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Suzuki K, Liebeskind DS, Nishi Y, Kutsuna A, Katano T, Sakamoto Y, Saito T, Aoki J, Matsumoto N, Nishiyama Y, Kimura K. A differential detailed diffusion-weighted imaging-ASPECTS for cerebral infarct volume measurement and outcome prediction. Int J Stroke 2023; 18:1202-1208. [PMID: 37332178 DOI: 10.1177/17474930231185468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
BACKGROUND Diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) has been used to estimate infarct core volume in acute stroke. However, the same and indiscriminate score deduction for punctate or confluent DWI high-intensity lesion might lead to variation in performance. AIMS To develop and evaluate a differential detailed DWI-ASPECTS method in comparison with the conventional DWI-ASPECTS in core infarct volume measurement and clinical outcome prediction. METHODS We retrospectively recruited patients with acute ischemic stroke (AIS) treated with endovascular treatment between April 2013 and October 2019. In differential detailed DWI-ASPECTS, restricted diffusion lesion that was punctate or less than half of a cortical region (M1-M6) would not lead to subtraction of point. A favorable outcome was modified Rankin Scale score ⩽2 at 90 days after stroke onset. RESULTS Among 298 AIS patients, mean age was 75 years (interquartile range (IQR) 67-82), and 194 patients (65%) were males. Mean infarct core volume was 11 mL (IQR 3-37). Overall, the score by detailed DWI-ASPECTS was significantly higher than conventional DWI-ASPECTS (8 (7-9) vs. 7 (5-9); P < 0.01). The detailed DWI-ASPECTS resulted in a higher correlation coefficient (r) for core infarct volume estimation than the conventional DWI-ASPECTS (r = 0.832 vs. 0.773; P < 0.01). Upon re-classification of those scored ⩽6 in conventional DWI-ASPECTS (n = 134) by detailed DWI-ASPECTS, the rate of favorable outcome in patients with detailed DWI-ASPECTS >6 was significantly higher than those with ⩽6 (29 (48%) vs. 14 (19%); P < 0.01). CONCLUSIONS Detailed DWI-ASPECTS appeared to provide a more accurate infarct core volume measurement and clinical outcome correlation than conventional DWI-ASPECTS among AIS patients treated with endovascular therapy.
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Affiliation(s)
- Kentaro Suzuki
- Department of Neurology, Nippon Medical School, Tokyo, Japan
- Department of Neurology and UCLA Stroke Center, University of California, Los Angeles, CA, USA
| | - David S Liebeskind
- Department of Neurology and UCLA Stroke Center, University of California, Los Angeles, CA, USA
| | - Yuji Nishi
- Department of Neurology, Nippon Medical School, Tokyo, Japan
| | - Akihito Kutsuna
- Department of Neurology, Nippon Medical School, Tokyo, Japan
| | - Takehiro Katano
- Department of Neurology, Nippon Medical School, Tokyo, Japan
| | - Yuki Sakamoto
- Department of Neurology, Nippon Medical School, Tokyo, Japan
| | - Tomonari Saito
- Department of Neurology, Nippon Medical School, Tokyo, Japan
| | - Junya Aoki
- Department of Neurology, Nippon Medical School, Tokyo, Japan
| | | | | | - Kazumi Kimura
- Department of Neurology, Nippon Medical School, Tokyo, Japan
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Nukovic JJ, Opancina V, Ciceri E, Muto M, Zdravkovic N, Altin A, Altaysoy P, Kastelic R, Velazquez Mendivil DM, Nukovic JA, Markovic NV, Opancina M, Prodanovic T, Nukovic M, Kostic J, Prodanovic N. Neuroimaging Modalities Used for Ischemic Stroke Diagnosis and Monitoring. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1908. [PMID: 38003957 PMCID: PMC10673396 DOI: 10.3390/medicina59111908] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/16/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023]
Abstract
Strokes are one of the global leading causes of physical or mental impairment and fatality, classified into hemorrhagic and ischemic strokes. Ischemic strokes happen when a thrombus blocks or plugs an artery and interrupts or reduces blood supply to the brain tissue. Deciding on the imaging modality which will be used for stroke detection depends on the expertise and availability of staff and the infrastructure of hospitals. Magnetic resonance imaging provides valuable information, and its sensitivity for smaller infarcts is greater, while computed tomography is more extensively used, since it can promptly exclude acute cerebral hemorrhages and is more favorable speed-wise. The aim of this article was to give information about the neuroimaging modalities used for the diagnosis and monitoring of ischemic strokes. We reviewed the available literature and presented the use of computed tomography, CT angiography, CT perfusion, magnetic resonance imaging, MR angiography and MR perfusion for the detection of ischemic strokes and their monitoring in different phases of stroke development.
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Affiliation(s)
- Jasmin J. Nukovic
- Faculty of Pharmacy and Health Travnik, University of Travnik, 72270 Travnik, Bosnia and Herzegovina
- Department of Radiology, General Hospital Novi Pazar, 36300 Novi Pazar, Serbia
| | - Valentina Opancina
- Department of Radiology, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
- Diagnostic Imaging and Interventional Neuroradiology Unit, Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
- Diagnostic and Interventional Neuroradiology Unit, A.O.R.N. Cardarelli, 80131 Naples, Italy
| | - Elisa Ciceri
- Diagnostic Imaging and Interventional Neuroradiology Unit, Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Mario Muto
- Diagnostic and Interventional Neuroradiology Unit, A.O.R.N. Cardarelli, 80131 Naples, Italy
| | - Nebojsa Zdravkovic
- Department of Biomedical Statistics and Informatics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Ahmet Altin
- Faculty of Medicine, Dokuz Eylul University, Izmir 35340, Turkey
| | - Pelin Altaysoy
- Faculty of Medicine, Bahcesehir University, Istanbul 34349, Turkey
| | - Rebeka Kastelic
- Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | | | - Jusuf A. Nukovic
- Faculty of Pharmacy and Health Travnik, University of Travnik, 72270 Travnik, Bosnia and Herzegovina
- Department of Radiology, General Hospital Novi Pazar, 36300 Novi Pazar, Serbia
| | - Nenad V. Markovic
- Department of Surgery, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Miljan Opancina
- Department of Biomedical Statistics and Informatics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
- Military Medical Academy, Faculty of Medicine, University of Defense, 11000 Belgrade, Serbia
| | - Tijana Prodanovic
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Merisa Nukovic
- Department of Radiology, General Hospital Novi Pazar, 36300 Novi Pazar, Serbia
| | - Jelena Kostic
- Department of Radiology, Medical Faculty, University of Belgrade, 11120 Beograd, Serbia
| | - Nikola Prodanovic
- Department of Surgery, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
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3
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Shulman JG, Abdalkader M. Imaging of Central Nervous System Ischemia. Continuum (Minneap Minn) 2023; 29:54-72. [PMID: 36795873 DOI: 10.1212/con.0000000000001185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVE This article describes imaging modalities used in the evaluation of patients presenting with symptoms of acute ischemic stroke. LATEST DEVELOPMENTS The year 2015 marked the beginning of a new era in acute stroke care with the widespread adoption of mechanical thrombectomy. Subsequent randomized controlled trials in 2017 and 2018 brought the stroke community even further into this new territory with the expansion of the eligibility window for thrombectomy using imaging-based patient selection, which led to an increase in the use of perfusion imaging. Now, after several years of routine use, the debate is ongoing as to when this additional imaging is truly required and when it results in unnecessary delays in time-sensitive stroke care. At this time, more than ever, a robust understanding of neuroimaging techniques, applications, and interpretation is essential for the practicing neurologist. ESSENTIAL POINTS CT-based imaging is the first step in most centers for the evaluation of patients presenting with symptoms of acute stroke because of its wide availability, speed, and safety. Noncontrast head CT alone is sufficient for IV thrombolysis decision making. CT angiography is very sensitive for the detection of large-vessel occlusion and can be used reliably to make this determination. Advanced imaging including multiphase CT angiography, CT perfusion, MRI, and MR perfusion can provide additional information useful for therapeutic decision making in specific clinical scenarios. In all cases, it is essential that neuroimaging be performed and interpreted rapidly to allow for timely reperfusion therapy.
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Fully automatic identification of post-treatment infarct lesions after endovascular therapy based on non-contrast computed tomography. Neural Comput Appl 2022. [DOI: 10.1007/s00521-022-08094-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Gollamudi J, Sartain SE, Navaei AH, Aneja S, Kaur Dhawan P, Tran D, Joshi J, Gidudu J, Gollamudi J, Chiappini E, Varricchio F, Law B, Munoz FM. Thrombosis and thromboembolism: Brighton collaboration case definition and guidelines for data collection, analysis, and presentation of immunization safety data. Vaccine 2022; 40:6431-6444. [PMID: 36150973 DOI: 10.1016/j.vaccine.2022.09.001] [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: 08/10/2022] [Accepted: 09/01/2022] [Indexed: 01/27/2023]
Abstract
This is a Brighton Collaboration case definition of thrombosis and thromboembolism to be used in the evaluation of adverse events following immunization, and for epidemiologic studies for the assessment of background incidence or hypothesis testing. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of SARS-CoV-2 vaccines. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected expert reviewers prior to submission.
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Affiliation(s)
- Jahnavi Gollamudi
- Department of Medicine, Section of Hematology, Baylor College of Medicine, Houston, TX, USA
| | - Sarah E Sartain
- Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, Houston, TX, USA
| | - Amir Hassan Navaei
- Pediatric Critical Care, Transfusion Medicine & Coagulation, Pediatrics and Pathology & Immunology Departments, Texas Children's Hospital, Baylor College of Medicine, 6701 Fannin St, Suite WB110, Houston 77021, TX, USA
| | - Satinder Aneja
- Department of Pediatrics, School of Medical Sciences & Research, Sharda University, Gr Noida, India
| | | | - Dat Tran
- Oregon Health Authority, Public Health Division, Acute and Communicable Disease Prevention Section, Portland, OR, USA
| | - Jyoti Joshi
- International Centre for Antimicrobial Resistance Solutions (ICARS), Orestads Boulevard 5, 2300 Copenhagen, Denmark
| | - Jane Gidudu
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Elena Chiappini
- Meyer University Hospital, Department of Health Science, University of Florence, Florence, Italy
| | | | - Barbara Law
- SPEAC, Brighton Collaboration, Independent Consultant, Vancouver, BC, Canada
| | - Flor M Munoz
- Department of Pediatrics, Section of Infectious Diseases, and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
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Dzialowski I, Puetz V, Parsons M, Bivard A, von Kummer R. Computed Tomography-Based Evaluation of Cerebrovascular Disease. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00047-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Hong JH, Jeon I, Seo Y, Kim SH, Yu D. Radiographic predictors of clinical outcome in traumatic brain injury after decompressive craniectomy. Acta Neurochir (Wien) 2021; 163:1371-1381. [PMID: 33404876 DOI: 10.1007/s00701-020-04679-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/11/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Primary decompressive craniectomy (DC) is considered for traumatic brain injury (TBI) patients with clinical deterioration, presenting large amounts of high-density lesions on computed tomography (CT). Postoperative CT findings may be suitable for prognostic evaluation. This study evaluated the radiographic predictors of clinical outcome and survival using pre- and postoperative CT scans of such patients. METHODS We enrolled 150 patients with moderate to severe TBI who underwent primary DC. They were divided into two groups based on the 6-month postoperative Glasgow Outcome Scale Extended scores (1-4, unfavorable; 5-8, favorable). Radiographic parameters, including hemorrhage type, location, presence of skull fracture, midline shifting, hemispheric diameter, effacement of cisterns, parenchymal hypodensity, and craniectomy size, were reviewed. Stepwise logistic regression analysis was used to identify the prognostic factors of clinical outcome and 6-month mortality. RESULTS Multivariable logistic regression analysis revealed that age (odds ratio [OR] = 1.09; 95% confidence interval [CI] 1.032-1.151; p = 0.002), postoperative low density (OR = 12.58; 95% CI 1.247-126.829; p = 0.032), and postoperative effacement of the ambient cistern (OR = 14.52; 95% CI 2.234-94.351; p = 0.005) and the crural cistern (OR = 4.90; 95% CI 1.359-17.678; p = 0.015) were associated with unfavorable outcomes. Postoperative effacement of the crural cistern was the strongest predictor of 6-month mortality (OR = 8.93; 95% CI 2.747-29.054; p = 0.000). CONCLUSIONS Hemispheric hypodensity and effacement of the crural and ambient cisterns on postoperative CT after primary DC seems to associate with poor outcome in patients with TBI.
