Diagnostic quality, radiation exposure, and biological damage and responses following exposure at different kv values during pulmonary CT angiography.

BACKGROUND

It is important to reduce the exposure to ionizing radiation, which is increasing due to medical diagnosis and treatments, and to determine the damage in the organism and the biological response to it. We aimed to investigate the radiological and biological effects of dose reduction in computed tomography pulmonary angiography (CTPA), which is increasingly used.

METHODS

123 patients who underwent CTPA with suspicion of pulmonary thromboembolism were divided into three groups and imaging was performed at three different kilovolt (kV) values (80, 100 and 120). Diagnostic quality, radiation exposure parameters (effective dose and dose length product [DLP]), oxidative stress parameters such as total oxidant status (TOS), malondialdehyde (MDA), oxidative stress index (OSI) and total antioxidant status (TAS) in pre- and post-scanning blood samples were evaluated. DNA was determined by comet assay.

RESULTS

No significant difference was found in terms of diagnostic quality between the three groups (p > .005). Radiation exposure parameters increased statistically significantly in line with the kV values (p < .05). The smallest increase in DNA damage after scan was detected in the group with the 80 kV(p = .001). The increase in TOS, MDA and OSI values after imaging in all three groups was not statistically significant (p > .005). The decrease in TAS values was statistically significant only in groups II and III (p < .005).

CONCLUSION

CTPA can be performed at a low kV of 80 kV without loss of diagnostic quality. Unlike the increase in DNA damage as the kV value increased, the increase in oxidative stress parameters was not found to be significant. In addition, the decrease in TAS value was significant only for the 100 kV and 120 kV groups.