ABSTRACT
BACKGROUND: In alveolar cleft patients, the amount of bone stock after alveolar bone grafting is mostly measured and analyzed by two-dimensional imaging, which can result in a large error. OBJECTIVE: To evaluate the 6-month osteogenesis of alveolar bone graft in alveolar cleft patients using cone beam CT. METHODS:Alveolar bone grafting was performed in 25 patients with unilateral complete alveolar cleft. The patients were folowed up for 6 months after surgery and the osteogenesis of the bone graft was evaluated by CBCT. RESULTS AND CONCLUSION:After the surgery, the labial bone support was better than the palatal one. There were significant differences in the alveolar bone thickness of the cleft region and the normal region of the central incisor as wel as the alveolar bone thickness of the cleft region and the normal region of the canine tooth 0 mm distant to the alveolar crest. These findings indicate that the palatal bone support is less than the labial one, and the bone support of the central incisor is not satisfactory, which provide the basis for the tooth movement in the alveolar bone grafting and the orthodontics treatment.
ABSTRACT
Objective To investigate the value of the adaptive statistical iterative reconstruction (ASIR) algorithm for reducing the radiation dose and optimizing the image quality in the low-dose spectral CT scanning in GSl (Gemstone spectral imaging) of the liver.Methods A total of 60 patients who underwent hepatic spectral CT scanning in GSI were enrolled in this study.The patients were randomly divided into two groups according to priority with 30 cases per group.Low-dose spectral CT scanning was used for group A, and images were reconstructed by ASIR 0 and 50％ , marked as A1 and A2.Group B was scanned with conventional dose of spectral CT, and images were reconstructed by Filtered back projection (FBP).Effective doses (E) for each group were calculated.Image quality was assessed by two radiologists, and the radiation doses were compared between groups A and B.Results All image quality of each group were good enough for clinical diagnosis.E for group A and B were (3.2 ±0.2) and (5.8 ± 0.2) mSv, respectively.There was statistical difference with image noise between group A and B(Z =-6.784,P ＜ 0.05).The image noise, SNR and CNR had statistical differences between group A and B (F =24.013, 15.646, 8.285, P ＜0.05).Compared with group A1, the image noise was lower, and the SNR and CNR were higher in groups A2 and B(P ＜ 0.05).There were no statistical differences of image noise, SNR and CNR between groups A2 and B (P ＞ 0.05).There were no statistical differences of the image quality score between groups A1, A2 and B (F =102.38,105.768, P ＜ 0.05).Conclusions ASIR combined with low-dose spectral CT scanning was helpful to reduce radiation dose and could obtain better image quality in hepatic CT examination.