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Pulli B, Schaefer PW, Hakimelahi R, Chaudhry ZA, Lev MH, Hirsch JA, González RG, Yoo AJ. Acute ischemic stroke: infarct core estimation on CT angiography source images depends on CT angiography protocol. Radiology 2011; 262:593-604. [PMID: 22187626 DOI: 10.1148/radiol.11110896] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To test whether the relationship between acute ischemic infarct size on concurrent computed tomographic (CT) angiography source images and diffusion-weighted (DW) magnetic resonance images is dependent on the parameters of CT angiography acquisition protocols. MATERIALS AND METHODS This retrospective study had institutional review board approval, and all records were HIPAA compliant. Data in 100 patients with anterior-circulation acute ischemic stroke and large vessel occlusion who underwent concurrent CT angiography and DW imaging within 9 hours of symptom onset were analyzed. Measured areas of hyperintensity at acute DW imaging were used as the standard of reference for infarct size. Information regarding lesion volumes and CT angiography protocol parameters was collected for each patient. For analysis, patients were divided into two groups on the basis of CT angiography protocol differences (patients in group 1 were imaged with the older, slower protocol). Intermethod agreement for infarct size was evaluated by using the Wilcoxon signed rank test, as well as by using Spearman correlation and Bland-Altman analysis. Multivariate analysis was performed to identify predictors of marked (≥20%) overestimation of infarct size on CT angiography source images. RESULTS In group 1 (n=35), median hypoattenuation volumes on CT angiography source images were slightly underestimated compared with DW imaging hyperintensity volumes (33.0 vs 41.6 mL, P=.01; ratio=0.83), with high correlation (ρ=0.91). In group 2 (n=65), median volume on CT angiography source images was much larger than that on DW images (94.8 vs 17.8 mL, P<.0001; ratio=3.5), with poor correlation (ρ=0.49). This overestimation on CT angiography source images would have inappropriately excluded from reperfusion therapy 44.4% or 90.3% of patients eligible according to DW imaging criteria on the basis of a 100-mL absolute threshold or a 20% or greater mismatch threshold, respectively. Atrial fibrillation and shorter time from contrast material injection to image acquisition were independent predictors of marked (≥20%) infarct size overestimation on CT angiography source images. CONCLUSION CT angiography protocol changes designed to speed imaging and optimize arterial opacification are associated with significant overestimation of infarct size on CT angiography source images.
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Affiliation(s)
- Benjamin Pulli
- Division of Neuroradiology and Interventional Neuroradiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Gray 241, Boston, MA 02114, USA
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Moon WJ, Choi JW, Roh HG, Lim SD, Koh YC. Imaging parameters of high grade gliomas in relation to the MGMT promoter methylation status: the CT, diffusion tensor imaging, and perfusion MR imaging. Neuroradiology 2011; 54:555-63. [PMID: 21833736 DOI: 10.1007/s00234-011-0947-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 07/26/2011] [Indexed: 01/20/2023]
Abstract
INTRODUCTION We hypothesized that methyl-guanine methyl transferase (MGMT) promoter methylation status, a predictor of the chemosensitivity for high grade gliomas (HGGs), may be associated with computed tomography (CT)/magnetic resonance (MR) imaging variables. METHODS Out of 38 consecutive patients with HGGs, 24 patients whose MGMT promoter methylation status was available [12 men and 12 women; median age, 49 years; age range, 22-79 years; WHO grade III (n = 7), WHO grade IV (n = 17)] were enrolled retrospectively. CT attenuation, apparent diffusion coefficient (ADC), fractional anisotropy (FA), and relative cerebral blood volume (rCBV) were measured for enhancing tumors. Qualitative imaging features were also analyzed. Mann-Whitney and Fisher's exact tests were used to evaluate relationships between MGMT promoter methylation status and imaging variables. RESULTS Maximum CT attenuation was significantly lower in the methylated MGMT promoter group than that in the unmethylated MGMT promoter group (30.3 ± 9.5 HU versus 39.2 ± 4.7 HU, respectively, p = 0.009). While ADC values tended to be higher in the methylated group than in the unmethylated group (p = 0.055), ADC ratio was significantly higher, and the FA and FA ratios were significantly lower in the methylated group than in the unmethylated group (p = 0.032, p = 0.006 and p = 0.007, respectively). In contrast, rCBV ratio did not differ between the two groups (p = 0.380). Regarding imaging features, only ill-defined margin was seen more frequently in the methylated group than in the unmethylated group (45.5% versus 7.7%, respectively, p = 0.048). CONCLUSION Preoperative imaging can predict MGMT promoter methylation status, which is of paramount importance for predicting treatment response to chemotherapy with an alkylating agent.
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Affiliation(s)
- Won-Jin Moon
- Department of Radiology, Konkuk University School of Medicine, 4-12, Hwayang-dong, Gwanjin-gu, Seoul, 143-792, South Korea.
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Abstract
Stroke is a heterogeneous syndrome caused by multiple mechanisms, all of which result in disruption of normal cerebral blood flow and thereby cause cerebral dysfunction. Its early diagnosis is important as its treatment is dependent on the time elapsed since ictus. Delay in diagnosis and treatment translates into increase neuronal loss and thereby increased morbidity. CT scan, and in particular perfusion CT, has helped greatly in the early diagnosis of stroke. This article is an endeavor to explain the pathophysiology of cerebral ischemia and the role of CT perfusion in detecting it.
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Affiliation(s)
- Niranjan Khandelwal
- Department of Radiodiagnosis and Imaging, PGIMER, Sector 12, Chandigarh, India
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104
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Seo HS, Na DG, Kim JH, Kim KW, Son KR. Correlation between CT and diffusion-weighted imaging of acute cerebral ischemia in a rat model. AJNR Am J Neuroradiol 2011; 32:728-33. [PMID: 21330394 DOI: 10.3174/ajnr.a2362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The quantitative temporal relationship between changes in CT attenuation, ADC value, and DWI signal intensity of acute ischemic tissue has not yet been determined in an animal model. This study was performed to determine the temporal relationship between CT attenuation, ADC value, and DWI signal intensity in acute cerebral ischemia. MATERIALS AND METHODS CT and DWI were performed at 1, 3, 5, 7, and 9 hours after left MCA occlusion in 11 rats. Mean values for CT attenuation, ADC, and DWI signal intensity were determined for the ischemic hemisphere and contralateral normal hemisphere. Temporal changes in each mean value and the relationship between CT attenuation and ADC value and DWI signal intensity were evaluated. RESULTS The decrease of CT attenuation and the increase of DWI signal intensity occurred gradually after MCA occlusion, while ADC value decreased rapidly at 1 hour. Although correlation was significant between time and rCT or rDWI (P<.01, respectively), no correlation between time and rADC was found (P=.33). There was a significant linear correlation between rCT and rDWI (r=0.497, P<.01), but no significant correlation between rCT and rADC (P=.509) was found. CONCLUSIONS The temporal change in CT attenuation was different from that in ADC value with no significant linear correlation between CT attenuation and ADC value for acute cerebral ischemia. However, rCT and rDWI showed a modest correlation.
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Affiliation(s)
- H S Seo
- Department of Radiology, Seoul National University College of Medicine, Seoul, Korea
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105
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Abstract
In this article the individual components of multimodal computed tomography and multimodal magnetic resonance imaging are discussed, the current status of neuroimaging for the evaluation of the acute ischemic stroke is presented, and the potential role of a combined multimodal stroke protocol is addressed.
