Fatty streaks are named for the yellow-white streak noted on the inner surface of the artery. This streak is actually made up of immune cells, including macrophages. Cholesterol accumulates within these macrophages, causing them to have a foamy appearance underneath the microscope. Because of this appearance, these cells are also referred to as foam cells.
There are currently no methods to detect fatty streaks in the body. While these macrophages lay down the groundwork for atherosclerosis, not all fatty streaks will ultimately become atherosclerotic plaques. Keeping your cholesterol levels low through , medication, or a combination of both - will help to prevent these fatty streaks from growing into plaques in your arteries.
Sources:
Kumar V, Abbas AK, and Fausto N. Robbins and Cotran Pathologic Basis of Disease. 7th edition. Elsevier Saunders, Philadelphia PA, 2005.

