Subcortical foci of increased signal intensity are frequently identified on MRI in the elderly. The lesions are compatible with various pathologic processes and MRI can only provide supportive data for a suspected diagnosis. Without the patient's clinical history the radiologist is not able to differentiate between real pathologic lesions and physiologic aging processes. The high sensitivity of MRI in detecting white matter lesions and the lack of specificity recommends an excellent teamwork between clinicians and radiologists.