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Affiliation(s)
- Carlos Leiva-Salinas
- Division of Neuroradiology, Department of Radiology, University of Virginia, 1215 Lee Street-New Hospital, 1st Floor, Room 1011, PO Box 800170, Charlottesville, VA 22908, USA
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Morita S, Suzuki M, Iizuka K. False-negative diffusion-weighted MRI in acute cerebellar stroke. Auris Nasus Larynx 2011; 38:577-82. [PMID: 21330074 DOI: 10.1016/j.anl.2011.01.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 01/18/2011] [Accepted: 01/20/2011] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To heighten physician awareness of false-negative diffusion-weighted (DW) magnetic-resonance imaging findings in patients with acute cerebellar infarction and the importance of periodically observing nystagmus after symptom onset. METHODS Between April 2007 and March 2010, we retrospectively reviewed the medical records of eight patients who had all complained of severe isolated vertigo or dizziness, and had visited an emergency department within 2-6h of its onset. Intracranial findings on initial magnetic resonance imaging (MRI) were normal. All patients had consulted our department for peripheral vestibular disorders. We periodically observed spontaneous and positional nystagmus 6-24h after symptom onset. RESULTS In three of the patients, the direction and/or type of nystagmus changed periodically. In four of the patients, severe vertigo, nausea, and vomiting persisted after the nystagmus had been resolved. A repeat MR examination was performed 24h after symptom onset because of the atypical pattern of nystagmus for benign peripheral vestibular disorders, at which point cerebellar infarction was detected. CONCLUSIONS Physicians who examine patients with acute severe isolated vertigo or dizziness should consider the possibility of false-negative DW MRI findings in case of hyperacute ischemic stroke. It is important to observe the nystagmus periodically after onset. The MR examination should be repeated more than 24h after symptom onset in patients with an atypical pattern of nystagmus for benign peripheral vestibular disorders.
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Affiliation(s)
- Shinya Morita
- Department of Otolaryngology, Kushiro City General Hospital, 1-12 Shunkodai, Kushiro, Hokkaido, Japan.
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107
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108
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Abstract
The imaging workup for patients with suspected acute ischemic stroke has advanced significantly over the past few years. Evaluation is no longer limited to noncontrast computed tomography, but now frequently also includes vascular and perfusion imaging. Although acute stroke imaging has made significant progress in the last few decades with the development of multimodal approaches, there are still many unanswered questions regarding their appropriate use in the setting of daily patient care. It is important for all physicians taking care of stroke patients to be familiar with current multimodal computed tomography and magnetic resonance imaging techniques, including their strengths, limitations, and their role in guiding therapy.
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Affiliation(s)
- Carlos Leiva-Salinas
- Department of Radiology, Neuroradiology Division, University of Virginia, Charlottesville, Virginia USA
| | - Max Wintermark
- Department of Radiology, Neuroradiology Division, University of Virginia, Charlottesville, Virginia USA
| | - Chelsea S. Kidwell
- Department of Neurology, Georgetown University Medical Center, 4000 Reservoir Road, NW, Building D, Suite 150, Washington, DC 20007 USA
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109
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Lopes L. Perfusion CT: Additional Diagnostic and Clinical Information in MCA Stroke. Neuroradiol J 2010; 23:651-8. [DOI: 10.1177/197140091002300602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 09/04/2010] [Indexed: 11/16/2022] Open
Affiliation(s)
- L. Lopes
- Neuroradiology Unit, Radiology Department, Prof. Dr. Fernando Fonseca Hospital; Lisbon, Portugal
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110
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Sharma M, Fox AJ, Symons S, Jairath A, Aviv RI. CT angiographic source images: flow- or volume-weighted? AJNR Am J Neuroradiol 2010; 32:359-64. [PMID: 21051518 DOI: 10.3174/ajnr.a2282] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE CTA-SI have been previously reported to correlate with CBV. We hypothesized that CTA-SI performed by modern multisection CT scanners are CBF-, not CBV-weighted. MATERIALS AND METHODS Sixty-four consecutive patients with anterior circulation stroke symptoms were selected from a stroke data base between June 2007 and January 2009. Two independent blinded readers calculated defect volumes of CTA-SI and PCCT, CBF, and CBV images. Spearman correlation of lesion volumes was performed. Linear regression and residual analysis demonstrated factors associated with outliers for CTA or PCCT for CBF and CBV volumes. RESULTS We found a strong positive correlation between CTA with CBF (r = 0.89, P < .0001) and between PCCT and CBV (r = 0.79, P < .0001). CTA to CBV (r = 0.5, P < .0001) and PCCT to CBF (r = 0.52, P < .0001) correlations were weaker. Positive CTA outliers had lower ASPECTS (P = .01), larger baseline CTA (149 ± 46 cm(3) versus 83 ± 32 cm(3); P = .002, respectively), and final infarct (190 ± 100 cm(3) versus 80 ± 50 cm(3); P = .09, respectively) volumes than nonoutliers. No baseline features were significantly related to PCCT outliers. There was no difference in the vessel occlusion sites for positive or negative outliers for CTA or PCCT (P = .55 and P = 1.00, respectively). CONCLUSIONS Our results indicate that CTA-SI are CBF- rather than CBV-weighted.
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Affiliation(s)
- M Sharma
- Department of Medical Imaging, University of Toronto, Sunnybrook Health Sciences Centre, Ontario, Canada
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112
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Huisa BN, Raman R, Ernstrom K, Tafreshi G, Stemer A, Meyer BC, Hemmen T. Alberta Stroke Program Early CT Score (ASPECTS) in patients with wake-up stroke. J Stroke Cerebrovasc Dis 2010; 19:475-9. [PMID: 20719536 DOI: 10.1016/j.jstrokecerebrovasdis.2010.03.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/15/2010] [Accepted: 03/30/2010] [Indexed: 11/28/2022] Open
Abstract
One-quarter of ischemic strokes occur during sleep, and affected patients are excluded from thrombolytic therapy because of an unknown time of stroke onset. It has been suggested that early ischemic changes detected on computed tomography (CT) are similar in patients with acute stroke and patients who recently awoke with stroke. We compared head CT scans using the Alberta Stroke Program Early CT Score (ASPECTS) in patients who were likely to suffer their stroke during sleep (awoke group) and a control group of patients with stroke of known onset time. Patients were recruited from a prospectively collected acute stroke database. The awoke group was defined as all ischemic stroke patients who were "last seen normal" more than 4 hours ago, arrived between 4 a.m. and 10 a.m., and underwent head CT within 15 hours of the time last seen normal. The control group was randomly selected from patients who underwent head CT within 4 hours of stroke onset. The ASPECTS evaluations were performed by investigators blinded to patient group and time of onset. A modified Rankin Scale (mRS) score was available in 15 awoke patients and 46 control patients at 90 days after stroke. Twenty-eight awoke patients and 68 control patients had suitable imaging for the ASPECTS. Baseline demographic characteristics and risk factors were similar in the 2 groups. The dichotomized ASPECTS analysis (≤7 vs 8-10) showed no significant differences between the groups. ASPECTS was 8-10 in 89.3% the awoke group and 95.6% in the control group (P=.353). There was a trend toward higher 90-day mRS score (0-1) in the awoke group versus controls (73% vs 45%; P=.079). Initial ASPECTS was similar in patients with wake-up stroke and those with 4 hours of symptoms. This suggests that a subset of wake-up stroke patients might be suitable for thrombolytic therapy.
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Affiliation(s)
- Branko N Huisa
- Department of Neurosciences, University of California San Diego, San Diego, California 92103-8466, USA.
