Systematic characterization of the computed tomography angiography spot sign in primary intracerebral hemorrhage identifies patients at highest risk for hematoma expansion: the spot sign score

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 > or =3 spot signs, a maximum axial dimension > or =5 mm, and maximum attenuation > or =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.

Conclusions: 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.

Figure

A 67-year-old man on warfarin therapy for atrial fibrillation and daily aspirin intake presents with syncope and increasing unresponsiveness (admission INR, 2.7). A, NCCT demonstrates a right thalamic ICH (24 mL) with associated IVH (6 mL). B, Axial CTA source image in spot windows demonstrates 3 foci of contrast pooling within the ICH with an attenuation ≥120 HU (arrowheads), consistent with spot signs (a total of 5 spot signs were identified). The largest spot sign measures 10 mm in maximum axial dimension and has an attenuation of 225 HU (spot sign score, 4). C, Delayed CTA acquisition 48 seconds after the first-pass CTA shows that the spot signs increased in volume and changed in morphology (arrowheads). D, NCCT 8 hours after the baseline CTA demonstrates marked interval expansion of both the ICH (94 mL) and IVH (82 mL). The patient died shortly after the follow-up NCCT.