Is there association between hyperdense middle cerebral artery sign on CT scan and time from XXXX onset within the first 24-hours?

@entity432 @entity715 @entity1 @entity64
BACKGROUND: The @entity432 ( @entity432 ) on CT brain scan is an assumed radiological marker of acute intra-arterial @entity715 . However, the relationship between @entity432 between time of @entity64 onset has not been adequately investigated, leading to uncertainty regarding its validity as a marker of acute ischaemia. We attempted to determine if the presence of the @entity432 is associated with time from @entity64 onset. METHODS: Retrospective cross-sectional study conducted in a tertiary referral centre. Consecutive @entity1 with acute @entity64 and confirmed middle cerebral @entity432 on initial CT angiogram from 2007-2011 were included. Visual estimation and manual measurement of Hounsfield units of affected and corresponding non-affected artery on non-contrast CT was completed and mean density was calculated from four separate readings. Primary outome measures were Time from @entity64 onset and @entity432 on both visual estimation and the ratio of mean value in Hounsfield Units (HU) of affected to non-affected artery. RESULTS: One hundred and fifty-four subjects with confirmed @entity432 on CT Angiogram were included in the study. There were no significant differences in age distribution or vascular risk factor presence between subjects with or without @entity432 . Subjects with @entity432 were less likely to be male (50.9  % vs 70.8  %, p   =   0.02).) @entity432 was found in 106 (68.8  %) of all subjects. Median NIHSS score at presentation was significantly higher in the @entity432 group (17 vs 12, p   =   0.02). No statistically significant association between @entity432 and @entity64 onset time or density ratio between affected and non-affected artery was detected overall within either the first 24-h or on subgroup analysis of those in the first 4.5-h. A small subgroup of three @entity1 with @entity64 onset greater than 24-h all had absent @entity432 . CONCLUSIONS: No evidence of a correlation between time of @entity64 onset and presence of a @entity432 within the first 24-h post acute @entity64 was identified. The @entity432 was associated with a higher NIHSS score at presentation.
