1.O-arm navigation versus C-arm navigation for guiding percutaneous long sacroiliac screws placement in treatment of Denis type Ⅱ sacral fractures.
Wei ZHOU ; Guodong WANG ; Xuan PEI ; Zhixun FANG ; Yu CHEN ; Suyaolatu BAO ; Jianan CHEN ; Ximing LIU
Chinese Journal of Reparative and Reconstructive Surgery 2024;38(1):28-34
OBJECTIVE:
To compare the effectiveness of O-arm navigation and C-arm navigation for guiding percutaneous long sacroiliac screws in treatment of Denis type Ⅱ sacral fractures.
METHODS:
A retrospective study was conducted on clinical data of the 46 patients with Denis type Ⅱ sacral fractures between April 2021 and October 2022. Among them, 19 patients underwent O-arm navigation assisted percutaneous long sacroiliac screw fixation (O-arm navigation group), and 27 patients underwent C-arm navigation assisted percutaneous long sacroiliac screw fixation (C-arm navigation group). There was no significant difference in gender, age, causes of injuries, Tile classification of pelvic fractures, combined injury, the interval from injury to operation between the two groups ( P>0.05). The intraoperative preparation time, the placement time of each screw, the fluoroscopy time of each screw during placement, screw position accuracy, the quality of fracture reduction, and fracture healing time were recorded and compared, postoperative complications were observed. Pelvic function was evaluated by Majeed score at last follow-up.
RESULTS:
All operations were completed successfully, and all incisions healed by first intention. Compared to the C-arm navigation group, the O-arm navigation group had shorter intraoperative preparation time, placement time of each screw, and fluoroscopy time, with significant differences ( P<0.05). There was no significant difference in screw position accuracy and the quality of fracture reduction ( P>0.05). There was no nerve or vascular injury during screw placed in the two groups. All patients in both groups were followed up, with the follow-up time of 6-21 months (mean, 12.0 months). Imaging re-examination showed that both groups achieved bony healing, and there was no significant difference in fracture healing time between the two groups ( P>0.05). During follow-up, there was no postoperative complications, such as screw loosening and breaking or loss of fracture reduction. At last follow-up, there was no significant difference in pelvic function between the two groups ( P>0.05).
CONCLUSION
Compared with the C-arm navigation, the O-arm navigation assisted percutaneous long sacroiliac screws for the treatment of Denis typeⅡsacral fractures can significantly shorten the intraoperative preparation time, screw placement time, and fluoroscopy time, improve the accuracy of screw placement, and obtain clearer navigation images.
Humans
;
Fracture Fixation, Internal/methods*
;
Retrospective Studies
;
Imaging, Three-Dimensional
;
Bone Screws
;
Surgery, Computer-Assisted
;
Tomography, X-Ray Computed
;
Spinal Fractures/surgery*
;
Fractures, Bone/surgery*
;
Pelvic Bones/injuries*
;
Postoperative Complications
;
Neck Injuries
2.Clinical and chest CT features of immune checkpoint inhibitor-related pneumonitis.
