Small hemorrhages vs. small calcifications in brain tumors: difficulty in differentiation by computed tomography.

The difficulty in differentiating multiple small hemorrhages from multiple small calcifications in brain tumors by computed tomography (CT) is discussed. Illustrative CT scans are presented and the theoretical basis for this problem is elaborated. The difficulty is attributed to the relatively large size of the voxel and the ensuing partial volume effect, particularly with small intraparenchymal lesions of different sizes and attenuations.