In which way could unequal power relations contribute to dr spread of hiv infections

If the male is more dominant he can force the woman into having sexual intercourse with him. This can spread HIV especially if the man had been sleeping around. 

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.