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Affiliation(s)
- Jung Ho Hong
- Department of Neurosurgery, Yeungnam University Hospital, Yeungnam University College of Medicine, 170, Hyeonchung street, Nam-Gu, Daegu, 42415, South Korea
| | - Ikchan Jeon
- Department of Neurosurgery, Yeungnam University Hospital, Yeungnam University College of Medicine, 170, Hyeonchung street, Nam-Gu, Daegu, 42415, South Korea
| | - Youngbeom Seo
- Department of Neurosurgery, Yeungnam University Hospital, Yeungnam University College of Medicine, 170, Hyeonchung street, Nam-Gu, Daegu, 42415, South Korea
| | - Seong Ho Kim
- Department of Neurosurgery, Yeungnam University Hospital, Yeungnam University College of Medicine, 170, Hyeonchung street, Nam-Gu, Daegu, 42415, South Korea
| | - Dongwoo Yu
- Department of Neurosurgery, Yeungnam University Hospital, Yeungnam University College of Medicine, 170, Hyeonchung street, Nam-Gu, Daegu, 42415, South Korea.
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8
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You J, Yu PLH, Tsang ACO, Tsui ELH, Woo PPS, Lui CSM, Leung GKK, Mahboobani N, Chu CY, Chong WH, Poon WL. 3D dissimilar-siamese-u-net for hyperdense Middle cerebral artery sign segmentation. Comput Med Imaging Graph 2021; 90:101898. [PMID: 33857830 DOI: 10.1016/j.compmedimag.2021.101898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 03/03/2021] [Accepted: 03/06/2021] [Indexed: 11/16/2022]
Abstract
The hyperdense middle cerebral artery sign (HMCAS) representing a thromboembolus has been declared as a vital CT finding for intravascular thrombus in the diagnosis of acute ischemia stroke. Early recognition of HMCAS can assist in patient triage and subsequent thrombolysis or thrombectomy treatment. A total of 624 annotated head non-contrast-enhanced CT (NCCT) image scans were retrospectively collected from multiple public hospitals in Hong Kong. In this study, we present a deep Dissimilar-Siamese-U-Net (DSU-Net) that is able to precisely segment the lesions by integrating Siamese and U-Net architectures. The proposed framework consists of twin sub-networks that allow inputs of left and right hemispheres in head NCCT images separately. The proposed Dissimilar block fully explores the feature representation of the differences between the bilateral hemispheres. Ablation studies were carried out to validate the performance of various components of the proposed DSU-Net. Our findings reveal that the proposed DSU-Net provides a novel approach for HMCAS automatic segmentation and it outperforms the baseline U-Net and many state-of-the-art models for clinical practice.
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Affiliation(s)
- Jia You
- Department of Statistics and Actuarial Science, The University of Hong Kong, Run Run Shaw Building, Pokfulam Road, Hong Kong
| | - Philip L H Yu
- Department of Statistics and Actuarial Science, The University of Hong Kong, Run Run Shaw Building, Pokfulam Road, Hong Kong; Department of Mathematics and Information Technology, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, New Territories, Hong Kong.
| | - Anderson C O Tsang
- Division of Neurosurgery, Department of Surgery, The University of Hong Kong, Room 701, Administration Building, Queen Mary Hospital, Pokfulam Road, Hong Kong
| | - Eva L H Tsui
- Department of Statistics and Data Science, Hospital Authority, Hospital Authority Building, 147B Argyle Street, Ma Tau Wai, Hong Kong
| | - Pauline P S Woo
- Department of Statistics and Data Science, Hospital Authority, Hospital Authority Building, 147B Argyle Street, Ma Tau Wai, Hong Kong
| | - Carrie S M Lui
- Department of Statistics and Data Science, Hospital Authority, Hospital Authority Building, 147B Argyle Street, Ma Tau Wai, Hong Kong
| | - Gilberto K K Leung
- Division of Neurosurgery, Department of Surgery, The University of Hong Kong, Room 701, Administration Building, Queen Mary Hospital, Pokfulam Road, Hong Kong
| | - Neeraj Mahboobani
- Department of Radiology and Imaging, Queen Elizabeth Hospital, 30 Gascoigne Road, Hong Kong, Hong Kong
| | - Chi-Yeung Chu
- Department of Radiology, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong
| | - Wing-Ho Chong
- Department of Radiology, Tuen Mun Hospital, 23 Tsing Chung Kong Road, Tuen Mun, Hong Kong
| | - Wai-Lun Poon
- Department of Radiology and Imaging, Queen Elizabeth Hospital, 30 Gascoigne Road, Hong Kong, Hong Kong
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Maresky HS, Rootman JM, Klar MM, Levitt M, Kossar AP, Zucker D, Glazier M, Kalmanovich-Avnery S, Aviv R, Ertl-Wagner B, Tal S. Bringing prevost's sign into the third dimension: Artificial intelligence estimation of conjugate gaze adjusted length (CGAL) and correlation with acute ischemic stroke. Medicine (Baltimore) 2020; 99:e23330. [PMID: 33285711 PMCID: PMC7717852 DOI: 10.1097/md.0000000000023330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Conjugate gaze deviation is associated with acute ischemic stroke (AIS), although previously only measured on a 2D plane. The current study evaluates 3D imaging efficacy to assess conjugate gaze deviation and correlate direction and strength of deviation to neuro-clinical findings.A retrospective analysis of 519 patients who had CT scans for suspected AIS at our institution. Direction and angle of eye deviation were calculated based on 2D axial images. Volumetric reconstruction of CT scans allowed for calculation of 3D conjugate gaze adjusted length (CGAL). Angle, direction, and vector strength of both 2D and 3D scans were calculated by an artificial intelligence algorithm and tested for agreement with hemispheric ischemia location. CGAL measurements were correlated to NIHSS scores. Follow up MRI data was used to evaluate the sensitivity and specificity of CGAL in the identification of AIS.The final analysis included 122 patients. A strong agreement was found between 3D gaze direction and hemispheric ischemia location. CGAL measurements were highly correlated with NIHSS score (r = .72, P = .01). A CGAL >0.25, >0.28, and >0.35 exhibited a sensitivity of 91%, 86%, and 82% and specificity of 66%, 89%, and 89%, respectively, in AIS identification. A CGAL >0.28 has the best sensitivity-specificity balance in the identification of AIS. A CGAL >0.25 has the highest sensitivity.Given CED's correlation with NIHSS score a 1/4 deviation in the ipsilateral direction is a sensitive ancillary radiographic sign to assist radiologists in making a correct diagnosis even when not presented with full clinical data.
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Affiliation(s)
- Hillel S. Maresky
- Department of Radiology, Shamir Medical Center, Zerifin
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- Department of Radiology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennyslvania
| | - Joseph M. Rootman
- Department of Psychology, University of British Columbia, Kelowna, BC, Canada
| | - Miriam M. Klar
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, New York
| | - Max Levitt
- Division of Urology, Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada
| | - Alexander P. Kossar
- Department of Surgery, NewYork-Presbyterian Hospital/Columbia University Irving Medical Center, New York, New York
| | - David Zucker
- Department of Radiology, Shamir Medical Center, Zerifin
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - Michael Glazier
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | | | - Richard Aviv
- Department of Radiology, The Ottawa Hospital and University of Ottawa, Ottawa
| | - Birgit Ertl-Wagner
- Division of Neuroradiology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sigal Tal
- Department of Radiology, Shamir Medical Center, Zerifin
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
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10
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Tao S, Rajendran K, Zhou W, Fletcher JG, McCollough CH, Leng S. Noise reduction in CT image using prior knowledge aware iterative denoising. Phys Med Biol 2020; 65. [PMID: 33065559 DOI: 10.1088/1361-6560/abc231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/16/2020] [Indexed: 11/11/2022]
Abstract
The clinical demand for low image noise often limits the slice thickness used in many CT applications. However, a thick-slice image is more susceptible to longitudinal partial volume effects, which can blur key anatomic structures and pathologies of interest. In this work, we develop a prior-knowledge-aware iterative denoising (PKAID) framework that utilizes spatial data redundancy in the slice increment direction to generate low-noise, thin-slice images, and demonstrate its application in non-contrast head CT exams. The proposed technique takes advantage of the low-noise of thicker images and exploits the structural similarity between the thick- and thin-slice images to reduce noise in the thin-slice image. Phantom data and patient cases (n=3) of head CT were used to assess performance of this method. Images were reconstructed at clinically-utilized slice thickness (5 mm) and thinner slice thickness (2 mm). PKAID was used to reduce image noise in 2 mm images using the 5 mm images as low-noise prior. Noise amplitude, noise power spectra (NPS), modulation transfer function (MTF), and slice sensitivity profiles (SSP) of images before/after denoising were analyzed. The NPS and MTF analysis showed that PKAID preserved noise texture and resolution of the original thin-slice image, while reducing noise to the level of thick-slice image. The SSP analysis showed that the slice thickness of the original thin-slice image was retained. Patient examples demonstrated that PKAID-processed, thin-slice images better delineated brain structures and key pathologies such as subdural hematoma compared to the clinical 5 mm images, while additionally reducing image noise. To test an alternative PKAID utilization for dose reduction, a head exam with 40% dose reduction was simulated using projection-domain noise insertion. The image of 5 mm slice thickness was then denoised using PKAID. The results showed that the PKAID-processed reduced-dose images maintained similar noise and image quality compared to the full-dose images.
