Abstract Body: Introduction: Hematoma expansion (HE) occurs in one-fourth of patients with acute intracerebral hematoma (ICH) and is associated with worse outcomes. Existing radiological markers of HE show modest predictive accuracy. We aim to investigate a novel radiological marker that co-localizes findings from non-contrast CT (NCCT) and CT angiography (CTA) to predict HE.
Methods: We analyzed 200 consecutive acute ICH patients admitted at Foothills Medical Centre in Calgary, Canada (development cohort) and analyzed 304 patients from the multicenter observational study PREDICT (validation cohort). The Black-&-White (B&W) sign was defined as any visually identified spot sign on CTA co-localized with a hypodensity sign on the corresponding NCCT (Figure 1). The primary outcome was hematoma expansion (≥6mL or ≥33%). Secondary outcomes included absolute (<3mL, 3-6mL, 6-12mL, ≥12mL) and relative (0%, <25%, 25-50%, 50-75%, or >75%) hematoma growth scales.
Results: In the development cohort, 22% (n=44) showed the spot sign, 34.5% (n=69) the hypodensity sign, and 7% (n=14) the B&W sign. Those with the B&W sign had higher proportions of HE (100% vs. 19.4%, p<0.001), greater absolute hematoma growth (23.37 mL [IQR=15.41-30.27] vs. 0 mL [IQR=0-2.39], p<0.001) and relative hematoma growth (120% [IQR=49-192] vs. 0% [0-15%], p<0.001) in comparison to those without. The B&W sign yielded a specificity of 100%, a PPV of 100%, and an accuracy of 82%.
In the validation cohort, 25% (n=76) showed the spot sign, 39.1% (n=119) the hypodensity sign, and 9.5% (n=29) the B&W sign. Those with B&W signs had higher proportions of HE (79.3% vs. 30.2%, p<0.001), greater absolute hematoma growth (19.1 mL [IQR=6.4-40] vs. 0.8 mL [0-5.6], p<0.001), and relative hematoma growth (92% [IQR=16-151%] vs. 9% [0-34%], p<0.001) in comparison to those without. The B&W sign yielded a specificity of 97%, a PPV of 79%, and an accuracy of 71%. We found a consistent progressive improvement in predicting HE when hypodensity and spot signs are absent, individually present, both present but not co-localized, and co-localized (Figures 2-3). The inter-rater agreement was excellent (k=0.84) in the development cohort, with a uniform imaging protocol of NCCT immediately followed by CTA at a single center, and moderate (k=0.54) in the validation cohort at multiple centers.
Conclusion: The Black-&-White sign is a robust predictor of hematoma expansion occurrence and hematoma expansion severity.