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113
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Huisman MHB, Velthuis BK, Kappelle LJ, Biessels GJ. Perfusion CT in suspected ischaemic stroke: red flags that should have been blue. J Neurol 2010; 258:155-8. [PMID: 20703886 PMCID: PMC3015460 DOI: 10.1007/s00415-010-5690-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 07/21/2010] [Accepted: 07/21/2010] [Indexed: 10/28/2022]
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Kidwell CS, Wintermark M. The role of CT and MRI in the emergency evaluation of persons with suspected stroke. Curr Neurol Neurosci Rep 2010; 10:21-8. [PMID: 20425222 DOI: 10.1007/s11910-009-0075-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As a growing number of therapeutic treatment options for acute stroke are being introduced, multimodal acute neuroimaging is assuming a growing role in the initial evaluation and management of patients. Multimodal neuroimaging, using either a CT or MRI approach, can identify the type, location, and severity of the lesion (ischemia or hemorrhage); the status of the cerebral vasculature; the status of cerebral perfusion; and the existence and extent of the ischemic penumbra. Both acute and long-term treatment decisions for stroke patients can then be optimally guided by this information.
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Affiliation(s)
- Chelsea S Kidwell
- Georgetown University Medical Center, 4000 Reservoir Road, Northwest, Building D, Suite 150, Washington, DC, 20007, USA.
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115
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Hopyan J, Ciarallo A, Dowlatshahi D, Howard P, John V, Yeung R, Zhang L, Kim J, MacFarlane G, Lee TY, Aviv RI. Certainty of stroke diagnosis: incremental benefit with CT perfusion over noncontrast CT and CT angiography. Radiology 2010; 255:142-53. [PMID: 20308452 DOI: 10.1148/radiol.09091021] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To systematically evaluate the diagnostic benefits and inter- and intraobserver reliability of an incremental computed tomographic (CT) protocol in the confirmation of clinically suspected stroke, with combined imaging and clinical data as the reference standard. MATERIALS AND METHODS Institutional review board approval was obtained, and participants gave informed consent. A total of 191 patients (mean age, 67 years +/- 16 [standard deviation]; 105 men) with strokelike symptoms of no more than 3 hours duration were recruited. Blinded review was performed by four readers with limited stroke imaging experience. Diagnostic confidence was recorded on a five-point scale. Logistic regression analysis was used to calculate the difference between the real and observed diagnoses, adjusting for confidence. Predictive effects of observed diagnostic performance and confidence score were quantified with the entropy r(2) value. Sensitivity, specificity, and confidence intervals were calculated while accounting for multiple reader assessments. Receiver operating characteristic (ROC) analyses, including area under the ROC curve, were conducted for three modalities in combination with confidence score. Inter- and intraobserver agreement was established with the Cohen kappa statistic. RESULTS The final diagnosis was infarct in 64% of the patients, transient ischemic attack in 18%, and stroke mimic in 17%. Large-vessel occlusion occurred in 70% of the patients with an infarct. Sensitivity for stroke determination with noncontrast CT, CT angiography, and CT perfusion increased by 12.4% over that with noncontrast CT and CT angiography and by 18.2% over that with only noncontrast CT for a confidence level of 4 or higher. The incremental protocol was more likely to enable confirmation of clinical stroke diagnosis (odds ratio, 13.3) than was noncontrast CT and CT angiography (odds ratio, 6.4) or noncontrast CT alone (odds ratio, 3.3), The area under the ROC curve was 0.67 for the combination of noncontrast CT and confidence score, 0.72 for the combination of CT angiography and confidence score, and 0.81 for the combination of CT perfusion and confidence score. Inter- and intraobserver agreement increased with progressive sequence use. CONCLUSION An incremental stroke protocol that includes CT perfusion increases diagnostic performance for stroke diagnosis and inter- and intraobserver agreement.
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Affiliation(s)
- Julia Hopyan
- Department of Diagnostic Imaging, Division of Neuroradiology, Room AG 31, Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, ON, Canada M4N 3M5
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Struffert T, Deuerling-Zheng Y, Kloska S, Engelhorn T, Strother CM, Kalender WA, Köhrmann M, Schwab S, Doerfler A. Flat detector CT in the evaluation of brain parenchyma, intracranial vasculature, and cerebral blood volume: a pilot study in patients with acute symptoms of cerebral ischemia. AJNR Am J Neuroradiol 2010; 31:1462-9. [PMID: 20378700 DOI: 10.3174/ajnr.a2083] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The viability of both brain parenchyma and vascular anatomy is important in estimating the risk and potential benefit of revascularization in patients with acute cerebral ischemia. We tested the hypothesis that when used in conjunction with IV contrast, FD-CT imaging would provide both anatomic and physiologic information that would correlate well with that obtained by using standard multisection CT techniques. MATERIALS AND METHODS Imaging of brain parenchyma (FD-CT), cerebral vasculature (FD-CTA), and cerebral blood volume (FD-CBV) was performed in 10 patients. All patients also underwent conventional multisection CT, CTA, CTP (including CBV, CTP-CBV), and conventional catheter angiography. Correlation of the corresponding images was performed by 2 experienced neuroradiologists. RESULTS There was good correlation of the CBV color maps and absolute values between FD-CBV and CTP-CBV (correlation coefficient, 0.72; P < .001). The Bland-Altman test showed a mean difference of CBV values between FD-CT and CTP-CBV of 0.04 ± 0.55 mL/100 mL. All vascular lesions identified with standard CTA were also visualized with FD-CTA. Visualization of brain parenchyma by using FD-CT was poor compared with that obtained by using standard CT. CONCLUSIONS Both imaging of the cerebral vasculature and measurements of CBV by using FD-CT are feasible. The resulting vascular images and CBV measurements compared well with ones made by using standard CT techniques. The ability to measure CBV and also visualize cerebral vasculature in the angiography suite may offer significant advantages in the management of patients. FD-CT is not yet equivalent to CT for imaging of brain parenchyma.
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Affiliation(s)
- T Struffert
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
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Hotter B, Pittl S, Ebinger M, Oepen G, Jegzentis K, Kudo K, Rozanski M, Schmidt WU, Brunecker P, Xu C, Martus P, Endres M, Jungehülsing GJ, Villringer A, Fiebach JB. Prospective study on the mismatch concept in acute stroke patients within the first 24 h after symptom onset - 1000Plus study. BMC Neurol 2009; 9:60. [PMID: 19995432 PMCID: PMC3224745 DOI: 10.1186/1471-2377-9-60] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 12/08/2009] [Indexed: 12/04/2022] Open
Abstract
Background The mismatch between diffusion weighted imaging (DWI) lesion and perfusion imaging (PI) deficit volumes has been used as a surrogate of ischemic penumbra. This pathophysiology-orientated patient selection criterion for acute stroke treatment may have the potential to replace a fixed time window. Two recent trials - DEFUSE and EPITHET - investigated the mismatch concept in a multicenter prospective approach. Both studies randomized highly selected patients (n = 74/n = 100) and therefore confirmation in a large consecutive cohort is desirable. We here present a single-center approach with a 3T MR tomograph next door to the stroke unit, serving as a bridge from the ER to the stroke unit to screen all TIA and stroke patients. Our primary hypothesis is that the prognostic value of the mismatch concept is depending on the vessel status. Primary endpoint of the study is infarct growth determined by imaging, secondary endpoints are neurological deficit on day 5-7 and functional outcome after 3 months. Methods and design 1000Plus is a prospective, single centre observational study with 1200 patients to be recruited. All patients admitted to the ER with the clinical diagnosis of an acute cerebrovascular event within 24 hours after symptom onset are screened. Examinations are performed on day 1, 2 and 5-7 with neurological examination including National Institute of Health Stroke Scale (NIHSS) scoring and stroke MRI including T2*, DWI, TOF-MRA, FLAIR and PI. PI is conducted as dynamic susceptibility-enhanced contrast imaging with a fixed dosage of 5 ml 1 M Gadobutrol. For post-processing of PI, mean transit time (MTT) parametric images are determined by deconvolution of the arterial input function (AIF) which is automatically identified. Lesion volumes and mismatch are measured and calculated by using the perfusion mismatch analyzer (PMA) software from ASIST-Japan. Primary endpoint is the change of infarct size between baseline examination and day 5-7 follow up. Discussions The aim of this study is to describe the incidence of mismatch and the predictive value of PI for final lesion size and functional outcome depending on delay of imaging and vascular recanalization. It is crucial to standardize PI for future randomized clinical trials as for individual therapeutic decisions and we expect to contribute to this challenging task. Trial Registration clinicaltrials.gov NCT00715533