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Affiliation(s)
- Shengzhen Tao
- Radiology, Mayo Clinic Minnesota, 200 First St SW, Rochester, Rochester, Minnesota, 55905-0002, UNITED STATES
| | - Kishore Rajendran
- Radiology, Mayo Clinic , 200 First street SW, Rochester, Minnesota, 55905, UNITED STATES
| | - Wei Zhou
- Radiology, University of Colorado Denver, Denver, Colorado, UNITED STATES
| | - Joel G Fletcher
- Radiology, Mayo Clinic , Rochester, Minnesota, UNITED STATES
| | - Cynthia H McCollough
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA, Rochester, Minnesota, UNITED STATES
| | - Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA, Rochester, UNITED STATES
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11
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Özen Olcay H, Çevik Y, Emektar E. Evaluation of Radiological Imaging Findings and Affecting Factors in Patients with Acute Ischemic Stroke. ANKARA MEDICAL JOURNAL 2018. [DOI: 10.17098/amj.497287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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12
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Automated detection of parenchymal changes of ischemic stroke in non-contrast computer tomography: A fuzzy approach. Biomed Signal Process Control 2018. [DOI: 10.1016/j.bspc.2018.05.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Gomolka RS, Chrzan RM, Urbanik A, Kazmierski R, Grzanka AD, Nowinski WL. Quantification of image contrast of infarcts on computed tomography scans. Neuroradiol J 2017; 30:15-22. [PMID: 28059673 DOI: 10.1177/1971400916678226] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Introduction Accurate identification of infarcts in non-contrast computed tomography (NC-CT) scans of the brain is fundamental in the diagnosis and management of patients with stroke. Quantification of image contrast properties at the boundaries of ischemic infarct regions in NC-CT can contribute to a more precise manual or automatic delineation of these regions. Here we explore these properties quantitatively. Methods We retrospectively investigated 519 NC-CT studies of 425 patients with clinically confirmed ischemic strokes. The average and standard deviation (SD) of patients' age was 67.5 ± 12.4 years and the average(median)±SD time from symptoms onset to NC-CT examination was 27.4(12)±35.7 h. For every scan with an ischemic lesion identified by experts, the image contrast of the lesion vs. normal surrounding parenchyma was calculated as a difference of mean Hounsfield Unit (HU) of 1-5 consecutive voxels (the contrast window width) belonging to the lesion and to the parenchyma. This contrast was calculated at each single voxel of ischemic lesion boundaries (previously delineated by the experts) in horizontal and vertical directions in each image. The distributions of obtained horizontal, vertical and both contrasts combined were calculated among all 519 NC-CTs. Results The highest applicative contrast window width was identified as 5 voxels. The ischemic infarcts were found to be characterized by 6.60 HU, 8.28 HU and 7.55 HU mean values for distributions of horizontal, vertical and combined contrasts. Approximately 40-50% of the infarct boundary voxels were found to refer to the image contrast below 5 HU. Conclusion Low image contrast of ischemic lesions prevents accurate delineation of the infarcts in NC-CT.
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Affiliation(s)
- R S Gomolka
- 1 The Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - R M Chrzan
- 2 Department of Radiology, Jagiellonian University, The Cracow University Hospital, Krakow, Poland
| | - A Urbanik
- 2 Department of Radiology, Jagiellonian University, The Cracow University Hospital, Krakow, Poland
| | - R Kazmierski
- 3 Department of Neurology and Cerebrovascular Diseases, Poznan University of Medical Sciences, Poznan, Poland
| | - A D Grzanka
- 1 The Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - W L Nowinski
- 4 John Paul II Center for Virtual Anatomy and Surgical Simulation, Cardinal Stefan Wyszynski, Warsaw, Poland
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Affiliation(s)
| | - N. Tambasco
- Dipartimento di Neurologia, Villa Pini d'Abruzzo; Chieti
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16
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Lövblad KO, Kiefer C, Oswald H, Arnold M, Nedeltchev K, Mattle H, Schroth G. Imaging the Ischemic Penumbra. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/197140090301600534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | | | | | - M. Arnold
- Department of Neurology, Inselspital, Bern; Switzerland
| | - K. Nedeltchev
- Department of Neurology, Inselspital, Bern; Switzerland
| | - H. Mattle
- Department of Neurology, Inselspital, Bern; Switzerland
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17
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Gomolka RS, Chrzan RM, Urbanik A, Nowinski WL. A Quantitative Method Using Head Noncontrast CT Scans to Detect Hyperacute Nonvisible Ischemic Changes in Patients With Stroke. J Neuroimaging 2016; 26:581-587. [PMID: 27238914 DOI: 10.1111/jon.12363] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 04/20/2016] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Because clinical evaluation of noncontrast computed tomography (CT) has a poor sensitivity in the evaluation of acute ischemic stroke, computer-aided diagnosis may be able to facilitate the performance. Recently, we introduced a computational method for the detection and localization of visible infarcts. Herein, we aimed to evaluate and extend a previous method, the Stroke Imaging Marker (SIM), to localize nonvisible hyperacute ischemia. MATERIALS AND METHODS On the basis of the SIM and its components-the ratio of percentile differences in subranges of Hounsfield Unit (HU) distribution (P-ratio), ratio of voxels count in ranges of brain CT intensity, median HU attenuation value-the infarct localization was performed in 140 early and follow-up scans of 70 patients. In none of the early scans was the infarct visible to a radiologist or an experienced stroke neuroradiologist. The infarcted hemisphere detection rate (HDR) and sensitivity of infarct localization were measured by overlapping the region of detected tissue in the initial scan, with the gold standard set for the fully visible stroke in the follow-up scan. RESULTS The best performance of the algorithm was found for the P-ratio including seven percentile subranges within the range of 35th-75th percentile. The modified SIM provided a 76% ischemic HDR and 54% sensitivity in spatial localization of hyperacute ischemia (68% among properly detected infarct sides). CONCLUSION The improved SIM is a dedicated and potentially useful tool for hyperacute nonvisible brain infarct detection from CT scans and may contribute to reduction of image-to-needle time in patients eligible for revascularization therapy.
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Affiliation(s)
- Ryszard S Gomolka
- Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland. .,Biomedical Imaging Lab, Agency for Science Technology and Research, Singapore.
| | - Robert M Chrzan
- Department of Radiology, Jagiellonian University, The Cracow University Hospital, Kraków, Poland
| | - Andrzej Urbanik
- Department of Radiology, Jagiellonian University, The Cracow University Hospital, Kraków, Poland
| | - Wieslaw L Nowinski
- Department of Radiology, University of Washington, University District Building, Seattle, WA.,John Paul II Center for Virtual Anatomy and Surgical Simulation, Cardinal Stefan Wyszyński University, Warsaw, Poland
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18
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Dzialowski I, Puetz V, Parsons M, von Kummer R. Computed Tomography-based Evaluation of Cerebrovascular Disease. Stroke 2016. [DOI: 10.1016/b978-0-323-29544-4.00047-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Garcia LHC, Ferreira BC. An ABC for decision making. Radiol Bras 2015; 48:101-10. [PMID: 25987751 PMCID: PMC4433301 DOI: 10.1590/0100-3984.2013.1846] [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: 07/01/2013] [Accepted: 02/07/2014] [Indexed: 11/22/2022] Open
Abstract
The present study was aimed at proposing a systematic evaluation of cranial computed tomography, identifying the main aspects to be analyzed in order to facilitate the decision making process regarding diagnosis and management in emergency settings. The present descriptive study comprised a literature review at the following databases: Access Medicine and Access Emergency Medicine (McGraw- Hill Education); British Medical Journal Evidence Center; UptoDate; Bireme; PubMed; Lilacs; SciELO; ProQuest; Micromedex (Thomson Reuters); Embase. Once the literature review was completed, the authors identified the main diseases with tomographic repercussions and proposed the present system to evaluate cranial computed tomography images. An easy-to-memorize ABC system will facilitate the decision making in emergency settings, as it covers the main diseases encountered by intensivists and emergency physicians, and provides a sequential guidance about anatomical structures to be investigated as well as their respective alterations.
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Affiliation(s)
- Luiz Henrique Costa Garcia
- General Surgeon, Intensive Medicine Specialist, Associação
de Medicina Intensiva Brasileira (AMIB), and Irmandade da Santa Casa de
Misericórdia de São Paulo, São Paulo, SP, Brazil
| | - Bruna Cortez Ferreira
- MD, Resident of Medical Practice at Hospital de Base de São
José do Rio Preto, São José do Rio Preto, SP, Brazil
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20
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Novotná J, Kadlecová P, Czlonkowska A, Brozman M, Švigelj V, Csiba L, Kõrv J, Demarin V, Vilionskis A, Mikulík R. Hyperdense cerebral artery computed tomography sign is associated with stroke severity rather than stroke subtype. J Stroke Cerebrovasc Dis 2014; 23:2533-2539. [PMID: 25267589 DOI: 10.1016/j.jstrokecerebrovasdis.2014.04.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 02/09/2014] [Accepted: 04/28/2014] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The hyperdense cerebral artery sign (HCAS) on unenhanced computed tomography (CT) in acute ischemic stroke is a valuable clinical marker, but it remains unclear if HCAS reflects clot composition or stroke etiology. Therefore, variables independently associated with HCAS were identified from a large international data set of patients treated with intravenous thrombolysis. METHODS All stroke patients undergoing intravenous thrombolysis from the Safe Implementation of Treatments in Stroke-EAST (SITS-EAST) database between February 2003 and December 2011 were analyzed. A general estimating equation model accounting for within-center clustering was used to identify factors independently associated with HCAS. RESULTS Of all 8878 consecutive patients, 8375 patients (94%) with available information about HCAS were included in our analysis. CT revealed HCAS in 19% of patients. Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 12, mean age was 67 ± 12 years, and 3592 (43%) patients were females. HCAS was independently associated with baseline NIHSS (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.10-1.12), vessel occlusion (OR, 5.02; 95% CI, 3.31-7.63), early ischemic CT changes (OR, 1.63; 95% CI, 1.31-2.04), year (OR, 1.07; 95% CI, 1.02-1.12), and age (10-year increments; OR, .90; 95% CI, .84-.96). Cardioembolic stroke was not associated with HCAS independently of baseline NIHSS. In different centers, HCAS was reported in 0%-50% of patients. CONCLUSIONS This study illustrates significant variation in detection of HCAS among stroke centers in routine clinical practice. Accounting for within-center data clustering, stroke subtype was not independently associated with HCAS; HCAS was associated with the severity of neurologic deficit.
