FRIDAY, June 10 (HealthDay News) -- The first device to perform simultaneous PET (position emission tomography) and MRI (magnetic resonance imaging) scans has been approved by the U.S. Food and Drug Administration, the agency said Friday.

PET scans involve injection of a radioactive tracer into the bloodstream, which gives doctors a glimpse of internal organs and tissue. MRI uses a magnetic field and radio waves to create detailed images of the body's organs, soft tissue and bones.

The Siemens Biograph mMR system creates both types of images at the same time, lowering overall radiation exposure and preventing the need to move a patient to two different scanners, the FDA said in a news release.

As with stand-alone MRIs, people with pacemakers, defibrillators and other implanted electronic devices should avoid the new system, since the scanner's strong magnetic fields could interfere with those devices, the agency said.

Siemens Medical Solutions is based in Malvern, Penn.

More information

Cleveland Clinic has more about PET scans and MRIs.