Shu Min Tao1,2, Fan Zhou1, U Joseph Schoepf3, Addison A Johnson3, Zhu Xiao Lin1, Chang Sheng Zhou1, Guang Ming Lu1, Long Jiang Zhang1. 1. 1 Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, PR China. 2. 2 Medical Imaging Center, Affiliated Hospital of Nantong University, Nantong, PR China. 3. 3 Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
Abstract
BACKGROUND: As abdominal computed tomography (CT) radiation dose can be higher compared with other organ systems, monitoring the radiation exposure from this exam type is especially important. PURPOSE: To evaluate the effect of abdominal contrast-enhanced CT (CE-CT) on levels of DNA double-strand breaks (DSBs) in peripheral blood lymphocytes. MATERIAL AND METHODS: This study was performed in two parts: (i) an in vitro study: venous blood samples from 12 volunteers were divided into four groups. Samples in group A did not undergo radiation exposure, while groups B, C, and D received one CT scan with 1-3 times the radiation dose equivalent to abdominal CE-CT scan, respectively; and (ii) an in vivo study: blood was taken before CT and 5 min after CT in 30 patients. Lymphocytes were isolated and stained by immunofluorescence of γ-H2AX protein. DSB levels were compared by variance analysis or paired t-test. The relationship between radiation dose and γ-H2AX focus increase was analyzed using Pearson correlation analysis. RESULTS: In the in vitro study, DSBs levels in groups B, C, and D were 49.4%, 96.6%, and 149.4% higher than those in Group A, respectively (all P < 0.001). Radiation dose in the four subgroups had a linear correlation to DSB levels ( P < 0.001). In the in vivo study, the DSB level was 43.5% higher after CT ( P < 0.001). CONCLUSION: Abdominal CE-CT significantly increased DSB levels in both in vitro and in vivo experiments. A positive linear correlation of CT radiation dose with intracellular DSBs levels was observed in the in vitro study.
BACKGROUND: As abdominal computed tomography (CT) radiation dose can be higher compared with other organ systems, monitoring the radiation exposure from this exam type is especially important. PURPOSE: To evaluate the effect of abdominal contrast-enhanced CT (CE-CT) on levels of DNA double-strand breaks (DSBs) in peripheral blood lymphocytes. MATERIAL AND METHODS: This study was performed in two parts: (i) an in vitro study: venous blood samples from 12 volunteers were divided into four groups. Samples in group A did not undergo radiation exposure, while groups B, C, and D received one CT scan with 1-3 times the radiation dose equivalent to abdominal CE-CT scan, respectively; and (ii) an in vivo study: blood was taken before CT and 5 min after CT in 30 patients. Lymphocytes were isolated and stained by immunofluorescence of γ-H2AX protein. DSB levels were compared by variance analysis or paired t-test. The relationship between radiation dose and γ-H2AX focus increase was analyzed using Pearson correlation analysis. RESULTS: In the in vitro study, DSBs levels in groups B, C, and D were 49.4%, 96.6%, and 149.4% higher than those in Group A, respectively (all P < 0.001). Radiation dose in the four subgroups had a linear correlation to DSB levels ( P < 0.001). In the in vivo study, the DSB level was 43.5% higher after CT ( P < 0.001). CONCLUSION: Abdominal CE-CT significantly increased DSB levels in both in vitro and in vivo experiments. A positive linear correlation of CT radiation dose with intracellular DSBs levels was observed in the in vitro study.
Entities:
Keywords:
CT; Computed tomography; DNA double-strand breaks; in vivo; radiation dose; γ-H2AX