different types of scan

Could you explain the difference between all the different scans and when you use one type verses another?  Which scan is most detailed to capture growths within the body?  If one had to pay for a scan, which one would you recommend...MRI, PET, CT, radioactive and possibly others I can't think of ???
Thanks so much for your reply

[Annekathryn Goodman, M.D.]

Hi Kimchi,
Certain scans are used to understand certain parts of the body better. For instance, an ultrasound is a great test to look at the ovaries. An MRI is  a great test to look at growths in the muscle of the uterus. Decisions about which scans to get are very individual and depend on the question being asked and the particular medical history of a person.
best wishes

[Kimchi]

Also with ultrasounds...what would you use to detect tumor, nodules, fluids, anything else not suppose to be inside..
Tks

[SimplyStar]

Mayo recommended the combo  CT/PET as being the best , miss you on the forum, are you ok?