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Affiliation(s)
- Jana Novotná
- International Clinical Research Center, Department of Neurology, St. Anne's Hospital, Brno, Czech Republic; Masaryk University, Brno, Czech Republic.
| | - Pavla Kadlecová
- International Clinical Research Center, St. Anne's Hospital, Brno, Czech Republic
| | - Anna Czlonkowska
- Second Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland; Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Warsaw, Poland
| | - Miroslav Brozman
- Department of Neurology, Faculty Hospital Nitra and Constantine the Philosopher University Nitra, Nitra, Slovakia
| | - Viktor Švigelj
- Department of Vascular Neurology and Neurological Intensive Care, University Medical Centre Ljubljana and Zdravstveni Nasveti, Ljubljana, Slovenia
| | - Laszlo Csiba
- Department of Neurology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Janika Kõrv
- Department of Neurology and Neurosurgery, University of Tartu, Tartu, Estonia
| | - Vida Demarin
- Department of Neurology, Sestre Milosrdnice University Hospital Center, Zagreb, Croatia
| | - Aleksandras Vilionskis
- Department of Neurology and Neurosurgery, Vilnius University and Republican Vilnius University Hospital, Vilnius, Lithuania
| | - Robert Mikulík
- International Clinical Research Center, Department of Neurology, St. Anne's Hospital, Brno, Czech Republic
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21
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Abstract
BACKGROUND Most strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and improve recovery after stroke in some people. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in selected patients within 4.5 hours of stroke in Europe and within three hours in the USA. There is an upper age limit of 80 years in some countries, and a limitation to mainly non-severe stroke in others. Forty per cent more data are available since this review was last updated in 2009. OBJECTIVES To determine whether, and in what circumstances, thrombolytic therapy might be an effective and safe treatment for acute ischaemic stroke. SEARCH METHODS We searched the Cochrane Stroke Group Trials Register (last searched November 2013), MEDLINE (1966 to November 2013) and EMBASE (1980 to November 2013). We also handsearched conference proceedings and journals, searched reference lists and contacted pharmaceutical companies and trialists. SELECTION CRITERIA Randomised trials of any thrombolytic agent compared with control in people with definite ischaemic stroke. DATA COLLECTION AND ANALYSIS Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We verified the extracted data with investigators of all major trials, obtaining additional unpublished data if available. MAIN RESULTS We included 27 trials, involving 10,187 participants, testing urokinase, streptokinase, rt-PA, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, while the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke. About 44% of the trials (about 70% of the participants) were testing intravenous rt-PA. In earlier studies very few of the participants (0.5%) were aged over 80 years; in this update, 16% of participants are over 80 years of age due to the inclusion of IST-3 (53% of participants in this trial were aged over 80 years). Trials published more recently utilised computerised randomisation, so there are less likely to be baseline imbalances than in previous versions of the review. More than 50% of trials fulfilled criteria for high-grade concealment; there were few losses to follow-up for the main outcomes.Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of participants who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.78 to 0.93). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.75, 95% CI 3.11 to 4.51), early death (OR 1.69, 95% CI 1.44 to 1.98; 13 trials, 7458 participants) and death by three to six months after stroke (OR 1.18, 95% CI 1.06 to 1.30). Early death after thrombolysis was mostly attributable to intracranial haemorrhage. Treatment within three hours of stroke was more effective in reducing death or dependency (OR 0.66, 95% CI 0.56 to 0.79) without any increase in death (OR 0.99, 95% CI 0.82 to 1.21; 11 trials, 2187 participants). There was heterogeneity between the trials. Contemporaneous antithrombotic drugs increased the risk of death. Trials testing rt-PA showed a significant reduction in death or dependency with treatment up to six hours (OR 0.84, 95% CI 0.77 to 0.93, P = 0.0006; 8 trials, 6729 participants) with significant heterogeneity; treatment within three hours was more beneficial (OR 0.65, 95% CI 0.54 to 0.80, P < 0.0001; 6 trials, 1779 participants) without heterogeneity. Participants aged over 80 years benefited equally to those aged under 80 years, particularly if treated within three hours of stroke. AUTHORS' CONCLUSIONS Thrombolytic therapy given up to six hours after stroke reduces the proportion of dead or dependent people. Those treated within the first three hours derive substantially more benefit than with later treatment. This overall benefit was apparent despite an increase in symptomatic intracranial haemorrhage, deaths at seven to 10 days, and deaths at final follow-up (except for trials testing rt-PA, which had no effect on death at final follow-up). Further trials are needed to identify the latest time window, whether people with mild stroke benefit from thrombolysis, to find ways of reducing symptomatic intracranial haemorrhage and deaths, and to identify the environment in which thrombolysis may best be given in routine practice.
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Affiliation(s)
- Joanna M Wardlaw
- University of EdinburghCentre for Clinical Brain SciencesThe Chancellor's Building49 Little France CrescentEdinburghUKEH16 4SB
| | - Veronica Murray
- Danderyd HospitalDepartment of Clinical Sciences, Karolinska InstitutetStockholmSwedenSE‐182 88
| | - Eivind Berge
- Oslo University HospitalDepartment of Internal MedicineOsloNorwayNO‐0407
| | - Gregory J del Zoppo
- University of WashingtonDepartment of Medicine (Division of Hematology), Department of Neurology325 Ninth AvenueBox 359756SeattleWashingtonUSA98104
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22
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Low E, Mathieson SR, Stevenson NJ, Livingstone V, Ryan CA, Bogue CO, Rennie JM, Boylan GB. Early postnatal EEG features of perinatal arterial ischaemic stroke with seizures. PLoS One 2014; 9:e100973. [PMID: 25051161 PMCID: PMC4106759 DOI: 10.1371/journal.pone.0100973] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 06/01/2014] [Indexed: 11/18/2022] Open
Abstract
Background Stroke is the second most common cause of seizures in term neonates and is associated with abnormal long-term neurodevelopmental outcome in some cases. Objective To aid diagnosis earlier in the postnatal period, our aim was to describe the characteristic EEG patterns in term neonates with perinatal arterial ischaemic stroke (PAIS) seizures. Design Retrospective observational study. Patients Neonates >37 weeks born between 2003 and 2011 in two hospitals. Method Continuous multichannel video-EEG was used to analyze the background patterns and characteristics of seizures. Each EEG was assessed for continuity, symmetry, characteristic features and sleep cycling; morphology of electrographic seizures was also examined. Each seizure was categorized as electrographic-only or electroclinical; the percentage of seizure events for each seizure type was also summarized. Results Nine neonates with PAIS seizures and EEG monitoring were identified. While EEG continuity was present in all cases, the background pattern showed suppression over the infarcted side; this was quite marked (>50% amplitude reduction) when the lesion was large. Characteristic unilateral bursts of theta activity with sharp or spike waves intermixed were seen in all cases. Sleep cycling was generally present but was more disturbed over the infarcted side. Seizures demonstrated a characteristic pattern; focal sharp waves/spike-polyspikes were seen at frequency of 1–2 Hz and phase reversal over the central region was common. Electrographic-only seizure events were more frequent compared to electroclinical seizure events (78 vs 22%). Conclusions Focal electrographic and electroclinical seizures with ipsilateral suppression of the background activity and focal sharp waves are strong indicators of PAIS. Approximately 80% of seizure events were the result of clinically unsuspected seizures in neonates with PAIS. Prolonged and continuous multichannel video-EEG monitoring is advocated for adequate seizure surveillance.
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Affiliation(s)
- Evonne Low
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Sean R. Mathieson
- Elizabeth Garrett Anderson Institute for Women's Health, University College London Hospital, London, United Kingdom
| | - Nathan J. Stevenson
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Vicki Livingstone
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - C. Anthony Ryan
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Conor O. Bogue
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Janet M. Rennie
- Elizabeth Garrett Anderson Institute for Women's Health, University College London Hospital, London, United Kingdom
| | - Geraldine B. Boylan
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research, Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
- * E-mail:
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23
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van Seeters T, Biessels GJ, Niesten JM, van der Schaaf IC, Dankbaar JW, Horsch AD, Mali WPTM, Kappelle LJ, van der Graaf Y, Velthuis BK. Reliability of visual assessment of non-contrast CT, CT angiography source images and CT perfusion in patients with suspected ischemic stroke. PLoS One 2013; 8:e75615. [PMID: 24116061 PMCID: PMC3792960 DOI: 10.1371/journal.pone.0075615] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/16/2013] [Indexed: 11/19/2022] Open
Abstract
Background and Purpose Good reliability of methods to assess the extent of ischemia in acute stroke is important for implementation in clinical practice, especially between observers with varying experience. Our aim was to determine inter- and intra-observer reliability of the 1/3 middle cerebral artery (MCA) rule and the Alberta Stroke Program Early CT Score (ASPECTS) for different CT modalities in patients suspected of acute ischemic stroke. Methods We prospectively included 105 patients with acute neurological deficit due to suspected acute ischemic stroke within 9 hours after symptom onset. All patients underwent non-contrast CT, CT perfusion and CT angiography on admission. All images were evaluated twice for presence of ischemia, ischemia with >1/3 MCA involvement, and ASPECTS. Four observers evaluated twenty scans twice for intra-observer agreement. We used kappa statistics and intraclass correlation coefficient to calculate agreement. Results Inter-observer agreement for the 1/3 MCA rule and ASPECTS was fair to good for non-contrast CT, poor to good for CT angiography source images, but excellent for all CT perfusion maps (cerebral blood volume, mean transit time, and predicted penumbra and infarct maps). Intra-observer agreement for the 1/3 MCA rule and ASPECTS was poor to good for non-contrast CT, fair to moderate for CT angiography source images, and good to excellent for all CT perfusion maps. Conclusion Between observers with a different level of experience, agreement on the radiological diagnosis of cerebral ischemia is much better for CT perfusion than for non-contrast CT and CT angiography source images, and therefore CT perfusion is a very reliable addition to standard stroke imaging.
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Affiliation(s)
- Tom van Seeters
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
| | - Geert Jan Biessels
- Department of Neurology, Utrecht Stroke Center, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Joris M. Niesten
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Jan Willem Dankbaar
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Alexander D. Horsch
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Radiology, Rijnstate Hospital, Arnhem, The Netherlands
| | - Willem P. T. M. Mali
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - L. Jaap Kappelle
- Department of Neurology, Utrecht Stroke Center, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Yolanda van der Graaf
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Birgitta K. Velthuis
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Bal S, Bhatia R, Menon BK, Shobha N, Puetz V, Dzialowski I, Modi J, Goyal M, Hill MD, Smith EE, Demchuk AM. Time Dependence of Reliability of Noncontrast Computed Tomography in Comparison to Computed Tomography Angiography Source Image in Acute Ischemic Stroke. Int J Stroke 2012; 10:55-60. [PMID: 22974504 DOI: 10.1111/j.1747-4949.2012.00859.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 01/31/2012] [Indexed: 11/29/2022]
Abstract
There is no consensus on how the reliability and predictive ability of noncontrast computed tomography (NCCT) and computed tomography angiography source image (CTASI) change over time from acute ischemic stroke onset. We hypothesized that the reliability for detecting early ischemic changes (EIC) would be lower in early time periods and that changes identified on CTASI would be more reliable across examiners than changes identified on NCCT. To address this, we compared the relationships between CTASI, NCCT, and final infarct in patients with initial computed tomography (CT) imaging at different time points after stroke onset. Patients with acute ischemic stroke with proximal anterior circulation occlusions (internal carotid artery, middle carotid artery M1, proximal M2) from Calgary CT Angiography (CTA) database were studied. The cohort was categorized in four groups based on time from stroke onset to baseline NCCT/CTA: 0–90 mins ( n = 69), 91–180 mins ( n = 88), 181–360 mins ( n = 46), and >360 mins ( n = 58). Median scores of NCCT-Alberta Stroke Program Early CT Score (ASPECTS), CTASI ASPECTS, and follow-up ASPECTS among different time categories were compared. To determine reliability, a subsample of NCCT brain and CTASI were interpreted at separate sessions weeks apart by two neuroradiologists and two stroke neurologists in random order. Median and mean ASPECTS ratings on NCCT and CTASI were higher than final ASPECTS in each time category ( P < 0·001 for all comparisons). CTASI ASPECTS was lower than NCCT ASPECTS in each time category, and differences were significant at 0–90 mins and 91–180 mins ( P < 0·001). The least agreement among readers was in detection of EIC on NCCT brain in the ultra-early phase (<90 mins) [intraclass correlation coefficient (ICC) = 0·48. By contrast, there was excellent agreement on EIC on CTASI regardless of time period (ICC = 0·87–0·96). Using ASPECTS methodology, CTASI is more reliable than NCCT at predicting final infarct extent particularly in the early time windows.
