Frequently used medical terms

We all come across these terms but sometimes we don’t get a clear idea. I note down here to remind myself and others in need.
MRI: Magnetic Resonance Imaging, test done by pushing in and out inside magnetic field in highly specialized equipment.

Mammograms: it is safe and highly accurate X-ray photograph of breast that is done to examine for breast cancer.
Mastectomy: it is the removal of breast organ to prevent spreading of cancer cells to other parts of the body or for other medical cause.

Ultra-sound: more advanced technique of testing, high frequency sound wave that converts things and movements in to images in a viewing screen.

PET: Positron Emission Tomography, newest technique where a radioactive material is injected in the body. And active cells which indicate cancer growth takes it thereby helps in finding cancer affected area or organ.