As a radiologic technologist, you interact with more patients in a single shift than most healthcare professionals see in a week. You move between exam rooms, touch equipment between every patient, position patients who may be colonized or infected with dangerous pathogens, and transport imaging equipment through hallways shared by the entire hospital. This unique workflow makes radiology departments a critical junction for infection transmission — and radiologic technologists a frontline defense against healthcare-associated infections (HAIs).
Healthcare-associated infections affect approximately 1 in 31 hospitalized patients on any given day, according to the CDC. Many of these infections are preventable through proper adherence to infection control practices. For rad techs, this isn't just about protecting yourself — it's about protecting every patient who follows, your colleagues, and the vulnerable immunocompromised patients who pass through your department.
The ARRT exam includes infection control and safety questions across multiple content categories, particularly in Patient Care (domain 1 of the ARRT Radiography exam). Understanding the hierarchy of infection control — from standard precautions to transmission-based precautions to sterilization — is essential for both clinical practice and exam success.
The ARRT exam routinely tests infection control concepts across three domains: Patient Care (standard precautions, PPE, hand hygiene), Safety (sterile technique, equipment disinfection), and Image Production (maintaining aseptic technique during mobile and portable exams). Expect at least 3–5 infection control questions on the registry exam.
To effectively prevent infection, you must first understand how infections spread. The CDC describes the chain of infection, a six-link model showing what must be present for an infection to occur. Break any single link, and transmission is prevented:
The pathogen (bacterium, virus, fungus, prion). Examples: Staphylococcus aureus, influenza virus, Clostridioides difficile.
Where the pathogen lives and multiplies. Human reservoirs (patients, staff), environmental surfaces, equipment, or water sources.
How the pathogen leaves the reservoir. Respiratory droplets, blood, wound drainage, feces, urine.
How the pathogen travels. Contact (direct/indirect), droplet, airborne, vector-borne, or vehicle-borne.
How the pathogen enters the new host. Mucous membranes, respiratory tract, broken skin, percutaneous (needlestick).
An individual at risk. Immunocompromised patients, the elderly, neonates, or anyone with breached skin or mucous membranes.
Why this matters to you: Every time you walk into an exam room, you are potentially a mode of transmission. Your hands, your uniform, and your equipment can all carry pathogens from one patient to the next. The goal of infection control is to break the chain at the point you can control — typically the mode of transmission link, through hand hygiene, barrier precautions (PPE), and equipment disinfection.
Standard precautions are the minimum infection prevention practices that apply to all patient care, regardless of suspected or confirmed infection status. They were developed by the CDC and are the cornerstone of healthcare infection control. Every rad tech must apply standard precautions during every patient interaction, every time.
1. Hand Hygiene — This is the single most important infection control measure. The CDC's Five Moments for Hand Hygiene apply to every radiology encounter:
Hands should be washed with soap and water for at least 20 seconds when visibly soiled, or after caring for patients with C. difficile (alcohol-based hand rubs are ineffective against C. difficile spores). In all other situations, an alcohol-based hand rub with 60–95% alcohol is the preferred method because it is faster, more effective, and gentler on skin.
2. Use of Personal Protective Equipment (PPE) — PPE creates a barrier between you and infectious material. The correct donning order is: gown first, then mask or respirator, then goggles or face shield, and finally gloves. The correct doffing order is: gloves first (they are most contaminated), then goggles or face shield, then gown, and finally mask or respirator. Perform hand hygiene between each doffing step.
3. Respiratory Hygiene / Cough Etiquette — All patients and visitors should be instructed to cover their mouth and nose with a tissue (or their elbow) when coughing or sneezing. Posted signs at radiology department entrances should instruct symptomatic patients to wear a surgical mask and notify staff immediately.
4. Safe Injection Practices — Use a sterile, single-use needle and syringe for each injection. Never reuse a needle for multiple patients. Clean the injection port with an alcohol swab before accessing. Needles should never be recapped — dispose of them immediately in a puncture-resistant sharps container.
5. Environmental Cleaning and Disinfection — All high-touch surfaces in the radiology department must be cleaned and disinfected between patients.
The X-ray tube housing and collimator handles are among the most contaminated surfaces in the radiology department. A study published in the American Journal of Infection Control found that X-ray tube housings tested positive for MRSA on 33% of surfaces sampled. Wipe down the tube housing, the control panel, exposure switch, and positioning sponges between every patient. For DR detectors and CR cassettes, use manufacturer-approved disinfectant wipes — harsh chemicals can damage the sensitive imaging components.
When a patient is known or suspected to have an infection that requires additional barriers, transmission-based precautions are added on top of standard precautions. The CDC defines three categories of transmission-based precautions, each with specific PPE and room requirements.
| Precaution Type | Pathogens Covered | Required PPE | Room Requirements |
|---|---|---|---|
| Contact | MRSA, VRE, C. difficile, norovirus, scabies, wound infections, draining abscesses | Gloves + gown. Add eye protection if splash risk exists. | Private room preferred. Dedicated equipment when possible. |
| Droplet | Influenza, COVID-19, meningococcal disease, pertussis, rhinovirus, mumps, rubella | Surgical mask + eye protection. Gown and gloves if contact risk. | Private room or cohort with same pathogen. Spatial separation ≥ 3 ft (1 m). |
| Airborne | Pulmonary tuberculosis (TB), measles (rubeola), chickenpox (varicella), disseminated herpes zoster (shingles) | N95 respirator (or PAPR if fit-tested N95 unavailable). Gown, gloves, eye protection. | Negative-pressure airborne infection isolation room (AIIR). N95 fit-testing required. |
Contact precautions are used for patients with infections spread by direct contact (touching the patient) or indirect contact (touching contaminated surfaces or equipment). For radiology, this means:
Droplet precautions are required when a patient has an infection spread by large respiratory droplets (particles > 5 microns). These droplets travel approximately 3–6 feet and are generated by coughing, sneezing, talking, or during procedures like suctioning and bronchoscopy. Key considerations for radiology:
Airborne precautions are the most stringent transmission-based precautions. They are required for pathogens that remain suspended in air for extended periods, such as Mycobacterium tuberculosis (TB), measles, and varicella. These tiny droplet nuclei (< 5 µm) can travel on air currents throughout a room — and beyond if the room is not properly ventilated.