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Affiliation(s)
- Benjamin Hotter
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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Brazzelli M, Sandercock PA, Chappell FM, Celani MG, Righetti E, Arestis N, Wardlaw JM, Deeks JJ. Magnetic resonance imaging versus computed tomography for detection of acute vascular lesions in patients presenting with stroke symptoms. Cochrane Database Syst Rev 2009:CD007424. [PMID: 19821415 DOI: 10.1002/14651858.cd007424.pub2] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) is increasingly used for the diagnosis of acute ischaemic stroke but its sensitivity for the early detection of intracerebral haemorrhage has been debated. Computed tomography (CT) is extensively used in the clinical management of acute stroke, especially for the rapid exclusion of intracerebral haemorrhage. OBJECTIVES To compare the diagnostic accuracy of diffusion-weighted MRI (DWI) and CT for acute ischaemic stroke, and to estimate the diagnostic accuracy of MRI for acute haemorrhagic stroke. SEARCH STRATEGY We searched MEDLINE and EMBASE (January 1995 to March 2009) and perused bibliographies of relevant studies for additional references. SELECTION CRITERIA We selected studies that either compared DWI and CT in the same patients for detection of ischaemic stroke or examined the utility of MRI for detection of haemorrhagic stroke, had imaging performed within 12 hours of stroke onset, and presented sufficient data to allow construction of contingency tables. DATA COLLECTION AND ANALYSIS Three authors independently extracted data on study characteristics and measures of accuracy. We assessed data on ischaemic stroke using random-effects and fixed-effect meta-analyses. MAIN RESULTS Eight studies with a total of 308 participants met our inclusion criteria. Seven studies contributed to the assessment of ischaemic stroke and two studies to the assessment of haemorrhagic stroke. The spectrum of patients was relatively narrow in all studies, sample sizes were small, there was substantial incorporation bias, and blinding procedures were often incomplete. Amongst the patients subsequently confirmed to have acute ischaemic stroke (161/226), the summary estimates for DWI were: sensitivity 0.99 (95% CI 0.23 to 1.00), specificity 0.92 (95% CI 0.83 to 0.97). The summary estimates for CT were: sensitivity 0.39 (95% CI 0.16 to 0.69), specificity 1.00 (95% CI 0.94 to 1.00). The two studies on haemorrhagic stroke reported high estimates for diffusion-weighted and gradient-echo sequences but had inconsistent reference standards. We did not calculate overall estimates for these two studies. We were not able to assess practicality or cost-effectiveness issues. AUTHORS' CONCLUSIONS DWI appears to be more sensitive than CT for the early detection of ischaemic stroke in highly selected patients. However, the variability in the quality of included studies and the presence of spectrum and incorporation biases render the reliability and generalisability of observed results questionable. Further well-designed studies without methodological biases, in more representative patient samples, with practicality and cost estimates are now needed to determine which patients should undergo MRI and which CT in suspected acute stroke.
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Affiliation(s)
- Miriam Brazzelli
- Division of Clinical Neurosciences, University of Edinburgh, Bramwell Dott Building, Western General Hospital, Crewe Road, Edinburgh, UK, EH4 2XU
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Puetz V, Dzialowski I, Hill MD, Demchuk AM. The Alberta Stroke Program Early CT Score in Clinical Practice: What have We Learned? Int J Stroke 2009; 4:354-64. [PMID: 19765124 DOI: 10.1111/j.1747-4949.2009.00337.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The introduction of brain imaging with computed tomography revolutionised the treatment of patients with acute ischaemic stroke. With the visual differentiation of haemorrhagic stroke from ischaemic stroke, thrombolytic therapy became feasible. The Alberta Stroke Program Early CT Score was devised to quantify the extent of early ischaemic changes in the middle cerebral artery territory on noncontrast computed tomography. With its systematic approach, the score is simple and reliable. However, the assessment of early ischaemic changes and Alberta Stroke Program Early CT scoring require training. The Alberta Stroke Program Early CT Score is a strong predictor of functional outcome. Furthermore, the effectiveness of intraarterial thrombolysis in patients with middle cerebral artery occlusion shows effect modification by the Alberta Stroke Program Early CT Score. This review summarises the Alberta Stroke Program Early CT Score methodology. We illustrate current knowledge regarding Alberta Stroke Program Early CT Score applied to clinical trials and comment on how Alberta Stroke Program Early CT Score may facilitate clinical treatment decision making and future trial design. Moreover, we introduce a modification of the Alberta Stroke Program Early CT Score methodology that disregards isolated cortical swelling, i.e. focal brain swelling without associated parenchymal hypoattenuation, as early ischaemic changes in the Alberta Stroke Program Early CT Score system.
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Affiliation(s)
- V. Puetz
- Department of Neurology, Dresden University Stroke Centre, University of Technology Dresden, Dresden, Germany
- Department of Clinical Neurosciences, Calgary Stroke Program, University of Calgary, Calgary, AB, Canada
| | - I. Dzialowski
- Department of Neurology, Dresden University Stroke Centre, University of Technology Dresden, Dresden, Germany
- Department of Clinical Neurosciences, Calgary Stroke Program, University of Calgary, Calgary, AB, Canada
| | - M. D. Hill
- Department of Clinical Neurosciences, Calgary Stroke Program, University of Calgary, Calgary, AB, Canada
| | - A. M. Demchuk
- Department of Clinical Neurosciences, Calgary Stroke Program, University of Calgary, Calgary, AB, Canada
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120
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121
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Imaging in Acute Stroke – a Personal View*. Clin Neuroradiol 2009; 19:20-30. [DOI: 10.1007/s00062-009-8030-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Accepted: 10/26/2008] [Indexed: 11/27/2022]
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122
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Siemonsen S, Mouridsen K, Holst B, Ries T, Finsterbusch J, Thomalla G, Ostergaard L, Fiehler J. Quantitative T2 Values Predict Time From Symptom Onset in Acute Stroke Patients. Stroke 2009; 40:1612-6. [PMID: 19325153 DOI: 10.1161/strokeaha.108.542548] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
We hypothesize that in comparison to diffusion-weighted imaging, quantitative T2 values (qT2) are more directly related to water uptake in ischemic tissue, depending on time from symptom onset. We measured the increase of qT2 in the infarct core to quantify the correlation between time from symptom onset and change in qT2.
Methods—
Thirty-six patients with acute ischemic stroke in the territory of the proximal middle cerebral artery underwent MRI including diffusion-weighted imaging, fluid-attenuated inversion recovery, and a triple-echo T2 sequence (calculation of T2 maps) within 6 hours after symptom onset. Regions of decreased apparent diffusion coefficient <550×10
−9
mm
2
/sec were defined and superimposed onto the corresponding T2 map and the unaffected side in the horizontally flipped maps. Differences of T2/apparent diffusion coefficient values between affected and unaffected side were calculated (differences of T2/differences of apparent diffusion coefficient). Fluid-attenuated inversion recovery images were rated for lesion visibility.
Results—
Differences of T2 showed a significant correlation with time from symptom onset (
R
=0.580;
P
<0.001). T2 values measured in patients with visible fluid-attenuated inversion recovery lesions were significantly higher than in those without visible hyperintensity (
P
<0.001). The accuracy of qT2 to predict a time from symptom onset <3 hours was 0.794, whereas the corresponding accuracy for visual assessment of fluid-attenuated inversion recovery images was 0.676.
