Imaging Room Classifications

Hospital imaging rooms should not be classified only by equipment type. They should be classified by what happens in the room, including the procedure performed, patient risk, level of invasiveness, anesthesia or sedation needs, infection control requirements, radiation or magnetic safety, and infrastructure required to support the modality.¹⁻³

The Facility Guidelines Institute separates imaging rooms into Class 1, Class 2, and Class 3 spaces. This classification helps determine room size, finishes, mechanical systems, electrical infrastructure, infection control, support spaces, and operational requirements.¹⁻³

Class 1 Imaging Room

A Class 1 imaging room is generally used for diagnostic imaging procedures.¹⁻³ These rooms may include CT, MRI, X ray, ultrasound, mammography, and diagnostic fluoroscopy, depending on the procedure and clinical use.

These rooms are planned around imaging equipment, patient positioning, technologist workflow, control areas, equipment access, shielding, and patient movement. Although they may not support invasive procedures, they can still require substantial infrastructure, including radiation shielding, magnetic safety planning, emergency power, cooling, equipment clearances, and imaging network connectivity.¹⁻³,⁵⁻¹¹

Key planning drivers include:

• Radiation shielding or magnetic shielding
• Equipment clearances
• Control room visibility
• Patient transfer space
• HVAC loads
• Power and emergency power needs
• Data and imaging network infrastructure
• Equipment replacement path
• Patient holding, changing, toilet access, and staff support

Class 2 Imaging Room

A Class 2 imaging room is used for diagnostic and therapeutic procedures.¹⁻³ These spaces may include interventional radiology, cardiac catheterization, electrophysiology, image guided biopsy, vascular procedures, fluoroscopy guided procedures, and certain CT guided procedures.

Class 2 rooms support more complex procedures than diagnostic imaging rooms. They may involve sterile technique, moderate sedation, procedure tables, booms, medical gases, anesthesia support, crash cart access, larger staff counts, and greater equipment density.¹⁻⁴,¹⁹

Key planning drivers include:

• Procedure level infection control
• Cleanable finishes
• Sterile supply access
• Medical gases
• Anesthesia support
• Dedicated equipment storage
• Patient prep and recovery
• Nurse charting and monitoring
• Larger clear floor areas
• Radiation protection
• Emergency response access
• Support for sedation or monitored anesthesia care

Hospital imaging room classifications should be based on actual clinical use. For example, a CT room used only for diagnostic scans may be planned as Class 1, while a CT room regularly used for guided procedures may need to be evaluated as a Class 2 imaging room.¹⁻³

Class 3 Imaging Room

A Class 3 imaging room supports surgical or invasive procedures performed with imaging.¹⁻³ Examples may include hybrid operating rooms, operating rooms with fixed C arms, surgical suites with integrated imaging, advanced endovascular operating rooms, neurosurgical operating rooms with intraoperative imaging, and orthopedic operating rooms with advanced imaging integration.

Class 3 rooms function as operating rooms. The imaging system is part of the surgical environment, so the room must satisfy operating room level requirements, including sterile field protection, surgical HVAC criteria, surgical lighting, booms, equipment integration, staff circulation, anesthesia support, medical gases, emergency power, and procedure support.¹⁻⁷,¹⁹

Key planning drivers include:

• Operating room standards
• Air changes and pressure relationships
• Temperature and humidity control
• Sterile field requirements
• Anesthesia work zone
• Booms and ceiling coordination
• Structural support for imaging equipment
• Radiation protection
• Larger room size
• Equipment integration
• Sterile processing and supply flow
• Patient transfer and recovery flow

Hospital Imaging Room Classifications by Imaging Modality

Modality	Primary Classification Consideration	Major Requirements
X ray	Usually Class 1	Shielding, control booth, power, equipment clearances¹⁻³,¹⁶
Fluoroscopy	Class 1 or Class 2	Radiation shielding, procedure support, possible sedation, medical gases¹⁻⁴,¹⁶,¹⁹
CT	Class 1 or Class 2	Shielding, electrical load, cooling, control room, injector support, equipment path¹⁻³,¹⁰,¹¹,¹⁶,²⁰
MRI	Usually Class 1, but operationally high risk	MRI safety zones, magnetic safety, shielding, quench path, cryogen planning, controlled access⁸,⁹
Ultrasound	Usually Class 1	Patient privacy, exam room workflow, data and power, cleanable surfaces¹⁻³
Mammography	Usually Class 1	Patient privacy, equipment clearances, shielding as required¹⁻³,¹⁶
Nuclear Medicine	Class 1 or Class 2 depending on procedure	Radioisotope handling, shielding, hot lab, decay storage, regulatory controls¹²,¹⁷,¹⁸
PET CT	Usually Class 1, sometimes higher depending on procedures	PET uptake rooms, hot lab, radiation safety, patient holding, shielding, CT infrastructure¹³,¹⁶⁻¹⁸
Interventional Radiology	Usually Class 2	Sterile procedure environment, radiation shielding, medical gases, anesthesia, recovery¹⁻⁴,¹⁶,¹⁹
Cath Lab or EP Lab	Usually Class 2	Procedure environment, radiation shielding, booms, gases, monitoring, control room¹⁻⁴,¹⁶,¹⁹
Hybrid OR	Class 3	Full OR infrastructure plus imaging equipment and radiation protection¹⁻⁷,¹⁶,¹⁹

