explained by the nonselective application of relative perfusion thresholds, which might be improved by more complex analytic procedures. The heterogeneity of the MRI signatures used for the definition of the mismatch are also responsible for disappointing results in the application of perfusion-weighted or diffusion-weighted MRI to the selection of patients for clinical trials. As long as validation of the mismatch selection paradigm is lacking, the use of this paradigm as a surrogate marker of outcome is limited.
Collapse
|
20
|
Luo Y, Gong Z, Zhou Y, Chang B, Chai C, Liu T, Han Y, Wang M, Qian T, Haacke EM, Xia S. Increased susceptibility of asymmetrically prominent cortical veins correlates with misery perfusion in patients with occlusion of the middle cerebral artery. Eur Radiol 2016; 27:2381-2390. [PMID: 27655300 DOI: 10.1007/s00330-016-4593-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/09/2016] [Accepted: 08/30/2016] [Indexed: 03/06/2023]
Abstract
OBJECTIVES To evaluate tissue perfusion and venous susceptibility in ischaemic stroke patients as a means to predict clinical status and early prognosis. METHODS A retrospective study of 51 ischaemic stroke patients were enrolled in this study. Susceptibility, perfusion and National Institute of Health stroke scale (NIHSS) were compared between patients with and without asymmetrically prominent cortical veins (APCVs). The correlation between susceptibility, perfusion and NIHSS was performed. RESULTS Compared to patients without APCVs, the age of patients with APCVs was statistically older (p = 0.017). Patients with APCVs at discharge showed clinical deterioration in their NIHSS. Mean transit time (MTT), time to peak (TTP) and cerebral blood flow (CBF) in the stroke hemisphere were statistically delayed/decreased in patients with and without APCVs (all p < 0.05). In patients with APCVs, the changes in susceptibility positively correlated with increases in MTT and TTP (p < 0.05). Susceptibility and TTP positively correlated and CBF negatively correlated with NIHSS both at admission and discharge (p < 0.05). CONCLUSIONS Patients with APCVs have a tendency of deterioration. The presence of APCVs indicates the tissue has increased oxygen extraction fraction. Increased susceptibility from APCVs positively correlated with the delayed MTT and TTP, which reflects the clinical status at admission and predicts an early prognosis. KEY POINTS • Patients with and without APCVs have similar misery perfusion. • Patients with APCVs have a tendency of deterioration compared to those without. • The presence of APCVs indicated the tissue has increased oxygen extraction fraction. • Increased susceptibility from APCVs positively correlated with the MTT and TTP. • Increased susceptibility from APCVs reflected the clinical status at admission.
Collapse
Affiliation(s)
- Yu Luo
- Radiology Department, Branch of Shanghai First Hospital No.1878, North Sichuan Road, Shanghai, China, 200081
| | - Zhongying Gong
- Neurological Department, Tianjin First Central Hospital, Tianjin, China, 300192
| | - Yongming Zhou
- Radiology Department, Branch of Shanghai First Hospital No.1878, North Sichuan Road, Shanghai, China, 200081
| | - Binge Chang
- Neurosurgery Department, Tianjin First Central Hospital, Tianjin, China, 300192
| | - Chao Chai
- Radiology Department, Tianjin First Central Hospital, Tianjin, China, 300192
| | - Taiyuan Liu
- Radiology Department, Zhengzhou University People's Hospital, Zhengzhou, China, 450003
| | - Yanhong Han
- Radiology Department, Zhengzhou University People's Hospital, Zhengzhou, China, 450003
| | - Meiyun Wang
- Radiology Department, Zhengzhou University People's Hospital, Zhengzhou, China, 450003.
| | - Tianyi Qian
- Siemens Healthcare, MR collaboration, Northeast Asia, No.7, Wangjing Zhonghuan South Road, Beijing, China, 100102
| | - E Mark Haacke
- Radiology Department, Wayne State University, Detroit, MI, USA
| | - Shuang Xia
- Radiology Department, Tianjin First Central Hospital, Tianjin, China, 300192.
| |
Collapse
|
21
|
Alves HCBR, Pacheco FT, Rocha AJ. Collateral blood vessels in acute ischemic stroke: a physiological window to predict future outcomes. ARQUIVOS DE NEURO-PSIQUIATRIA 2016; 74:662-70. [PMID: 27224313 DOI: 10.1590/0004-282x20160050] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 02/08/2016] [Indexed: 12/20/2022]
Abstract
Collateral circulation is a physiologic pathway that protects the brain against ischemic injury and can potentially bypass the effect of a blocked artery, thereby influencing ischemic lesion size and growth. Several recent stroke trials have provided information about the role of collaterals in stroke pathophysiology, and collateral perfusion has been recognized to influence arterial recanalization, reperfusion, hemorrhagic transformation, and neurological outcomes after stroke. Our current aim is to summarize the anatomy and physiology of the collateral circulation and to present and discuss a comprehensible review of the related knowledge, particularly the effects of collateral circulation on the time course of ischemic injury and stroke severity, as well as imaging findings and therapeutic implications.
Collapse
Affiliation(s)
- Heitor Castelo Branco Rodrigues Alves
- Santa Casa de São Paulo, Faculdade de Ciências Médicas, Divisao de Neuroradiologia, São Paulo SP, Brasil;,Fleury Medicina e Saúde, Divisao de Neuroradiologia, São Paulo SP, Brasil
| | - Felipe Torres Pacheco
- Santa Casa de São Paulo, Faculdade de Ciências Médicas, Divisao de Neuroradiologia, São Paulo SP, Brasil;,Fleury Medicina e Saúde, Divisao de Neuroradiologia, São Paulo SP, Brasil
| | - Antonio J Rocha
- Santa Casa de São Paulo, Faculdade de Ciências Médicas, Divisao de Neuroradiologia, São Paulo SP, Brasil;,Fleury Medicina e Saúde, Divisao de Neuroradiologia, São Paulo SP, Brasil
| |
Collapse
|
22
|
Mundiyanapurath S, Ringleb PA, Diatschuk S, Eidel O, Burth S, Floca R, Möhlenbruch M, Wick W, Bendszus M, Radbruch A. Time-dependent parameter of perfusion imaging as independent predictor of clinical outcome in symptomatic carotid artery stenosis. BMC Neurol 2016; 16:50. [PMID: 27094741 PMCID: PMC4837540 DOI: 10.1186/s12883-016-0576-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 04/14/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Carotid artery stenosis is a frequent cause of ischemic stroke. While any degree of stenosis can cause embolic stroke, a higher degree of stenosis can also cause hemodynamic infarction. The hemodynamic effect of a stenosis can be assessed via perfusion weighted MRI (PWI). Our aim was to investigate the ability of PWI-derived parameters such as TTP (time-to-peak) and T(max) (time to the peak of the residue curve) to predict outcome in patients with unilateral acute symptomatic internal carotid artery (sICA) stenosis. METHODS Patients with unilateral acute sICA stenosis (≥50% according to NASCET), without intracranial stenosis or occlusion, who underwent PWI, were included. Clinical characteristics, volume of restricted diffusion, volume of prolonged TTP and T(max) were retrospectively analyzed and correlated with outcome represented by the modified Rankin Scale (mRS) score at discharge. TTP and T(max) volumes were dichotomized using a ROC curve analysis. Multivariate analysis was performed to determine which PWI-parameter was an independent predictor of outcome. RESULTS Thirty-two patients were included. Degree of stenosis, volume of visually assessed TTP and volume of TTP ≥2 s did not distinguish patients with favorable (mRS 0-2) and unfavorable (mRS 3-6) outcome. In contrast, patients with unfavorable outcome had higher volumes of TTP ≥4 s (9.12 vs. 0.87 ml; p = 0.043), TTP ≥6 s (6.70 vs. 0.20 ml; p = 0.017), T(max) ≥4 s (25.27 vs. 0.00 ml; p = 0.043), T(max) ≥6 s (9.21 vs. 0.00 ml; p = 0.017), T(max) ≥8 s (6.86 vs. 0.00 ml; p = 0.011) and T(max) ≥10s (5.94 vs. 0.00 ml; p = 0.025) in univariate analysis. Multivariate logistic regression showed that NIHSS score on admission (Odds Ratio (OR) 0.466, confidence interval (CI) [0.224;0.971], p = 0.041), T(max) ≥8 s (OR 0.025, CI [0.001;0.898] p = 0.043) and TTP ≥6 s (OR 0.025, CI [0.001;0.898] p = 0.043) were independent predictors of clinical outcome. CONCLUSION As they stood out in multivariate regression and are objective and reproducible parameters, PWI-derived volumes of T(max) ≥8 s and TTP ≥6 s might be superior to degree of stenosis and visually assessed TTP maps in predicting short term patient outcome. Future studies should assess if perfusion weighted imaging might guide the selection of patients for recanalization procedures.
