The Food and Drug Administration announced Friday it had approved the first application that doctors can use to view medical images and make diagnoses using an iPhone or iPad.

The app enables doctors to view images produced by such diagnostics tests as CT scans, MRIs and PET scans.

It "is not intended to replace full workstations and is indicated for use only when there is no access to a workstation," the FDA said. But the new app "provides physicians with the ability to immediately view images and make diagnoses without having to be back at the workstation or wait for film," said William Maisel, the FDA's chief scientist and deputy director for science in the Center for Devices and Radiological Health.

The images taken in the hospital or doctor's office are compressed so they can be transferred via a secure network to portable wireless device using software called Mobile MIM, which is made by MIM Software Inc. in Cleveland.

The software "allows the physician to measure distance on the image and image intensity values and display measurement lines, annotations and regions of interest," the FDA said.

Before approving the app, the agency "reviewed performance test results on various portable devices" that measured brightness, image quality and distortion, the agency said. Participants agreed that the device was sufficient for diagnostic image interpretation.