Application of iterative algorithm in temporal bone MSCT:An experimental study

Objective To investigate the influences of iterative algorithm(using iDose algorithm) on image quality and radiation dose in temporal bone MSCT.Methods A proper cadaveric head based on the noise level in routine clinical MSCT examination protocol with filtered back-projection(FBP) algorithm was selected as the research object.The cadaveric head was scanned with different effective tube current,and the images were reconstructed with FBP and iDose algorithms,respectively.The subjective and objective evaluations were performed for all the images,and the optimal parameter combination was found.The values of CT volume dose index and dose length product(DLP) at various scan parameters and reconstruction algorithms were analyzed,and effective doses of subject were calculated as well.Results The noise level of iDose algorithm was lower than that of FBP under the same effective tube current,and it decreased with the increasing of iDose levels.The noise level decreased with the increasing of the effective tube current under different effective tube current.The combination of 100 mAs/silce and iDose 5 algorithm could met the requirements of clinical diagnosis,and the noise level of resultant images was lower than that obtained with the combination of 200 mAs/silce and FBP algorithm.The diagnostic acceptability of coronary images was slightly higher than that of axial images.Conclusion The iDose algorithm can not only meet the requirements of the temporal bone CT image quality,but also reduce the radiation dose of the patients.