CT Angiography and Doppler Sonography for Emergency Assessment in Acute Basilar Artery Ischemia

Background and Purpose-Patients with acute ischemic stroke and intracranial arterial obstructions have a poor prognosis and a high probability of deteriorating at 24 hours. We aimed to evaluate the diagnostic accuracy of power motion mode Doppler (PMD-TCD) compared with CT angiography as standard in diagnosing intracranial arterial obstructions in patients presenting with ischemic stroke of Ͻ24 hours. Methods-Consecutive patients presenting with acute ischemic stroke to the emergency department underwent highresolution brain CT angiography and PMD-TCD within a 6-hour difference. Results-A total of 100 patients were included. PMD-TCD demonstrated 34 intracranial occlusions and CTA 33. There were 6 false-positives and 4 false-negative diagnoses with PMD-TCD. PMD-TCD had a positive likelihood ratio of 13.7, a negative likelihood ratio of 0.19, sensitivity of 81.8%, and specificity of 94% for detecting an arterial occlusion in any specific artery.Results for the middle cerebral artery were: positive likelihood ratio 24.6, negative likelihood ratio 0.045, sensitivity 95.6%, and specificity 96.2%. For the anterior circulation, the results were: positive likelihood ratio 18.5, negative likelihood ratio 0, sensitivity 100%, and specificity 94.5%. For the posterior circulation, the results were: positive likelihood ratio Ͼ1000, negative likelihood ratio 0.42, sensitivity 57.1%, and specificity 100%. The post-test probability for any occluded artery when PMD-TCD was positive increased for any admission National Institutes of Health Stroke Scale score but was especially remarkable for National Institutes of Health Stroke Scale scores between 7 and 15 points. Conclusions-PMD-TCD is valid compared with CT angiography for the diagnosis of arterial occlusions in patients with acute ischemic stroke, especially in middle cerebral artery obstructions.

Section: Discussionsupporting

confidence: 93%

Accuracy of Transcranial Doppler Compared With CT Angiography in Diagnosing Arterial Obstructions in Acute Ischemic Strokes

Brunser

Lavados

Hoppe

et al. 2009

“…Previous studies comparing CTA with conventional angiography by Knauth et al 5 showed agreement in 11 of 11 patients (100%), by Brandt et al 6 When CTA is compared with all DSAs, both acute and subacute, agreement is still good (86%) despite the fact that subacute angiograms might differ from the acute CTA because of spontaneous recanalization or subsequent reocclusion. When CTA is compared with all possible follow-up testing (DSA, MRA, and brain imaging studies), there is overall confirmation of the CTA reading in 80% of cases.…”

Section: Discussionmentioning

confidence: 85%

“…CT angiography (CTA) is potentially useful for this purpose: previous studies evaluating CTA in acute stroke have demonstrated its feasibility and have shown good correlation with other vascular imaging modalities. [5][6][7][8] We sought to provide further data on the accuracy of CTA in acute stroke and to investigate its ability to predict clinical outcome.…”

mentioning

confidence: 99%

CT Angiography in Acute Ischemic Stroke

Verro

Tanenbaum

Borden

et al. 2002

Background and Purpose — We sought to evaluate the ability of CT angiography (CTA) to determine vessel occlusion before acute stroke treatment and to predict its impact on patient outcome. Methods — Consecutive patients with acute focal neurological deficits received immediate brain CTA. Occlusion on CTA was correlated with other neuroimaging studies and clinical outcome. Results — Diagnostic CTA was obtained in 54 patients: catheter angiography (digital subtraction angiography) confirmed the CTA findings in 12 of 14 patients (86%). CTA results were consistent with at least 1 other neuroimaging study in 40 of 50 patients (80%). Patients with occlusion on CTA had significantly worse discharge National Institutes of Health Stroke Scale (NIHSS) score (mean 14.3 versus 4.5, P =0.0023). In multivariate analysis, both CTA-determined presence of occlusion and admission NIHSS score were independent predictors of clinical outcome. Conclusions — In our study there was good agreement between acute CTA interpretation and subsequent imaging studies. CTA evidence of occlusion correlated strongly and independently with poor clinical outcome. CTA provides relevant data regarding vessel patency in acute stroke, which may be of value in selecting patients for aggressive treatment.