Conclusions—
T2 values demonstrated a strong correlation with time from onset, suggesting different pathophysiologic mechanisms than diffusion restriction. Whereas fluid-attenuated inversion recovery only provides binary information on lesion visibility, T2 values correlate well with time from symptom onset, and are free from operator bias, increasing reproducibility to determine time from symptom onset.
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Affiliation(s)
- Susanne Siemonsen
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Kim Mouridsen
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Brigitte Holst
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Thorsten Ries
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Jürgen Finsterbusch
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Götz Thomalla
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Leif Ostergaard
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Jens Fiehler
- From the Department of Neuroradiology (S.S., B.H., T.R., J. Fiehler), Systems Neuroscience (J. Finsterbusch), and Department of Neurology (G.T.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Center for Functionally Integrative Neuroscience (CFIN) (K.M., L.O.), Department of Neuroradiology, Aarhus University Hospital, Denmark
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Abstract
A multimodal CT protocol provides a comprehensive noninvasive survey of acute stroke patients with accurate demonstration of the site of arterial occlusion and its hemodynamic tissue status. It combines widespread availability with the ability to provide functional characterization of cerebral ischemia, and could potentially allow more accurate selection of candidates for acute stroke reperfusion therapy. This article discusses the individual components of multimodal CT and addresses the potential role of a combined multimodal CT stroke protocol in acute stroke therapy.
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Affiliation(s)
- Carlos J Ledezma
- Morristown Memorial Hospital, Department of Radiology, 100 Madison Avenue, Morristown, NJ 07962, USA
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124
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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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125
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Stroke – imaging and therapy. Clin Neuroradiol 2008. [DOI: 10.1017/cbo9780511551925.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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126
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Abstract
Combining perfusion CT (CTP) with CT angiography (CTA) and noncontrast CT (NCCT) provides much more information about acute stroke pathophysiology than NCCT alone. This multimodal CT approach adds only a few minutes to the standard NCCT and is more accessible and rapidly available in most centres than MRI. CTP can distinguish between infarct core and penumbra, which is not possible with NCCT alone. A small infarct core and large penumbra, plus the presence of vessel occlusion on CTA may be an ideal imaging 'target' for thrombolysis. To date, multimodal CT has predominantly been assessed in hemispheric stroke due to its limited spatial coverage. This will become less of an issue as slice coverage continues to improve with new generation CT scanners. Apart from the concepts above, more specific CTP and CTA criteria that increase (or decrease) probability of response to thrombolytic treatment are yet to be determined. Nonetheless, CTP thus has the potential to improve patient selection for thrombolysis.
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Affiliation(s)
- Mark W Parsons
- Department of Neurology, John Hunter Hospital, and Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia.
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127
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Leitlinien zum Management von Patienten mit akutem Hirninfarkt oder TIA der Europäischen Schlaganfallorganisation 2008. DER NERVENARZT 2008; 79:936-57. [DOI: 10.1007/s00115-008-2531-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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128
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Moustafa RR, Baron JC. Clinical review: Imaging in ischaemic stroke--implications for acute management. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 11:227. [PMID: 17875224 PMCID: PMC2556770 DOI: 10.1186/cc5973] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Imaging has become a cornerstone of stroke management, translating pathophysiological knowledge to everyday decision-making. Plain computed tomography is widely available and remains the standard for initial assessment: the technique rules out haemorrhage, visualizes the occluding thrombus and identifies early tissue hypodensity and swelling, which have different implications for thrombolysis. Based on evidence from positron emission tomography (PET), however, multimodal imaging is increasingly advocated. Computed tomography perfusion and angiography provide information on the occlusion site, on recanalization and on the extent of salvageable tissue. Magnetic resonance-based diffusion-weighted imaging (DWI) has exquisite sensitivity for acute ischaemia, however, and there is increasingly robust evidence that DWI combined with perfusion-weighted magnetic resonance imaging (PWI) and angiography improves functional outcome by selecting appropriate patients for thrombolysis (small DWI lesion but large PWI defect) and by ruling out those who would receive no benefit or might be harmed (very large DWI lesion, no PWI defect), especially beyond the 3-hour time window. Combined DWI–PWI also helps predict malignant oedema formation and therefore helps guide selection for early brain decompression. Finally, DWI–PWI is increasingly used for patient selection in therapeutic trials. Although further methodological developments are awaited, implementing the individual pathophysiologic diagnosis based on multimodal imaging is already refining indications for thrombolysis and offers new opportunities for management of acute stroke patients.
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Affiliation(s)
- Ramez Reda Moustafa
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Jean-Claude Baron
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 2QQ, UK
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129
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Veronel D, Ringelstein A, Cohnen M, Yong M, Siebler M, Seitz RJ. Systemic thrombolysis based on CT or MRI stroke imaging. J Neuroimaging 2008; 18:381-7. [PMID: 18494775 DOI: 10.1111/j.1552-6569.2007.00230.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Computed tomography (CT) and magnetic resonance imaging (MRI) are tools of investigation in acute stroke. We wondered if the additional information offered by MRI outweighs the disadvantage of its longer scanning duration for systemic thrombolysis. METHODS Two hundred ninety-four consecutive patients (66 +/- 13 years) were subjected to thrombolysis between 1999 and 2004. Inclusion criteria were ischemic infarction, scoring at entry and discharge with the NIH stroke scale and modified Rankin scale, systemic thrombolysis within 3 hours after symptom onset, multimodal MRI or standard CT. Subgroup analysis of 42 patients compared standard CT with CT and CT angiography. RESULTS Patients were similarly affected on admission (P > .1). At discharge, 6 days after stroke onset, the patients investigated with MRI were less impaired than those investigated with standard CT (P < .05). Symptomatic hemorrhage was rare in both groups. Also, patients investigated with CT and CT angiography were less impaired at discharge than those with standard CT (P < .02). A multifactorial regression showed that systolic blood pressure, glucose level and initial neurological impairment determined the neurological outcome at discharge. CONCLUSIONS Systolic blood pressure, glucose level and neurological impairment but not the imaging modality determined the neurological outcome following systemic thrombolysis in the 3-hour window.
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Affiliation(s)
- Dimitro Veronel
- Department of Neurology, University Hospital Düsseldorf, Düsseldorf, Germany
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130
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Guidelines for management of ischaemic stroke and transient ischaemic attack 2008. Cerebrovasc Dis 2008; 25:457-507. [PMID: 18477843 DOI: 10.1159/000131083] [Citation(s) in RCA: 1673] [Impact Index Per Article: 104.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Accepted: 03/27/2008] [Indexed: 12/13/2022] Open
Abstract
This article represents the update of the European Stroke Initiative Recommendations for Stroke Management. These guidelines cover both ischaemic stroke and transient ischaemic attacks, which are now considered to be a single entity. The article covers referral and emergency management, Stroke Unit service, diagnostics, primary and secondary prevention, general stroke treatment, specific treatment including acute management, management of complications, and rehabilitation.