Qian ZHANG ; Shi Jun ZHAO ; Shu Hang WANG ; Xiu Li TAO ; Ning WU
Chinese Journal of Oncology 2023;45(2):182-187
Objective: To explore the clinical and chest computed tomography (CT) features and the outcome of immune checkpoint inhibitor-related pneumonitis (CIP). Methods: Clinical and chest CT data of 38 CIP patients with malignant tumors from the Cancer Hospital, Chinese Academy of Medical Sciences between August 2017 and April 2021 were retrospectively reviewed, and the outcomes of pneumonitis were followed up. Results: The median time from the administration of immune checkpoint inhibitors (ICIs) to the onset of CIP was 72.5 days in 38 patients with CIP, and 22 patients developed CIP within 3 months after the administration of ICIs. The median occurrence time of CIP in 24 lung cancer patients was 54.5 days, earlier than 119.0 days of non-lung cancer patients (P=0.138), with no significant statistical difference. 34 patients (89.5%) were accompanied by symptoms when CIP occurred. The common clinical symptoms were cough (29 cases) and dyspnea (27 cases). The distribution of CIP on chest CT was asymmetric in 31 cases and symmetrical in 7 cases. Among the 24 lung cancer patients, inflammation was mainly distributed ipsilateral to the primary lung cancer site in 16 cases and diffusely distributed throughout the lung in 8 cases. Ground glass opacities (37 cases) and consolidation (30 cases) were the common imaging manifestations, and organizing pneumonia (OP) pattern (15 cases) was the most common pattern. In 30 CIP patients who were followed up for longer than one month, 17 cases had complete absorption (complete absorption group), and 13 cases had partial absorption or kept stable (incomplete absorption group). The median occurrence time of CIP in the complete absorption group was 55 days, shorter than 128 days of the incomplete absorption group (P=0.022). Compared with the incomplete absorption group, there were less consolidation(P=0.010) and CIP were all classified as hypersensitivity pneumonitis (HP) pattern (P=0.004) in the complete absorption group. Conclusions: CIP often occurs within 3 months after ICIs treatment, and the clinical and CT findings are lack of specificity. Radiologic features may have a profound value in predicting the outcome of CIP.
Humans
;
Immune Checkpoint Inhibitors/adverse effects*
;
Retrospective Studies
;
Pneumonia/drug therapy*
;
Lung Neoplasms/drug therapy*
;
Tomography, X-Ray Computed/methods*
3.The performance of digital chest radiographs in the detection and diagnosis of pulmonary nodules and the consistency among readers.
Min LIANG ; Shi Jun ZHAO ; Li Na ZHOU ; Xiao Juan XU ; Ya Wen WANG ; Lin NIU ; Hui Hui WANG ; Wei TANG ; Ning WU
Chinese Journal of Oncology 2023;45(3):265-272
Objective: To investigate the detection and diagnostic efficacy of chest radiographs for ≤30 mm pulmonary nodules and the factors affecting them, and to compare the level of consistency among readers. Methods: A total of 43 patients with asymptomatic pulmonary nodules who consulted in Cancer Hospital, Chinese Academy of Medical Sciences from 2012 to 2014 and had chest CT and X-ray chest radiographs during the same period were retrospectively selected, and one nodule ≤30 mm was visible on chest CT images in the whole group (total 43 nodules in the whole group). One senior radiologist with more than 20 years of experience in imaging diagnosis reviewed CT images and recording the size, morphology, location, and density of nodules was selected retrospectively. Six radiologists with different levels of experience (2 residents, 2 attending physicians and 2 associate chief physicians independently reviewed the chest images and recorded the time of review, nodule detection, and diagnostic opinion. The CT imaging characteristics of detected and undetected nodules on X images were compared, and the factors affecting the detection of nodules on X-ray images were analyzed. Detection sensitivity and diagnosis accuracy rate of 6 radiologists were calculated, and the level of consistency among them was compared to analyze the influence of radiologists' seniority and reading time on the diagnosis results. Results: The number of nodules detected by all 6 radiologists was 17, with a sensitivity of detection of 39.5%(17/43). The number of nodules detected by ≥5, ≥4, ≥3, ≥2, and ≥1 physicians was 20, 21, 23, 25, and 28 nodules, respectively, with detection sensitivities of 46.5%, 48.8%, 53.5%, 58.1%, and 65.1%, respectively. Reasons for false-negative result of detection on X-ray images included the size, location, density, and morphology of the nodule. The sensitivity of detecting ≤30 mm, ≤20 mm, ≤15 mm, and ≤10 mm nodules was 46.5%-58.1%, 45.9%-54.1%, 36.0%-44.0%, and 36.4% for the 6 radiologists, respectively; the diagnosis accuracy rate was 19.0%-85.0%, 16.7%-6.5%, 18.2%-80.0%, and 0%-75.0%, respectively. The consistency of nodule detection among 6 doctors was good (Kappa value: 0.629-0.907) and the consistency of diagnostic results among them was moderate or poor (Kappa value: 0.350-0.653). The higher the radiologist's seniority, the shorter the time required to read the images. The reading time and the seniority of the radiologists had no significant influence on the detection and diagnosis results (P>0.05). Conclusions: The ability of radiographs to detect lung nodules ≤30 mm is limited, and the ability to determine the nature of the nodules is not sufficient, and the increase in reading time and seniority of the radiologists will not improve the diagnostic accuracy. X-ray film exam alone is not suitable for lung cancer diagnosis.
