Comparison of pediatric temporal bone computed tomography at 100kVp with tin filtration versus conventional protocol

Background Reducing the radiation dose of pediatric temporal bone computed tomography (CT) has always been a challenge. Objective To compare radiation doses and conspicuity of anatomic landmarks of the pediatric temporal bone between the CT protocol using spectral beam shaping at 100 kVp with a dedicated tin filter (Sn100 kVp) and the conventional protocol (100 kVp). Matetials and Methods : In total 100 children who had undergone head CT for diagnostic purposes and were found to have normal anatomical inner and middle ear structures were included in this study, of these, 50 children were examined with the Sn100kVp protocol and 50 with the conventional protocol. Subjective and objective image qualities, including visualization of temporal bone structures, image quality, image noise, and radiation doses, were compared between the two groups. Results The mean dose length product and effective dose (ED) of the Sn100 kVp scans (ED:0.03 ± 0.01 mSv) were significantly lower than those of the 100kVp scans ( ED: 0.50 ± 0.14 mSv, p < 0.001). The signal-to-noise ratio was slightly lower in the Sn100kVp scans than in the 100kVp scans, except for the squamous bone. However, the subjective evaluation of anatomic landmarks was not significantly different between the two groups, except for the labyrinth. Conclusion Temporal bone CT performed at 100 kVp with an additional tin fifilter for spectral shaping markedly reduced radiation dose and maintained good anatomic conspicuity in pediatric patients compared with conventional temporal bone CT .