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131
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Lin K, Rapalino O, Law M, Babb JS, Siller KA, Pramanik BK. Accuracy of the Alberta Stroke Program Early CT Score during the first 3 hours of middle cerebral artery stroke: comparison of noncontrast CT, CT angiography source images, and CT perfusion. AJNR Am J Neuroradiol 2008; 29:931-6. [PMID: 18272553 DOI: 10.3174/ajnr.a0975] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The Alberta Stroke Program Early CT Score (ASPECTS) is a reliable method of delineating the extent of middle cerebral artery (MCA) stroke. Our aim was to retrospectively compare the accuracy of ASPECTS on noncontrast CT, CT angiography (CTA) source images, and CT perfusion maps of cerebral blood volume (CBV) during the first 3 hours of middle cerebral artery (MCA) stroke. MATERIALS AND METHODS First-time patients with MCA stroke who presented <3 hours from symptom onset and were evaluated by noncontrast CT/CTA/CT perfusion, had confirmed acute nonlacunar MCA infarct on diffusion-weighted MR imaging (DWI) within 7 days, and had follow-up angiography were included. Patients were excluded for persistent MCA occlusion or stenosis. Two raters through consensus assigned an ASPECTS on the noncontrast CT, CTA source images, and the section-selective (2 x 12 mm coverage) CT perfusion CBV maps. ASPECTS on follow-up DWI served as the reference standard. For each CT technique, the detection rates of regional infarction, the mean ASPECTS, and the linear correlation to final ASPECTS were determined and compared. P values <.05 were considered significant. RESULTS Twenty-eight patients satisfied the criteria with DWI performed at a mean of 50.3 hours (range, 22-125 hours) post-CT imaging. Of 280 ASPECTS regions, 100 were infarcted on DWI. The accuracy of noncontrast CT, CTA source images, and CT perfusion CBV for detecting regional infarct was 80.0%, 84.3%, and 96.8%, respectively (P < .0001). The mean ASPECTSs of noncontrast CT, CTA source images, CT perfusion CBV, and DWI were 8.4 +/- 1.8, 8.0 +/- 1.8, 6.8 +/- 1.9, and 6.5 +/- 1.8, respectively. The mean noncontrast CT and CTA source image ASPECTS was different from that of DWI (P < .05). Correlation of noncontrast CT, CTA source images, and CT perfusion CBV ASPECTS with final ASPECTS was r(2) = 0.34, r(2) = 0.42, and r(2) = 0.91, respectively. CONCLUSION In a retrospective cohort of MCA infarcts imaged <3 hours from stroke onset, ASPECTS was most accurately determined on CT perfusion CBV maps.
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Affiliation(s)
- K Lin
- Department of Radiology, New York University Medical Center, New York, NY, USA.
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132
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Endovascular treatment in proximal and intracranial carotid occlusion 9 hours after symptom onset. Neuroradiology 2008; 50:599-604. [DOI: 10.1007/s00234-008-0385-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2008] [Accepted: 03/11/2008] [Indexed: 10/22/2022]
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133
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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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134
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Okazaki S, Moriwaki H, Minematsu K, Naritomi H. Extremely Early Computed Tomography Signs in Hyperacute Ischemic Stroke as a Predictor of Parenchymal Hematoma. Cerebrovasc Dis 2008; 25:241-6. [DOI: 10.1159/000113862] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Accepted: 09/21/2007] [Indexed: 11/19/2022] Open
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135
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Lee JY, Kim SH, Lee MS, Park SH, Lee SS. Prediction of clinical outcome with baseline and 24-hour perfusion CT in acute middle cerebral artery territory ischemic stroke treated with intravenous recanalization therapy. Neuroradiology 2008; 50:391-6. [DOI: 10.1007/s00234-007-0358-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Accepted: 12/14/2007] [Indexed: 11/28/2022]
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136
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Agrawal A, Joharapurkar SR, Gharde P. Ischemic stroke in a child mistaken as functional disorder. Clin Neurol Neurosurg 2007; 109:876-9. [PMID: 17719721 DOI: 10.1016/j.clineuro.2007.07.007] [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: 05/21/2007] [Revised: 07/03/2007] [Accepted: 07/13/2007] [Indexed: 12/21/2022]
Abstract
Stroke is a rare but increasingly recognized disorder in children. Lack of published clinical trials and experience in most institutions has resulted in significant challenges for clinicians who manage children with stroke. We report a case of 16-year-old male child who was presented with history of sudden onset of weakness 2 months back and before he could consult the physician, the weakness improved significantly and a misdiagnosis of functional disorder was made at a peripheral hospital. Children with stroke may have subtle manifestations and to make an early diagnosis of stroke in children there is need of awareness about this entity in children.
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Affiliation(s)
- Amit Agrawal
- Department of Surgery, Datta Meghe Institute of Medical Sciences, Sawangi (Meghe), Wardha 442005, Maharashtra, India.
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137
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Aviv RI, Mandelcorn J, Chakraborty S, Gladstone D, Malham S, Tomlinson G, Fox AJ, Symons S. Alberta Stroke Program Early CT Scoring of CT perfusion in early stroke visualization and assessment. AJNR Am J Neuroradiol 2007; 28:1975-80. [PMID: 17921237 DOI: 10.3174/ajnr.a0689] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Qualitative CT perfusion (CTP) assessment by using the Alberta Stroke Program Early CT Score (ASPECTS) allows rapid calculation of infarct extent for middle cerebral artery infarcts. Published thresholds exist for noncontrast CT (NCCT) ASPECTS, which may distinguish outcome/complication risk, but early ischemic signs are difficult to detect. We hypothesized that different ASPECTS thresholds exist for CTP parameters versus NCCT and that these may be superior at predicting clinical and radiologic outcome in the acute setting. MATERIALS AND METHODS Thirty-six baseline acute stroke NCCT and CTP studies within 3 hours of symptoms were blindly reviewed by 3 neuroradiologists, and ASPECTS were assigned. Treatment response was defined as major neurologic improvement when a > or =8-point National Institutes of Health Stroke Scale improvement at 24 hours occurred. Follow-up NCCT ASPECTS and 90-day modified Rankin score (mRS) were radiologic and clinical reference standards. Receiver operating characteristic curves derived optimal thresholds for outcome. RESULTS Cerebral blood volume and NCCT ASPECTS had similar radiologic correlations (0.6 and 0.5, respectively) and best predicted infarct size in the absence of major neurologic improvement. A NCCT ASPECT threshold of 7 and a cerebral blood volume threshold of 8 discriminated patients with poor follow-up scans (P < .0002 and P = .0001) and mRS < or =2 (P = .001 and P < .001). Only cerebral blood volume predicted major neurologic improvement (P = .02). Interobserver agreement was substantial (intraclass correlation coefficient, 0.69). Cerebral blood volume ASPECTS sensitivity, specificity, positive predictive value, and negative predictive value for clinical outcome were 60%, 100%, 100%, and 45%, respectively. No patients with cerebral blood volume ASPECTS <8 achieved good clinical outcome. CONCLUSION Cerebral blood volume ASPECTS is equivalent to NCCT for predicting radiologic outcome but may have an additional benefit in predicting patients with major neurologic improvement.
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Affiliation(s)
- R I Aviv
- Division of Neuroradiology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
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138
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Tountopoulou A, Ahl B, Weissenborn K, Becker H, Goetz F. Intra-arterial thrombolysis using rt-PA in patients with acute stroke due to vessel occlusion of anterior and/or posterior cerebral circulation. Neuroradiology 2007; 50:75-83. [DOI: 10.1007/s00234-007-0306-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 09/02/2007] [Indexed: 10/22/2022]
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139
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Muir KW, Baird-Gunning J, Walker L, Baird T, McCormick M, Coutts SB. Can the Ischemic Penumbra Be Identified on Noncontrast CT of Acute Stroke? Stroke 2007; 38:2485-90. [PMID: 17673708 DOI: 10.1161/strokeaha.107.484592] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Early ischemic changes on noncontrast CT in acute stroke include both hypoattenuation and brain swelling, which may have different pathophysiological significance.
Methods—
Noncontrast CT and CT perfusion brain scans from patients with suspected acute stroke <6 hours after onset were reviewed. Five raters independently scored noncontrast CTs blind to clinical data using the Alberta Stroke Program Early CT Score (ASPECTS). Each ASPECTS region was scored as hypodense or swollen. A separate reviewer measured time to peak and cerebral blood volume in each ASPECTS region on CT perfusion. Time to peak and cerebral blood volume were compared for each region categorized as normal, hypodense, or isodense and swollen.
