Ventricular enlargement in multiple sclerosis: a comparison of three-dimensional and linear MRI estimates

Atrophy of central white matter is related to irreversible clinical disabil ity in multiple sclerosis (MS) and ventricular enlargement may be a sensiti ve marker of this tissue loss. Therapeutic trials in MS have provided MRI d ata for investigation of cerebral atrophy in MS. These studies use almost e xclusively two-dimensional (2-D) images, which may be limited in the assess ment of three-dimensional (3-D) structures. We used 3-D MRI data to estimat e ventricular volumes in 40 patients with MS and 10 healthy controls, to lo ok at associations with clinical disability and the stage of the disease. W e then compared simple linear measures of ventricular size from conventiona l 2-D images, with 3-D volume estimates to establish the best available lin ear indices of ventricular volume. Mean ventricular volumes were increased in the patients and significantly larger in the more disabled patients. The estimated volume of the third ventricle obtained from 3-D MRI showed the s trongest association with the clinical stage of the disease, duration of sy mptoms and levels of disability. Finally, we confirmed that in patients wit h MS accurate data on ventricular size can be obtained from 2-D images by t wo simple and convenient linear measures, the width of the third ventricle and of the anterior horn of the lateral ventricle.