Humans
;
Retrospective Studies
;
Solitary Pulmonary Nodule/diagnostic imaging*
;
Radiography
;
Multiple Pulmonary Nodules/diagnostic imaging*
;
Tomography, X-Ray Computed/methods*
;
Lung Neoplasms/diagnostic imaging*
;
Sensitivity and Specificity
;
Radiographic Image Interpretation, Computer-Assisted/methods*
4.China National Lung Cancer Screening Guideline with Low-dose Computed Tomography (2023 Version).
Chinese Journal of Lung Cancer 2023;26(1):1-9
Lung cancer is the leading cause of cancer-related death in China. The effectiveness of low-dose computed tomography (LDCT) screening has been further validated in recent years, and significant progress has been made in research on identifying high-risk individuals, personalizing screening interval, and management of screen-detected findings. The aim of this study is to revise China national lung cancer screening guideline with LDCT (2018 version). The China Lung Cancer Early Detection and Treatment Expert Group (CLCEDTEG) designated by the China's National Health Commission, and China Lung Oncolgy Group experts, jointly participated in the revision of Chinese lung cancer screening guideline (2023 version). This revision is based on the recent advances in LDCT lung cancer screening at home and abroad, and the epidemiology of lung cancer in China. The following aspects of the guideline were revised: (1) lung cancer risk factors besides smoking were considered for the identification of high risk population; (2) LDCT scan parameters were further classified; (3) longer screening interval is recommended for individuals who had negative LDCT screening results for two consecutive rounds; (4) the follow-up interval for positive nodules was extended from 3 months to 6 months; (5) the role of multi-disciplinary treatment (MDT) in the management of positive nodules, diagnosis and treatment of lung cancer were emphasized. This revision clarifies the screening, intervention and treatment pathways, making the LDCT screening guideline more appropriate for China. Future researches based on emerging technologies, including biomarkers and artificial intelligence, are needed to optimize LDCT screening in China in the future.
.
Humans
;
Lung Neoplasms/epidemiology*
;
Early Detection of Cancer/methods*
;
Artificial Intelligence
;
Mass Screening/methods*
;
Tomography, X-Ray Computed/methods*
;
China/epidemiology*
5.Application of Three-dimensional Computed Tomography Bronchography and Angiography Combined with Perfusion Area Identification Technique in Uniport Thoracoscopic Complex Segmentectomy.
Yuanbo LI ; Yi ZHANG ; Xiuyi ZHI ; Lei SU ; Baodong LIU
Chinese Journal of Lung Cancer 2023;26(1):17-21
BACKGROUND:
With the extensive application of segmental lung resection in the treatment of early-stage lung cancer, how to complete segmentectomy more accurately and minimally invasively has become a research hotspot. The aim of this study is to explore the application of three-dimensional computed tomography bronchography and angiography (3D-CTBA) combined with perfusion area recognition technique in single-hole thoracoscopic complex segmentectomy.
METHODS:
From January 2021 to January 2022, the clinical data of 112 consecutive patients undergoing single-port thoracoscopic complex segmentectomy in the Department of Thoracic Surgery, Xuanwu Hospital, Capital Medical University were retrospectively analyzed. The three-dimensional reconstruction combined with perfusion area identification technique was used to perform the operation and the clinical data were analyzed.
RESULTS:
The average operation time was (141.1±35.4) min; the initial time of intersegmental plane display was (12.5±1.7) s; the maintenance time of intersegmental plane was (114.3±10.9) s; the intersegmental plane was clearly displayed (100%); the amount of bleeding was [10 (10, 20)] mL; the total postoperative drainage volume was (380.5±139.7) mL; the postoperative extubation time was (3.9±1.2) d; and the postoperative hospitalization time was (5.2±1.6) d. Postoperative complications occurred in 8 cases.
