You raise some valid points. Recently I went through an incident that caused the need for in depth medical treatment. Out of 9 MRI's, I finally got one of my upper neck. Something showed up to the right of my spine, about 2.5 inches above the collar line, and about .75 inches in. It glows about 3 times as bright as the bones in my spine, and brightness equals density in an MRI. For some strange reason, the doctor didn't want to talk about it, and that phase of the imaging I wasn't given a copy of. Very odd.