ABSTRACT
Enhancing lesions, T2-hyperintense lesions and T1-hypointense lesions (T1 black holes) are the basis for the three classic measures of multiple sclerosis (MS) pathology visible by conventional magnetic resonance imaging (MRI), and are the cornerstone of MRI-based outcomes in MS clinical trials. These measures provide an insight into multiple aspects of disease extent and severity, which are useful on a daily basis in the clinic1,2, as well as in population studies and MS clinical trials. The three ‘conventional’ measures of MS are independent but interrelated, and complement analyses of the diffuse pathology3 revealed by advanced quantitative measures of normal-appearing brain tissue (e.g. magnetization transfer imaging, diffusion-and relaxation-based imaging and proton magnetic resonance (MR) spectroscopy) and atrophy measures of the brain and spinal cord. Because the focal pathology contributes to the diffuse pathology
in normal-appearing tissue through secondary neuronal degeneration and other mechanisms, these classes of measure (conventional and advanced quantitative) are not entirely independent.
