Sacral edema: computed tomographic and anatomical observations

Abstract

Sacral edema is a widely recognized clinical sign. Hitherto there has been no method of radiological confirmation, nor has the anatomy of this sign been well described. In a prospective study of 100 patients referred for abdominopelvic computed tomography (CT), 17 showed radiological evidence of sacral edema. It was demonstrated clinically in 12 of these 17 patients, leaving five patients with apparent CT evidence of sacral edema in whom this was not demonstrated clinically. In two patients with clinical evidence of sacral edema, their tissue planes in this region appeared normal on CT. The edema fluid accumulates in an intermediate plane of fibrous tissue within the subcutaneous fatty layer of the trunk. In those 17 patients with CT evidence of edema, the center of the fluid accumulation was situated over the lumbar rather than the sacral spine, suggesting that the term "sacral" edema is something of a misnomer.