NRSB RRS cheat sheet

ALARA: As Low As Reasonably Achievable; dose limits: effective 50 mSv/year for radiation workers, 1 mSv/year for public; equivalent 150 mSv/year for lens of eye, 500 mSv/year for skin, hands, feet.

Cardinal principles of radiation protection: time, distance, shielding. Doubling distance reduces dose by factor of 4 (inverse square law).

Occupancy factor (T): full occupancy T=1, partial T=2, occasional T=4; workload (W) in mA-min/week; use formula: barrier thickness from tables using W, T, and distance (d).

Primary protective barrier: attenuates useful beam; secondary barrier: attenuates leakage and scatter. Lead aprons minimum 0.25 mm Pb equivalent; 0.5 mm Pb for fluoroscopy.

Personnel monitoring: film badge, TLD, OSL; worn at collar level outside apron; second badge under apron if pregnant or high dose. Report doses monthly.

Pregnancy: declare voluntarily; fetal dose limit 0.5 mSv/month, 5 mSv total gestation; use additional shielding and collimation.

Dose area product (DAP) and air kerma are dose metrics in fluoroscopy; typical fluoroscopy dose rates: 1-5 mGy/min in normal mode, higher in high-level control.

Scatter radiation: increases with patient thickness, field size, and kVp; use collimation to reduce scatter; lead shielding reduces scatter by 90-95%.

X-ray tube: cathode (filament) emits electrons; anode (tungsten target) produces X-rays. mAs controls quantity (density); kVp controls quality (penetration and contrast).

Inverse square law: intensity inversely proportional to square of distance (I1/I2 = (d2/d1)^2).

15% rule: to maintain density, increase kVp by 15% and halve mAs (or decrease kVp by 15% and double mAs).

Heel effect: X-ray intensity lower on anode side; place thicker body part toward cathode.

Focal spot size: smaller focal spot improves spatial resolution; large focal spot for high mA. Blooming effect at high mA.

Grid: improves contrast by absorbing scatter; grid ratio = height/width; typical 8:1 to 16:1; Bucky factor = incident/transmitted radiation.

Automatic exposure control (AEC): ionization chambers measure radiation reaching IR; minimum response time; backup timer.

Digital image characteristics: spatial resolution (pixel size), contrast resolution (bit depth), noise (quantum mottle), modulation transfer function (MTF).

Patient identification: two identifiers (name, DOB, MRN) before procedure; verify order and pregnancy status.

Vital signs: normal adult: BP <120/80 mmHg, HR 60-100 bpm, RR 12-20/min, Temp 36.5-37.5°C, SpO2 ≥95%.

Contrast media: iodinated (ionic/nonionic) for CT/IVU; gadolinium for MRI; barium sulfate for GI. Check allergies, renal function (eGFR), and metformin use.

Anaphylactoid reaction: mild (nausea, hives) treat with antihistamine; moderate (vomiting, urticaria) require observation; severe (laryngeal edema, hypotension) require epinephrine, oxygen, IV fluids.

Extravasation: stop injection, elevate limb, cold compress, document; monitor for compartment syndrome.

Infection control: standard precautions (hand hygiene, gloves, gown, mask, eye protection); contact, droplet, airborne precautions.

Patient transfer: use gait belt, lock wheels, lower bed, ensure adequate assistance; body mechanics: wide base, bend knees, keep load close.

Immobilization: sandbags, sponges, tape; for pediatrics use distraction, parental presence, immobilization devices.

Chest PA: upright, 72 inches SID, breath in, arms out of lung fields; evaluation: 10 posterior ribs, clavicles symmetric, scapulae out of lung fields.

Abdomen AP supine: 40 inches SID, include symphysis pubis to diaphragm; for obstruction use upright or decubitus.

C-spine lateral: 72 inches SID, shoulders down, visualize C1-C7; open mouth odontoid for C1-C2.

Lumbar spine: AP, lateral, oblique; 40 inches SID; lateral spot for lumbosacral junction.

Extremities: include joint above and below; use 40-48 inches SID; collimate to part.

Skull: PA, lateral, Townes; 40 inches SID; orbitomeatal line perpendicular for lateral.

Fluoroscopy: barium swallow, upper GI, barium enema, arthrography; use spot films and last image hold.

Anatomy: bony landmarks: C7 vertebra prominens, T7 level of inferior scapula, L4 iliac crest, L5 posterior superior iliac spine (PSIS).

Image quality: density (brightness), contrast, spatial resolution, distortion, artifacts; evaluate with criteria: position, collimation, exposure index (EI), and absence of motion.

Exposure index (EI): digital systems; EI within manufacturer range; deviation index (DI) = 10 log(EI/EI_target).

Reject analysis: track reasons (positioning, exposure, artifacts, motion); aim for <5% reject rate.

Quality control tests: daily (collimator, detector), weekly (phantom image), monthly (kVp, mAs, timer), annually (calibration).

Collimation: must be within 2% of SID; check with coins or markers; collimation reduces dose and improves contrast.

Artifacts: grid lines (grid cutoff, misalignment), motion (blur), double exposure, detector artifacts (dead pixels), processing artifacts.

Monitor calibration: SMPTE or TG-18 pattern; luminance 350-500 cd/m2; ambient light low; clean screens.

Repeat rate: monitor and analyze; causes: positioning errors, patient motion, incorrect exposure factors, equipment malfunction.

Scope of practice: defined by state law and facility policy; radiographer performs imaging procedures under supervision of radiologist; cannot interpret images or prescribe.

Ethics: beneficence, nonmaleficence, autonomy, justice; informed consent: patient must understand procedure, risks, benefits, alternatives; document.

Confidentiality: HIPAA; protect patient health information (PHI); minimum necessary standard; report breaches.

Professionalism: ARRT Standards of Ethics; report violations; avoid conflicts of interest; maintain competence through continuing education (24 credits per biennium).

Patient rights: respect, privacy, dignity; right to refuse; advance directives; cultural competence.

Legal: malpractice (negligence: duty, breach, causation, damages); respondeat superior; good Samaritan laws; scope of practice violations.

Documentation: accurate, timely, objective; errors corrected with single line and initials; no alterations.

Communication: SBAR (Situation, Background, Assessment, Recommendation) for handoffs; disclose errors per policy.