R&D DIGEST

Neuroradiologists at the University of Cincinnati have come up with a plan for better identifying difficult-to-diagnose brain clots.

The team's method involves combining standard magnetic resonance imaging (MRI) systems with contrast-enhancing techniques. These techniques, known as magnetic resonance venography, produce clear pictures of abnormal flow areas within vessels of the brain. The combined system could lead to better identification of blood clots that are in the veins of the brain.

According to its authors, this is the first study to find correlation between MRI scans and contrast imaging with respect to detecting chronic thrombosis. “Detailed contrast-enhanced techniques produce more-defined distinctions between abnormal and normal veins in the membrane around the brain,” explains James Leach. He is a neuroradiologist and associate professor at the university and is principal investigator of the study.

Leach says that the combination of imaging tools gives the researchers a better understanding of the disease progression by showing abnormal blood flow areas. These areas are warning signs of blocked passages that could require surgery or other medical therapy. The contrast-enhanced MRIs can also identify the areas where flow has been partially reestablished after a vessel block has occurred.

The team used these contrast-enhanced techniques in combination with standard MRI scans to evaluate a small subgroup of patients who showed clinical features consistent with partially recanalized chronic dural sinus thrombosis. This is a condition in which blood flow in the membrane surrounding the brain has been partially reestablished from a previously blocked vessel. Partial blockage can increase the risk of stroke or other neurological problems, such as chronic headache.

“In cases where the patient has an ongoing partial or full blockage, the blood clot organizes into a more solid lesion, forms connective scar tissue, and can develop small vessels in an attempt to restore blood flow,” Leach explains. “This was very difficult to diagnose correctly using previous techniques.”

Leach says that being able to recognize the characteristics of the condition through imaging can help explain the cause of patient symptoms, such as persistent headache, that are otherwise mysterious. He says that the imaging may also eventually lead to better treatment and prevention techniques for some patients. “If we can more easily characterize the patient's problem as chronic instead of acute, it could alter the way we prescribe anticoagulation [clot-busting] drugs to treat thesymptoms,” says Leach. “Further research is needed to see whether this can affect patient therapy clinically.”

The research was reported in the April issue of the American Journal of Neuroradiology.

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