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Affiliation(s)
- Simerpreet Bal
- Department of Clinical Neurosciences, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
- Section of Neurology, Department of Internal Medicine, Health sciences Centre, Winnipeg, Canada
| | - Rohit Bhatia
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Bijoy K. Menon
- Department of Clinical Neurosciences, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
| | - Nandavar Shobha
- Department of Clinical Neurosciences, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
| | - Volker Puetz
- Department of Neurology, University of Dresden, Dresden, Germany
| | | | - Jayesh Modi
- Department of Radiology, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
| | - Mayank Goyal
- Department of Radiology, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
| | - Michael D. Hill
- Department of Clinical Neurosciences, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
| | - Eric E. Smith
- Department of Clinical Neurosciences, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
| | - Andrew M. Demchuk
- Department of Clinical Neurosciences, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, Hotchkiss Brain Institute University of Calgary, Calgary, Alberta, Canada
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Nemoto EM, Mendez O, Kerr ME, Firlik A, Stevenson K, Jovin T, Yonas H. CT Density Changes with Rapid Onset Acute, Severe, Focal Cerebral Ischemia in Monkeys. Transl Stroke Res 2012; 3:369-74. [PMID: 24323812 DOI: 10.1007/s12975-012-0193-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 05/01/2012] [Accepted: 05/07/2012] [Indexed: 01/22/2023]
Abstract
Computerized tomography (CT) is the most often used imaging modality in the evaluation of acute clinical stroke. However, the rapidity with which CT density changes occur after acute, severe, focal ischemia cannot be determined clinically. Even if the time of symptom onset is known, clinical stroke severity is highly variable. We studied the time course of CT density change after severe, rapid onset, acute, focal ischemia as documented by stable xenon CT cerebral blood flow (CBF) in monkeys. Eight monkeys (Macaca mulatta) were subjected to transorbital occlusion of the left posterior cerebral, anterior, middle, and internal carotid arteries to induce focal ischemia. CT density Hounsfield units (HU), CBF by stable xenon CT, arterial blood pressure, and blood gases were measured before occlusion, immediately after occlusion, at 30 min, and hourly for up to 6 h. Occlusion of the cerebral arteries decreased CBF to 8 ± 5 ml/100 g/ min within 15 min postocclusion. At 6 h, CBF was unchanged at 9 ± 4 ml/100 g/ min. CT density within the ischemic core fell from 42 to 38 HU immediately after occlusion (P < 0.05), rose transiently, then fell at 2 h (P < 0.01) and plateaued at 36 ± 5 HU for a total decrease of 4-5 HU between 4 and 6 h poststroke. Changes in CT density lag severe focal ischemia by 2 h. Thus, when CT hypodensity is seen in acute stroke, it is likely 2 h old. It also provides an explanation for the phenomenon of clinical CT mismatch with clinical deficits and normal CT.
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Affiliation(s)
- Edwin M Nemoto
- Department of Neurosurgery, University of New Mexico, 1101 Yale Blvd, Domenici Hall, BRaIN Center Rm. 1131B, Albuquerque, NM, 87106, USA,
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26
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Ünlüer EE, Yaka E, Akhan G, Limon Ö, Kara PH, Yavaşi Ö, Vandenberk N, Nazli YE, Kutluk K. Ability of emergency physicians to detect early ischemic changes of acute ischemic stroke on cranial computed tomography. Med Princ Pract 2012; 21:534-7. [PMID: 22653221 DOI: 10.1159/000339116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 04/12/2012] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE The objective of this study was to evaluate the ability of emergency physicians (EPs) to diagnose early ischemic changes due acute ischemic stroke on cranial computed tomography (CT). SUBJECTS AND METHODS Three EPs interpreted CT scans obtained within 3 h of symptom onset in 50 patients with acute stroke. The CT scans were interpreted by the EPs and compared to official neuroradiologist reports as a gold standard. ĸ statistics were calculated to determine agreement among the three readers. Sensitivities and specificities were analyzed for each reader. RESULTS The EPs' sensitivities were 50, 45.5, and 45.5%, and specificities were 64.3, 82.1, and 64.3%, respectively. Focal parenchymal hypodensity was the criterion for which the EPs were the most sensitive (77.3%). The ability of EPs to recognize early ischemic changes on CT scans in acute ischemic stroke was moderate based on sensitivities. CONCLUSION Based on this study, EPs must be trained especially for recognizing early ischemic changes in acute ischemic stroke to improve their accuracy of interpretation.
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Affiliation(s)
- Erden Erol Ünlüer
- Department of Emergency Medicine, Izmir Ataturk Research and Training Hospital, Izmir, Turkey. erolerdenun @ yahoo.com
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Semenov S, Moldavskaya I, Shatokhina M, Semenov A, Barbarash L. How to Distinguish between Venous and Arterial Strokes and Why? Neuroradiol J 2011; 24:289-99. [DOI: 10.1177/197140091102400219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 01/03/2011] [Indexed: 11/15/2022] Open
Abstract
Cerebral venous infarct is considered to be rare (0–5% of all strokes). In some cases venous infarcts with no specific signs on conventional CT or MR study are not diagnosed due to incomplete examination. A venous infarct more often (63%) than an arterial (15%) infarct is accompanied by hemorrhage (primary or secondary in the early period) and a high risk of hemorrhage should be a contraindication to intravenous thrombolysis. Consequently, the definition of the kind of a stroke should lead to different therapeutic tactics. Using MR and CT angiographic and perfusion techniques in the urgent examination of patients with an infarct, considering time necessary for the “time window”, can lead to exact diagnosis and fewer complications.
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Affiliation(s)
- S. Semenov
- Research Institute of Cardiovascular Disorders; Kemerovo, Russia
| | - I. Moldavskaya
- Research Institute of Cardiovascular Disorders; Kemerovo, Russia
| | - M. Shatokhina
- Research Institute of Cardiovascular Disorders; Kemerovo, Russia
| | - A. Semenov
- Research Institute of Cardiovascular Disorders; Kemerovo, Russia
| | - L. Barbarash
- Research Institute of Cardiovascular Disorders; Kemerovo, Russia
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Abstract
BACKGROUND The majority of strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and could improve recovery after stroke. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in highly selected patients within three hours of stroke. OBJECTIVES To assess the safety and efficacy of thrombolytic agents in patients with acute ischaemic stroke. SEARCH STRATEGY We searched the Cochrane Stroke Group Trials Register (last searched October 2008), MEDLINE (1966 to October 2008) and EMBASE (1980 to October 2008). We contacted researchers and pharmaceutical companies, attended relevant conferences and handsearched pertinent journals. SELECTION CRITERIA Randomised trials of any thrombolytic agent compared with control in patients with definite ischaemic stroke. DATA COLLECTION AND ANALYSIS Two review authors applied the inclusion criteria and extracted data. We assessed trial quality. We verified the extracted data with the principal investigators of all major trials. We obtained both published and unpublished data if available. MAIN RESULTS We included 26 trials involving 7152 patients. Not all trials contributed data to each outcome. The trials tested urokinase, streptokinase, recombinant tissue plasminogen activator, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke; three trials started treatment up to nine hours and one small trial up to 24 hours after stroke. About 55% of the data (patients and trials) come from trials testing intravenous tissue plasminogen activator. Very few of the patients (0.5%) were aged over 80 years. Many trials had some imbalances in key prognostic variables. Several trials did not have complete blinding of outcome assessment. Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of patients who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.81, 95% confidence interval (CI) 0.73 to 0.90). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.49, 95% CI 2.81 to 4.33) and death by three to six months after stroke (OR 1.31, 95% CI 1.14 to 1.50). Treatment within three hours of stroke appeared more effective in reducing death or dependency (OR 0.71, 95% CI 0.52 to 0.96) with no statistically significant adverse effect on death (OR 1.13, 95% CI 0.86 to 1.48). There was heterogeneity between the trials in part attributable to concomitant antithrombotic drug use (P = 0.02), stroke severity and time to treatment. Antithrombotic drugs given soon after thrombolysis may increase the risk of death. AUTHORS' CONCLUSIONS Overall, thrombolytic therapy appears to result in a significant net reduction in the proportion of patients dead or dependent in activities of daily living. This overall benefit was apparent despite an increase both in deaths (evident at seven to 10 days and at final follow up) and in symptomatic intracranial haemorrhages. Further trials are needed to identify which patients are most likely to benefit from treatment and the environment in which thrombolysis may best be given in routine practice.
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Affiliation(s)
- Joanna M Wardlaw
- Division of Clinical Neurosciences, University of Edinburgh, Western General Hospital, Crewe Rd, Edinburgh, UK, EH4 2XU
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Sims JR, Gharai LR, Schaefer PW, Vangel M, Rosenthal ES, Lev MH, Schwamm LH. ABC/2 for rapid clinical estimate of infarct, perfusion, and mismatch volumes. Neurology 2009; 72:2104-10. [PMID: 19528517 DOI: 10.1212/wnl.0b013e3181aa5329] [Citation(s) in RCA: 318] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Rapid and easy clinical assessments for volumes of infarction and perfusion mismatch are needed. We tested whether simple geometric models generated accurate estimates of these volumes. METHODS Acute diffusion-weighted image (DWI) and perfusion (mean transit time [MTT]) in 63 strokes and established infarct volumes in 50 subacute strokes were measured by computerized planimetry. Mismatch was defined as MTT/DWI > or = 1.2. Observers, blinded to planimetric values, measured lesions in three perpendicular axes A, B, and C. Geometric estimates of sphere, ellipsoid, bicone, and cylinder were compared to planimetric volume by least-squares linear regression. RESULTS The ABC/2 formula (ellipsoid) was superior to other geometries for estimating volume of DWI (slope 1.16, 95% confidence interval [CI] 0.94 to 1.38; R(2) = 0.91, p = 0.001) and MTT (slope 1.11, 95% CI 0.99 to 1.23; R(2) = 0.89, p = 0.001). The intrarater and interrater reliability for ABC/2 was high for both DWI (0.992 and 0.965) and MTT (0.881 and 0.712). For subacute infarct, the ABC/2 formula also best estimated planimetric volume (slope 1.00, 95% CI 0.98 to 1.19; R(2) = 0.74, p = 0.001). In general, sphere and cylinder geometries overestimated all volumes and bicone underestimated all volumes. The positive predictive value for mismatch was 92% and negative predictive value was 33%. CONCLUSIONS Of the models tested, ABC/2 is reproducible, is accurate, and provides the best simple geometric estimate of infarction and mean transit time volumes. ABC/2 has a high positive predictive value for identifying mismatch greater than 20% and might be a useful tool for rapid determination of acute stroke treatment.
