Fig. 2. Lateral ventricle volume changes in a surgical patient. Sample cortical magnetic resonance image pairs (baseline, first follow-up) show lateral ventricle enlargement subsequent to surgery for a mild cognitive impairment patient. The percent volume change for this particular subject from the pre- to postsurgical interval was 7.13%, about 33% greater than the average post surgery change. White arrow  indicates lateral ventricle; black arrow  indicates hippocampus. MCI = mild cognitive impairment.