Perfusion CT is proving useful as a way to get more information on some ischemic stroke patients' brains. It can tell, for instance, whether too much brain tissue has already died because of a lack of blood, or whether there are areas that are still getting some blood flow and could be saved if clotbusters were given. Recent research at other institutions has helped develop thresholds of brain blood flow, volume and flow rates to tell if tissue is dead (infarcted) or just blood-starved (ischemic).
The U-M team also notes that perfusion CT may be useful in patients who have survived a type of stroke known as a subarachnoid hemorrhage, caused by a burst aneurysm that bleeds onto the surface of the brain. Only a combination of quick action and neurosurgical skill can close the leak and save the patient's life. But even if they survive, patients have a high risk of ischemic stroke within hours or days of surgery, if their repaired blood vessels start to constrict uncontrollably. Many die or experience major disability. Perfusion CT can monitor for this condition, called cerebral vasospasm, and speed treatment.
Lastly, Hoeffner and her colleagues note that perfusion CT is in the early stages of development for patients with brain tumors. Because tumors need to form new blood vessels to feed themselves, and because new blood vessels have walls that are super-permeable, the technique lends itself to mapping tumors and assessing their rate of growth and stage.
Suresh Mukherji, M.D., director of the U-M Division of Neuroradiology, praises Hoeffner for spreading the word about the technique's many uses. "Dr. Hoeffner's work and her lectures at national meetings establishes her as one of the leading authorities on perfusion CT not only in the U.S., but worldwide," he says. "Her work will provide the framework for integrating perfusion CT into day-to-day practice."