Predictive Value of CTA Spot Sign on Hematoma Expansion in Intracerebral Hemorrhage Patients

Abstract

Hematoma expansion (HE) occurs in approximately one-third of patients with intracerebral hemorrhage and leads to high rates of mortality and morbidity. Currently, contrast extravasation within hematoma, termed the spot sign on computed tomography angiography (CTA), has been identified as a strong independent predictor of early hematoma expansion. Past studies indicate that the spot sign is a dynamic entity and is indicative of active hemorrhage. Furthermore, to enhance the spot sign's accuracy of predicting HE, spot parameters observed on CTA or dynamic CTA were used for its quantification. In addition, spot signs detected on multiphase CTA and dynamic CTA are shown to have higher sensitivity and specificity when compared with simple standardized spot sign detection in recent studies. Based on the spot sign, novel methods such as leakage sign and rate of contrast extravasation were explored to redefine HE prediction in combination with clinical characteristics and spot sign on CTA to assist clinical judgment. The spot sign is an accepted independent predictor of active hemorrhage and is used in both secondary intracerebral hemorrhage and the process of surgical assessment for hemorrhagic risk in patients with ischemic stroke. Spot sign predicts patients at high risk for hematoma expansion.

Figure 1

These images depict a left hemisphere ICH. A single sign with a spot-like appearance on CTA (orange arrow). The hyperdense area (blue arrow) in the first picture signifies an early hematoma in a baseline noncontrast CT. The second image shows that a spot sign (orange arrow) within the hematoma (green arrow) is discontinuous to any outside vessels and has a higher CT HU than the background hematoma in real CTA. The third image shows an expanding hematoma (blue arrow) in a 24 h follow-up noncontrast CT. Image provided by Dr. Andrew M. Demchuk, M.D., FRCPC.

Figure 2

This schematic highlights several important parameters in detecting spot sign.

Figure 3

This graphic represents 8 other causes for spot sign on CTA, vascular mimickers (fibrin globules, micro-arteriovenous malformation (micro-AVM), aneurysm, microvascular aneurysm, Moyamoya, and pial arteriovenous fistula) and nonvascular mimickers (tumor and choroid plexus calcification). This suggests that not all positive spot signs represent ongoing bleeding and clinical judgment and other diagnostic tools should be utilized.

Figure 4

This figure demonstrates the process of hematoma expansion and its secondary effects. Spot sign on CTA (computed tomography angiography) and CTP (computed tomography perfusion) and leakage sign on CTA are strong predictors of hematoma expansion. Utilizing spot sign in acute initial hemorrhage can help reduce secondary brain injury and inflammation and thus reduce morbidity and mortality associated with hematoma expansion.