Ciura VA, Brouwers HB, Pizzolato R, Ortiz CJ, Rosand J, Goldstein JN, et al. Spot Sign on 90-Second Delayed Computed Tomography Angiography Improves Sensitivity for Hematoma Expansion and Mortality: Prospective Study. Stroke. 2014
Prachi Mehndiratta, MD
It is common knowledge amongst the stroke community that a spot sign seen on a CT angiogram predicts hematoma expansion in patients with Intracerebral hemorrhage (ICH). Size of the hematoma is an independent predictor of poor outcome and all attempts are made to prevent the increase in size by use of hemostatic medications and blood pressure control. The authors of this study hypothesize that addition of a 90 second delayed CT would help capture additional ICH patients with the spot sign and increase the sensitivity for predicting hematoma expansion and poor outcome. Patients with spontaneous ICH were enrolled prospectively between February 2012 and August 2013 and underwent a non-contrast head CT, immediately followed by CTA of the head with a 90 second delayed acquisition through the hematoma volume.
All CTA studies were independently reviewed by two board-certified radiologists and the spot sign was identified as a focus of contrast pooling within the ICH with an attenuation ≥120 HU that was discontinuous from normal or abnormal vasculature adjacent to the ICH and was of any size and morphology. Hematoma expansion was considered significant if the volume increased by 6ml or by 33% from baseline. A multivariate logistic regression model was utilized to analyze data and sensitivity, specificity and positive/negative predictive values were calculated.
A total of 121 patients were enrolled in the study however only 74 had follow up CT scans and were included in the primary analysis. A total of 15 patients had a positive spot sign detected on any CTA and the overall rate of hematoma expansion was 15%. Hematoma expansion was predominantly seen in the spot sign positive group (47% vs. 7%). Accuracy measures for the spot sign on delayed CTA were: sensitivity 55%, specificity 87%, PPV 43%, NPV 92%, accuracy 82%. When the CT scans for all 121 patients were analyzed the spot sign was seen on 36 scans, with 15 detected exclusively on the delayed 90 second imaging. The presence of a spot sign and high blood glucose levels were independent predictors of mortality in the multivariate logistic regression model. Greater than 95% of these patients with a positive spot sign were dead at follow up.
This study re-enforces that spot sign is a predictor of hematoma expansion and poor outcome. The 90 second sequence is cost effective and time efficient however the numbers in the study are really small. The question arises – are we going to try everything to detect a spot sign? The authors conclude that the delayed 90 second sequence may help select patients eligible hemostatic intervention but we need to ask ourselves if it really changes clinical practice. Although the spot sign is predictive of expansion, it is only seen in a small percent of patients with ICH and a delayed CT has a sensitivity of 55% to detect a spot sign. If a safe hemostatic medication is available and approved, I wonder if we would be so selective in its use. Let’s reserve our judgement till the SPOTLIGHT (spot sign selection of intracerebral hemorrhage to guide hemostatic therapy trial) is on ICH treatment with hemostatic therapy.