Abstract: To investigate the weight of the Adaptive Statistical Reconstruction-V (Asir-V) algorithm to obtain the best image quality while reducing the effective radiation dose in adult paranasal sinus Revolution CT examination of 70 kVp. Revolution CT was applied to perform paranasal sinus scans in 20 cases of adults. The scanning conditions were 70 kVp, 230 mA. The original projection data, a total of 120 images were obtained, were reconstructed by using different weights (0, 20%, 40%, 60%, 80%, 100%) of the Pos-Asir-V technique. Six groups of each case of pictures were subjective rated and objective evaluated. The objective evaluation included the evaluation of noise (standard deviations, SD) and contrast noise ratio (CNR). The subjective rating was evaluated by two evaluation physicians for image quality scores and for their subjective consistency. After each patient had completed the scan, its dose-length product (dose-length product, DLP) and CT volumetric dose index (CT dose indexvolume, CTDI_vol) were recorded and their average effective radiation dose (effective dose, ED) was calculated. The objective evaluation results showed that the Asir-V image noise with different weights decreased with the Asir-V weight, the CNR increased with the Asir-V weight, and the effective radiation dose(ED) significantly decreased compared with the average radiation dose of the regular head and neck CT examination. The subjective evaluation results showed that the Asir-V image scores with different weights were different, with a high score of 60% at Asir-V, and the subjective evaluation of two doctors was good. Combined with the subjective and objective evaluation results, it is concluded that the image of Asir-V 60% in 70 kVp, 230 mA adult paranasal sinus Revolution CT examination could meet the needs of clinical diagnosis and significantly reduce the effective radiation dose.

Key words: computed tomography, Adaptive Statistical Iterative Reconstruction-V(Asir-V), adult, paranasal sinus, radiation dose