Collapse
Affiliation(s)
- Sibu Mundiyanapurath
- Department of Neurology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany.
| | - Peter Arthur Ringleb
- Department of Neurology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany
| | - Sascha Diatschuk
- Department of Neuroradiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany.,German Cancer Research Center, Department of Radiology, INF 280, Heidelberg, 69120, Germany
| | - Oliver Eidel
- Department of Neuroradiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany
| | - Sina Burth
- Department of Neuroradiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany
| | - Ralf Floca
- German Cancer Research Center, Department of Radiology, INF 280, Heidelberg, 69120, Germany
| | - Markus Möhlenbruch
- Department of Neuroradiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany
| | - Wolfgang Wick
- Department of Neurology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany.,CCU Neurooncology, German cancer Consortium (DKTK) & German Cancer Research Center (DKFZ), INF 280, Heidelberg, 69120, Germany
| | - Martin Bendszus
- Department of Neuroradiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany
| | - Alexander Radbruch
- Department of Neuroradiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, 69120, Germany.,German Cancer Research Center, Department of Radiology, INF 280, Heidelberg, 69120, Germany
| |
Collapse
|
23
|
Lopez-Mejia M, Roldan-Valadez E. Comparisons of Apparent Diffusion Coefficient Values in Penumbra, Infarct, and Normal Brain Regions in Acute Ischemic Stroke: Confirmatory Data Using Bootstrap Confidence Intervals, Analysis of Variance, and Analysis of Means. J Stroke Cerebrovasc Dis 2016; 25:515-22. [PMID: 26654670 DOI: 10.1016/j.jstrokecerebrovasdis.2015.10.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/20/2015] [Accepted: 10/31/2015] [Indexed: 02/08/2023] Open
|
24
|
|
25
|
Abstract
In acute stroke, the major factor for recovery is the early use of thrombolysis aimed at arterial recanalization and reperfusion of ischemic brain tissue. Subsequently, neurorehabilitative training critically improves clinical recovery due to augmention of postlesional plasticity. Neuroimaging and electrophysiology studies have revealed that the location and volume of the stroke lesion, the affection of nerve fiber tracts, as well as functional and structural changes in the perilesional tissue and in large-scale bihemispheric networks are relevant biomarkers of post-stroke recovery. However, associated disorders, such as mood disorders, epilepsy, and neurodegenerative diseases, may induce secondary cerebral changes or aggravate the functional deficits and, thereby, compromise the potential for recovery.
Collapse
Affiliation(s)
- Rüdiger J Seitz
- Department of Neurology, Centre of Neurology and Neuropsychiatry, LVR-Klinikum Düsseldorf, Heinrich-Heine-University Düsseldorf , Düsseldorf , Germany ; Biomedical Research Centre, Heinrich-Heine-University Düsseldorf , Düsseldorf , Germany ; Florey Institute of Neuroscience and Mental Health, University of Melbourne , Parkville, VIC , Australia
| | - Geoffrey A Donnan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne , Parkville, VIC , Australia
| |
Collapse
|
26
|
Kang J, Jung C, Kim N, Son YR, Choi B, Kim JH, Lee JS, Lee J, Lee J, Jang MS, Yang MH, Han MK, Bae HJ. A Simple Geometric Assessment of Perfusion Lesion Volume at Hyperacute Stage of Ischemic Stroke in Patients with Symptomatic Steno-Occlusion of Major Cerebral Arteries and Risk of Subsequent Cerebral Ischemic Events. J Stroke Cerebrovasc Dis 2015; 24:2669-75. [PMID: 26476587 DOI: 10.1016/j.jstrokecerebrovasdis.2015.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 05/20/2015] [Accepted: 05/26/2015] [Indexed: 11/25/2022] Open
Abstract
Our objective is to elucidate the association of baseline perfusion lesion volume on perfusion-weighted magnetic resonance imaging (PWI) obtained at hyperacute stage of ischemic stroke with subsequent cerebral ischemic events (SIEs) in patients with symptomatic steno-occlusion of major cerebral arteries. Using a prospective stroke registry database, patients arriving within 24 hours of onset with symptomatic steno-occlusion of major supratentorial cerebral arteries were identified. On baseline PWI, time-to-peak lesion volume (TTP-LV) was determined by a simple geometric method and dichotomized into the highest tertile (large) and the other tertiles (small to medium) according to the vascular territory of occluded arteries. Primary outcome was a time to SIE up to 1 year after stroke onset. A total of 385 patients (a median time delay from onset to arrival, 2.2 hours) were enrolled. During the first year of stroke, the SIE rate of the large TTP-LV group was twice that of the small-to-medium TTP-LV group (35.7% versus 17.4%; P < .001). Large TTP-LV independently raised the hazard of SIE (hazard ratio, 2.24; 95% confidence interval, 1.45-3.44). This study demonstrates that TTP-LV on PWI measured through a simple geometric method at an emergency setting can be used to predict progression or recurrence of ischemic stroke in patients with symptomatic steno-occlusion of major cerebral arteries.
Collapse
Affiliation(s)
- Jihoon Kang
- Department of Neurology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea
| | - Cheolkyu Jung
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Nayoung Kim
- Department of Neurology, Cerebrovascular Center, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Yoo Ri Son
- Department of Neurology, Cerebrovascular Center, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Byungse Choi
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Jae-Hyoung Kim
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Ji Sung Lee
- Clinical Research Center, Asan Medical Center, Seoul, Republic of Korea
| | - Juneyoung Lee
- Department of Biostatistics, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jun Lee
- Department of Neurology, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Myung Suk Jang
- Department of Neurology, Cerebrovascular Center, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Mi Hwa Yang
- Department of Neurology, Cerebrovascular Center, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Moon-Ku Han
- Department of Neurology, Cerebrovascular Center, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea
| | - Hee-Joon Bae
- Department of Neurology, Cerebrovascular Center, Seoul National University Bundang Hospital, Seoul National University, Seongnam, Republic of Korea.
