Abstract 342: Novel “Hyperdense Sign” Window Improves Detection of Hyperdense Sign in Patients Presenting with Ischemic Stroke
Year: 2024
Type: conference-abstract
Abstract: Introduction Imaging modalities for acute ischemic stroke patients include non‐contrast CT head (NCCT) and contrast‐based imaging. On NCCT, a hyperdense sign suggestive of underlying thrombus correlates to a large vessel occlusion (LVO) on contrast based imaging. Previous studies show that hyperdense signs are visualized in 30‐52% of patients presenting with an LVO. While standard (5mm) cut CT can miss hyperdense signs, they can be better detected on newer NCCT with thin (0.625mm) cuts. The Hounsfield unit (HU) range of a hyperdense sign is +50 to +75, so the windowing of NCCT images to enhance these HU ranges also improves visualization. Hyperdense signs on NCCT can help guide selection for mechanical thrombectomy (MT) when advanced imaging is unavailable or inadequate. Methods At our community‐based university medical center, we conducted a retrospective cohort study of acute ischemic stroke patients presenting with an intracranial LVO and were taken for MT from July 2019 to March 2024. We retrospectively assessed axial standard (5mm) cut and thin (0.625mm) cut NCCT imaging in patients for hyperdense signs spanning from the carotid terminus to the distal M1 segment. To improve visualization, we further used a novel “hyperdense window,” with a window center of 50 and window width of 25. The location of the hyperdense region was confirmed with the location of LVO on contrast‐based imaging including CT angiogram, CT perfusion, and digital subtraction angiography during MT. Results The mean age of the patients in the study was 67 years; 54% were male and 46% were female. Of the patients with confirmed intracranial LVO on contrast‐based studies, 77.4% (n=147) had unilateral hyperdense signs on NCCT thin cuts that correlated to area of LVO. Of the remaining 22.6% (n=43) of patients, 58.1% (n=25) had an absence of a hyperdense sign and 41.9% (n=18) of patients had bilateral hyperdense signs on NCCT. Contrast based imaging confirmed LVO in all patients included in the study. Conclusion Compared to previous studies, thin cut NCCT combined with a novel “hyperdense window” on NCCT improved visualization of hyperdense signs representing LVO at the internal carotid terminus and/or first segment of the middle cerebral artery. We propose that when combined with a clinical presentation, a hyperdense sign on NCCT may be sufficient evidence to proceed to MT without the need for contrast‐based imaging. While advanced imaging should not be delayed, interpretation of thin cut NCCT may lead to earlier mobilization of the intervention team. More studies are needed to evaluate the utility of thin cut NCCT alone for selection of patients with LVO and whether outcome metrics such as reperfusion time or modified Rankin scale improve.
Authors: S. Scarpiello, A. Amireh, T. Snyder, J. Haimi, H. Zacharatos, S. Mehta, B. Jankowitz
Institution: John F. Kennedy Medical Center
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,300
OpenAlex ID: W4406396347