Sensitivity of Hyperdense Basilar Artery Sign on Non-Enhanced Computed Tomography

Purpose The hyperdense basilar artery sign (HBAS) is an indicator of vessel occlusion on non contrast-enhanced computer tomography (NECT) in acute stroke patients. Since basilar artery occlusion (BAO) is associated with a high mortality and morbidity, its early detection is of great clinical value. We sought to analyze the influence of density measurement as well as a normalized ratio of Hounsfield unit/hematocrit (HU/Hct) ratio on the detection of BAO on NECT in patients with suspected BAO. Materials and Methods 102 patients with clinically suspected BAO were examined with NECT followed immediately by Multidetector computed tomography Angiography. Two observers independently analyzed the images regarding the presence or absence of HBAS on NECT and performed HU measurements in the basilar artery. Receiver operating characteristic curve analysis was performed to determine the optimal density threshold for BAO using attenuation measurements or HU/Hct ratio. Results Sensitivity of visual detection of the HBAS on NECT was relatively low 81% (95%-CI, 54–95%) while specificity was high 91% (95%-CI, 82–96%). The highest sensitivity was achieved by the combination of visual assessment and additional quantitative attenuation measurements applying a cut-off value of 46.5 HU with 94% sensitivity and 81% specificity for BAO. A HU/Hct ratio >1.32 revealed sensitivity of 88% (95%-CI, 60–98%) and specificity of 84% (95%-CI, 74–90%). Conclusion In patients with clinically suspected acute BAO the combination of visual assessment and additional attenuation measurement with a cut-off value of 46.5 HU is a reliable approach with high sensitivity in the detection of BAO on NECT.

[1]  M. Reiser,et al.  Different Imaging Strategies in Patients With Possible Basilar Artery Occlusion , 2015, Stroke.

[2]  J. Fiehler,et al.  Thoracic Pathologies on Scout Views and Bolus Tracking Slices for Computed Tomographic Cerebral Angiography , 2015, Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren.

[3]  J. Fiehler,et al.  Sensitivity of visual and quantitative detection of middle cerebral artery occlusion on non-contrast-enhanced computed tomography , 2014, Neuroradiology.

[4]  J. Wardlaw,et al.  Imaging of acute stroke prior to treatment: current practice and evolving techniques. , 2014, The British journal of radiology.

[5]  F. De Keyzer,et al.  CT Density Measurement and H:H Ratio Are Useful in Diagnosing Acute Cerebral Venous Sinus Thrombosis , 2013, American Journal of Neuroradiology.

[6]  Jean-Christophe Ferré,et al.  Systematic combined noncontrast CT-CT angiography in the management of unexplained nontraumatic coma. , 2013, The American journal of emergency medicine.

[7]  A. Algra,et al.  Time is Brain(stem) in Basilar Artery Occlusion , 2012, Stroke.

[8]  J. Bernardes,et al.  The limits of agreement and the intraclass correlation coefficient may be inconsistent in the interpretation of agreement. , 2011, Journal of clinical epidemiology.

[9]  D. Tanné,et al.  Treatment and outcomes of acute basilar artery occlusion in the Basilar Artery International Cooperation Study (BASICS): a prospective registry study , 2009, The Lancet Neurology.

[10]  K. Furie,et al.  Hyperdense Basilar Artery Sign on Unenhanced CT Predicts Thrombus and Outcome in Acute Posterior Circulation Stroke , 2009, Stroke.

[11]  F. Buonanno,et al.  CT Angiography in the Rapid Triage of Patients with Hyperacute Stroke to Intraarterial Thrombolysis: Accuracy in the Detection of Large Vessel Thrombus , 2001, Journal of computer assisted tomography.

[12]  W. Hacke,et al.  CT angiography and Doppler sonography for emergency assessment in acute basilar artery ischemia. , 1999, Stroke.

[13]  A. Silman,et al.  Statistical methods for assessing observer variability in clinical measures. , 1992, BMJ.

[14]  D. Altman,et al.  STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT , 1986, The Lancet.

[15]  H. Hacker,et al.  CT diagnosis of basilar artery occlusion. , 1983, AJNR. American journal of neuroradiology.

[16]  R. Alvarez,et al.  An inaccuracy in computed tomography: the energy dependence of CT values. , 1977, Radiology.

[17]  J. R. Landis,et al.  The measurement of observer agreement for categorical data. , 1977, Biometrics.

[18]  A. Beckett,et al.  AKUFO AND IBARAPA. , 1965, Lancet.

[19]  M. Reiser,et al.  Hyperdense basilar artery sign—a reliable sign of basilar artery occlusion , 2011, Neuroradiology.