Which of the following is NOT considered an infectious agent or caused by an infectious agent? A. Ringworm
B. Atherosclerosis
C. Syphillis
D. Strep bacteria

So that you don't get baby's but also prevents stis such as hiv

1. a lack of knowledge

Unlike  ct scans, which use x-rays,  mri scans  use powerful magnetic fields and radio frequency pulses to produce detailed pictures of organs, soft tissues, bone and other internal body structures.  differences between  normal and abnormal tissue is often clearer on an  mri  image than a  ct.you can see more with a mri scan. for example on an mri you can see internal bleeding.