Spot Sign in Intracerebral Hemorrhage: Critical Reappraisal and Future Clinical Implications

Hematoma expansion (HE) is a common occurrence affecting around 10% to 30% of patients with acute intracerebral hemorrhage within the initial hours from symptom onset and is the only modifiable factor associated with poor clinical outcomes. The detection of contrast extravasation on computed tomography (CT) angiography, known as the spot sign, was initially embraced as a promising radiological marker for predicting HE that could aid patient selection for acute interventions aimed at minimizing HE. However, the initial enthusiasm waned as clinical studies failed to show clear clinical benefits of hemostatic treatments when patients were selected based on the presence of this imaging marker. In this narrative review, we provide a comprehensive summary of the pathophysiology, definitions, imaging protocols, and predictive performance of the CT angiography spot sign, along with the clinical studies that have selected and treated patients based on its presence. Finally, we delve into some nuances of the spot sign that can enhance its predictive performance and help stratify HE risk with greater precision. These features include static findings observed on single-phase CT angiography (ie, number, volume, CT density, and colocalization with hypodensities), as well as dynamic findings identified on multiphase/dynamic CT angiography (ie, timing of appearance, volume increase, volume decrease for tissue dispersion, and CT density changes). In this reappraisal of the spot sign, we aim to reinvigorate research on advanced neuroimaging in intracerebral hemorrhage that could lead to a more accurate HE prediction. This could facilitate better selection for therapies aimed at preventing HE or surgical approaches to address the bleeding source.