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Affiliation(s)
- J R Sims
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, 02129, USA.
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Dzialowski I, Puetz V, von Kummer R. [Computed tomography in acute ischemic stroke. Current developments compared with stroke MRI]. DER NERVENARZT 2009; 80:137-146. [PMID: 19139839 DOI: 10.1007/s00115-008-2594-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Modern multimodal acute stroke computed tomography (CT) includes noncontrast cranial CT (NCT), CT angiography (CTA), and CT perfusion imaging (CTP). Compared to stroke MRI, NCT is faster and easier. Multimodal CT can determine acute stroke etiology: Is arterial occlusion or intracerebal hemorrhage present? How extensive are the perfusion disturbance and infarct core, respectively? The information from NCT is sufficient for making acute stroke thrombolysis decisions within 4.5 h from symptom onset. The therapeutic effect of CTA and CTP--as well as acute stroke MRI--on improved functional outcome has still not been established.
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Affiliation(s)
- I Dzialowski
- Klinik für Neurologie, Technische Universität Dresden, Universitätsklinikum Carl-Gustav-Carus, Fetscherstrasse 74, 01307, Dresden, Deutschland
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Tsivgoulis G, Saqqur M, Sharma VK, Lao AY, Hoover SL, Alexandrov AV. Association of pretreatment ASPECTS scores with tPA-induced arterial recanalization in acute middle cerebral artery occlusion. J Neuroimaging 2008; 18:56-61. [PMID: 18190497 DOI: 10.1111/j.1552-6569.2007.00169.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE The Alberta Stroke Program Early CT-Score (ASPECTS) assesses early ischemic changes within the middle cerebral artery (MCA) and predicts poor outcome and increased risk for thrombolysis-related symptomatic ICH. We evaluated the potential relationship between pretreatment ASPECTS and tPA-induced recanalization in patients with MCA occlusions. SUBJECTS & METHODS Consecutive patients with acute ischemic stroke due to MCA occlusion were treated with standard IV-tPA and assessed with transcranial Doppler (TCD) for arterial recanalization. Early recanalization was determined with previously validated Thrombolysis in Brain Ischemia (TIBI) flow-grading system at 120 minutes after tPA-bolus. All pretreatment CT-scans were prospectively scored by trained investigators blinded to TCD findings. Functional outcome at 3 months was evaluated using the modified Rankin Scale (mRS). RESULTS IV-tPA was administered in 192 patients (mean age 68 +/- 14 years, median NIHSS-score 17). Patients with complete recanalization (n= 51) had higher median pretreatment ASPECTS (10, interquartile range 2) than patients with incomplete or absent recanalization (n= 141; median ASPECTS 9, interquartile range 3, P= .034 Mann-Whitney U-test). An ASPECTS < or =6 was documented in 4% and 17% of patients with present and absent recanalization, respectively (P= .019). Pretreatment ASPECTS was associated with complete recanalization (OR per 1-point increase: 1.54; 95% CI 1.06-2.22, P= .023) after adjustment for baseline characteristics, risk factors, NIHSS-score, pretreatment TIBI grades and site of arterial occlusion on baseline TCD. Complete recanalization (OR: 33.97, 95% CI 5.95-185.99, P < .001) and higher ASPECTS (OR per 1-point increase: 1.91; 95% CI 1.17-3.14, P= .010) were independent predictors of good functional outcome (mRS 0-2). CONCLUSIONS Higher pretreatment ASPECT-scores are associated with a greater chance of complete recanalization and favorable long-term outcome in tPA-treated patients with acute MCA occlusion.
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Affiliation(s)
- Georgios Tsivgoulis
- Neurosonology and Stroke Research Program, Barrow Neurological Institute, Phoenix, Arizona, USA.
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Mahajan V, Minshew PT, Khoury J, Shu PP, Muzaffar M, Abruzzo T, Leach JL, Tomsick TA. Eye position information on CT increases the identification of acute ischemic hypoattenuation. AJNR Am J Neuroradiol 2008; 29:1144-6. [PMID: 18356473 DOI: 10.3174/ajnr.a0995] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE It is possible that identification of eye deviation may sensitize a scan reader to early brain hypodensity associated with an arterial occlusive process. Our aim was to investigate the value of observing eye deviation on blinded CT identification of early hypoattenuation following ischemic infarct. MATERIALS AND METHODS Two staff and 2 fellow neuroradiologists reviewed 75 brain CT scans obtained within 3 hours of acute ischemia from subjects in the Interventional Management of Stroke Study. Films were reviewed 3 months apart, the first time with tape over the eyes on the images, the second with the eyes visible. Readers were asked if early hypoattenuation in the middle cerebral artery (MCA) distribution or if a hyperattenuated MCA was present. kappa statistics were calculated to determine agreement among the 4 readers and between each of the 2 readings by the same reader, not only for the original interpretation of the blinded study neuroradiologist but also for the Alberta Stroke Program Early CT Score (ASPECTS) for each subject assigned by an unblinded expert panel. A generalized estimating equations modeling approach was used to look at the overall effect of including eye information for agreement between interpretations. RESULTS Eye information availability was associated with improved agreement for detection of early ischemic hypoattenuation not only among the 4 readers but also between the 4 readers and both the blinded study neuroradiologist (P = .02) and the unblinded expert ASPECTS panel. When comparing first and second readings for hypoattenuation, we also noted increased mean values for sensitivity (46.8% first, 56.5% second), specificity (78.2%, 80.2%), positive predictive value (72.0%, 80.7%), negative predictive value (55.5%, 61.0%), and percentage agreement (61.0%, 67.5%). CONCLUSION Observation of CT eye deviation significantly improves reader identification of acute ischemic hypoattenuation.
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Affiliation(s)
- V Mahajan
- Department of Radiology, SUNY Downstate Medical Center, Brooklyn, NY, USA
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Phan TG, Donnan GA, Koga M, Mitchell LA, Molan M, Fitt G, Chong W, Holt M, Reutens DC. Assessment of suitability of thrombolysis in middle cerebral artery infarction: a proof of concept study of a stereologically-based technique. Cerebrovasc Dis 2007; 24:321-7. [PMID: 17690543 DOI: 10.1159/000106977] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Accepted: 03/29/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The extent of cerebral ischemia, assessed by the Alberta Stroke Program Early CT Score (ASPECTS) method and unaided visual determination of the CT Summit Criterion, correlates with increased risk of intracerebral hemorrhage following rt-PA administration. Concerns about the accuracy of the unaided visual assessment in the estimation of infarct size and the conservative nature of the ASPECTS method led us to develop a new method (MCAGrid) based on stereological grid counting and a digital atlas of the middle cerebral artery (MCA) infarct territory. METHODS We tested the hypotheses that the stereological method increases the accuracy of infarct estimation and that the number of patients deemed eligible for thrombolysis is greater with this method than with existing methods. Four experienced radiologists with extensive neuroradiological experience examined the CT images of 19 patients with MCA territory stroke and determined patient eligibility for thrombolysis by: unaided visual determination of the CT Summit Criterion, MCAGrid, and the ASPECTS score. The chi(2) test was used to compare the differences in the number of patients deemed 'eligible' for thrombolysis by the 3 imaging methods. Further, the unaided visual assessment and MCAGrid were compared with volumes calculated following manual segmentation of infarct, and the sensitivity, specificity and positive and negative likelihood ratios for these techniques were calculated. RESULTS In general, MCAGrid was better than unaided visual assessment in the prediction of >1/3 involvement of the MCA territory by infarct. The number of patients considered as 'eligible' for thrombolysis based on imaging criteria was significantly lower when ASPECTS criteria (15/76) were used than when unaided visual determination of the CT Summit Criterion (32/76; p < 0.01) or MCAGrid (59/76; p < 0.001) criteria were used. CONCLUSION The choice of methods for rating infarct extent affects the number of patients 'eligible' for thrombolysis significantly. Furthermore, MCAGrid increased the accuracy with which infarct extent was estimated. These results provide justification for a prospective study of this technique in the setting of acute stroke.
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Affiliation(s)
- Thanh G Phan
- National Stroke Research Institute, Melbourne, Australia
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Bisdas S, Therapidis P, Kerl JM, Papadopoulos N, Burck I, Herzog C, Vogl TJ. Value of cerebral perfusion computed tomography in the management of intensive care unit patients with suspected ischaemic cerebral pathology after cardiac surgery. Eur J Cardiothorac Surg 2007; 32:521-6. [PMID: 17611118 DOI: 10.1016/j.ejcts.2007.05.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Revised: 05/30/2007] [Accepted: 05/31/2007] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVE Adverse neurologic outcomes, like stroke, in intensive care unit (ICU) patients after cardiac surgery can have devastating consequences, among them increased mortality risk and, among survivors, loss of independence and a diminished quality of life. Non-contrast computed tomography (CT) remains a widely utilised modality for assessing stroke; however, it has a low sensitivity in the acute phase. Perfusion CT (PCT) has the potential of imaging stroke in its hyperacute phase. We evaluated the feasibility and results of the method among patients from the ICU. METHODS The NCCT and PCT images of 33 retrospectively identified patients were included in this study. The diagnostic contribution of the PCT to patient management was classified according to one of three categories: (A) those that changed the preliminary (NCCT) diagnosis; (B) those that revealed additional pathology and/or specified more exactly findings that have been detected by NCCT or clinically suspected; and (C) confirmed the preliminary diagnosis. Neurologic outcome variables were also documented and associated with PCT lesions. RESULTS Fifteen patients after coronary artery bypass graft (CABG) operation, 14 patients after CABG and valve surgery, and 4 patients after an aortic dissection (Type A) surgery underwent a NCCT with PCT 2.4+/-1.3 days after the operation. Twenty patients had bilateral internal carotid artery (ICA) stenosis (>50%), 11 patients had unilateral ICA stenosis (>75%), and 2 patients had no ICA stenosis. In nine patients (27.2%) the PCT changed the initial diagnosis of the NCCT and revealed ischaemic pathology. In 24 patients (72.7%), the performed PCT revealed additional pathology and/or more completely characterised findings that have been detected by the initial NCCT. In nine patients, PCT confirmed only the initial diagnosis. Patients with normal PCT findings had a favourable outcome; patients with large lesions in PCT in one or more vascular territories had an unfavourable outcome; seven patients with lesions in basal ganglia and/or semioval centre had a favourable outcome. CONCLUSIONS PCT shows a greater sensitivity in detecting and mapping acute ischaemic stroke in ICU patients (after cardiac surgery) in whom conventional imaging findings are not in line with the severity of the clinical condition.