CONCLUSIONS
The advantages of 3D-CTBA combined with perfusion area recognition technique are fast, accurate and safe in identifying intersegmental boundary in single-port thoracoscopic complex segmentectomy, which could provide guidances for accuratding resection of tumors, shortening operation time and reducing surgical complications.
Humans
;
Lung Neoplasms/pathology*
;
Bronchography
;
Pneumonectomy/methods*
;
Retrospective Studies
;
Thoracic Surgery, Video-Assisted/methods*
;
Tomography, X-Ray Computed
;
Angiography/methods*
;
Perfusion
6.Value of fractional flow reserve derived from coronary computed tomographic angiography and plaque quantitative analysis in predicting adverse outcomes of non-obstructive coronary heart disease.
Jun LIU ; Yong WU ; Hong HUANG ; Peng WANG ; Qinghua WU ; Hongyan QIAO
Chinese Critical Care Medicine 2023;35(6):615-619
OBJECTIVE:
To investigate the value of coronary computed tomographic angiography (CCTA)-based fractional flow reserve (CT-FFR) and plaque quantitative analysis in predicting adverse outcomes in patients with non-obstructive coronary heart disease (CAD).
METHODS:
Clinical data of patients with non-obstructive CAD who underwent CCTA at the Affiliated Hospital of Jiangnan University from March 2014 to March 2018 were retrospectively analyzed and followed up, and the occurrence of major adverse cardiovascular event (MACE) was recorded. The patients were divided into MACE and non-MACE groups according to the occurrence of MACE. The clinical data, CCTA plaque characteristics including plaque length, stenosis degree, minimum lumen area, total plaque volume, non-calcified plaque volume, calcified plaque volume, plaque burden (PB) and remodelling index (RI), and CT-FFR were compared between the two groups. Multivaritate Cox proportional risk model was used to evaluate the relationship between clinical factors, CCTA parameters and MACE. The receiver operator characteristic curve (ROC curve) was used to assess the predictive power of outcome prediction model based on different CCTA parameters.
RESULTS:
Finally 217 patients were included, of which 43 (19.8%) had MACE and 174 (80.2%) did not. The median follow-up interval was 24 (16, 30) months. The CCTA showed that patients in the MACE group had more severe stenosis than that in the non-MACE group [(44.3±3.8)% vs. (39.5±2.5)%], larger total plaque volume and non-calcified plaque volume [total plaque volume (mm3): 275.1 (197.1, 376.9), non-calcified plaque volume (mm3): 161.5 (114.5, 307.8) vs. 117.9 (77.7, 185.5)], PB and RI were larger [PB: 50.2% (42.1%, 54.8%) vs. 45.1% (38.2%, 51.7%), RI: 1.19 (0.93, 1.29) vs. 1.03 (0.90, 1.22)], CT-FFR value was lower [0.85 (0.80, 0.88) vs. 0.92 (0.87, 0.97)], and the differences were statistically significant (all P < 0.05). Cox regression analysis showed that non-calcified plaques volume [hazard ratio (HR) = 1.005. 95% confidence interval (95%CI) was 1.025-4.866], PB ≥ 50% (HR = 3.146, 95%CI was 1.443-6.906), RI ≥ 1.10 (HR = 2.223, 95%CI was 1.002-1.009) and CT-FFR ≤ 0.87 (HR = 2.615, 95%CI was 1.016-6.732) were independent predictors of MACE (all P < 0.05). The model based on CCTA stenosis degree+CT-FFR+quantitative plaque characteristics (including non-calcified plaque volume, RI, PB) [area under the ROC curve (AUC) = 0.91, 95%CI was 0.87-0.95] had significantly better predictive efficacy for adverse outcomes than the model based on CCTA stenosis degree (AUC = 0.63, 95%CI was 0.54-0.71) and the model based on CCTA stenosis degree+CT-FFR (AUC = 0.71, 95%CI was 0.63-0.79; both P < 0.01).