Results—
Scans of 32 subjects a median 155 minutes after onset yielded 228 regions with both CT perfusion and noncontrast CT data. Isodense swelling was associated with significantly higher cerebral blood volume (
P
=0.016) and with penumbral perfusion (posttest:pretest likelihood ratio 1.44 [95% CI: 0.68 to 2.90]), whereas hypodensity was associated with more severe time to peak delay and with core perfusion (likelihood ratio 3.47 [95% CI: 1.87 to 6.34]). Neither isodense swelling nor hypodensity was sensitive for prediction of perfusion pattern, but appearances were highly specific (87.2% and 91.0% for penumbra and core, respectively). Intrarater agreement was good or excellent, but interrater agreement for both hypodensity and swelling was poor.
Conclusions—
Regions exhibiting hypoattenuation are likely to represent the infarct core, whereas regions that are isodense and swollen have increased cerebral blood volume and are more likely to signify penumbral perfusion. Although noncontrast CT is not sensitive for detection of core and penumbra, appearances are specific. Some information on tissue viability can therefore be obtained from noncontrast CT.
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Affiliation(s)
- Keith W Muir
- Division of Clinical Neurosciences, University of Glasgow, Glasgow, Scotland, UK.
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140
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Sasaki T, Sasaki M, Hanari T, Gakumazawa H, Noshi Y, Okumura M. Improvement in image quality of noncontrast head images in multidetector-row CT by volume helical scanning with a three-dimensional denoising filter. ACTA ACUST UNITED AC 2007; 25:368-72. [PMID: 17705009 DOI: 10.1007/s11604-007-0145-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 03/19/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE The aim of this study was to improve the contrast-to-noise ratio on noncontrast head computed tomography (CT) images, which are crucial for assessing patients with acute ischemic stroke. We applied a technique combining volume helical scanning with a three-dimensional (3D) denoising filter. MATERIALS AND METHODS We scanned phantoms for low-contrast resolutions and helical/cone-beam artifacts as well as stroke patients using a 16-row multidetector-row CT (MDCT) unit. Volume helical scans with 1-mm collimation and nonhelical scans with 8-mm thickness were performed. From the 1-mm thick volume data, 8-mm thick contiguous images were generated before and after applying a 3D denoising filter. RESULTS On images stacked from volume data, the contrast-to-noise ratio was significantly improved by the 3D denoising filter and was nearly the same as that on nonhelical images. On stacked volume images, artifacts due to the cone beam and the helical scan were increased with larger helical pitches, but bone-related streak artifacts in the posterior fossa and underneath the calvarium were reduced when compared with nonhelical images. CONCLUSION Volume helical scan with a 3D denoising filter effectively improves image quality in noncontrast head MDCT images.
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Affiliation(s)
- Tadashi Sasaki
- Center for Radiological Sciences, Iwate Medical University Hospital, 19-1 Uchimaru, Morioka, 020-8505, Japan.
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141
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von Kummer R, Dzialowski I. Should MRI replace CT for the routine evaluation of acute stroke? NATURE CLINICAL PRACTICE. NEUROLOGY 2007; 3:428-9. [PMID: 17646861 DOI: 10.1038/ncpneuro0532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 04/30/2007] [Indexed: 05/16/2023]
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142
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Dzialowski I, Klotz E, Goericke S, Doerfler A, Forsting M, von Kummer R. Ischemic Brain Tissue Water Content: CT Monitoring during Middle Cerebral Artery Occlusion and Reperfusion in Rats1. Radiology 2007; 243:720-6. [PMID: 17400758 DOI: 10.1148/radiol.2432060137] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively perform computed tomography (CT) in rats to determine whether ischemic edema can be reversed by using early arterial reperfusion. MATERIALS AND METHODS This study was approved by the local animal protection committee. A suture model was used to occlude the right middle cerebral artery (MCA) in rats for 1, 2, 3, or 4 hours. X-ray attenuation of the brain was measured directly before reperfusion and repeatedly during reperfusion for up to 24 hours. Infarct volumes were determined with triphenyltetrazolium chloride staining. Means of attenuation and infarct volume were compared between hemispheres and groups with a paired t test and analysis of variance. Mixed linear models were applied to compare attenuation among groups over time. RESULTS During MCA occlusion, attenuation decreased to 69.3 HU +/- 1.9 (standard deviation) after 1 hour (n=12), 66.6 HU +/- 2.0 after 2 hours (n=10), 65.4 HU +/- 2.9 after 3 hours (n=11), and 64.1 HU +/- 1.8 after 4 hours (n=9) (P<.0001). After reperfusion, attenuation remained stable in the 1-hour occlusion group (P=.16) but further and steadily declined in the 2-, 3-, and 4-hour occlusion groups (P<.001). Attenuation during reperfusion in the 1-hour occlusion group differed significantly from that in the 2-, 3-, and 4-hour occlusion groups. CONCLUSION CT is able to help monitor ischemic edema after MCA occlusion and reperfusion. Ischemic brain edema was not consistently reversible with reperfusion, even after 1 hour of occlusion, and further increased with reperfusion induced at 2 hours or later.
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Affiliation(s)
- Imanuel Dzialowski
- Department of Neuroradiology, Universitaetsklinikum Carl Gustav Carus, University of Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.
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143
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Aviv R, Shelef I, Malam S, Chakraborty S, Sahlas D, Tomlinson G, Symons S, Fox A. Early stroke detection and extent: impact of experience and the role of computed tomography angiography source images. Clin Radiol 2007; 62:447-52. [DOI: 10.1016/j.crad.2006.11.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 11/03/2006] [Accepted: 11/08/2006] [Indexed: 10/23/2022]
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144
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Przelaskowski A, Sklinda K, Bargieł P, Walecki J, Biesiadko-Matuszewska M, Kazubek M. Improved early stroke detection: Wavelet-based perception enhancement of computerized tomography exams. Comput Biol Med 2007; 37:524-33. [PMID: 16999952 DOI: 10.1016/j.compbiomed.2006.08.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nonenhanced computerized tomography (CT) exams were used to detect acute stroke by notification of hypodense area. Infarction perception improvement by data denoising and local contrast enhancement in multi-scale domain was proposed. The wavelet-based image processing method enhanced the subtlest signs of hypodensity, which were often invisible in standard CT scan review. Thus improved detection efficiency of perceptual ischemic changes was investigated. Data processing became more effective by initial segmentation of brain tissue and extraction of regions susceptible to tissue density changes. The new method was experimentally verified. Sensitivity of stroke diagnosis increased to 56.3% in comparison to 12.5% of standard CT scan preview.
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Affiliation(s)
- A Przelaskowski
- Institute of Radioelectronics, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warszawa, Poland.
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145
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Butcher KS, Lee SB, Parsons MW, Allport L, Fink J, Tress B, Donnan G, Davis SM. Differential Prognosis of Isolated Cortical Swelling and Hypoattenuation on CT in Acute Stroke. Stroke 2007; 38:941-7. [PMID: 17272776 DOI: 10.1161/01.str.0000258099.69995.b6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
The Alberta Stroke Program Early CT Score (ASPECTS) is a validated method of assessing parenchymal ischemic changes, including focal swelling and hypoattenuation. The hypothesis that these signs result from different pathophysiological processes was tested by comparing CT with diffusion and perfusion- weighted MRI.
Methods—
MRI and CT were performed, within 2 hours of each other, in 30 ischemic stroke patients <17 hours after symptom onset. Relative apparent diffusion coefficient, relative cerebral blood flow, and relative cerebral blood volume were calculated for individual cortical ASPECTS regions. Regional infarction was assessed on days 3 to 5.
