Sizing Imaging and Procedure Rooms

Imaging and procedure rooms fall into several size categories — small procedure rooms, typical imaging rooms, or larger specialty imaging rooms. Diagnostic equipment has generally become more compact over time. For example, equipment used for chest X-rays, mammography, ultrasound, and pulmonary and neurodiagnostic testing is compact and commonly mobile, requiring only a small procedure room. Most general radiographic and fluoroscopic equipment can be accommodated in a typical imaging room. Computed tomography (CT) units are also becoming more compact but require a contiguous control room. Magnetic resonance imaging (MRI) and interventional procedure suites require a larger footprint that includes the procedure room, control room, and adjacent space for equipment (or system) components. Imaging equipment may also require lead shielding, enhanced floor loading capacity, and other unique design features. The FGI Guidelines also classify imaging rooms based on different levels of patient acuity and intervention.


Traditionally, imaging services were used only for diagnostic purposes. Today, they are increasingly used for imaging-guided interventions and treatment planning optimization. They are integrated into all healthcare subspecialties — not just pieces of hardware organized in a centralized department. Particularly related to the melding of interventional radiology and minimally-invasive, image-guided, and traditional open surgical techniques, the FGI Guidelines have established three classification levels for imaging rooms to reflect different levels of patient acuity and intervention. Most diagnostic radiography, fluoroscopy, mammography, CT, MRI, nuclear medicine, and ultrasound tests do not require monitoring or sedation and would be performed in a Class 1 imaging room. Imaging rooms used for minimally-invasive procedures (e.g., biopsies) that require clinical monitoring and moderate sedation would be considered a Class 2 imaging room.

  • Class 1 imaging room (or exam/procedure room) — accessed from an unrestricted area — patient care requiring a high level of disinfection or sterile instruments; not requiring the environmental controls of a procedure room; also used for diagnostic radiography, fluoroscopy, mammography, CT, MRI, ultrasound, and other imaging modalities; unrestricted area.
  • Class 2 imaging room (or procedure room) — accessed from an unrestricted or semi-restricted area — patient care requiring a high level of disinfection or sterile instruments and some environmental controls; not requiring the environmental controls of an operating room; also used for coronary, neurological, or peripheral angiography, and electrophysiology procedures; semi-restricted area.
  • Class 3 imaging room (or operating room) — accessed from a semi-restricted area — patient care requiring invasive procedures and physiological monitoring, active life support anticipated; restricted area.


Although the FGI classification system dictates design details, environmental controls, and other infrastructure requirements, the imaging equipment generally dictates the size of the room. Imaging equipment ranges from portable (such as ultrasound) to very large (like an MRI unit). The required clearances around the equipment and the corresponding size of the procedure room can vary greatly. Vendors typically specify clearances and required minimum room sizes (inside wall-to-wall dimensions) for each piece of equipment. These dimensions, including ceiling height, are critical to proper installation and efficient operation of the equipment. Also, provisions need to be made to deliver and replace large, fixed equipment units. Class 2 and 3 imaging rooms should have a physically separate control room and most require a contiguous equipment (or system component) room whose minimum size is also specified by the manufacturer.

Some guidelines for sizing imaging and other procedure rooms include:

  • Small procedure room at 120 to 160 NSF (11.2 to 14.9 NSM) — to accommodate a small, portable or fixed piece of equipment (with operator’s console/alcove) along with a chair for the operator, patient chair, and patient treatment bed or table. Mobile equipment can usually be accommodated in an amply-sized clinic exam or treatment room.
  • Typical imaging room at 180 to 220 NSF (16.7 to 20.4 NSM) — Class 1 — to accommodate fixed imaging equipment for general radiography (smaller room size) or fluoroscopy or nuclear medicine procedures (larger room size) along with an operator’s console (alcove) and a patient exam table. These modalities would require Class 1 imaging rooms under the FGI classification system.
  • Large specialty procedure room at 320 to 600+ NSF (29.7 to 55.7+ NSM) — Class 1 — to accommodate fixed equipment for CT, positron emission tomography (PET), self-shielded MRI, single photon emission computed tomography (SPECT), and other hybrid imaging equipment.
  • Interventional procedure room at 480 to 600 NSF (44.6 to 55.7 NSM) — Class 2 — to accommodate fixed imaging equipment for interventional procedures such as angioplasty, cardiac catheterization, and endovascular surgical neuroradiology.
  • Hybrid operating room at 750 to 900 NSF (69.7 to 83.6 NSM) — Class 3 — with permanently-installed imaging equipment that can be used for traditional surgery, image-guided surgery, or a combination of procedure types.
  • Control room at 100 to 180+ NSF (9.3 to 16.7+ NSM) — to contain the operator’s console; contiguous with the procedure room with doors leading both into the procedure room and to the corridor; the size depends on the number of operator consoles, and two procedure rooms may share a single control room.
  • Equipment (or system) component room at 100 to 160 NSF (9.3 to 14.9 NSM) — to house ancillary equipment components; generally contiguous with the procedure room with access via sliding doors; the size depends on vendor specifications.

Note: Net square feet/meters (NSF/NSM) represents the inside wall-to-wall dimensions of individual rooms. More detailed information on determining types, numbers, and sizes of imaging and other procedure rooms can be found in the SpaceMed Guide.

See related post: Estimating Diagnostic Imaging Space Based on the Number of Procedure Rooms.

This article is an update of a previous post.