The diagnosis is initially suggested by CT, MRI, or angiogram. In fact, the name derives from its angiographic image; the “puff of smoke,” which is how moyamoya loosely translates from Japanese, refers to the appearance of multiple compensatorily dilated striate vessels seen on angiography. Contrast-enhanced T1-weighted images are better than FLAIR images for depicting the leptomeningeal ivy sign in moyamoya disease.