| |
Collapse
|
27
|
Förster A, Mürle B, Kerl HU, Wenz H, Al-Zghloul M, Habich S, Groden C. Sparing of the hippocampus indicates better collateral blood flow in acute posterior cerebral artery occlusion. Int J Stroke 2015; 10:1287-93. [PMID: 26045188 DOI: 10.1111/ijs.12531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 04/08/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND In acute posterior cerebral artery, occlusion involvement of the hippocampus is a common finding. Nevertheless, until today, infarction and ischemic lesion evolution in the hippocampus has not been studied systematically. AIM Evaluation of hippocampal infarction patterns in posterior cerebral artery occlusion in the very early phase (≤six-hours) and ischemic lesion evolution on follow-up magnetic resonance imaging in relation to collateral blood flow assessed by a magnetic resonance imaging-based approach was conducted. METHODS In 28 patients [mean age 69·4 ± 13·8 years, 19 (67·9%) males, 10 (32·1%) females] with proximal posterior cerebral artery occlusion, magnetic resonance imaging findings were analyzed, with emphasis on hippocampal infarction patterns on diffusion-weighted images and collateralization on dynamic 4D angiograms derived from perfusion-weighted raw images. RESULTS On initial diffusion-weighted images, we identified all known hippocampal infarction patterns: type 1 (complete) in 6/18 (33·3%) patients, type 2 (lateral) in 10/18 (55·6%) patients, and type 3 (dorsal) and type 4 (circumscribed) in 1/18 (5·6%) patient respectively. On dynamic 4D angiograms, the grade of collateralization was classified as 1 in 9 (32·1%), 2 in 1 (3·6%), 3 in 10 (35·7%), and 4 in 8 (28·6%) patients. On follow-up diffusion-weighted images, we found new ischemic lesions in three and infarction growth in the hippocampus in five patients. Patients with better collateralization (grades 3 and 4) less often had hippocampal infarctions on initial (P = 0·003)/follow-up diffusion-weighted images (P = 0·046) as well as type 1 on initial (P = 0·007)/follow-up diffusion-weighted images (P = 0·005). CONCLUSIONS Involvement of the hippocampus in proximal posterior cerebral artery occlusion is frequently but not obligatorily observed and highly dependent on the extent of collateralization. The same holds true for hippocampal infarction patterns.
Collapse
Affiliation(s)
- Alex Förster
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | - Bettina Mürle
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | - Hans U Kerl
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | - Holger Wenz
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | - Mansour Al-Zghloul
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | - Sonia Habich
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | - Christoph Groden
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| |
Collapse
|
28
|
Hansen MB, Nagenthiraja K, Ribe LR, Dupont KH, Østergaard L, Mouridsen K. Automated estimation of salvageable tissue: Comparison with expert readers. J Magn Reson Imaging 2015; 43:220-8. [DOI: 10.1002/jmri.24963] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/15/2015] [Indexed: 11/07/2022] Open
Affiliation(s)
- Mikkel B. Hansen
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University; Aarhus Denmark
| | - Kartheeban Nagenthiraja
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University; Aarhus Denmark
| | - Lars R. Ribe
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University; Aarhus Denmark
| | - Kristina H. Dupont
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University; Aarhus Denmark
- Department of Neuroradiology; Aarhus University Hospital; Aarhus Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University; Aarhus Denmark
- Department of Neuroradiology; Aarhus University Hospital; Aarhus Denmark
| | - Kim Mouridsen
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University; Aarhus Denmark
| |
Collapse
|
29
|
Sohn SW, Park HS, Cha JK, Kim DH, Kang MJ, Choi JH, Nah HW, Huh JT. Relative CBV ratio on perfusion-weighted MRI indicates the probability of early recanalization after IV t-PA administration for acute ischemic stroke. J Neurointerv Surg 2015; 8:235-9. [PMID: 25583534 DOI: 10.1136/neurintsurg-2014-011501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 12/19/2014] [Indexed: 11/03/2022]
Abstract
BACKGROUND We hypothesized that the relative cerebral blood volume (rCBV) ratio on perfusion-weighted imaging (PWI) using MRI might serve as a predictor of early recanalization (ER) after intravenous tissue plasminogen activator (IV t-PA) administration for acute ischemic stroke. METHODS Patients with acute middle cerebral artery (MCA) ischemic stroke (IS) were enrolled in the study. They were evaluated by MRI, including PWI and diffusion-weighted imaging, before administration of IV t-PA and underwent digital subtraction angiography (DSA) of the brain within 2 h after t-PA administration. We compared the rCBV ratio on PWI between patients with and without ER on DSA and investigated the proportion of patients with an excellent outcome at 90 days after t-PA administration (modified Rankin Scale score 0-1) among those with and without ER. RESULTS 85 patients with acute MCA IS were included; 16 patients (18.8%) experienced ER on DSA after IV t-PA administration. Patients with ER more frequently had an excellent outcome at 90 days than those without ER. The rCBV ratio on PWI was higher in the ER group (1.01±0.21, p<0.01) than in the non-ER group (0.82±0.18). After adjusting for the presence of atrial fibrillation and the serum glucose level, the rCBV ratio on PWI (OR 1.07; 95% CI 1.02 to 1.12; p<0.01) was a significant independent indicator of ER. CONCLUSIONS The results of this study suggest that the rCBV ratio on PWI might serve as a useful indicator of ER after IV t-PA administration.
Collapse
Affiliation(s)
- Sang-Wook Sohn
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Hyun-Seok Park
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Jae-Kwan Cha
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Dae-Hyun Kim
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Myung-Jin Kang
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Jae-Hyung Choi
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Hyun-Wook Nah
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| | - Jae-Taeck Huh
- Busan-Ulsan Regional Cardio-Cerebral Vascular Center, Dong-A University Hospital, Busan, Korea
| |
Collapse
|
30
|
Nasel C, Kalcher K, Boubela R, Moser E. Improved quantification of cerebral hemodynamics using individualized time thresholds for assessment of peak enhancement parameters derived from dynamic susceptibility contrast enhanced magnetic resonance imaging. PLoS One 2014; 9:e114999. [PMID: 25521121 PMCID: PMC4270773 DOI: 10.1371/journal.pone.0114999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 11/17/2014] [Indexed: 11/18/2022] Open
Abstract
Purpose Assessment of cerebral ischemia often employs dynamic susceptibility contrast enhanced magnetic resonance imaging (DSC-MRI) with evaluation of various peak enhancement time parameters. All of these parameters use a single time threshold to judge the maximum tolerable peak enhancement delay that is supposed to reliably differentiate sufficient from critical perfusion. As the validity of this single threshold approach still remains unclear, in this study, (1) the definition of a threshold on an individual patient-basis, nevertheless (2) preserving the comparability of the data, was investigated. Methods The histogram of time-to-peak (TTP) values derived from DSC-MRI, the so-called TTP-distribution curve (TDC), was modeled using a double-Gaussian model in 61 patients without severe cerebrovascular disease. Particular model-based zf-scores were used to describe the arterial, parenchymal and venous bolus-transit phase as time intervals Ia,p,v. Their durations (delta Ia,p,v), were then considered as maximum TTP-delays of each phase. Results Mean-R2 for the model-fit was 0.967. Based on the generic zf-scores the proposed bolus transit phases could be differentiated. The Ip-interval reliably depicted the parenchymal bolus-transit phase with durations of 3.4 s–10.1 s (median = 4.3s), where an increase with age was noted (∼30 ms/year). Conclusion Individual threshold-adjustment seems rational since regular bolus-transit durations in brain parenchyma obtained from the TDC overlap considerably with recommended critical TTP-thresholds of 4 s–8 s. The parenchymal transit time derived from the proposed model may be utilized to individually correct TTP-thresholds, thereby potentially improving the detection of critical perfusion.