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Affiliation(s)
- Sotirios Bisdas
- Department of Radiology, Johann Wolfgang Goethe University Hospital, Frankfurt, Germany.
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Lansberg MG, Albers GW, Wijman CAC. Symptomatic intracerebral hemorrhage following thrombolytic therapy for acute ischemic stroke: a review of the risk factors. Cerebrovasc Dis 2007; 24:1-10. [PMID: 17519538 DOI: 10.1159/000103110] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Accepted: 12/21/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Symptomatic intracerebral hemorrhage (SICH) following thrombolytic therapy for acute ischemic stroke is associated with a high rate of morbidity and mortality. Knowledge of the risk factors associated with SICH following thrombolyitc therapy may provide insight into the pathophysiological mechanisms underlying the development of SICH, lead to the development of treatments that reduce the risk of SICH and have implications for the design of future stroke trials. METHODS Relevant studies were identified through a search in Pubmed. Included studies used multivariate analyses to identify independent risk factors for SICH following thrombolytic therapy. For each variable that was found to have a significant association with SICH, a secondary literature search was conducted to identify additional reports on the specific relationship between that variable and SICH. SUMMARY OF REVIEW Twelve studies met inclusion criteria for the systematic review. Extent of hypoattenuated brain parenchyma on pretreatment CT and elevated serum glucose or history of diabetes were independent risk factors for thrombolysis-associated SICH in six of the twelve studies. Symptom severity was an independent risk factor in three of the studies and advanced age, increased time to treatment, high systolic blood pressure, low platelets, history of congestive heart failure and low plasminogen activator inhibitor levels were found to be independent risk factors for SICH in a single study. Although these data should not alter the current guidelines for the use of rt-PA in acute stroke, they may help develop future strategies aimed at reducing the rate of thrombolysis-associated SICH.
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Abstract
Thrombolytic therapy has led to a higher proportion of patients presenting to hospital early, and this, with parallel developments in imaging technology, has greatly improved the understanding of acute stroke pathophysiology. Additionally, MRI, including diffusion-weighted imaging (DWI) and gradient echo, or T2*, imaging is important in understanding basic structural information--such as distinguishing acute ischaemia from haemorrhage. It has also greatly increased sensitivity in the diagnosis of acute cerebral ischaemia. The pathophysiology of the ischaemic penumbra can now be assessed with CT or MRI-based perfusion imaging techniques, which are widely available and clinically applicable. Pathophysiological information from CT or MRI increasingly helps clinical trial design, may allow targeted therapy in individual patients, and may extend the time scale for reperfusion therapy.
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Affiliation(s)
- Keith W Muir
- Division of Clinical Neurosciences, University of Glasgow, Institute of Neurological Sciences, Southern General Hospital, Glasgow
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Choi JY, Porche NA, Albright KC, Khaja AM, Ho VS, Grotta JC. Using Telemedicine to Facilitate Thrombolytic Therapy for Patients with Acute Stroke. Jt Comm J Qual Patient Saf 2006; 32:199-205. [PMID: 16649650 DOI: 10.1016/s1553-7250(06)32025-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Recent stroke-care requirements state that all stroke patients should be screened for intravenous recombinant tissue plasminogen activator (rt-PA) and treated, if the appropriate inclusion and exclusion criteria are met. Two community hospitals 90-130 miles east of Houston deployed telemedicine (videoteleconferencing) to provide acute stroke consultative services. DEVELOPING A TELEMEDICINE CAPACITY: According to the Brain Attack Coalition's recommendations, neurosurgical services need to be accessible within two hours. Given their incomplete neurology coverage, the remote-site hospitals identified telemedicine as the best option, with the University of Texas Health Science Center at Houston stroke team as the provider of expertise. RESULTS In the 13 months preceding the telemedicine project (January 2003-March 2004), 2 (.8%) of 327 patients received rt-PA, compared with 14 (4.3%) of 328 patients during the telemedicine project (April 2004-May 2005), p < .001). Seven patients had > or = 4 points improvement in a stroke scale at 24 hours posttreatment. Three patients worsened during the 24-hour assessment. No intracerebral hemorrhages occurred. Door-to-needle median time was 85 minutes (range, 27-165 minutes). DISCUSSION Telemedicine facilitated thrombolytic therapy for acute stroke patients and is intended not to replace care provided by remote-site providers but rather to address a time- and spatially related emergency need.
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Affiliation(s)
- John Y Choi
- Department of Neurology, University of Texas Health Science Center, Houston, USA.
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Abstract
Noncontrast head CT has an important role in the work-up of acute stroke by excluding intracranial hemorrhage and by directly visualizing the parenchymal changes of early infarct. However, noncontrast CT has limited sensitivity and moderate interobserver variability in detecting early infarcts. This article reviews the noncontrast CT appearance and clinical significance of parenchymal changes in early infarct and discusses techniques to optimize their detection.
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Affiliation(s)
- David Vu
- Neuroradiology Division, Massachusetts General Hospital and Harvard Medical School, Boston 02114-2696, USA
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Ho SSY, Lam WWM, Wong KS, Leung CSF, Metreweli C. Potential Value of Poststroke Extracranial Arterial Blood Flow Volume in the Prediction of Stroke Functional Outcome. Cerebrovasc Dis 2006; 21:54-9. [PMID: 16282691 DOI: 10.1159/000089595] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Accepted: 08/19/2005] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Cerebral vasoreactivity and collateral circulation are important protective mechanisms against cerebral ischemia. Previous studies suggest that the efficiency of these mechanisms can be reflected by extracranial arterial blood flow volume. Brain damage leading to neurological impairments can influence patients' functional recovery after stroke. This study attempted to explore the potential value of post stroke extracranial arterial blood flow volume in the prediction of stroke patients' functional outcome. METHODS We prospectively studied 362 consecutive patients who were hospitalized for recent acute strokes. All patients underwent extracranial arterial blood flow volume measurement of the carotid and vertebral arteries by color velocity imaging quantification within 3 days after admission. Their functional recovery was assessed 6 months after stroke. The effect of post stroke extracranial arterial blood flow volume on patients' functional outcome was tested by multivariate ordinal regression after controlling for other independent variables. Significance was at p<0.05. RESULTS Post stroke extracranial arterial blood flow volume together with age, pre-stroke modified Rankin scale, the National Institutes of Health Stroke Scale and diabetes mellitus had significant effects on the patients' 6-month functional outcome as measured by the modified Rankin scale after controlling for other independent variables (p<0.05). CONCLUSIONS Post stroke extracranial arterial blood flow volume is an independent outcome predictor. The graded predictive power of this parameter is potentially more superior than other outcome predictors by allowing classification of stroke outcome according to the degree of severity. A large prospective study is thus warranted to investigate its clinical value in the management of stroke patients.
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Affiliation(s)
- Stella S Y Ho
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SAR, China.
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Thomassen L, Waje-Andreassen U, Naess H, Aarseth J, Russell D. Combined Carotid and Transcranial Ultrasound Findings Compared with Clinical Classification and Stroke Severity in Acute Ischemic Stroke. Cerebrovasc Dis 2006; 21:86-90. [PMID: 16330869 DOI: 10.1159/000090008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Accepted: 09/08/2005] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The aim of this study was to assess the association between cerebral hemodynamics and the clinical picture as defined by the Oxfordshire Community Stroke Project (OCSP) classification, as well as the clinical severity as defined by the National Institute of Health Stroke Scale (NIHSS) within the first 6 h of an acute middle cerebral artery (MCA) stroke onset. METHODS 70 unselected patients were grouped according to the OCSP classification and NIHSS. All patients immediately had extracranial and transcranial Doppler (TCD) ultrasound examinations. RESULTS In the study population as a whole, there was a significant association between intracranial vascular pathology and the OCSP classification (p<0.001) as well as the NIHSS score (p<0.001). In patients with severe stroke, however, TCD demonstrated the hypothesized proximal MCA(1) occlusion in only 34% of patients with an OCSP-defined total anterior circulation syndrome and in 42% of patients with an NIHSS score of >or=15. In moderate stroke, the OCSP classification was misleading in almost half of the patients with a partial anterior circulation syndrome, i.e. a hypothesized distal MCA(2) occlusion suitable for thrombolysis. CONCLUSIONS Neither the OCSP classification nor the NIHSS grading provided reliable information about the site or presence of intracranial arterial occlusion in acute stroke within the first 6 h after stroke onset in the individual patient. The results of this study strongly suggest that selection of acute ischemic stroke patients for thrombolysis should also include an assessment of cerebral hemodynamics.
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Affiliation(s)
- Lars Thomassen
- Department of Neurology, Haukeland University Hospital, Bergen, Norway.
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Lövblad KO, Baird AE. Actual diagnostic approach to the acute stroke patient. Eur Radiol 2005; 16:1253-69. [PMID: 16372164 DOI: 10.1007/s00330-005-0103-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 11/18/2005] [Accepted: 11/25/2005] [Indexed: 10/25/2022]
Abstract
Since acute stroke is now considered a potentially treatable medical emergency, a rapid and correct diagnosis must be made. The first step is to exclude hemorrhage, then to visualize any early ischemic changes, demonstrate the presence of hypoperfusion and locate the presence of a vascular underlying pathology as well as elucidate the presence of a potential penumbra (tissue at risk). Thanks to improvements and advances in both MR and CT technology, this can now be done in a number of ways. At the moment, CT is the most widely available and fast method for obtaining imaging of the brain and neck vessels of patients presenting with acute stroke. MRI can provide more precise information, although it remains slightly more time-consuming, but is, however, the method of choice for follow-up imaging. The main point is to take the one-stop-shopping approach where imaging of the vessels and brain is done from the aortic arch to the circle of Willis in one single session in order to have all the necessary information in the acute phase.
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Affiliation(s)
- Karl-Olof Lövblad
- Neuroradiology Unit, Radiology Department, SRRI, HUG Geneva University Hospital, 24 rue Micheli-du-Crest, 1211 Geneva 14, Switzerland.
