AJR: Best practices for CT dose reduction

Community radiologists can select from an array of dose management strategies to “counter the wave of alarm over the small and unproven risks of low-dose radiation that is sweeping the country and threatens to undermine the considerable benefits that accrue from careful and judicious use of modern CT technology,” according to a clinical perspective published in this month's American Journal of Roentgenology.

Given the current heightened concerns over radiation dose, Fergus V. Coakley, MD, of the department of radiology at the University of California, San Francisco, and colleagues compiled a list of reasonable measures that community radiologists could employ to respond to public concerns.

The list includes:

• Provision of patient information material that emphasizes the balance between risks and benefits. Coakley suggested reminding patients that everyone is exposed to background radiation on a daily basis and framing cancer risk in positive and familiar terms.
• Review of protocols and indications. This includes accepting low-dose, noisy images for scans where image quality suffices for diagnostic purposes such as renal colic studies. Sites also can review maximum tube potential, tube current, table speed and gantry radiation, preferably with a medical physicist, to minimize radiation dose.
• Promotion of nonionizing studies—MRI and ultrasound—as appropriate.
• Implementation of decision support software to alert users to recent similar studies or low utility orders that may not generate clinically useful data.
• Consideration of “smart” automatic tube current modulation to reduce dose.
• Use of bismuth shields.
• Provision of training to technologists to check reference dose measurements and empowering them to implement adjustments or inform radiologists if reference levels will be exceeded.
• Implementation of adaptive statistical iterative reconstruction, which can cut dose by 32 to 65 percent.
• Calculation of radiation dose. Although calculations are inexact, they can raise “radiation consciousness and allow early recognition of unusually high doses that may require protocol changes or educational feedback to technologists,” wrote Coakley and colleagues.
• Consideration of dose reporting. This suggestion may raise anxiety among patients or referring physicians and should be weighed carefully, noted the authors.

Radiology practices have multiple options for addressing radiation dose concerns and should consider how such strategies fit into their practices, concluded the researchers.