ISSN 1004-4140
CN 11-3017/P
Founded in 1992, bimonthly
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Institute of Geophysics, China Earthquake Administration
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Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Advances in CT and MRI Monitoring of Crohn's Disease
CHEN Yunhui, YANG Yaying, PENG Chao, HU Juan
 doi: 10.15953/j.ctta.2021-001
Abstract(0) HTML PDF(0)
Abstract:
Crohn's disease is a disease with a long course, complex evolution and extensive involvement, with alternating phases of activity and remission, which have a huge impact on the life quality of patients. How to accurately and comprehensively identify and assess the onset, progression and regression of the disease, such as whether it is in the active phase, the nature of intestinal strictures, and the presence of other systemic lesions, is particularly important to guide treatment. Evaluation modalities that rely solely on clinical indicators or endoscopy are increasingly recognized as flawed by studies. With increased disease awareness and rapid development of examination modalities, the role of medical imaging in this disease cannot be ignored. And this review will focus on the value of CT and MRI for monitoring Crohn's disease in active, fibrosis, intestinal luminal strictures, abscess/fistulas, and extragastrointestinal lesions, as well as related emerging technologies and sequences.
CT Theory
Industrial CT Rotation Center Calibration Method Based on Weighted Average
LV Zhentao, GUI Zhiguo, LIU Yi, ZHANG Pengcheng
2021, 30(5): 539-546.   doi: 10.15953/j.1004-4140.2021.30.05.01
Abstract(109) PDF(32)
Abstract:
The precise positioning of the rotation center is an important condition for reconstructing high-quality CT images. In this paper we propose a center rotation calibration method based on weighted average. First we divide the projection sinogram into two sets of projection data by limit of 180°, thus we can figure out the calibration coefficient of the two sets of projection data and their corresponding detector probes. Then we use the maximum and the sub-maximal cross-correlation coefficients to obtain the actual rotation center coordinates by weighting average the coordinate values of the detector elements. The algorithm proposed in this paper is completely based on the original projection data. There is no need to determine the geometric parameters of the CT measurement, and we can acquire sub-pixel level accuracy of the rotation center without interpolating the projection data in advance. The accuracy is higher while the implementation is quite simple.
Geotomography
Application of Broadband Seismic Data Processing Technology in the Description of Natural Gas Hydrate Ore Body
WANG Zhaoqi, LI Lin, WANG Bin, WANG Xuefeng, LI Lisheng
2021, 30(5): 547-554.   doi: 10.15953/j.1004-4140.2021.30.05.02
Abstract(56) PDF(15)
Abstract:
A set of seismic data broadband processing technology based on adaptive ghost wave suppression is proposed to improve the resolution of data, which is difficult to be solved in natural gas hydrate (NGH) drilling. Firstly, ghost wave suppression technology based on upstream and downstream wave field separation is used to suppress the ghost wave of source and cable. Then the high quality velocity field is obtained by high precision grid tomography inversion velocity modeling technology while the imaging accuracy of hydrate layer is further improved by prestack depth migration imaging. The practice shows that compared with the conventional treatment, the broadband treatment provides clearer seismic characteristics and more detailed information, which is more conducive to the accurate description of the NGH ore body.
Industrical CT
Research of Bone Mineral Density Energy Spectrum Detection Technology Based on High-compact Support Moving Least Square Method
LIU Ping, LI Miao, ZHANG Yanqi, MOU Xiaoshuang, ZHANG Youfeng, XI Shouzhi, ZHANG Baoqiang
2021, 30(5): 555-565.   doi: 10.15953/j.1004-4140.2021.30.05.03
Abstract(64) PDF(5)
Abstract:
The dual-energy X-ray bone densitometer system is the "gold standard" for current X-ray bone density measurement technology, which holds unique advantages such as high measurement accuracy, little time cost and low dosage. In this paper, semiconductor CdZnTe detector module was used to build a bone mineral density energy spectrum measurement platform operated by semiconductor photon. Based on the characteristics of CdZnTe semiconductor detector, we performed the moving least square algorithm on the high-low energy fitting and correction of different materials. The moving least-squares algorithm changes the degree influenced by the surrounding nodes of the target data point through the weight function, which can make the fitting direction of the data point more flexible. The research analyzed the data processing flow of the moving least- squares algorithm performed on the dual-energy X-ray bone density measurement value, and completed the bone density measurement experiment operated by the high-low energy fitting and correction algorithm based on the moving least-squares. According to the experimental results, in this paper we designed and intended to achieve that the dual-energy fitting technology of bone density based on the moving least-squares algorithm can achieve better fitting error accuracy in practical applications, the average fitting error of the detector pixel unit under high-energy conditions is 0.032% while the average fitting error under low-energy conditions is 0.036%. Further data analysis showed that the difference of fitting error between the edge pixels and the center pixels under high and low energy conditions was only 0.012% and 0.011% respectively. This algorithm can effectively improve the bone mineral density measurement accuracy of semiconductor detectors, and reduce the influence of errors caused by the the pixels at the edge of the detector. The photon-counting detectors have an improving effect on the bone density mineral diagnosis influenced by pixel differnce of linear array or plane array photon counting semiconductor detectors.
