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.
Atherosclerosis is a disease in which plaque builds up inside your arteries. Plaque is a sticky substance made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. That limits the flow of oxygen-rich blood to your body. Coronary artery disease.