Amichai Joshua Erdfarb MD, Presenter: Nothing to Disclose

Richard Zampolin MD, Abstract Co-Author: Nothing to Disclose

Alan H. Schoenfeld MS, Abstract Co-Author: Nothing to Disclose

Allan L. Brook MD, Abstract Co-Author: Advisor, CareFusion Corporation

Jacqueline Anne Bello MD, Abstract Co-Author: Nothing to Disclose

Judah Burns MD, Abstract Co-Author: Nothing to Disclose

Ongoing monitoring of patient radiation exposure with data analysis aimed at patient dose reduction is an important component of practice quality improvement programs. Although frequently used, total fluoroscopy time alone is an imprecise indicator of patient radiation exposure. In addition to time, dose depends on additional parameters including collimation, planes imaged, frame rate, fluoroscopy mode, and number of digital subtraction acquisitions. The purpose of this study is to identify a more meaningful metric of radiation utilization to be used by physicians, in the course of continued self-assessment, and by institutions, as part of quality assurance monitoring.

Fluoroscopy times (FT) and dose area products (DAP) available for 170 of 175 consecutive diagnostic cerebral angiograms, performed between April 2011 and March 2012, were used to calculate a DAP to FT ratio. Descriptive statistics were generated to identify appropriate targets for self assessment and quality improvement initiatives.

The total FT used during diagnostic cerebral angiography ranged from 2.9 – 54.1 min (mean: 10.5 +/- 6.2 min) with associated DAPs ranging from 25.0 – 384.0 Gy*cm-squared (mean: 112.4 +/- 60.9 Gy*cm-squared). The radiation exposure per unit time, calculated as the DAP delivered per minute of FT, ranged from 2.7 – 51.5 Gy*cm-squared/min (mean: 12.3 +/- 7.1 Gy*cm-squared/min). The Pearson’s correlation coefficient of FT to DAP was 0.4076.

Fluoroscopy time poorly correlates with DAP and is therefore not a useful index for radiation exposure monitoring. DAP alone conveys total dose but does not reflect the efficiency of radiation utilization. The ratio of DAP to fluoroscopy time is a readily calculable metric associated with diagnostic cerebral angiography, which more accurately reflects an operator’s control of patient radiation exposure per unit time than FT or DAP alone. In conjunction with exam type, DAP, and FT, this ratio can be used by individuals, to monitor and refine their technique, and by institutions, to develop more meaningful benchmarks with which to evaluate radiation utilization efficiency.

The DAP to FT ratio reflects radiation utilization efficiency during angiography, and, when used in conjunction with other metrics, can enhance quality assurance and improvement initiatives.

Erdfarb, A, Zampolin, R, Schoenfeld, A, Brook, A, Bello, J, Burns, J, Toward the Development of More Meaningful Metrics of Radiation Utilization: The Relationship of Fluoroscopy Time to Radiation Exposure in Diagnostic Cerebral Angiography.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12027690.html