Systematic Characterization of the Computed Tomography Angiography Spot Sign in Primary Intracerebral Hemorrhage Identifies Patients at Highest Risk for Hematoma Expansion

Abstract

Background and Purpose The presence of active contrast extravasation (the spot sign) on computed tomography (CT) angiography has been recognized as a predictor of hematoma expansion in patients with intracerebral hemorrhage. We aim to systematically characterize the spot sign to identify features that are most predictive of hematoma expansion and construct a spot sign scoring system. Methods We retrospectively reviewed CT angiograms performed in all patients who presented to our emergency department over a 9-year period with primary intracerebral hemorrhage and had a follow-up noncontrast head CT within 48 hours of the baseline CT angiogram. Three neuroradiologists reviewed the CT angiograms and determined the presence and characteristics of spot signs according to strict radiological criteria. Baseline and follow-up intracerebral hemorrhage volumes were determined by computer-assisted volumetric analysis. Results We identified spot signs in 71 of 367 CT angiograms (19%), 6 of which were delayed spot signs (8%). The presence of any spot sign increased the risk of significant hematoma expansion (69%, OR=92, P<0.0001). Among the spot sign characteristics examined, the presence of ≥3 spot signs, a maximum axial dimension ≥5 mm, and maximum attenuation ≥180 Hounsfield units were independent predictors of significant hematoma expansion, and these were subsequently used to construct the spot sign score. In multivariate analysis, the spot sign score was the strongest predictor of significant hematoma expansion, independent of time from ictus to CT angiogram evaluation. Conclusion The spot sign score predicts significant hematoma expansion in primary intracerebral hemorrhage. If validated in other data sets, it could be used to select patients for early hemostatic therapy.

Therapeutic Strategies in Acute Intracerebral Hemorrhage

“…1) [36][37][38]. The prevalence of the CTA spot sign decreases as time from onset to CTA increases, but its presence remains predictive of hematoma expansion independent of time from onset to CTA [36,38]. Several other studies showed that the CTA spot sign is predictive of mortality and poor outcome [45,46].…”

“…The occurrence of hematoma expansion is related to initial hematoma size; smaller hematomas are less likely to expand [16,34,35]. Other risk factors for expansion include early presentation [36], warfarin use [16,18], and contrast extravasation on CT angiography (CTA) [36][37][38]. The latter will be discussed more extensively in the "Neuroimaging" section.…”

“…The presence of this contrast, which has been termed a "spot sign," is an independent predictor of which patients will go on to suffer hematoma expansion ( Fig. 1) [36][37][38]. The prevalence of the CTA spot sign decreases as time from onset to CTA increases, but its presence remains predictive of hematoma expansion independent of time from onset to CTA [36,38].…”

Treatment Targets in Intracerebral Hemorrhage

“…One way to improve patient selection for hemostatic treatment is to predict which patients are more likely to have significant HE and target that group for treatment. A radiographic marker of HE, the spot sign, has been retrospectively evaluated, and its presence has been found to be correlated with the risk for HE [57][58][59]. The spot sign represents a small focus or larger area of contrast extravasation within the hematoma on CT angiography, most often seen on source images [57].…”

“…A radiographic marker of HE, the spot sign, has been retrospectively evaluated, and its presence has been found to be correlated with the risk for HE [57][58][59]. The spot sign represents a small focus or larger area of contrast extravasation within the hematoma on CT angiography, most often seen on source images [57]. In addition, contrast extravasation, seen on routine head CT after CT angiography, as pooling of contrast within the hematoma, may be a more sensitive predictor of ICH growth with a better negative predictive value than the spot sign [60].…”