Since the Bank Secrecy Act of 1973 requires your bank to microfilm all of your checks and hold these records for six years, the state can get intimate details of your life from a study of your checking account.
The rap against MRIs as a diagnostic tool for low back pain is not that the scans usually reveal nothing, or even that they're expensive, it's that they often show a lot of abnormalities in the back that may have nothing to do with the source of your pain.
Main article: Phase Contrast Magnetic Resonance Imaging. Phase Contrast MRI (PC-MRI) is used to measure flow velocities in the body. It is mainly used to measure blood flow in the heart and throughout the body. PC-MRI can be considered a method of Magnetic Resonance Velocimetry.