Table 13

Dose Minimization Strategies

X-Ray FluoroscopyUse alternative nonradiation-based imaging techniques (ultrasound, magnetic resonance imaging, electromagnetic mapping) when appropriate.Radiological equipment: Current state-of-the-art equipment calibrated for minimal dose exposures.Operator conduct: Optimal system positioning, minimal imaging field size, minimal exposure time.X-ray system operating modes: Slowest frame rate and the smallest dose per frame consistent with diagnostic quality imaging and appropriate procedure guidance.Medical personnel protection: Optimal use of protective garments and shields, maximize distance from the x-ray source, and minimize patient exposure (which, in turn, minimizes medical personnel exposure).
X-Ray CTStudy appropriateness: Ensure that an x-ray CT examination is the optimal imaging technique to answer the clinical question.Radiological equipment: Equipment should be current state of the art, in good working order, and calibrated for minimal dose exposures.Scan protocol: Select the lowest-dose scan protocol that will provide images of diagnostic quality to answer the clinical question.Scan size: Confine the imaged body region to the smallest area needed to answer the clinical question.
Nuclear CardiologyStudy appropriateness: Ensure that nuclear cardiology study is the optimal imaging technique to answer the clinical question. Consider PET rather than SPECT imaging if feasible and appropriate.Imaging equipment: Equipment should be current state of the art, in good working order, and calibrated for minimal dose exposures.Scan protocol: Select a stress-rest protocol when appropriate (according to ASNC guidelines).Radiopharmaceutical choice: Tc-99m is preferred for SPECT. Avoid Tl-201 except for studies focused particularly on myocardial viability issues.Radiopharmaceutical dose: Use the smallest injected dose that will provide sufficient counts for imaging in a practical time period.

ASNC = American Society of Nuclear Cardiology; CT = computed tomographic; PET = positron emission tomography; SPECT = single-photon emission computed tomography; Tc = technetium; Tl = thallium.