OBJECTIVES: Computed tomography (CT) exams contribute for a large part to the population's radiation burden. This study addresses the question if dose settings of scanners expressed by dose-length product (DLP) are correlated with directly measurable biological effects in patients. METHODS: DLP, blood dose, effective dose and DNA damage were analyzed for patients undergoing a thoracic or abdominal contrast CT scan on two CT scanners with different dose settings. The DNA damage was assessed by scoring γ-H2AX foci representing DNA double-strand breaks (DSBs) in patient's lymphocytes. Blood dose was calculated using the ImPACT software. RESULTS: The CT system operating at higher dose settings represented by higher DLP values, resulted in a significantly higher number of radiation-induced γ-H2AX foci in patient's lymphocytes (DLP: 2.1 times higher; γ-H2AX foci: 2.3 times higher; p<0.05). Plotting γ-H2AX foci versus blood dose showed a systematic increase of DNA damage with dose. In vitro experiments ruled out a possible X-ray enhancement of DNA damage effect by contrast agent. CONCLUSIONS: Present study demonstrates that optimization of DLP setting of scanners results in a reduction of X-ray effects in patients.
OBJECTIVES: Computed tomography (CT) exams contribute for a large part to the population's radiation burden. This study addresses the question if dose settings of scanners expressed by dose-length product (DLP) are correlated with directly measurable biological effects in patients. METHODS: DLP, blood dose, effective dose and DNA damage were analyzed for patients undergoing a thoracic or abdominal contrast CT scan on two CT scanners with different dose settings. The DNA damage was assessed by scoring γ-H2AX foci representing DNA double-strand breaks (DSBs) in patient's lymphocytes. Blood dose was calculated using the ImPACT software. RESULTS: The CT system operating at higher dose settings represented by higher DLP values, resulted in a significantly higher number of radiation-induced γ-H2AX foci in patient's lymphocytes (DLP: 2.1 times higher; γ-H2AX foci: 2.3 times higher; p<0.05). Plotting γ-H2AX foci versus blood dose showed a systematic increase of DNA damage with dose. In vitro experiments ruled out a possible X-ray enhancement of DNA damage effect by contrast agent. CONCLUSIONS: Present study demonstrates that optimization of DLP setting of scanners results in a reduction of X-ray effects in patients.
Authors: Brunhild M Halm; Adrian A Franke; Jennifer F Lai; Helen C Turner; David J Brenner; Vatche M Zohrabian; Robert DiMauro Journal: Pediatr Radiol Date: 2014-04-23
Authors: Brunhild M Halm; Adrian A Franke; Jennifer F Lai; Xingnan Li; Laurie J Custer; Ian Pagano; Robert V Cooney; Helen C Turner; David J Brenner Journal: Hawaii J Med Public Health Date: 2015-03
Authors: Christophe E Redon; Urbain Weyemi; Palak R Parekh; Dejun Huang; Allison S Burrell; William M Bonner Journal: Biochim Biophys Acta Date: 2012-03-09
Authors: Richard Harbron; Elizabeth A Ainsbury; Simon D Bouffler; Rick J Tanner; Jonathan S Eakins; Mark S Pearce Journal: Br J Radiol Date: 2017-08-22 Impact factor: 3.039