Abstract 115: Venous Phase Acquisition Is the Best Bolus Timing to Increase Spot Sign Detection in ICH, But Frequency and Extent of Hematoma Expansion Are Greater in Spot Signs Detected in the Arterial Phase of CTA
Background: Although the PREDICT study validated the spot sign for predicting significant hematoma expansion (HE) in acute intracerebral hemorrhage (ICH), the sensitivity was 51% and PPV 61%. Recent studies suggest that second pass imaging can increase the yield of contrast extravasation. The present analysis aimed to determine the frequency of spot sign depending on the phase of image acquisition, and whether an early phase spot sign has greater HE compared to later phases.
Methods: The PREDICT study was a multicentric, prospective, observational cohort study of ICH patients presented <6 hours. A blinded neurologist measured the Hounsfield units of an arterial and venous structure at three levels on CTA source images. The nearest structure to ICH was chosen to classify each study into the phase of acquisition. CTA were classified in 10 phases from early triggering to steady state, including arterial peak (5), arterial-venous equilibrium (6), and venous peak (7). Significant HE was defined as ICH enlargement >33% or >6mL at 24 hours.
Results: Overall (n=378), 77.5% of CTA were acquired in arterial phases. The spot sign occurred in 29.6%, and there was a trend to more frequent detection in the venous phases (37.6% vs. 27.3%, p=0.066) and in later image acquisition phases (p=0.141; Fig). HE analysis was limited to 318 patients: 26.7% presented spot sign and 32.4% experienced significant HE. In spot-sign positive group, there was a trend that HE occurred more frequently in earlier image acquisition phases (p=0.193, Fig). Similarly, median total hematoma enlargement (ICH+IVH) was greater in earlier phases (p=0.041; Fig).
Conclusions: This analysis highlights improved spot sign detection with later image acquisition in venous phase of CTA. However spot signs identified in the arterial phase are associated with more frequent hematoma expansion and greater extent. A two phase CTA is optimal in ICH patients and should include image acquisition in the arterial and venous phases.
- © 2012 by American Heart Association, Inc.