Estimation of the effects of medical diagnostic radiation exposure based on DNA damage

Abstract

X-rays are widely applied in the medical field for the diagnosis and treatment of diseases. Among the uses of X-rays in diagnosis, computed tomography (CT) has been established as one of the most informative diagnostic radiology examinations. Moreover, recent advances in CT scan technology have made this examination much easier and more informative and increased its application, especially in Japan. However, the radiation dose of CT scans is higher than that of simple X-ray examinations. Therefore, the health risk of a CT scan has been discussed in various studies, but is still controversial. Consequently, the biological and cytogenetic effects of CT scans are being analyzed. Here, we summarize the recent findings concerning the biological and cytogenetic effects of ionizing radiation from a CT scan, by focusing on DNA damage and chromosome aberrations.

Fig. 1.

Various methods used for the estimation of the biological effects of medical radiation. (A) γ-H2AX foci (yellow arrow) in PBLs after irradiation; (B) dicentric chromosome in a metaphase lymphocyte after Giemsa staining; (C) dicentric chromosome (yellow arrow) and acentric fragment (white arrow) in metaphase chromosomes after PNA-FISH using telomere/centromere probes; (D) chromosome aberration in metaphase chromosomes after multi-color FISH using chromosome painting probes; (E) PCC-ring chromosome in PBLs after irradiation; (F) MN (yellow arrow) in binucleated cells after DAPI staining.