Collapse
Affiliation(s)
- Christian Nasel
- Department of Radiology, University Hospital Tulln, Karl Landsteiner University of Health Sciences, Tulln, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
- * E-mail:
| | - Klaudius Kalcher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Roland Boubela
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Ewald Moser
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
31
|
Sebastian R, Schein MG, Davis C, Gomez Y, Newhart M, Oishi K, Hillis AE. Aphasia or Neglect after Thalamic Stroke: The Various Ways They may be Related to Cortical Hypoperfusion. Front Neurol 2014; 5:231. [PMID: 25477859 PMCID: PMC4237053 DOI: 10.3389/fneur.2014.00231] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/26/2014] [Indexed: 11/17/2022] Open
Abstract
Although aphasia and hemispatial neglect are classically labeled as cortical deficits, language deficits or hemispatial neglect following lesions to subcortical regions have been reported in many studies. However, whether or not aphasia and hemispatial neglect can be caused by subcortical lesions alone has been a matter of controversy. It has been previously shown that most cases of aphasia or hemispatial neglect due to acute non-thalamic subcortical infarcts can be accounted for by concurrent cortical hypoperfusion due to arterial stenosis or occlusion, reversible by restoring blood flow to the cortex. In this study, we evaluated whether aphasia or neglect occur after acute thalamic infarct without cortical hypoperfusion due to arterial stenosis or occlusion. Twenty patients with isolated acute thalamic infarcts (10 right and 10 left) underwent MRI scanning and detailed cognitive testing. Results revealed that 5/10 patients with left thalamic infarcts had aphasia and only 1 had cortical hypoperfusion, whereas 2/10 patients with right thalamic infarcts had hemispatial neglect and both had cortical hypoperfusion. These findings indicate that aphasia was observed in some cases of isolated left thalamic infarcts without cortical hypoerfusion due to arterial stenosis or occlusion (measured with time-to-peak delays), but neglect occurred after isolated right thalamic infarcts only when there was cortical hypoperfusion due to arterial stenosis or occlusion. Therefore, neglect after acute right thalamic infarct should trigger evaluation for cortical hypoperfusion that might improve with restoration of blood flow. Further investigation in a larger group of patients and with other imaging modalities is warranted to confirm these findings.
Collapse
Affiliation(s)
- Rajani Sebastian
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mara G. Schein
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cameron Davis
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yessenia Gomez
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Melissa Newhart
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kenichi Oishi
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Argye E. Hillis
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
32
|
Yeo LLL, Paliwal P, Teoh HL, Seet RC, Chan BP, Ting E, Venketasubramanian N, Leow WK, Wakerley B, Kusama Y, Rathakrishnan R, Sharma VK. Assessment of intracranial collaterals on CT angiography in anterior circulation acute ischemic stroke. AJNR Am J Neuroradiol 2014; 36:289-94. [PMID: 25324493 DOI: 10.3174/ajnr.a4117] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE Intracranial collaterals influence the prognosis of patients treated with intravenous tissue plasminogen activator in acute anterior circulation ischemic stroke. We compared the methods of scoring collaterals on pre-tPA brain CT angiography for predicting functional outcomes in acute anterior circulation ischemic stroke. MATERIALS AND METHODS Two hundred consecutive patients with acute anterior circulation ischemic stroke treated with IV-tPA during 2010-2012 were included. Two independent neuroradiologists evaluated intracranial collaterals by using the Miteff system, Maas system, the modified Tan scale, and the Alberta Stroke Program Early CT Score 20-point methodology. Good and extremely poor outcomes at 3 months were defined by modified Rankin Scale scores of 0-1 and 5-6 points, respectively. RESULTS Factors associated with good outcome on univariable analysis were younger age, female sex, hypertension, diabetes mellitus, atrial fibrillation, small infarct core (ASPECTS ≥8), vessel recanalization, lower pre-tPA NIHSS scores, and good collaterals according to Tan methodology, ASPECTS methodology, and Miteff methodology. On multivariable logistic regression, only lower NIHSS scores (OR, 1.186 per point; 95% CI, 1.079-1.302; P = .001), recanalization (OR, 5.599; 95% CI, 1.560-20.010; P = .008), and good collaterals by the Miteff method (OR, 3.341; 95% CI, 1.203-5.099; P = .014) were independent predictors of good outcome. Poor collaterals by the Miteff system (OR, 2.592; 95% CI, 1.113-6.038; P = .027), Maas system (OR, 2.580; 95% CI, 1.075-6.187; P = .034), and ASPECTS method ≤5 points (OR, 2.685; 95% CI, 1.156-6.237; P = .022) were independent predictors of extremely poor outcomes. CONCLUSIONS Only the Miteff scoring system for intracranial collaterals is reliable for predicting favorable outcome in thrombolyzed acute anterior circulation ischemic stroke. However, poor outcomes can be predicted by most of the existing methods of scoring intracranial collaterals.
Collapse
Affiliation(s)
- L L L Yeo
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - P Paliwal
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - H L Teoh
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - R C Seet
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.) Yong Loo Lin School of Medicine (R.C.S., V.K.S.), National University of Singapore, Singapore
| | - B P Chan
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - E Ting
- Department of Diagnostic Imaging (E.T.), National University Health System, Singapore
| | - N Venketasubramanian
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - W K Leow
- Department of Computer Science (W.K.L.)
| | - B Wakerley
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - Y Kusama
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - R Rathakrishnan
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.)
| | - V K Sharma
- From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., H.L.T., R.C.S., B.P.C., N.V., B.W., Y.K., R.R., V.K.S.) Yong Loo Lin School of Medicine (R.C.S., V.K.S.), National University of Singapore, Singapore
| |
Collapse
|
33
|
Hickok G, Rogalsky C, Chen R, Herskovits EH, Townsley S, Hillis AE. Partially overlapping sensorimotor networks underlie speech praxis and verbal short-term memory: evidence from apraxia of speech following acute stroke. Front Hum Neurosci 2014; 8:649. [PMID: 25202255 PMCID: PMC4142788 DOI: 10.3389/fnhum.2014.00649] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/04/2014] [Indexed: 11/29/2022] Open
Abstract
We tested the hypothesis that motor planning and programming of speech articulation and verbal short-term memory (vSTM) depend on partially overlapping networks of neural regions. We evaluated this proposal by testing 76 individuals with acute ischemic stroke for impairment in motor planning of speech articulation (apraxia of speech, AOS) and vSTM in the first day of stroke, before the opportunity for recovery or reorganization of structure-function relationships. We also evaluated areas of both infarct and low blood flow that might have contributed to AOS or impaired vSTM in each person. We found that AOS was associated with tissue dysfunction in motor-related areas (posterior primary motor cortex, pars opercularis; premotor cortex, insula) and sensory-related areas (primary somatosensory cortex, secondary somatosensory cortex, parietal operculum/auditory cortex); while impaired vSTM was associated with primarily motor-related areas (pars opercularis and pars triangularis, premotor cortex, and primary motor cortex). These results are consistent with the hypothesis, also supported by functional imaging data, that both speech praxis and vSTM rely on partially overlapping networks of brain regions.
Collapse
Affiliation(s)
- Gregory Hickok
- Department of Cognitive Sciences, Center for Language Science, Center for Cognitive Neuroscience and Engineering, University of California Irvine, CA, USA
| | - Corianne Rogalsky
- Department of Speech and Hearing Science, Arizona State University Tempe, AZ, USA
| | - Rong Chen
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Baltimore, MD, USA
| | - Edward H Herskovits
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Baltimore, MD, USA
| | - Sarah Townsley
- Department of Neurology, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Argye E Hillis
- Department of Neurology, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Cognitive Science, Johns Hopkins University Baltimore, MD, USA
| |
Collapse
|
34
|
Kortte KB, McWhorter JW, Pawlak MA, Slentz J, Sur S, Hillis AE. Anosognosia for hemiplegia: The contributory role of right inferior frontal gyrus. Neuropsychology 2014; 29:421-32. [PMID: 25133319 DOI: 10.1037/neu0000135] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Awareness of motor functioning is most likely a complex process that requires integration of sensory-motor feedback to constantly update the system on the functioning of the limb during motor behavior. Using lesion mapping procedures and behavioral measures, the current study aimed to evaluate neural correlates of anosognosia for hemiplegia (AHP) in the acute stage (first 48 hr) of right hemisphere stroke. METHOD Thirty-five individuals with right hemisphere stroke who presented to an urban medical center within 24 hr of symptom onset were included in the study. All 35 individuals had hemiplegia, and 8 of these individuals exhibited AHP. RESULTS Fisher's exact test statistical map of lesion-deficit association (range is between-log(p) 4 to 11) found maximal value of 10.9 located in pars orbitalis (Brodmann's Area 47; BA). In this selected location, 6 out of 8 patients with AHP had tissue abnormality, whereas none of the unaffected subjects had tissue abnormality in BA 47. Right BA 44/45 was also found to be lesioned more frequently in individuals with AHP (75%) than without AHP (11%). CONCLUSIONS The current study findings provide preliminary support for unique involvement of the right inferior frontal gyrus (IFG), pars orbitalis (BA 47) in AHP. The current data suggest that frontal operculum may play a key role in awareness of limb functioning.
