Brain lesions are abnormal areas of tissue in your brain. Most likely, you've learned that you have a brain lesion or brain lesions as an incidental finding after having a brain-imaging test — such as magnetic resonance imaging (MRI) or a computerized tomography (CT) scan — performed for some reason. On MRI images, for example, brain lesions appear as dark or light spots that don't look like normal brain tissue.

If you've been diagnosed with something described as a brain lesion, it implies that the cause of the abnormal-appearing area cannot be diagnosed by the image alone, and further evaluation is necessary.

A brain lesion may involve small to large areas of your brain, and the severity of the underlying condition may range from relatively minor to life-threatening.

Oct. 25, 2011