A frequently tested ARRT distinction: Airborne precautions require an N95 respirator (or PAPR) because droplet nuclei can bypass surgical masks. Droplet precautions require a surgical mask because large droplets fall to the ground within 3–6 feet. Remember the pneumonic: "MTV" — Measles, Tuberculosis, Varicella (chickenpox) need Airborne; everything else respiratory (flu, COVID, pertussis) is Droplet.
Key considerations for airborne precautions in radiology:
Not all medical equipment requires the same level of disinfection. The Spaulding classification system categorizes equipment by the risk of infection associated with its use, guiding the appropriate disinfection or sterilization method:
| Classification | Definition | Radiology Examples | Required Processing |
|---|---|---|---|
| Critical | Enters sterile tissue or vascular system | Surgical instruments, biopsy needles, angiographic catheters, contrast injection kits | Sterilization (autoclave, ethylene oxide, or hydrogen peroxide plasma) |
| Semicritical | Contacts mucous membranes or non-intact skin | Endocavitary probes (transvaginal, transrectal ultrasound), laryngoscope blades, barium enema tips | High-level disinfection (≥ 20 min in ≥ 2% glutaraldehyde, ortho-phthalaldehyde, or chlorine dioxide) |
| Noncritical | Contacts intact skin only (or no direct contact) | X-ray tube housing, DR detector, CR cassettes, positioning sponges, control panel, patient bed, blood pressure cuff, lead aprons | Low- to intermediate-level disinfection (EPA-registered hospital disinfectant or disinfectant wipes) |
DR detectors and CR cassettes are noncritical items but are expensive and sensitive. Use only manufacturer-approved disinfectant wipes — typically alcohol-based wipes (70% isopropyl alcohol) or quaternary ammonium compound wipes. Avoid bleach-based wipes on DR detectors, as they can degrade the detector surface and cause image artifacts. For CR cassettes, clean the cassette face after every use and periodically clean the phosphor plate with approved solutions to remove residue that causes artifacts.
Performing a portable chest X-ray on a patient in isolation requires careful planning. Follow this step-by-step approach to protect yourself and prevent cross-contamination:
Each modality has unique infection control requirements. For MRI, the bore surfaces and patient positioning pads should be disinfected between patients. MRI-safe disinfectant wipes (non-metallic, non-magnetic) must be used — check with your MRI safety officer for approved products. For ultrasound, gel should be single-patient use (not shared bottles). Transducers require cleaning based on their Spaulding classification: skin-surface probes (noncritical) need low-level disinfection; endocavitary probes (semicritical) need high-level disinfection between patients. Always use a sterile probe cover for interventional or intraoperative procedures.
When scanning an isolation patient in CT, plan the scan time carefully. If the patient is on airborne precautions, they should wear a surgical mask. The scanner console in the control room provides a physical barrier — the technologist typically does not need to wear PPE while operating the console. However, anyone entering the scan room to position the patient must wear the appropriate PPE. After the patient leaves, disinfect the scan table and any surfaces touched (vertical laser alignment lights, head holder, positioning aids).
Rad techs should be up to date on all recommended healthcare worker vaccinations per the CDC's Advisory Committee on Immunization Practices (ACIP). These typically include:
Applying infection control principles in real-world situations is what the ARRT exam — and clinical practice — demands. Consider these common radiology scenarios:
Scenario 1: A patient on contact precautions for MRSA requires a portable AP chest X-ray. When you arrive, the patient is lying supine in bed. You place the DR detector behind the patient's back using a plastic sleeve. After the exposure, you notice the detector slipped partially out of the sleeve. What should you do next?
Solution: Clean the DR detector with an approved disinfectant wipe immediately. Document that the detector was in contact with the patient's bed linens (indirect contamination). Notify lead technologist if the detector manufacturer's cleaning protocol requires specific steps.
Scenario 2: You are assigned to fluoroscopy for an upper GI series on a patient who has tested positive for C. difficile. What preparation is needed?
Solution: C. difficile requires contact precautions plus sporicidal disinfection (alcohol-based hand rubs do not kill C. difficile spores). Wear gown and gloves. Use soap and water for hand hygiene instead of alcohol-based rub. The fluoroscopy table, image intensifier, and all controls must be disinfected with a bleach-based (sodium hypochlorite 1:10) sporicidal agent after the procedure.
Scenario 3: A patient presents to the emergency department with suspected active tuberculosis. The physician orders a PA and lateral chest X-ray. How should this be managed?
Solution: The patient should be placed on airborne precautions immediately. If a portable chest X-ray in the negative-pressure AIIR room is not possible (e.g., the equipment cannot achieve diagnostic quality), the patient should wear a surgical mask during transport to the X-ray room. The X-ray room must be a negative-pressure AIIR. Staff entering the room must wear an N95 respirator (fit-tested). After the patient leaves, the room should remain vacant for sufficient time for air changes (typically 30–60 minutes).
Keep these core principles in mind every shift:
Try these ARRT-style multiple choice questions based on this article. Click an option to check your answer — correct answers turn green, wrong ones turn red.