Fig 1.

Inaccuracy of volumetric measurements at the lesion surface. The grid represents voxel boundaries; the solid line represents an acute ischemic lesion. Voxels outlined in gray are the surface voxels, ie, those voxels with lesion margins. The sum of the surface voxel volume is a measure of the potential measurement error due to partial volume effects, which results from discretization at the lesion surface (the net volume uncertainty per surface voxel has been defined as half of the volume of the voxel in both the positive and negative directions). Standard resolution leads to large surface volume and thus has the potential for large measurement errors (A). Increasing the spatial resolution substantially reduces the surface volume and thereby decreases the potential measurement error (B).