Figure 2

Examples of cases with (A, B) and without (C, D) positional brain shift (PBS). (A) A 70-year-old woman with ventriculoperitoneal shunt, who underwent craniectomy because of surgical site infection. Computed tomography (CT) scan images obtained on postoperative day (POD) 7 showed a remarkable PBS. (B) A 53-year-old man who underwent frontal craniotomy for clipping of a distal anterior cerebral artery aneurysm. In total, 14.9 mL of residual air, which moved upward according to positional change, thereby compressing the frontal lobe, was evident on CT scan images on POD 7. (C) A 41-year-old woman who underwent resection of left temporal glioma. CT scan images on POD 7 did not show PBS around the resection cavity. (D) A 55-year-old man who underwent craniectomy for traumatic brain injury. CT scan images on POD 17 did not show PBS. However, subcutaneous fluid collection indicated a positional shift.