Collapse
Affiliation(s)
- Kathleen B Kortte
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine
| | | | - Mikolaj A Pawlak
- Department of Neurology and Cerebrovascular Disorders, Poznan University of Medical Sciences
| | - Jamie Slentz
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine
| | - Sandeepa Sur
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine
| | - Argye E Hillis
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine
| |
Collapse
|
35
|
Sawicki M, Bohatyrewicz R, Safranow K, Walecka A, Walecki J, Rowinski O, Solek-Pastuszka J, Czajkowski Z, Guzinski M, Burzynska M, Wojczal J. Computed tomographic angiography criteria in the diagnosis of brain death-comparison of sensitivity and interobserver reliability of different evaluation scales. Neuroradiology 2014; 56:609-20. [PMID: 24801451 PMCID: PMC4125746 DOI: 10.1007/s00234-014-1364-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 04/08/2014] [Indexed: 11/14/2022]
Abstract
INTRODUCTION The standardized diagnostic criteria for computed tomographic angiography (CTA) in diagnosis of brain death (BD) are not yet established. The aim of the study was to compare the sensitivity and interobserver agreement of the three previously used scales of CTA for the diagnosis of BD. METHODS Eighty-two clinically brain-dead patients underwent CTA with a delay of 40 s after contrast injection. Catheter angiography was used as the reference standard. CTA results were assessed by two radiologists, and the diagnosis of BD was established according to 10-, 7-, and 4-point scales. RESULTS Catheter angiography confirmed the diagnosis of BD in all cases. Opacification of certain cerebral vessels as indicator of BD was highly sensitive: cortical segments of the middle cerebral artery (96.3 %), the internal cerebral vein (98.8 %), and the great cerebral vein (98.8 %). Other vessels were less sensitive: the pericallosal artery (74.4 %), cortical segments of the posterior cerebral artery (79.3 %), and the basilar artery (82.9 %). The sensitivities of the 10-, 7-, and 4-point scales were 67.1, 74.4, and 96.3 %, respectively (p<0.001). Percentage interobserver agreement in diagnosis of BD reached 93 % for the 10-point scale, 89 % for the 7-point scale, and 95 % for the 4-point scale (p=0.37). CONCLUSIONS In the application of CTA to the diagnosis of BD, reducing the assessment of vascular opacification scale from a 10- to a 4-point scale significantly increases the sensitivity and maintains high interobserver reliability.
Collapse
Affiliation(s)
- Marcin Sawicki
- Department of Diagnostic Imaging and Interventional Radiology, Pomeranian Medical University, Clinical Hospital No1, Unii Lubelskiej 1, Szczecin, 71252, Poland,
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
The rCBV ratio on perfusion-weighted imaging reveals the extent of blood flow on conventional angiography after acute ischemic stroke. Clin Neurol Neurosurg 2014; 122:54-8. [DOI: 10.1016/j.clineuro.2014.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 04/03/2014] [Accepted: 04/09/2014] [Indexed: 11/18/2022]
|
37
|
Hirano T. Searching for Salvageable Brain: The Detection of Ischemic Penumbra Using Various Imaging Modalities? J Stroke Cerebrovasc Dis 2014; 23:795-8. [DOI: 10.1016/j.jstrokecerebrovasdis.2013.10.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 10/07/2013] [Accepted: 10/07/2013] [Indexed: 11/25/2022] Open
|
38
|
Wu TC, Sitton C, Potter A, Bowry R, Sahota P, Cai C, Hui P, Chen Z, Gonzales N, Barreto A, Lopez G, Grotta JC, Savitz SI. CTP infarct core may predict poor outcome in stroke patients treated with IV t-PA. J Neurol Sci 2014; 340:165-9. [PMID: 24694764 DOI: 10.1016/j.jns.2014.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 03/03/2014] [Accepted: 03/12/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND Computerized tomography perfusion (CTP) has been widely studied in assessing physiological brain tissue parameters in patients with acute ischemic stroke (AIS). The utility of CTP to predict clinical outcome in patients with AIS treated with intravenous tissue plasminogen activator (IV t-PA) is controversial. We reviewed CTP data in AIS patients treated with IV t-PA to uncover potential predictors of clinical outcome. METHODS We retrospectively identified AIS patients from our stroke registry (7/07 to 2/10) who underwent CTP on arrival and then received IV t-PA. A neuroradiologist blinded to outcome performed all CTP parameter measurements on a commercially available Siemens Neuro PCT workstation. Tissue at risk (TAR) was defined as the area of infarct territory with a relative time to peak (rTTP) greater than 4s. Non-viable tissue (NVT) was defined as the area of infarct territory with absolute cerebral blood volume (CBV) less than 2 ml/100g and cerebral blood flow (CBF) less than 12.7 ml/100g/min. Penumbra was defined as the area of (TAR) minus the area of (NVT). Excellent clinical outcome was defined as mRS (0-1), good clinical outcome was defined as mRS (0-2), and poor clinical outcome was defined as mRS (4-6), all measured at hospital discharge and 90 days if available. Recanalization data was obtained when available by comparing pre-thrombolytic CTA data and post-treatment MRA/CTA images by a single blinded radiologist. RESULTS We identified 61 patients that met our inclusion criteria with a mean age of 68 (29-94), median NIHSS on admission of 13 (1-40), and median discharge mRS of 4 (0-6). Using multivariate logistic regression and ordinal logistic regression controlling for age and admission NIHSS, none of the CTP parameters were statistically associated with excellent or good clinical outcome (mRS<2). Using multivariate analysis controlling for age and admission NIHSS, NVT area>30 cm(2) (OR=5.12, CI: 0.95-27, p=0.05) was statistically associated with poor clinical outcome at discharge. NVT area ≥ 30 cm(2) was a potential predictor of poor outcome at discharge even when controlling for age and NIHSS. CONCLUSION CTP parameters derived from commercially available software and published thresholds yield little predictive value for good clinical outcomes for AIS patients treated with IV t-PA but may be useful in predicting poor clinical outcome especially if the area of non-viable tissue is greater than 30 cm(2).
Collapse
Affiliation(s)
- Tzu-Ching Wu
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA.
| | - Clark Sitton
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Andrew Potter
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Ritvij Bowry
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Preeti Sahota
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Chunyan Cai
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Peng Hui
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Zhongxue Chen
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Nicole Gonzales
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Andrew Barreto
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - George Lopez
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - James C Grotta
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| | - Sean I Savitz
- Department of Neurology, University of Texas-Houston Medical School, Houston, TX, USA
| |
Collapse
|
39
|
Sebastian R, Gomez Y, Leigh R, Davis C, Newhart M, Hillis AE. The roles of occipitotemporal cortex in reading, spelling, and naming. Cogn Neuropsychol 2014; 31:511-28. [PMID: 24527769 DOI: 10.1080/02643294.2014.884060] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We evaluated the hypothesis that Brodmann's area (BA) 37 within left occipitotemporal cortex has at least two important functions in lexical processing. One role is the computation of case-, font-, location-, and orientation-independent grapheme descriptions for written word recognition and production (reading and spelling). This role may depend on the medial part of BA 37, in left midfusiform gyrus. The second role is in accessing modality-independent lexical representations for output, for naming and for reading and spelling of irregular or exception words. This role may depend on the lateral part of BA 37 in inferior temporal cortex. We tested these hypotheses in 234 participants with acute left hemisphere ischaemic stroke who underwent magnetic resonance imaging (MRI) and language testing within 48 hours of onset of stroke symptoms.
