Andrea Morotti, MD
Li Q, Liu Q-J, Yang W-S, Wang X-C, Zhao L-B, Xiong X, et al. Island Sign: An Imaging Predictor for Early Hematoma Expansion and Poor Outcome in Patients With Intracerebral Hemorrhage. Stroke. 2017
Intracerebral Hemorrhage (ICH) is a dynamic disease, with up to half of the patients experiencing active bleeding in the acute phase. Hematoma growth represents a potential therapeutic target to improve patients’ outcome. Rapid identification of subjects at high risk of hematoma growth is, therefore, crucial in clinical practice and in the setting of clinical trials testing anti-expansion treatments. The CT angiography (CTA) spot sign is a robust marker of ICH expansion. However, CTA is not available in many institutions, and a large proportion of ICH patients do not receive a CTA as part of their diagnostic workup 1. This highlights the need for novel markers of hematoma growth that do not require a CTA.
Using a well-characterized cohort including 252 ICH patients, Qi Li and colleagues described the island sign, a novel marker of hematoma growth that can be evaluated on baseline non-contrast CT (NCCT). The island sign was defined as presence of at least 3 scattered small hematomas all separate from the main hemorrhage or at least 4 small hematomas, some or all of which may be connected with the main hemorrhage. An illustrative example of the island sign is provided in Figure 1. ICH expansion was defined as hematoma growth > 6mL or > 33% from baseline hematoma volume.
Figure 1. Illustration of island sign. Axial noncontrast computed tomography (CT) images of 4 patients with CT island sign.