MRI Specific Requirements

MRI requires special planning because the primary hazard is not ionizing radiation. The primary hazard is the magnetic field. MRI planning should address controlled access, ferromagnetic screening, patient and staff safety, MR safe and MR conditional equipment, emergency procedures, and operational safety protocols.⁸,⁹

• Key MRI requirements include:
• ACR Zone I through Zone IV planning
• Controlled access into the scanner room
• Ferromagnetic screening
• Clearly defined patient, staff, and equipment pathways
• 5 gauss line review
• RF shielding
• Magnetic shielding if required
• Quench pipe routing
• Cryogen venting
• Equipment room cooling
• Emergency shutdown procedures
• MR safe or MR conditional equipment
• Patient lift and stretcher compatibility
• Coordination with anesthesia if sedation is used

MRI rooms also need careful siting. Designers should avoid placing MRI near large moving metal objects, elevators, loading docks, major electrical equipment, vibration sources, or areas where the magnetic field could interfere with adjacent operations.⁸,⁹

CT and Radiation Based Imaging Requirements

CT, fluoroscopy, PET CT, nuclear medicine, X ray, cath labs, and interventional radiology require radiation protection planning. This typically includes a shielding report prepared by a qualified medical physicist or radiation physicist.¹⁰,¹¹,¹⁶,²⁰

For CT, accreditation and quality control requirements include equipment performance testing, quality control documentation, scanner evaluation, dose management, and involvement of qualified imaging professionals and medical physicists.¹⁰,¹¹,²⁰

Key requirements include:

• Lead shielding or equivalent wall construction
• Shielded doors, frames, windows, and control booths
• Radiation warning signage
• Control room visibility
• Interlocks where required
• Staff dosimetry program
• Medical physicist review
• Equipment quality control program
• Emergency power as required by hospital policy and clinical use
• Heat rejection and HVAC capacity
• Data infrastructure for PACS and image transfer

Nuclear Medicine and PET CT Requirements

Nuclear medicine and PET CT require both imaging planning and radioactive material management. These rooms often have different support needs than standard diagnostic imaging rooms because they involve radiopharmaceutical receiving, storage, preparation, administration, imaging, patient holding, and radioactive waste handling.¹²,¹³,¹⁷,¹⁸

Key requirements include:

• Hot lab
• Dose storage
• Radiopharmaceutical receiving area
• Uptake rooms for PET
• Patient toilets designed for radioactive patient use where required
• Decay storage
• Radiation shielding
• Staff dosimetry
• Regulatory compliance
• Cleanable surfaces
• Controlled patient flow
• Separation between injected and non injected patients where needed

PET and nuclear medicine programs should also maintain documented quality control processes and comply with applicable accreditation and radioactive materials requirements.¹²,¹³,¹⁷,¹⁸

Operational and Accreditation Requirements

Imaging departments must be planned not only for construction compliance, but also for long term operational readiness. Accreditation expectations may include staff qualifications, imaging equipment performance evaluations, MRI safety risk management, radiation safety procedures, CT dose documentation, quality control logs, and medical physicist involvement.¹⁰⁻¹⁴,²⁰

Important operational requirements include:

• Staff qualifications
• Equipment maintenance records
• Preventive maintenance
• Annual performance evaluations
• Medical physicist testing
• MRI safety training
• Radiation safety officer involvement
• Patient screening procedures
• Contrast safety protocols
• Emergency response planning
• Quality control logs
• Ongoing accreditation readiness

Infection Control and Renovation Requirements

Imaging projects often occur inside active hospitals, outpatient centers, emergency departments, cancer centers, or surgical environments. Renovation work should address infection control, dust control, patient separation, temporary barriers, negative air where required, above ceiling work, water system risks, and interim life safety conditions.¹⁵

For Class 2 and Class 3 imaging rooms, infection control planning should also consider procedure type, sterile supplies, staff flow, patient prep and recovery, clean and soiled movement, and the level of environmental control required for the clinical use.¹⁻⁴,¹⁵

Early Planning Questions for Any Imaging Project

Before beginning design, the project team should confirm:

• What modality is being installed?
• Is this diagnostic only, therapeutic, interventional, or surgical?
• Will sedation or anesthesia be used?
• Will invasive procedures be performed?
• Will sterile supplies be opened in the room?
• How many staff will be in the room during peak use?
• What equipment vendor and model has been selected?
• What are the vendor’s room, power, cooling, and clearance requirements?
• Is radiation shielding required?
• Is magnetic shielding or RF shielding required?
• Is a medical physicist involved?
• What is the equipment delivery and replacement path?
• What existing utilities are available?
• Does the project affect adjacent occupied clinical areas?
• Are there infection control or phasing constraints?
• Will the room need emergency power?
• How will patients move from registration to prep, imaging, recovery, and discharge?

