Application of adaptive statistical iterative reconstruction in low dose temporal bone CT scan of children

Objective: To evaluate clinical use of adaptive statistical iterative reconstruction (ASiR) method in low-dose scan on children temporal bone by comparison of radiation dose delivered by GE Discovert HD CT 750 scan and GE Lightspeed VCT64 scan. Method: Sixty patients with congenital deafness were divided into two groups according to gender, age (each N = 30). Group a received low-dose CT scan on temporal bone by GE Discovery HDCT 750 (preset NI = 12), and the original images were reconstructed with ASiR (weighted value = 40%). Group B received CT scan by GE Lightspeed VCT 64 (preset NI = 8), and the original images were reconstructed with filter back projection (FBP). Data were collected and analysed using the SPSS 18.0 software. Resultes: The mean value of electric current of average tube and CTDI_vol were significantly different between group A and B [(110.40 ± 21.72) mA vs. (168.56 ± 24.36) mA, and (26.43 ± 3.48) mGy vs. (39.66 ± 4.17) mGy, respectively (t = -9.76, -3.31, P < 0.05)]. The noise index was (33.13 ± 2.68) in group A and (33.79 ± 2.93) in group B respectively, and the results had no statistical significance (P > 0.05). Subjective scores of the images were (4.06 ± 0.03) and (4.05 ± 0.03), with no statistical significance either (P > 0.05). Conclusions: On a condition of achieving same image quality, CT scan program using GE Discovery HD CT 750 with 40% ASiR reconstruction and 4 units NI value enhancement could effectively reduce radiation dose on children's temporal bone compared to FBP method using GE Lightspeed VCT 64. (authors)