Hypodensities in a hematoma within the first 48 hours after an acute intracerebral hemorrhage (ICH) may predict its expansion, a retrospective study suggests.

Such hypodensities detected with noncontrast computed tomography (NCCT) “can predict hemorrhage expansion due to ongoing bleeding, independent of other imaging and clinical predictors,” Dr. Gregoire Boulouis of Massachusetts General Hospital and Harvard Medical School in Boston told Reuters Health by email.

“Hemorrhage expansion is an ominous sign associated with poor functional outcome and higher mortality. To date, no acute intervention has effectively improved the clinical outcome of ICH patients. These findings substantially improve our ability to predict the risk of hematoma expansion and to understand the processes that indicate ongoing bleeding,” he added.

As reported online June 20 in JAMA Neurology, Dr. Boulouis and his colleagues first reviewed data on 784 patients admitted with ICH between 1994 and 2012. In this development cohort, they examined NCCT findings for hypodensities; then, they replicated their findings in 245 patients admitted with ICH between 2013 and 2015.

The researchers determined the association between hypodensities and hematoma expansion (>6 cm3 or 33% of baseline volume) by multivariable logistic regression after controlling for other variables associated with hematoma expansion in univariate analyses.

Overall, 321 patients (31.2%) had NCCT scans that showed hypodensities at baseline: 222 (28.3%) in the development cohort and 99 (40.4%) in the replication cohort (kappa=0.87 for interrater reliability). Hypodensities were seen in 86 of 163 patients with hematoma expansion vs 136 of 621 patients without hematoma expansion (52.8% vs 21.9%; P<0.001).

In a multivariate model, the association between hypodensities and hematoma expansion was significant (odds ratio, 3.42; 95% confidence interval, 2.21 to 5.31; P<0.001). A CT angiography spot sign, a shorter time to CT, warfarin use, and older age were other independent predictors of hematoma expansion. The independent predictive value of hypodensities was also found in the replication cohort (odds ratio, 4.37; 95% confidence interval, 2.05 to 9.62; P<0.001).

Dr. Louis R. Caplan, a neurologist at Beth Israel Deaconess Medical Center in Boston who wrote an editorial about the study, said in a phone interview, “Hemorrhages gradually get larger over time until they stabilize, and doctors are struggling for ways to stop them from growing.”

“The advantage of this study is that it gives us a new simpler way to identify expanding hematomas so we can stop the bleeding and lower the pressure. Whereas other tests require more technology, this test requires only a look at a regular scan,” he said.

“Our ability to recognize which hemorrhages are likely to expand and the quantifiable and measureable variables involved in expansion – cause, size, location, drainage, time since onset of symptoms – can help us select the appropriate patients for aggressive treatment to limit expansion and it can inform further therapeutic studies,” Dr. Caplan said.

Dr. Boulouis said his group’s results need to be replicated in an independent cohort, and that CT hypodensities may eventually serve as a simple widely used tool to help doctors manage patients according to their risk of hematoma expansion.

“It is still unclear what the CT hypodensities represent. They may be the direct or indirect marker of ongoing bleeding or a marker of hemorrhage ‘immaturity,'” he added.

Two of his coauthors have grants from the National Institutes of Health. Dr. Boulouis is funded in part by a J. William Fulbright Scholarship and a Monahan Foundation Biomedical Research Grant.