fig 8.

Egg phantom imaged using same parameters as those used for the postmortem brain imaging.

A, T1-weighted image of all three eggs (3-minute boiled [left], fresh [middle], and hard boiled [right]) show central relative hyperintensity corresponding to the yolk, the region of higher cholesterol content. The rim (egg white) is relatively hypointense and is probably related to high water content.

B, Corresponding proton density–weighted image shows that the yolk is hypointense with respect to the relatively hyperintense egg white.

C, Corresponding T2-weighted image shows that the yolk is hypointense with respect to the egg white. The egg white is brighter in the fresh egg and darker on the hard-boiled egg, probably reflecting the amount of free water it contains. The appearance of liquid, semisolid, and solid cholesterol is nearly identical in all sequences. Note that the imaging features of this phantom closely follow those seen in the postmortem study (fig 3) and in some in vivo colloid cysts (fig 5).

D, EDX analysis of a hard-boiled egg (mostly yolk) shows sulphur (S), chloride (Cl) and calcium (Ca). The large peak of phosphorus (p) is due to contamination of the yolk by egg white. There are no paramagnetic substances that could be responsible for the appearance of the eggs on MR imaging.