Imaging of Central Nervous System Tumors

I remember the day when I first saw a magnetic resonance (MR) imaging of a patient with glioblastoma multiforme more than two decades ago. I vividly recall the stunning rim of irregular and ominous pattern of enhancement, a large dark area of central necrosis, angry looking edema and mass effect, and unmistakable destruction of the neighboring brain. From that day forward, I never lost my focus, fear, and fascination with tumors of the central nervous system (CNS), especially their variable appearance on imaging and wondering how one histologic type of tumor can look so very different on imaging--