CONCLUSIONS
CT-FFR and plaque quantitative analysis based on CCTA are helpful in predicting adverse outcomes in patients with non-obstructive CAD. Non-calcified plaque volume, RI, PB and CT-FFR are important predictors of MACE. Compared with the prediction model based on stenosis degree and CT-FFR, the combined plaque quantitative index can significantly improve the prediction efficiency of adverse outcomes in patients with non-obstructive CAD.
Humans
;
Fractional Flow Reserve, Myocardial
;
Coronary Angiography/methods*
;
Constriction, Pathologic
;
Retrospective Studies
;
ROC Curve
;
Predictive Value of Tests
;
Plaque, Atherosclerotic/diagnostic imaging*
;
Coronary Stenosis/diagnostic imaging*
;
Tomography, X-Ray Computed
;
Coronary Artery Disease/diagnostic imaging*
7.Application of intraoperative CT-assisted positioning in difficult cases of cochlear implantation.
Fan ZHANG ; Xing LU ; Wenjing ZHANG ; Lu LI ; Han XUAN ; Zhaobing QIN
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2023;37(5):329-333
Objective:To report the experience of using CT-guided cochlear implant surgery in difficult cases such as severe inner ear deformities and anatomical abnormalities, and to discuss the application value of intraoperative CT-assisted localization in difficult cases of cochlear implant surgery. Methods:Retrospectively analyzed the clinical data of 23 cases of difficult cochlear implant surgery cases completed by our team with the assistance of intraoperative CT, and collected their medical data, including preoperative imaging manifestations, surgical conditions, and intraoperative imaging images for evaluation. Results:During the study period, 23 difficult cases(27 ears) underwent cochlear implantation under the guidance of intraoperative CT, and 4 cases were bilaterally implanted. Including 6 cases of incomplete segmentation type Ⅰ(IP-Ⅰ), 1 case of incomplete segmentation type Ⅱ(IP-Ⅱ), 10 cases of incomplete segmentation type Ⅲ(IP-Ⅲ), 3 cases of common cavity deformity(CC) and 3 cases of cochlear ossification after meningitis. Facial nerve anatomy was abnormal in 9 cases, cerebrospinal fluid "blowout" was serious in 14 cases, electrode position was abnormal in 3 cases requiring intraoperative adjustment of electrode position, anatomical difficulties required intraoperative CT to assist in finding anatomical landmarks in 2 cases, and electrodes were not fully implanted in 3 cases. Conclusion:When faced with difficult cases with challenging and complex temporal bone anatomy, intraoperative CT can accurately evaluate the electrode position and provide intraoperative anatomical details, allowing immediate adjustment of the electrode position if necessary, providing safety guarantee for difficult cases of cochlear implant surgery and ensure accurate implantation of electrodes.
Humans
;
Cochlear Implantation/methods*
;
Retrospective Studies
;
Tomography, X-Ray Computed/methods*
;
Cochlea
;
Cochlear Implants
8.Sex Estimation of Han Adults in Western China Based on Three-Dimensional Cranial CT Reconstruction.
Xiao-Tong YANG ; Cheng-Hui SUN ; Yong-Gang MA ; Yong-Jie CAO ; Jian XIONG ; Ji ZHANG ; Ping HUANG
Journal of Forensic Medicine 2023;39(1):27-33
OBJECTIVES:
To examine the reliability and accuracy of Walker's model for estimating the sex of Han adults in western China by using cranium three-dimensional (3D) CT reconstruction, and to study the suitable cranial sex estimation model for Han people in western China.
METHODS:
A total of 576 cranial CT 3D reconstructed images from Hanzhong Hospital in Shaanxi Province from 2017 to 2021 were collected. These images were divided into the experimental group with 486 samples and the validation group with 90 samples. Walker's model was used by observer 1 to estimate the sex of experimental group samples. The logistic function applicable to Han people in western China was corrected by observer 1. The 90 samples in the validation group were scored and substituted into the modified logistic function to complete the back substitution test by observer 1, 2 and 3.
