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

Abstract

PurposeThe 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 Methods102 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.ResultsSensitivity 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%).ConclusionIn 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.

The CT‐Defined Hyperdense Arterial Sign as a Marker for Acute Intracerebral Large Vessel Occlusion

“…Several previous studies have aimed to define the utility of the HAS, particularly in patients with BA occlusions . When an acute ischemic stroke patient with an LVO presents to the hospital, the clinical team reviews the patient's clinical presentation, neurologic examination, and NCCT/CTA/CTP imaging before deciding whether the patient is a candidate for thrombectomy.…”

“…18 Several previous studies have aimed to define the utility of the HAS, particularly in patients with BA occlusions. 10,11 When an acute ischemic stroke patient with an LVO presents to the hospital, the clinical team reviews the patient's clinical presentation, neurologic examination, and NCCT/CTA/CTP imaging before deciding whether the patient is a candidate for thrombectomy. Previously conducted studies assessing the utility of HAS did not take into account the patient's neurologic presentation to help determine the potential location of occlusion.…”

“…Hyperdense attenuation in LVO on NCCT imaging has been shown to represent a thromboembolic vessel occlusion in the setting of acute ischemic stroke . Previous studies have shown that the hyperdense arterial sign (HAS) is a specific but not sensitive marker for identifying acute ischemic strokes …”

“…8,9 Previous studies have shown that the hyperdense arterial sign (HAS) is a specific but not sensitive marker for identifying acute ischemic strokes. [10][11][12][13] Most studies investigating the utility of the HAS primarily have involved the review of NCCT images of acute ischemic stroke patients, independent of the patient's initial neurologic presentation. 10,11,14 However, the neurological presentation of a patient suspected of acute ischemic stroke provides valuable localizing information and can identify the cerebral territory at risk.…”

“…[10][11][12][13] Most studies investigating the utility of the HAS primarily have involved the review of NCCT images of acute ischemic stroke patients, independent of the patient's initial neurologic presentation. 10,11,14 However, the neurological presentation of a patient suspected of acute ischemic stroke provides valuable localizing information and can identify the cerebral territory at risk. Thus, providing clinical context to NCCT imaging may increase the utility and sensitivity of the HAS as a reliable marker for vessel occlusion.…”