Radiation Protection and Radiologic Technology Laws, Ethics and Professional Practice
Radiation Protection and Radiologic Technology Laws
Principles
Justification, optimization, and dose limitation support ALARA. Time, distance, and shielding are the practical tools. The inverse-square law makes distance powerful: doubling distance quarters dose. Use the shortest fluoroscopy time, last-image hold, pulsed fluoroscopy, collimation, and appropriate shielding.
Dose limits
For occupationally exposed workers, the effective dose limit is 50 mSv per year; for the public, 1 mSv per year. Lens limit is 150 mSv per year and skin/extremity 500 mSv per year. The fetus limit is 0.5 mSv per month after declaration of pregnancy. Limits exclude background and medical exposure and are not thresholds for harm.
Protection practice
Use 0.5 mm Pb-equivalent aprons and thyroid shields, collimate, use gonadal shielding when appropriate, and monitor with dosimeters. Report overexposures. State law and licensure govern who may operate equipment and require continuing education.
Traps
Limits are effective dose, not equivalent dose for every tissue. Public and occupational limits differ. A pregnant worker may continue working with careful monitoring. Distance protects better than a thin apron.
Worked example: If scatter dose is 0.8 mSv/h at 1 m, at 2 m it is 0.8/2^2 = 0.2 mSv/h.
Ethics and Professional Practice
Ethical principles
Autonomy respects the patient's informed choice; beneficence promotes good; nonmaleficence avoids harm; justice demands fairness; veracity requires honesty; fidelity requires keeping commitments. Confidentiality is both ethical and legal.
Informed consent
Valid consent requires capacity, disclosure of information, understanding, voluntariness, and documentation. Consent may be withdrawn. Minors and incapacitated patients require appropriate surrogate consent, subject to state law and emergency exceptions.
Professional standards
Know the ARRT Standards of Ethics and scope of practice, state licensure, and employer policy. Practice within your credentials, protect patient privacy, avoid social-media disclosures, and report errors and unsafe conditions. Fraud, impairment, and boundary violations are reportable.
Traps
Battery can occur when treatment proceeds without valid consent; negligence requires duty, breach, causation, and damages. The standard of care is what a reasonable practitioner would do, not the best possible care. Confidentiality survives death in many jurisdictions.
Worked example: A competent adult refuses contrast. Document the refusal, notify the physician, and do not proceed; coercing the patient risks battery and ethical violation.