LTE uses two different radio links for downlink and uplink, that is, from tower to device, and vice versa. For the downlink, LTE uses an OFDMA (orthogonal frequency division multiple access), which requires MIMO.
What you are referring to is called plaque, and it's a hallmark of atherosclerosis or arteriosclerosis (they both mean the same thing). Basically, cholesterol deposits end up lining the interior walls (lumen, intima) of the arteries narrowing the opening.
The fatty deposits, called atheroma, are made up of cholesterol and other waste substances. The build-up of atheroma on the walls of the coronary arteries makes the arteries narrower, restricting the flow of blood to the heart muscle.