Collapse
Affiliation(s)
- Rajani Sebastian
- a Department of Neurology , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | | | | | | | | | | |
Collapse
|
40
|
Ford AL, An H, Kong L, Zhu H, Vo KD, Powers WJ, Lin W, Lee JM. Clinically relevant reperfusion in acute ischemic stroke: MTT performs better than Tmax and TTP. Transl Stroke Res 2014; 5:415-421. [PMID: 24500786 DOI: 10.1007/s12975-014-0325-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 12/11/2013] [Accepted: 01/05/2014] [Indexed: 10/25/2022]
Abstract
While several MRI parameters are used to assess tissue perfusion during hyperacute stroke, it is unclear which is optimal for measuring clinically relevant reperfusion. We directly compared mean transit time (MTT) prolongation (MTTp), time-to-peak (TTP), and time-to-maximum (Tmax) to determine which best predicted neurological improvement and tissue salvage following early reperfusion. Acute ischemic stroke patients underwent three MRIs: <4.5 h (tp1), at 6 h (tp2), and at 1 month after onset. Perfusion deficits at tp1 and tp2 were defined by MTTp, TTP, or Tmax beyond four commonly used thresholds. Percent reperfusion (%Reperf) was calculated for each parameter and threshold. Regression analysis was used to fit %Reperf for each parameter and threshold as a predictor of neurological improvement [defined as admission National Institutes of Health Stroke Scale (NIHSS)-1 month NIHSS (∆NIHSS)] after adjusting for baseline clinical variables. Volume of reperfusion, for each parameter and threshold, was correlated with tissue salvage, defined as tp1 perfusion deficit volume-final infarct volume. Fifty patients were scanned at 2.7 and 6.2 h after stroke onset. %Reperf predicted ∆NIHSS for all MTTp thresholds, for Tmax >6 s and >8 s, but for no TTP thresholds. Tissue salvage significantly correlated with reperfusion for all MTTp thresholds and with Tmax >6 s, while there was no correlation with any TTP threshold. Among all parameters, reperfusion defined by MTTp was most strongly associated with ∆NIHSS (MTTp >3 s, P = 0.0002) and tissue salvage (MTTp >3 s and 4 s, P < 0.0001). MTT-defined reperfusion was the best predictor of neurological improvement and tissue salvage in hyperacute ischemic stroke.
Collapse
Affiliation(s)
- Andria L Ford
- Department of Neurology, Washington University School of Medicine
| | - Hongyu An
- Department of Radiology, University of North Carolina at Chapel Hill
| | - Linglong Kong
- Department of Mathematical and Statistical Sciences, University of Alberta
| | - Hongtu Zhu
- Department of Biostatistics, University of North Carolina at Chapel Hill
| | - Katie D Vo
- Department of Radiology, Washington University School of Medicine
| | - William J Powers
- Department of Neurology, University of North Carolina at Chapel Hill
| | - Weili Lin
- Department of Radiology, University of North Carolina at Chapel Hill
| | - Jin-Moo Lee
- Department of Neurology, Washington University School of Medicine.,Department of Radiology, Washington University School of Medicine
| |
Collapse
|
41
|
Pettigrew C, Hillis AE. Role for Memory Capacity in Sentence Comprehension: Evidence from Acute Stroke. APHASIOLOGY 2014; 28:1258-1280. [PMID: 25221377 PMCID: PMC4158714 DOI: 10.1080/02687038.2014.919436] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Previous research has suggested that short-term and working memory resources play a critical role in sentence comprehension, especially when comprehension mechanisms cannot rely on semantics alone. However, few studies have examined this association in participants in acute stroke, before the opportunity for therapy and reorganization of cognitive functions. AIMS The present study examined the hypothesis that severity of short-term memory deficit due to acute stroke predicts the severity of impairment in the comprehension of syntactically complex sentences. Furthermore, we examined the association between damage to the short-term and working memory network and impaired sentence comprehension, as an association would be predicted by the previous hypothesis. METHODS & PROCEDURES 47 participants with acute stroke and 14 participants with a transient ischemic attack (TIA; the control group) were included in the present study. Participants received a language battery and clinical or research scans within 48 hours of hospital admittance. The present study focused on the behavioral data from the short-term memory and working memory span tasks and a sentence-picture matching comprehension task included in this battery. Using regression analyses, we examined whether short-term and working memory measures explained significant variance in sentence comprehension performance. OUTCOMES & RESULTS Consistent with prior research, short-term memory explained significant variance in sentence comprehension performance in acute stroke; in contrast, working memory accounted for little variance beyond that which was already explained by short-term memory. Furthermore, ischemia that included the short-term/working memory network was sufficient to cause sentence comprehension impairments for syntactically complex sentences. CONCLUSIONS The present study suggests that short-term memory resources are an important source of sentence comprehension impairments.
Collapse
Affiliation(s)
- Corinne Pettigrew
- Department of Neurology, Division of Cognitive Neuroscience Johns Hopkins University School of Medicine 1620 McElderry Street Baltimore, MD, 21205
| | - Argye E Hillis
- Department of Neurology Johns Hopkins University School of Medicine 600 North Wolfe Street Baltimore, MD 21287 (410) 614-2381
| |
Collapse
|
42
|
Nagenthiraja K, Walcott BP, Hansen MB, Ostergaard L, Mouridsen K. Automated decision-support system for prediction of treatment responders in acute ischemic stroke. Front Neurol 2013; 4:140. [PMID: 24133479 PMCID: PMC3783931 DOI: 10.3389/fneur.2013.00140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 09/07/2013] [Indexed: 11/23/2022] Open
Abstract
MRI is widely used in the assessment of acute ischemic stroke. In particular, it identifies the mismatch between hypoperfused and the permanently damaged tissue, the PWI-DWI mismatch volume. It is used to help triage patients into active or supportive treatment pathways. COMBAT Stroke is an automated software tool for estimating the mismatch volume and ratio based on MRI. Herein, we validate the decision made by the software with actual clinical decision rendered. Furthermore, we evaluate the association between treatment decisions (both automated and actual) and outcomes. COMBAT Stroke was used to determine PWI-DWI mismatch volume and ratio in 228 patients from two European multi-center stroke databases. We performed confusion matrix analysis to summarize the agreement between the automated selection and the clinical decision. Finally, we evaluated the clinical and imaging outcomes of the patients in the four entries of the confusion matrix (true positive, true negative, false negative, and false positive). About 186 of 228 patients with acute stroke underwent thrombolytic treatment, with the remaining 42 receiving supportive treatment only. Selection based on radiographic criteria using COMBAT Stroke classified 142 patients as potential candidates for thrombolytic treatment and 86 for supportive treatment; 60% sensitivity and 29% specificity. The patients deemed eligible for thrombolytic treatment by COMBAT Stroke demonstrated significantly higher rates of compromised tissue salvage, less neurological deficit, and were more likely to experience thrombus dissolving and reestablishment of normal blood flow at 24 h follow-up compared to those who were treated without substantial PWI-DWI mismatch. These results provide evidence that COMBAT Stroke, in addition to clinical assessment, may offer an optimal framework for a fast, efficient, and standardized clinical support tool to select patients for thrombolysis in acute ischemic stroke.