“…Although high-level evidence regarding the role of thrombolytic therapy in such cases is lacking, it is clear that early diagnosis is essential if direct or supportive measures are to be of benefit. 1 Computed tomography angiography (CTA) has been shown to be highly accurate in detecting acute basilar artery occlusion, 2,3 and other forms of advanced imaging, including MRI with perfusion imaging, have been used to assess the viability of tissue in patients with basilar artery occlusion. 4 Despite this, most community medical centers do not yet routinely perform advanced imaging in stroke patients, but rather continue to rely on unenhanced CT for their clinical decision-making.…”

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confidence: 99%

Hyperdense Basilar Artery Sign on Unenhanced CT Predicts Thrombus and Outcome in Acute Posterior Circulation Stroke

Goldmakher

Camargo

Furie

et al. 2009

Background and Purpose-In acute stroke patients, the presence of a hyperdense middle cerebral artery sign on unenhanced CT is a specific but insensitive indicator of acute thrombosis. Our purpose was to determine whether the hyperdense basilar artery (HDBA) sign has utility in detecting thrombosis and predicting outcome in patients presenting with signs and symptoms of posterior circulation stroke. Methods-Unenhanced CT scans obtained within 24 hours of symptom onset in 95 patients with suspected posterior circulation stroke were reviewed. Three neuroimagers blinded to clinical outcome and results of the concurrent CT angiography (which served as the reference standard) rated presence of HDBA sign on a 5-point scale for level of certainty (1ϭdefinitely absent; 5ϭdefinitely present). Receiver operating characteristic curve analysis was performed. Short-term outcome was measured by discharge National Institute of Health Stroke Scale (NIHSS) scores; long-term outcome was measured by 6-month modified Rankin score (dichotomized, poor outcome defined as modified Rankin score Ͼ2). The following variables were correlated with short-term and long-term outcome by univariate analysis: HDBA sign, age, sex, time from stroke onset to imaging, admission NIHSS, history of stroke/TIA, atrial fibrillation, coronary artery disease, hypertension, diabetes, hypercholesterolemia, tobacco use, and thrombolysis. Variables showing correlation with PϽ0.1 were included in multiple regression analysis. Results-Using a level of certainty cutoff score of Ն4 (probable, definite), HDBA sign had 71% sensitivity, 98% specificity, 94% accuracy, 83% positive predictive value, and 95% negative predictive value for basilar artery occlusion. In univariate analysis, factors significantly correlated with discharge NIHSS were: admission NIHSS (PϽ0.0001; rϭ0.77), HDBA sign (Pϭ0.01), and diabetes (Pϭ0.02). Factors showing significant correlation or association with poor long-term outcome were age (Pϭ0.02), admission NIHSS (Pϭ0.007), HDBA sign (Pϭ0.02), and history of stroke or TIA (Pϭ0.007). The odds ratio of HDBA sign for predicting poor long-term outcome was 5.3 (95% CI, 1.1-33.3). In multiple regression analysis, the only independent predictors of discharge NIHSS were admission NIHSS (PϽ0.0001) and HDBA sign (Pϭ0.004). Significant independent predictors of poor long-term outcome were age (Pϭ0.02), admission NIHSS (Pϭ0.008), history of stroke/TIA (Pϭ0.03), and HDBA sign (Pϭ0.05). Conclusion-In patients presenting with a high pretest probability of posterior circulation stroke based on clinical symptoms, the presence of the HDBA sign on unenhanced CT is a strong predictor of basilar artery thrombosis, and both short-and long-term outcome.