Vivek Rai, MD
Rodriguez-Luna D, Dowlatshahi D, Aviv RI, Molina CA, Silva Y, Dzialowski I, et al. Venous Phase of Computed Tomography Angiography Increases SpotSign Detection, but Intracerebral Hemorrhage Expansion Is Greater inSpot Signs Detected in Arterial Phase. Stroke. 2014.
The ‘Spot Sign’, a tiny, enhancing foci within acute hematoma detected on CT Angiogram, has been shown to be of predictive value for expansion of intracerebral hemorrhage (ICH). The predicting hematoma growth and outcome in intracerebral hemorrhage using contrast bolus CT (PREDICT) study validated the computed tomography angiography (CTA) spot sign for predicting significant ICH expansion in a prospective multicenter study. However, the accuracy of this sign was only modest. The authors hypothesized that variability in CTA acquisition may be one reason.
Aiming to determine the frequency of spot sign and its relationship with ICH expansion, Rodriguez-Luna et al present the results of this post-hoc analysis of CTA source images of the entire PREDICT cohort. The authors report that out of 371 patients, spot sign was present in 29.9% and was more frequently seen in venous phase as compared with arterial phase (39% versus 27.3%, P=0.041). CTA spot sign was also closely associated with total hematoma enlargement and significant hematoma expansion.
In this study, most (77.9%) of the CTA images were obtained in arterial phase, which may have limited the statistical power to analyze the differences between the two phases. Even so, the results support the existing evidence that later phase study may be more sensitive for detection of spot sign. The results may have important implications for ongoing and future clinical trials studying hemostatic therapies for ICH.
The results suggests that multiphase CTA including arterial and venous acquisitions could be optimal in ICH patients and this may help is identifying the patients most likely to expand and, by extension, likely to benefit from early hemostatic therapies. More research is needed to understand whether this will translate into better clinical outcomes but this study definitely lays the groundwork for more studies in future.