RESULTS:
The accuracy of sex estimation of Han adults in western China was 63.2%-77.2% by applying Walker's model. The accuracy of modified logistic function was 82.9%. The accuracy of sex estimation through back substitution test by 3 observers was 75.6%-91.1%, with a Kappa value of 0.689 (P<0.05) for inter-observer consistency and 0.874 (P<0.05) for intra-observer consistency.
CONCLUSIONS
There are great differences in bone characteristics among people from different regions. The modified logistic function can achieve higher accuracy in Han adults in western China.
Humans
;
Adult
;
Reproducibility of Results
;
Sex Determination by Skeleton/methods*
;
Forensic Anthropology
;
Skull/anatomy & histology*
;
Imaging, Three-Dimensional
;
China
;
Tomography, X-Ray Computed
9.CT perfusion combined with energy spectrum imaging to evaluate the short-term efficacy of bronchial arterial chemoembolization for lung cancer.
Lin Qiang LAI ; Gui Han LIN ; Wei Yue CHEN ; Jian Fei TU ; Jian Song JI
Chinese Journal of Internal Medicine 2023;62(5):539-544
Objective: To evaluate the clinical value of dynamic volumetric CT perfusion combined with energy spectrum imaging in bronchial arterial chemoembolization (BACE) in patients with lung cancer. Methods: The data of 31 patients with lung cancer confirmed by pathology and treated with BACE in Lishui Central Hospital from January 2018 to February 2022 were retrospectively collected, including 23 men and 8 women, aged 31-84 (67) years. All patients received perfusion scans of lesion sites within 1 week before surgery and 1 month after surgery. We collected and compared the changes in preoperative and postoperative perfusion parameters such as blood flow (BF), blood volume (BV), mean through time (MTT), permeability surface (PS) and energy spectrum parameters including arterial phase CT value (CTA), venous phase CT value (CTV), arterial phase iodine concentration (ICA), venous phase of iodine concentration (ICV), arterial standardization iodine concentration (NICA), and intravenous standardized iodine concentration (NICV) to confirm the significance of these parameters in evaluating the short-term efficacy of BACE in the treatment of advanced lung cancer. Data normality was tested using the Kolmogorov-Smirnov test and normally distributed measurement data are expressed here as mean ± standard deviation; the independent-samples t-test was used for comparisons between two groups. The measurement data that were not normally distributed are expressed as median (interquartile interval) [M (Q1, Q3)], and the comparison between the two groups used the Kruskal-Wallis test. Count data are expressed as cases (%), and comparisons between groups used the χ2 test. Results: The objective response rate (ORR) and disease control rate (DCR) at 1 month after BACE were 54.8% (17/31) and 96.8% (30/31), respectively. CT perfusion parameters and energy spectrum parameters of patients before and after BACE treatment were compared. The results showed that BF, BV, MTT, ICA, ICV and NICV were significantly decreased after BACE treatment compared with before treatment, and the differences were statistically significant[58.06 (40.47,87.22) vs.23.57(10.92, 36.24) ml·min-1·100g-1,3.33(2.86,6.09) vs.2.12(1.96,3.61)ml/100g,2.70(2.19,3.88) vs.1.53 (1.12,2.25)s, 3.51 (3.11,4.14)vs.1.74 (1.26,2.50)mg/ml,2.00 (1.30,2.45) vs.1.32(0.92,1.76)mg/ml,0.51(0.42,0.57) vs.0.33(0.23,0.39)](all P<0.05). At the same time, compared with the non-remission group, the study results showed that the difference of parameters in remission group before and after BACE was more obvious, including ΔBF, ΔBV, ΔMTT, ΔPS, ΔCTA, ΔCTV, ΔICA, ΔICV, ΔNICA, ΔNICV were significantly increased, and the difference was statistically significant [36.82(32.38, 45.34) vs.9.50(-1.43, 12.34) ml·min-1·100g-1,4.46(2.52, 5.79) vs.0.22(-0.76, 4.09) ml/100g,4.22(2.25, 6.77) vs.0.43(-2.53, 1.88) s,10.07 (2.89, 13.13) vs.-2.01(-6.77, 4.28) ml·min-1·100g-1,14.22(11.88, 20.57) vs.4.18(-5.25, 6.37) HU, 34.6(14.88, 43.15) vs.11.60(0.26, 25.05) HU,0.95(0.54, 1.47) vs.0.11(0.20, 0.59) mg/ml,1.57(1.10, 2.38) vs. 0.26(-0.21, 0.63) mg/ml,0.05(0.03, 0.08) vs.-0.02(-0.04, 0.01),0.18(0.13, 0.21)vs. 0.11(-0.06, 0.16)](all P<0.05). Conclusions: CT perfusion combined with spectral imaging could effectively evaluate the changes in tumor vascular perfusion in patients with advanced lung cancer before and after BACE treatment, which has important value in judging the short-term efficacy after treatment.