Practical Takeaway

The safest way to classify a hospital imaging room is to start with the procedure, not the machine. A CT scanner, fluoroscopy unit, or MRI suite may look like an equipment planning exercise, but the actual classification depends on clinical use, patient acuity, sedation, invasiveness, infection control, radiation or magnetic safety, and operational workflow.¹⁻⁴

For planning purposes:

Class 1 supports diagnostic imaging.¹⁻³
Class 2 supports diagnostic and therapeutic procedures.¹⁻³
Class 3 supports surgical procedures with imaging.¹⁻³

The classification then informs room size, finish level, HVAC, electrical systems, shielding, medical gases, support spaces, staffing workflow, patient safety measures, and accreditation readiness.¹⁻²⁰

References

1. Facility Guidelines Institute. Guidelines for Design and Construction of Hospitals. Facility Guidelines Institute; 2022.
2. Facility Guidelines Institute. Guidelines for Design and Construction of Outpatient Facilities. Facility Guidelines Institute; 2022.
3. Facility Guidelines Institute. Application Guidance: Invasive Procedure, Procedure Room, Operating Room, and Imaging Room Classification. Facility Guidelines Institute; 2023. Accessed May 4, 2026.
4. American Society of Heating, Refrigerating and Air Conditioning Engineers; American Society for Health Care Engineering. ANSI/ASHRAE/ASHE Standard 170: Ventilation of Health Care Facilities. ASHRAE; 2025.
5. National Fire Protection Association. NFPA 99: Health Care Facilities Code. National Fire Protection Association; 2024.
6. National Fire Protection Association. NFPA 70: National Electrical Code. National Fire Protection Association; 2023.
7. National Fire Protection Association. NFPA 101: Life Safety Code. National Fire Protection Association; 2024.
8. American College of Radiology. MR Safety Resources. American College of Radiology. Accessed May 4, 2026.
9. Pedrosa I, Barkovich AJ, Kanal E, et al. American College of Radiology Manual on MR Safety: 2024 update and revisions. Radiology. 2025;315(1). doi:10.1148/radiol.241405.
10. American College of Radiology. Computed Tomography Accreditation. American College of Radiology. Accessed May 4, 2026.
11. American College of Radiology. Quality Control: CT. Revised March 21, 2025. Accessed May 4, 2026.
12. American College of Radiology. Quality Control: Nuclear Medicine. Revised August 13, 2025. Accessed May 4, 2026.
13. American College of Radiology. Quality Control: PET. Revised October 9, 2025. Accessed May 4, 2026.
14. The Joint Commission. Protecting Patients and Providers in Imaging. The Joint Commission. Accessed May 4, 2026.
15. Sehulster L, Chinn RYW; Centers for Disease Control and Prevention; Healthcare Infection Control Practices Advisory Committee. Guidelines for environmental infection control in health care facilities. MMWR Recomm Rep. 2003;52(RR 10):1 42. Updated July 2019.
16. National Council on Radiation Protection and Measurements. Structural Shielding Design for Medical X Ray Imaging Facilities. NCRP Report No. 147. National Council on Radiation Protection and Measurements; 2004.
17. Nuclear Regulatory Commission. 10 CFR Part 35: Medical Use of Byproduct Material. Nuclear Regulatory Commission. Accessed May 4, 2026.
18. Nuclear Regulatory Commission. Consolidated Guidance About Materials Licenses: Program Specific Guidance About Medical Use Licenses. NUREG 1556, Vol 9, Rev 3. Nuclear Regulatory Commission; 2019.
19. American Society of Anesthesiologists. Statement on Nonoperating Room Anesthetizing Locations. American Society of Anesthesiologists. Accessed May 4, 2026.
20. American Association of Physicists in Medicine. AAPM medical physics practice guideline 1.a: CT protocol management and review practice guideline. J Appl Clin Med Phys. 2013;14(5):3 12.

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About ARCHSOL, LLC

ARCHSOL is an Arizona-based healthcare architecture and planning firm focused on designing high-performing environments that support clinical care, operational efficiency, and long-term adaptability. The firm partners with health systems and providers on projects ranging from ambulatory facilities to major hospital expansions, bringing a strong understanding of complex healthcare environments, infrastructure, and phasing within active campuses. ARCHSOL integrates Real Time Visualization into its workflow to help stakeholders experience spaces early, align decisions, and reduce uncertainty. With a collaborative, hands-on approach, the team delivers thoughtful solutions that simplify complexity and support both providers and the communities they serve.

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