Collapse
Affiliation(s)
- Kartheeban Nagenthiraja
- Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University , Aarhus , Denmark ; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School , Boston, MA , USA
| | | | | | | | | |
Collapse
|
43
|
Forkert ND, Kaesemann P, Treszl A, Siemonsen S, Cheng B, Handels H, Fiehler J, Thomalla G. Comparison of 10 TTP and Tmax estimation techniques for MR perfusion-diffusion mismatch quantification in acute stroke. AJNR Am J Neuroradiol 2013; 34:1697-703. [PMID: 23538410 DOI: 10.3174/ajnr.a3460] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The mismatch between lesions identified in perfusion- and diffusion-weighted MR imaging is typically used to identify tissue at risk of infarction in acute stroke. The purpose of this study was to analyze the variability of mismatch volumes resulting from different time-to-peak or time-to-maximum estimation techniques used for hypoperfused tissue definition. MATERIALS AND METHODS Data of 50 patients with middle cerebral artery stroke and intracranial vessel occlusion imaged within 6 hours of symptom onset were analyzed. Therefore, 10 different TTP/Tmax techniques and delay thresholds between +2 and +12 seconds were used for calculation of perfusion lesions. Diffusion lesions were semiautomatically segmented and used for mismatch quantification after registration. RESULTS Mean volumetric differences up to 40 and 100 mL in individual patients were found between the mismatch volumes calculated by the 10 TTP/Tmax estimation techniques for typically used delay thresholds. The application of typical criteria for the identification of patients with a clinically relevant mismatch volume resulted in different mismatch classifications in ≤24% of all cases, depending on the TTP/Tmax estimation method used. CONCLUSIONS High variations of tissue-at-risk volumes have to be expected when using different TTP/Tmax estimation techniques. An adaption of different techniques by using correction formulas may enable more comparable study results until a standard has been established by agreement.
Collapse
|
44
|
Shinoyama M, Nakagawara J, Yoneda H, Suzuki M, Ono H, Kunitsugu I, Kamiyama K, Osato T, Nakamura H. Initial 'TTP Map-Defect' of Computed Tomography Perfusion as a Predictor of Hemorrhagic Transformation of Acute Ischemic Stroke. Cerebrovasc Dis Extra 2013; 3:14-25. [PMID: 23637697 PMCID: PMC3617882 DOI: 10.1159/000346113] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Hemorrhagic transformation (HT) following acute ischemic stroke is a major problem, especially for the indication of reperfusion therapy including intravenous administration of recombinant tissue plasminogen activator (IV rt-PA). The specific predictive factors of HT have not yet been established. The present study evaluated the findings of computed tomography perfusion (CTP) images as predictors of subsequent HT to identify patients with low HT risk for reperfusion therapy such as IV rt-PA. Methods We retrospectively reviewed 68 consecutive stroke patients (41 males; mean age 72.9 years) with steno-occlusive lesions in the major trunk, including 10 patients who underwent IV rt-PA. Each HT was detected on a follow-up T2*-weighted magnetic resonance image until 2 weeks after stroke onset and categorized into four groups [hemorrhagic infarction (HI) type 1 and 2, and parenchymal hematoma (PH) type 1 and 2] according to the European Cooperative Acute Stroke Study (ECASS) classification. We assessed clinical features and radiological findings between the HT and non-HT groups or the PH2 and non-PH2 groups. The efficacy of initial time to peak (TTP) mapping of CTP for predicting HT or PH2 was evaluated. Results Thirty-four patients (50%) developed subsequent HT: 18 (52.9%) had HI and 16 (47.1%) had PH, including 9 PH2 patients (13.2%). IV rt-PA was not significantly associated with HT or PH2 occurrence. Forty of the 68 patients (59%) revealed defect areas on the initial TTP mapping (TTP map-defect), and 34 of these 40 patients (85%) developed secondary HT and 9 patients (22.5%) developed PH2. Initial ‘TTP map-defect’ was significantly associated with the occurrence of HT (p < 0.0001) and PH2 (p = 0.0070). Thirty of the 34 patients (88.2%) in the HT group experienced delayed recanalization of the occluded vessels, in contrast to only 8 of the 34 patients (23.6%) in the non-HT group. All patients of the PH2 group showed recanalization (p = 0.0042). In 40 ‘TTP map-defect’-positive patients, delayed recanalization was associated with the occurrence of HT (p < 0.0001) and PH2 (p = 0.0491). All 28 patients without ‘TTP map-defect’ did not develop HT, including 8 patients (28.6%) with delayed recanalization. Conclusions Initial ‘TTP map-defect’ of CTP could accurately predict HT risk including PH2 risk and identify low-risk patients even in the delayed period.
Collapse
Affiliation(s)
- Mizuya Shinoyama
- Department of Neurosurgery, Nakamura Memorial Hospital, Sapporo, Japan ; Department of Neurosurgery, Yamaguchi University School of Medicine, Yamaguchi, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Oldag A, Goertler M, Bertz AK, Schreiber S, Stoppel C, Heinze HJ, Kopitzki K. Assessment of cortical hemodynamics by multichannel near-infrared spectroscopy in steno-occlusive disease of the middle cerebral artery. Stroke 2013; 43:2980-5. [PMID: 23091122 DOI: 10.1161/strokeaha.112.656710] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE In a pilot study we evaluated near-infrared spectroscopy as to its potential benefit in monitoring patients with steno-occlusive disease of a major cerebral artery for alterations in cortical hemodynamics. METHODS Cortical maps of time-to-peak (TTP) in 10 patients unilaterally affected by severe stenosis or occlusion of the middle cerebral artery were acquired by multichannel near-infrared spectroscopy after bolus application of indocyanine green. Hemodynamic manifestations were assessed by comparison between affected and unaffected hemisphere and evaluated for common constituents by principal component analysis. In one patient, TTP values were compared with those obtained by dynamic susceptibility contrast imaging. RESULTS TTP was increased on the affected hemisphere in 9 patients. Mean difference in TTP between hemispheres was 0.44 second (P<0.05) as compared with a mean lateral difference of 0.12 second found in a control group of 10 individuals. In group analysis a significant rise in TTP was found in the distribution of the affected middle cerebral artery, whereas principal component analysis suggests augmentation of hemodynamic effects toward the border zones as a dominant pattern. A linear correlation of 0.61 between TTP values determined by dynamic susceptibility contrast MRI and near-infrared spectroscopy was found to be statistically significant (P<0.001). CONCLUSIONS Multichannel near-infrared spectroscopy might facilitate detection of disease-related hemodynamic changes as yet only accessible by tomographic imaging modalities. Being indicative for hypoperfusion and collateral flow increased values of TTP, as found to a varying extent in the present patient group, might be of clinical relevance.
Collapse
Affiliation(s)
- Andreas Oldag
- Department of Neurology, Otto-von-Guericke University, Madgeburg, Germany
| | | | | | | | | | | | | |
Collapse
|
46
|
Abstract
PET and MRI provide complementary information in the study of the human brain. Simultaneous PET/MRI data acquisition allows the spatial and temporal correlation of the measured signals, creating opportunities impossible to realize using stand-alone instruments. This paper reviews the methodologic improvements and potential neurologic and psychiatric applications of this novel technology. We first present methods for improving the performance and information content of each modality by using the information provided by the other technique. On the PET side, we discuss methods that use the simultaneously acquired MRI data to improve the PET data quantification. On the MRI side, we present how improved PET quantification can be used to validate several MRI techniques. Finally, we describe promising research, translational, and clinical applications that can benefit from these advanced tools.