Male
;
Humans
;
Female
;
Retrospective Studies
;
Tomography, X-Ray Computed/methods*
;
Lung Neoplasms
;
Iodine
;
Perfusion
10.Metal artifact reduction and clinical verification in oral and maxillofacial region based on deep learning.
Wei ZENG ; Shan Luo ZHOU ; Ji Xiang GUO ; Wei TANG
Chinese Journal of Stomatology 2023;58(6):540-546
Objective: To construct a kind of neural network for eliminating the metal artifacts in CT images by training the generative adversarial networks (GAN) model, so as to provide reference for clinical practice. Methods: The CT data of patients treated in the Department of Radiology, West China Hospital of Stomatology, Sichuan University from January 2017 to June 2022 were collected. A total of 1 000 cases of artifact-free CT data and 620 cases of metal artifact CT data were obtained, including 5 types of metal restorative materials, namely, fillings, crowns, titanium plates and screws, orthodontic brackets and metal foreign bodies. Four hundred metal artifact CT data and 1 000 artifact-free CT data were utilized for simulation synthesis, and 1 000 pairs of simulated artifacts and metal images and simulated metal images (200 pairs of each type) were constructed. Under the condition that the data of the five metal artifacts were equal, the entire data set was randomly (computer random) divided into a training set (800 pairs) and a test set (200 pairs). The former was used to train the GAN model, and the latter was used to evaluate the performance of the GAN model. The test set was evaluated quantitatively and the quantitative indexes were root-mean-square error (RMSE) and structural similarity index measure (SSIM). The trained GAN model was employed to eliminate the metal artifacts from the CT data of the remaining 220 clinical cases of metal artifact CT data, and the elimination results were evaluated by two senior attending doctors using the modified LiKert scale. Results: The RMSE values for artifact elimination of fillings, crowns, titanium plates and screws, orthodontic brackets and metal foreign bodies in test set were 0.018±0.004, 0.023±0.007, 0.015±0.003, 0.019±0.004, 0.024±0.008, respectively (F=1.29, P=0.274). The SSIM values were 0.963±0.023, 0.961±0.023, 0.965±0.013, 0.958±0.022, 0.957±0.026, respectively (F=2.22, P=0.069). The intra-group correlation coefficient of 2 evaluators was 0.972. For 220 clinical cases, the overall score of the modified LiKert scale was (3.73±1.13), indicating a satisfactory performance. The scores of modified LiKert scale for fillings, crowns, titanium plates and screws, orthodontic brackets and metal foreign bodies were (3.68±1.13), (3.67±1.16), (3.97±1.03), (3.83±1.14), (3.33±1.12), respectively (F=1.44, P=0.145). Conclusions: The metal artifact reduction GAN model constructed in this study can effectively remove the interference of metal artifacts and improve the image quality.
Humans
;
Tomography, X-Ray Computed/methods*
;
Deep Learning
;
Titanium
;
Neural Networks, Computer
;
Metals
;
Image Processing, Computer-Assisted/methods*
;
Algorithms

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