Results—
Isolated focal swelling was seen in 25 ASPECTS cortical regions from 6 patients. Cortical hypoattenuation was observed in 25 regions from 11 patients. Median relative apparent diffusion coefficient was significantly lower in hypoattenuated regions (0.84; interquartile range, 0.66 to 0.91) relative to those with focal swelling (0.97; interquartile range, 0.91 to 1.01;
P
<0.001). Median relative cerebral blood flow in focal swelling regions (81.0%; interquartile range, 70.4 to 93.0) was similar to that of tissue that appeared normal on CT (71.8%; interquartile range, 47.1 to 94.5). In hypoattenuated regions, relative cerebral blood flow was significantly decreased (37.0%; interquartile range, 25.6 to 70.2;
P
=0.002). Median relative cerebral blood volume was increased (121.1%; interquartile range, 112.0 to 130.3) in focal swelling regions, relative to normal-appearing tissue (94.7%; interquartile range, 62.0 to 114.6;
P
<0.001), but decreased in hypoattenuated regions (58.9%; interquartile range, 47.5 to 92.7;
P
=0.012). Infarction occurred in all hypoattenuated regions, but only in 32% of those with focal swelling.
Conclusions—
Elevated relative cerebral blood volume and normal relative apparent diffusion coefficient in ASPECTS regions with focal swelling on CT is consistent with penumbral tissue. Isolated focal swelling is not always associated with infarction. These results support removal of focal swelling from the ASPECTS system.
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Affiliation(s)
- Kenneth S Butcher
- Department of Neurology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia.
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146
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Affiliation(s)
- Seung-Koo Lee
- Department of Radiology, Yonsei University College of Medicine, Korea.
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147
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Davis DP, Robertson T, Imbesi SG. Diffusion-weighted magnetic resonance imaging versus computed tomography in the diagnosis of acute ischemic stroke. J Emerg Med 2006; 31:269-77. [PMID: 16982360 DOI: 10.1016/j.jemermed.2005.10.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 06/16/2005] [Accepted: 10/04/2005] [Indexed: 11/21/2022]
Abstract
Current treatment protocols using reperfusion therapy for acute ischemic stroke rely on non-contrast computed tomography (NCCT), with most indications including the absence of acute hemorrhage or large volume of infarction in the presence of clinical signs and symptoms. This predictably results in a significant incidence of the administration of reperfusion therapy to patients with "stroke mimics," such as migraine headache or Todd's paralysis after a seizure. Diffusion-weighted imaging (DWI) is a technique based on magnetic resonance imaging (MRI) that may be more sensitive and specific for acute cerebral ischemia than NCCT. In addition, data for techniques such as perfusion-weighted imaging can be acquired with minimal additional time required. This may allow better risk assessment of a clinical response to reperfusion therapy vs. the possibility of hemorrhagic complications. This article describes a methodical review of studies comparing the sensitivity, specificity, positive predictive value, and negative predictive value of DWI vs. NCCT in the evaluation of acute ischemic stroke. Data from studies meeting our screening criteria are combined to produce overall values for each.
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Affiliation(s)
- Daniel P Davis
- Department of Emergency Medicine, University of California at San Diego, San Diego, California, USA
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148
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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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149
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Fainardi E, Tagliaferri MF, Compagnone C, Tanfani A, Cocciolo F, Battaglia R, Frattarelli M, Pascarella R, Targa L, Chieregato A. Regional cerebral blood flow levels as measured by xenon-CT in vascular territorial low-density areas after subarachnoid hemorrhage are not always ischemic. Neuroradiology 2006; 48:685-90. [PMID: 16804690 DOI: 10.1007/s00234-006-0111-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Accepted: 04/10/2006] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The aim of this study was to assess regional cerebral blood flow (rCBV) in areas of CT hypoattenuation appearing in the postoperative period in patients treated for aneurysmal subarachnoid hemorrhage (SAH) using xenon-enhanced CT scanning (Xe-CT). METHODS We analyzed 15 patients (5 male and 10 female; mean age 49.7+/-12.1 years) with SAH on CT performed on admission to hospital and who showed a low-density area within a well-defined vascular territory on CT scans after clipping or coiling of a saccular aneurysm. All zones of hypoattenuation were larger than 1 cm(2) and showed signs of a mass effect suggesting a subacute phase of evolution. Two aneurysms were detected in two patients. Aneurysms were located in the middle cerebral artery (n=7), in the anterior communicating artery (n=6), in the internal carotid artery (n=3), and in the posterior communicating artery (n=1). Treatments were surgical (n=8), endovascular (n=2) or both (n=1). A total of 36 Xe-CT studies were performed and rCBF values were measured in two different regions of interest (ROI): the low-density area, and an area of normal-appearing brain tissue located symmetrically in the contralateral hemisphere. RESULTS rCBF levels were significantly lower in the low-density area than in the contralateral normal-appearing area (P<0.01). In the low-density areas, irreversible ischemia (CBF <10 ml/100 g per minute) was present in 11/36 lesions (30.6%), ischemic penumbra (CBF 10-20 ml/100 g per minute) and oligemia (CBF 20-34 ml/100 g per minute) in 8/36 lesions (22.2%), relative hyperemia (CBF 34-55 ml/100 g per minute) in 7/36 lesions (19.4%), and absolute hyperemia (CBF >55 ml/100 g per minute) in 2/36 lesions (5.6%). CONCLUSION Our study confirmed that rCBF is reduced in new low-density lesions related to specific vascular territories. However, only about one-third of the lesions showed rCBF levels consistent with irreversible ischemia and in a relatively high proportion of lesions, rCBF levels indicated penumbral, oligemic and hyperemic areas.
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Affiliation(s)
- E Fainardi
- Neuroradiology Unit, Department of Neurosciences, Arcispedale S Anna, Corso della Giovecca 203, 44100, Ferrara, Italy.
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150
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Strbian D, Karjalainen-Lindsberg ML, Tatlisumak T, Lindsberg PJ. Cerebral mast cells regulate early ischemic brain swelling and neutrophil accumulation. J Cereb Blood Flow Metab 2006; 26:605-12. [PMID: 16163296 DOI: 10.1038/sj.jcbfm.9600228] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We previously observed degranulated mast cells (MC) in association with perivascular brain edema formation during focal cerebral ischemia. Brain MC are typically located perivascularly and contain potent fast-acting vasoactive and proteolytic substances. We examined in a rat model of transient middle cerebral artery occlusion (MCAO) whether, in the early phase of ischemia, MC regulate microcirculation, the blood-brain barrier (BBB) permeability, and edema formation. First, animals received MC inhibitor (cromoglycate), MC-degranulating drug (compound 48/80), or saline. Thereafter, we performed transient MCAO in gene-manipulated MC-deficient rats and their wild-type (WT) littermates, calculating brain swelling, visualizing BBB leakage by intravenously administered Evans blue albumin, and determining neutrophil infiltration with light microscopy. Cerebral blood flow, monitored by laser-Doppler flowmetry in separate experiments, was similar among pharmacological treatments. Ischemic swelling resulted in increased hemispheric volume of 13.4%+/-1.0% in controls, 8.1%+/-0.4% (39% reduction) after cromoglycate, and 25.2%+/-2.0% (89% increase) after compound 48/80 (P<0.05). Early ischemic BBB leakage was reduced by 51% after cromoglycate, and 50% enhanced by compound 48/80 (P<0.05). The cromoglycate group showed 37% less postischemic neutrophil infiltration than did controls (P<0.05). Furthermore, MC-deficient rats responded to focal ischemia with 58% less brain swelling (6.7%+/-1.2%) than did their WT littermates (15.8%+/-1.4%, P<0.05). Blood-brain barrier damage was 47% lower in MC-deficient rats than in the WT (P<0.05). Neutrophil infiltration after MCAO was decreased 47% in MC-deficient rats in comparison to WT (P<0.05). Pharmacological MC inhibition thus appears to deserve further investigation regarding reduction of brain swelling and inflammation early after stroke.
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Affiliation(s)
- Daniel Strbian
- Department of Neurology, Helsinki University Central Hospital and Neuroscience Program, University of Helsinki, Helsinki, Finland
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