Weekly Feedback Helps Reduce CT Angiography Radiation Dose

July 23, 2013

Physicians used significantly lower radiation doses for cardiac CT angiography when weekly dose reports provided feedback on the tests performed.

Weekly dose report feedback of cardiac computed tomography angiography (CCTA) significantly reduces overall radiation doses and reduces the number of high-dose outliers, according to a study published in Academic Radiology.

How CCTA is performed depends on the experience and education of the physicians and technologists performing the exams, which may mean that the ideal radiation doses are not always used. Researchers from Massachusetts General Hospital and Harvard Medical School evaluated real-time feedback by weekly dose reports to see if this would have an effect on everyday practice.

The researchers analyzed 450 patients who underwent physician-supervised CCTA for clinically indicated native coronary evaluation between April 2011 and January 2013. A total of 150 patients were assessed before the initiation of weekly dose report (preintervention period: April to September 2011) and 150 patients after the initiation (postintervention period: September 2011 to February 2012).

Results were compared to a late control group consisting of 150 consecutive CCTA exams, which were performed after the study (September 2012 to January 2013). Patient characteristics and effective radiation were recorded and compared.

The findings showed that the total radiation dose was significantly lower in the postintervention period (3.4 mSv [1.7–5.7] and in the late control group (3.3 mSv [2.0–5.3] versus the preintervention period (4.1 mSv [2.1–6.6] (P = .005).

It was also found that the proportion of high-dose outliers decreased in the postintervention period and late control period (exams with less than 10 mSv were 88.0 percent preintervention versus 97.3 percent postintervention versus 95.3 percent late control.

Exams of less than 15 mSv were:

  • Preintervention group: 98 percent
  • Postintervention group : 100 percent
  • Late control group : 98.7 percent

Exams of less than 20.0 mSv were:

  • Preintervention group:  98.7 percent
  • Postintervention group: 100 percent
  • Late control group: 100.0 percent

The authors concluded that this feedback report helped reduce the exam-related doses and overall dose reductions were maintained beyond the initial study period.