Recommendations on Standards for the Design of Medical Diagnostic Equipment for Adults with Disabilities, Advisory Committee Final Report

4.3.1 Overview of Imaging Equipment and Regulatory Environment

Diagnostic imaging equipment uses either ionizing radiation or a very strong magnetic field to produce the images used to diagnose a wide range of medical conditions, such as fractures, blood vessel blockages, various tissue abnormalities, and tumors. These machines typically involve a large capital outlay, last for many years of service, are operated by qualified technicians, and represent significant investments to health care facilities. Generally, this equipment is permanently mounted in a fixed installation within specially designed spaces that must perform specific essential functions, including supporting heavy weight, eliminating vibration, shielding ionizing radiation or magnetic fields, and having specialized high power capacity electrical service (see Section 7 for further description).

All testing using diagnostic imaging equipment is performed only under an order or prescription from a physician. Thus, before patients can have these tests, they must be evaluated by a physician, who then determines and requests the most appropriate diagnostic imaging test for the required evaluation. Diagnostic imaging equipment is operated only by trained and qualified technologists, who must be present during the examination. These technologists are present to assist patients, regardless of their physical abilities, onto the imaging equipment table and must ensure patients are properly positioned for the imaging procedure. Technologists also explain the purpose and necessary actions while they carry out the test. This equipment does not have patient “operable parts” – patients do not activate, deactivate, or adjust the imaging devices.

As described more fully in Sections 2.5 and 7.4, the U.S. Food and Drug Administration (FDA) regulates the majority of diagnostic imaging equipment as Class II medical devices, which need pre-market approval by FDA (510(k) clearance) prior to being placed on the market. The equipment must be designed and manufactured under the Quality System Regulations for medical devices, 21CFR820, which includes design controls and good manufacturing practices. An Occupational Safety and Health Administration (OSHA) credentialed Nationally Recognized Testing Laboratory must test and certify the equipment to demonstrate that it meets the basic safety and essential performance standards required by IEC 60601-1, as well as the applicable IEC 60601-1 series of collateral and particular standards. Devices that produce X-rays must also be certified by FDA as meeting the applicable performance standards for radiation safety found in 21CFRSubchapter J. The design process must include risk-management in accordance with ISO 14971. The Nuclear Regulatory Commission regulates the radioactive sources and radiopharmaceuticals used by nuclear medicine and PET equipment.