Collapse
Affiliation(s)
- Ciprian Catana
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
| | | | | | | |
Collapse
|
47
|
Hakimelahi R, Yoo AJ, He J, Schwamm LH, Lev MH, Schaefer PW, González RG. Rapid identification of a major diffusion/perfusion mismatch in distal internal carotid artery or middle cerebral artery ischemic stroke. BMC Neurol 2012; 12:132. [PMID: 23121836 PMCID: PMC3519648 DOI: 10.1186/1471-2377-12-132] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 10/25/2012] [Indexed: 11/10/2022] Open
Abstract
Background We tested the hypothesis that in patients with occlusion of the terminal internal carotid artery and/or the proximal middle cerebral artery, a diffusion abnormality of 70 ml or less is accompanied by a diffusion/perfusion mismatch of at least 100%. Methods Sixty-eight consecutive patients with terminal ICA and/or proximal MCA occlusions and who underwent diffusion/perfusion MRI within 24 hours of stroke onset were retrospectively identified. DWI and mean transit time (MTT) volumes were measured. Prospectively, 48 consecutive patients were identified with the same inclusion criteria. DWI and time to peak (TTP) lesion volumes were measured. A large mismatch volume was defined as an MTT or TTP abnormality at least twice the DWI lesion volume. Results In the retrospective study, 49 of 68 patients had a DWI lesion volume ≤ 70 ml (mean 20.2 ml; SEM 2.9 ml). A DWI/MTT mismatch of > 100% was observed in all 49 patients (P < .0001). In the prospective study, there were 35/48 patients with DWI volumes ≤ 70 ml (mean 18.7 ml; SEM 3.0 ml). A mismatch > 100% was present in all 35 (P < .0001). Conclusions Acute stroke patients with major anterior circulation artery occlusion are exceedingly likely to have a major diffusion/perfusion mismatch if the diffusion lesion volume is 70 ml or less. This suggests that physiology-based patient assessments may be made using only vessel imaging and diffusion MRI as a simple alternative to perfusion imaging.
Collapse
Affiliation(s)
- Reza Hakimelahi
- Neuroradiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | | | | | | | | | | | | |
Collapse
|
48
|
Drier A, Tourdias T, Attal Y, Sibon I, Mutlu G, Lehéricy S, Samson Y, Chiras J, Dormont D, Orgogozo JM, Dousset V, Rosso C. Prediction of subacute infarct size in acute middle cerebral artery stroke: comparison of perfusion-weighted imaging and apparent diffusion coefficient maps. Radiology 2012; 265:511-7. [PMID: 22923715 DOI: 10.1148/radiol.12112430] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare perfusion-weighted (PW) imaging and apparent diffusion coefficient (ADC) maps in prediction of infarct size and growth in patients with acute middle cerebral artery infarct. MATERIALS AND METHODS This study was approved by the local institutional review board. Written informed consent was obtained from all 80 patients. Subsequent infarct volume and growth on follow-up magnetic resonance (MR) images obtained within 6 days were compared with the predictions based on PW images by using a time-to-peak threshold greater than 4 seconds and ADC maps obtained less than 12 hours after middle cerebral artery infarct. ADC- and PW imaging-predicted infarct growth areas and infarct volumes were correlated with subsequent infarct growth and follow-up diffusion-weighted (DW) imaging volumes. The impact of MR imaging time delay on the correlation coefficient between the predicted and subsequent infarct volumes and individual predictions of infarct growth by using receiver operating characteristic curves were assessed. RESULTS The infarct volume measurements were highly reproducible (concordance correlation coefficient [CCC] of 0.965 and 95% confidence interval [CI]: 0.949, 0.976 for acute DW imaging; CCC of 0.995 and 95% CI: 0.993, 0.997 for subacute DW imaging). The subsequent infarct volume correlated (P<.0001) with ADC- (ρ=0.853) and PW imaging- (ρ=0.669) predicted volumes. The correlation was higher for ADC-predicted volume than for PW imaging-predicted volume (P<.005), but not when the analysis was restricted to patients without recanalization (P=.07). The infarct growth correlated (P<.0001) with PW imaging-DW imaging mismatch (ρ=0.470) and ADC-DW imaging mismatch (ρ=0.438), without significant differences between both methods (P=.71). The correlations were similar among time delays with ADC-predicted volumes but decreased with PW imaging-based volumes beyond the therapeutic window. Accuracies of ADC- and PW imaging-based predictions of infarct growth in an individual prediction were similar (area under the receiver operating characteristic curve [AUC] of 0.698 and 95% CI: 0.585, 0.796 vs AUC of 0.749 and 95% CI: 0.640, 0.839; P=.48). CONCLUSION The ADC-based method was as accurate as the PW imaging-based method for evaluating infarct growth and size in the subacute phase.
Collapse
Affiliation(s)
- Aurélie Drier
- AP-HP Service de Neuroradiologie and AP-HP Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Cheng B, Rosenkranz M, Krützelmann A, Fiehler J, Forkert ND, Gerloff C, Thomalla G. The extent of perfusion deficit does not relate to the visibility of acute ischemic lesions on fluid-attenuated inversion recovery imaging. J Neuroimaging 2012; 23:215-8. [PMID: 22818219 DOI: 10.1111/j.1552-6569.2012.00708.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Fluid-attenuated inversion recovery imaging (FLAIR) has been suggested as a surrogate marker of lesion age in acute ischemic stroke. In a subgroup analysis, we evaluated whether the extent of perfusion deficit influences FLAIR lesion visibility and thus plays a role as a confounding variable in the interpretation of FLAIR images. METHODS A subgroup of patients from a previous study evaluating the use of FLAIR imaging as a surrogate marker of lesion age within the first 6 hours of ischemic stroke were examined to determine the influence of the amount of perfusion deficit on FLAIR lesion visibility. RESULTS N = 48 patients were included into the analysis. In positive and negative FLAIR lesion cases the extent of perfusion deficits did not differ significantly (150 mL vs. 197 mL, P = .730) nor influenced FLAIR visibility independently. In contrast, diffusion weighted imaging (DWI) lesion volumes were larger (34 mL vs. 14 mL, P = .008) and time from symptom onset longer (180 vs. 120 minute, P = .071) in FLAIR-positive cases. CONCLUSION Visibility of FLAIR lesions in acute stroke imaging is influenced by lesion size and time from symptom onset to MRI, but not by the amount of perfusion deficit calculated by time-to-peak (TTP) measurements.
Collapse
Affiliation(s)
- Bastian Cheng
- Klinik und Poliklinik für Neurologie, Kopf- und Neurozentrum, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
In ischemic stroke, positron-emission tomography (PET) established the imaging-based concept of penumbra. It defines hypoperfused, but functionally impaired, tissue with preserved viability that can be rescued by timely reperfusion. Diffusion-weighted and perfusion-weighted (PW) magnetic resonance imaging (MRI) translated the concept of penumbra to the concept of mismatch. However, the use of mismatch-based patient stratification for reperfusion therapy remains a matter of debate. The equivalence of mismatch and penumbra, as well as the validity of the classical mismatch concept is questioned for several reasons. First, methodological differences between PET and MRI lead to different definitions of the tissue at risk. Second, the mismatch concept is still poorly standardized among imaging facilities causing relevant variability in stroke research. Third, relevant conceptual issues (e.g., the choice of the adequate perfusion measure, the best quantitative approach to perfusion maps, and the required size of the mismatch) need further refinement. Fourth, the use of single thresholds does not account for the physiological heterogeneity of the penumbra and probabilistic approaches may be more promising. The implementation of this current knowledge into an optimized state-of-the-art mismatch model and its validation in clinical stroke studies remains a major challenge for future stroke research.
Collapse
Affiliation(s)
- Jan Sobesky
- Department of Neurology and Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin, Berlin, Germany.
| |
Collapse
|