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Wardlaw JM, Mielke O. Early Signs of Brain Infarction at CT: Observer Reliability and Outcome after Thrombolytic Treatment—Systematic Review. Radiology 2005; 235:444-53. [PMID: 15858087 DOI: 10.1148/radiol.2352040262] [Citation(s) in RCA: 181] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To review systematically all reported early computed tomographic (CT) signs in acute ischemic stroke to determine interobserver agreement and the relationship between early CT signs and patient outcome with or without thrombolysis. MATERIALS AND METHODS A systematic review of the literature was conducted by using Cochrane Stroke Group methodology to identify studies published between 1990 and 2003 that were performed to assess interobserver agreement about early signs of infarction on CT scans obtained within 6 hours after onset of stroke symptoms and determine the relation of early signs of infarction to clinical outcome, including any interactive effect of thrombolysis. Interobserver agreement was measured with the kappa statistic, sensitivity, and specificity. The relation of early signs to clinical outcome with or without thrombolysis was assessed with calculated odds ratios and 95% confidence intervals. RESULTS In 15 studies of interobserver agreement (median of 30 CT scans and six raters), the prevalence of all early infarction signs was 61% +/- 21 (standard deviation). Interobserver agreement (kappa statistics) ranged from 0.14 to 0.78 for any early infarction sign. The mean sensitivity and specificity for detection of early infarction signs with CT were 66% (range, 20%-87%) and 87% (range, 56%-100%), respectively. Experience improved detection, but knowledge of symptoms did not. In 15 studies of early infarction signs and outcome (including seven thrombolysis trials) in 3468 patients, any early infarction sign increased the risk of poor outcome (odds ratio, 3.11; 95% confidence interval: 2.77, 3.49). Two studies that sought interaction between early infarction signs and thrombolysis found no evidence that thrombolysis given in the presence of early infarction signs resulted in worse outcome than that due to early signs alone. CONCLUSION Further work is required to determine which signs are most reliably detected, whether scoring systems help to improve detection, and whether any early infarction sign should influence decisions concerning thrombolysis.
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Affiliation(s)
- Joanna M Wardlaw
- Division of Clinical Neurosciences, University of Edinburgh, Western General Hospital, Crewe Rd, Edinburgh EH4 2XU, Scotland.
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Bisdas S, Donnerstag F, Ahl B, Bohrer I, Weissenborn K, Becker H. Comparison of Perfusion Computed Tomography With Diffusion-Weighted Magnetic Resonance Imaging in Hyperacute Ischemic Stroke. J Comput Assist Tomogr 2004; 28:747-55. [PMID: 15538146 DOI: 10.1097/00004728-200411000-00004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE In this study, perfusion CT and diffusion-weighted magnetic resonance imaging (DWI) were compared as means of assessing the ischemic brain in hyperacute stroke. METHODS Twenty patients with ischemic stroke underwent perfusion computed tomography (CT) and magnetic resonance imaging (MRI) studies <3 hours after stroke onset. Cerebral blood flow thresholds were used to delineate the ischemic lesion, penumbra, and infarct. Correlations between the volume of the hypoperfused areas, the abnormality volume in admission DWI and follow-up CT/MRI studies, and the clinical National Institutes of Health Stroke Scale (NIHSS) scores were performed. RESULTS The volume of the ischemic (core and penumbra) lesion on admission perfusion CT was correlated with the volume of admission DWI abnormalities (r=0.89, P=0.001). The infarcted core tissue volume (on admission CT) correlated more strongly (r=0.77, P=0.0001) than the admission DWI abnormality volume (r=0.69, P=0.002) with the follow-up infarct volume on fluid-attenuated inversion recovery images. A correlation was demonstrated between infarct volume in perfusion CT and follow-up DWI abnormality volume (r=0.89, r=0.77, P=0.002). Significant correlations were found between ischemic and infarct region volumes in perfusion CT and NIHSS admission and follow-up scores (P < or = 0.01). CONCLUSIONS Both imaging modalities provide a sufficient assessment of the hyperacute brain infarct, with significant correlation between them and the clinical condition at admission. Perfusion CT allows differentiation of the penumbra and infarct core region with significant predictive value of follow-up infarct volume and clinical outcome.
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Affiliation(s)
- Sotirios Bisdas
- Department of Neuroradiology, Hannover Medical School, Hannover, Germany.
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Ryoo JW, Na DG, Kim SS, Lee KH, Lee SJ, Chung CS, Choi DS. Malignant Middle Cerebral Artery Infarction in Hyperacute Ischemic Stroke. J Comput Assist Tomogr 2004; 28:55-62. [PMID: 14716233 DOI: 10.1097/00004728-200401000-00009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE The purpose of this study was to compare the incidence of large hypoperfusion (greater than two-thirds of MCA territory) on computed tomography (CT) perfusion maps between hyperacute middle cerebral artery (MCA) stroke patients without or with malignant cerebral edema. METHODS Twenty-seven patients diagnosed with a hyperacute MCA stroke who had an initial National Institutes of Health Stroke Scale (NIHSS) score greater than 10 were included. Multiphasic perfusion CT was performed within 6 hours of symptom onset. Patients were divided into 2 groups: the malignant group (n = 11), composed of patients who died within 7 days, and the nonmalignant group, which included all other patients (n = 16). Unenhanced CT and CT perfusion maps were assessed and compared between the 2 groups with special emphasis on examining the CT findings, including hyperdense MCA sign, large (greater than two-thirds) hypoattenuation and hypoperfusion in the MCA territory, and hypoattenuation in the basal ganglia and other vascular territories. RESULTS The incidence of large hypoattenuation (greater than two-thirds of MCA territory) on unenhanced CT and large hypoperfusion on CT perfusion maps differed significantly between the 2 groups (P < 0.05). Large hypoperfusion on the CT total perfusion map was most accurate (93%) among various CT findings for the prediction of malignant MCA infarction with high sensitivity (91%), specificity (94%), and positive predictive value (91%). CONCLUSIONS The incidence of large hypoperfusion on a CT perfusion map was higher in the malignant group than the nonmalignant group. CT perfusion maps may provide added information about cerebral perfusion and could be a useful predictor of malignant MCA infarction.
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Affiliation(s)
- Jae Wook Ryoo
- Department of Radiology, Sungkyunkwan University School of Medicine, Samsung Medical Center, 50 Ilwon-Dong, Kangnam-Ku, Seoul 135-710, Korea
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Georgiadis D, Schwab S, Hacke W. Critical Care of the Patient with Acute Stroke. Stroke 2004. [DOI: 10.1016/b0-44-306600-0/50060-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Provenzale JM, Jahan R, Naidich TP, Fox AJ. Assessment of the patient with hyperacute stroke: imaging and therapy. Radiology 2003; 229:347-59. [PMID: 14595138 DOI: 10.1148/radiol.2292020402] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neuroimaging is an important part of the assessment of patients with hyperacute stroke. As new treatments that may reverse cerebral ischemia have been developed, the role of neuroimaging has changed from simply anatomic depiction of early infarction to identification, by means of physiologic (rather than simply anatomic) information, of regions that are at risk for infarction. The goal of such imaging techniques is to monitor successes and complications of recently developed treatments such as thrombolysis.
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Affiliation(s)
- James M Provenzale
- Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710-3808, USA
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Wardlaw JM, West TM, Sandercock PAG, Lewis SC, Mielke O. Visible infarction on computed tomography is an independent predictor of poor functional outcome after stroke, and not of haemorrhagic transformation. J Neurol Neurosurg Psychiatry 2003; 74:452-8. [PMID: 12640062 PMCID: PMC1738395 DOI: 10.1136/jnnp.74.4.452] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To examine a very large dataset to provide a robust answer to the question of whether visible infarction on computed tomography was (a) an independent predictor of functional outcome at all times up to 48 hours after stroke, and (b) independently associated with haemorrhagic transformation, with or without antithrombotic treatment. METHODS The study assessed associations between visible infarction, time to randomisation, baseline neurological deficit, stroke syndrome, allocated aspirin or heparin treatment, recurrent haemorrhagic stroke, early death and six month functional outcome in the International Stroke Trial. RESULTS Of 12 550 patients, 6267 (50%) had visible infarction up to 48 hours after stroke. The prevalence of visible infarction increased with increasing time from onset and extent of the stroke syndrome. Visible infarction was independently associated with increased death within 14 days (odds ratio (OR) 1.17, 95% CI 1.02 to 1.35), and of death or dependency at six months (OR 1.42, 95% CI 1.31 to 1.55), an absolute increase of 13%, or 130 per 1000 more dead or dependent patients with visible infarction than without it. There was no significant independent relation between visible infarction and fatal or non-fatal haemorrhagic transformation, or interaction between visible infarction and aspirin or heparin treatment allocation with six month functional outcome. CONCLUSIONS Visible infarction on computed tomography up to 48 hours after stroke is an independent adverse prognostic sign.
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Affiliation(s)
- J M Wardlaw
- Department of Clinical Neurosciences, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, Scotland, UK.
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Furuya Y, Hlatky R, Valadka AB, Diaz P, Robertson CS. Comparison of cerebral blood flow in computed tomographic hypodense areas of the brain in head-injured patients. Neurosurgery 2003; 52:340-5; discussion 345-6. [PMID: 12535362 DOI: 10.1227/01.neu.0000043931.83041.aa] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2002] [Accepted: 10/14/2002] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Hypodense lesions identified on computed tomographic (CT) scans are often assumed to indicate ischemia. The purpose of this study was to investigate regional cerebral blood flow (rCBF) in hypodense areas of the brain after severe traumatic brain injury. METHODS CBF was measured by stable xenon-enhanced CT scans. Hypodense areas were identified, and rCBF values as well as CT density were averaged for the region. RESULTS Thirty (60%) of the 50 patients had a total of 45 hypodense regions, which were associated with either contusion (n = 30) or areas of infarction (n = 15). rCBF in the hypodense regions was variable, ranging from a low of 3.3 to a high of 72.5 ml/100 g/min. The cause of the lesion was the major factor associated with the level of rCBF. Although the average decrease in CT density was similar for the two types of lesions, the average rCBF was significantly lower and the difference in rCBF between the lesion and the contralateral side was greater when the hypodense lesion was associated with a contusion. A critical reduction in rCBF (<20 ml/100 g/min) was found in 19 (63%) of the hypodense regions associated with contusions but in only 4 (27%) of those from areas of infarction. CONCLUSION Hypodensity on plain CT scans does not always indicate reduction in CBF. This association was found more commonly when the low-density area was associated with a contusion. In hypodense areas associated with infarction, rCBF was variable and not commonly in the ischemic range at the time the CBF measurement was obtained.
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MESH Headings
- Adult
- Blood Flow Velocity/physiology
- Brain/blood supply
- Brain Concussion/diagnostic imaging
- Brain Concussion/surgery
- Cerebral Infarction/diagnostic imaging
- Cerebral Infarction/surgery
- Dominance, Cerebral/physiology
- Female
- Glasgow Coma Scale
- Head Injuries, Closed/diagnostic imaging
- Head Injuries, Closed/surgery
- Hematoma, Epidural, Cranial/diagnostic imaging
- Hematoma, Epidural, Cranial/surgery
- Hematoma, Subdural, Acute/diagnostic imaging
- Hematoma, Subdural, Acute/surgery
- Humans
- Male
- Middle Aged
- Radiography
- Regional Blood Flow/physiology
- Sensitivity and Specificity
- Xenon
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Affiliation(s)
- Yu Furuya
- Department of Neurosurgery, St. Marianna University School of Medicine, Kawasaki, Japan
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