Answer: Epiploic Appendigitis

Findings:

• a fat-density ovoid structure adjacent to colon, usually 1.5- 3.5cm in diameter 2
• thin high-density rim (1-3mm thick) 5-6
• surrounding inflammatory fat stranding, and thickening of the adjacent peritoneum

directly from: http://radiopaedia.org/articles/epiploic-appendagitis

nice review article: http://pubs.rsna.org/doi/pdf/10.1148/rg.256055030