Medical Imaging and Image Processing
Study on the Value of Predicting Prostate Cancer in the Grey Zone of PSA by Use of PI-RADS v2.1 Combined with PSA-related Indicators
ZHANG Subo, XU Yongjun, SUN Yi, WAN Jinxin, ZHAO Yan, LIU Jingfang, WANG Rui
2021, 30(5): 567-574.   doi: 10.15953/j.1004-4140.2021.30.05.04
Abstract(39) PDF(6)
Abstract:
Objective: We intend to investigate the diagnostic value of establishing the Logistic regression model based on Prostate Imaging Report and Data System (PI-RADS v2.1) combined with prostate specific antigen (PSA) which is applied in PSA gray area(4~10ng/mL) prostate cancer. Materials and Methods: We retrospectively analyzed the pathologically-certified clinical data of 49 cases with prostate cancer (PCa) and 118 non-cancer cases who underwent prostate biopsy, the data covered age, tPSA, fPSA, PI-RADS v2.1 evaluation, PSAD and fPSA/tPSA. We performed logistic regression analysis on the indicators with statistical difference between the groups, and obtained ascertained independent PCa predictors, furthermore we respectively established regression prediction model by combination with PI-RADS v2.1 evaluation. The diagnostic efficacy of each model was evaluated by the operating characteristic curve (ROC) of subjects. Results: (1) There was no significant statistical difference in age, tPSA and fPSA between the PCa and non-cancer patients. But evaluation of PI-RADS v2.1, fPSA/tPSA, and PSAD showed significant statistical differences. (2) Logistic regression analysis indicated that PI-RADS v2.1evaluation, PSAD, and fPSA/tPSA are independent predictors of PCa; we established prediction models A and B as follows;Model A: Logit (P)=-10.82+2.32×PI-RADS v2.1+11.89×PSAD; Model B: Logit (P)=-6.13+2.19×PI-RADS v2.1-12.02×fPSA/tPSA. The area under the ROC curve was respectively 0.918 and 0.893, both were higher than the PI-RADS v2.1 evaluation independently applied, and we found that the differences were statistically significant. The sensitivity of model A was 0.843 and the specificity was 0.829, which showed better diagnostic efficacy compared with the sensitivity and specificity we got when the PI-RADS v2.1 evaluation was independently used (sensitivity 0.767 and specificity 0.801).Conclusion: The Logistic model established by combing PI-RADS v2.1 evaluation with PSA-related indicators showed better diagnostic efficacy in PSA grey area prostate cancer than PI-RADS v2.1 applied independently, in this way unnecessary needle biopsy can be avoided, and would play a significant instructive role in optimizing clinical treatment strategies.
Characteristic Analysis of the Time-density Curve of Volume Shuttle CT Perfusion of Benign Parotid Tumors
YANG Zhenxing, HAO Fene, ZHAO Lei, YANG Xiaoguang, LIU aishi
2021, 30(5): 575-582.   doi: 10.15953/j.1004-4140.2021.30.05.05
Abstract(42) PDF(12)
Abstract:
Objective: We intend to explore the value of volume shuttle CT perfusion time-density curve characteristics combined with morphological parameters when applied in the differentiation diagnosis of parotid benign tumors. Methods: We performed volume shuttle CT perfusion imaging on 100 collected patients with parotid tumor before operation and got confirmed by the pathology after operation. The image data acquired was sent to the workstation and PACS system. We observed and analyzed the morphological parameters (location, size, density, boundary, neck lymph node, heightened amplitude of enhanced scan) and types of time-density curve, then adopted χ2 test to deal with enumeration data comparison. The enumeration data matched with normal distribution was dealt with two independent samples t test, the rest data was dealt with rank sum test, test level α=0.05. Results: There was no statistical difference in the morphological parameters of benign parotid tumors (pleomorphic adenoma, adenolymphoma, basal cell adenoma; and myoepithelioma), but we found statistical difference in time-density curves. Conclusion: CT perfusion time-density curve characteristics combined with morphological parameters are of great value in the differentiation diagnosis of parotid benign tumors, and have important guiding significance for the selection of surgical procedures.
CT Features of Pulmonary Infection in Elderly Patients with Type 2 Diabetes Mellitus
ZHANG Fengling, ZHAO Li, LIU Jiabao
2021, 30(5): 583-590.   doi: 10.15953/j.1004-4140.2021.30.05.06
Abstract(41) PDF(7)
Abstract:
Objective: To analyze the clinical and CT features of elderly patients with type 2 diabetes mellitus complicated with pulmonary infection. Methods: A total of 150 elderly patients with type 2 diabetes mellitus and pulmonary infection treated in our hospital from May 2019 to May 2021 were analyzed retrospectively. Results: The positive rate of pathogenic bacteria was 90% (135/150), most of which were gram negative. The CT manifestations of 150 patients were mainly lobular pneumonia, lobar pneumonia, pulmonary tuberculosis, pulmonary abscess and fungal infection, and the number of the cases were 62, 41, 31, 9, 7 respectively;Lobular pneumonia and pulmonary tuberculosis were mainly distributed in multiple lobes while lobar pneumonia and pulmonary fungal infection were mainly distributed in single lobe; Among the 150 ceses, there were 101 cases with good blood glucose control and 49 cases with poor blood glucose control. We compared the healing efficacy betwwen the two groups, and found that the difference was statistically significant. Conclusion: Elderly patients with type 2 diabetes are easily associated with pulmonary infection. CT can accurately analyze the pathological changes in the lung.
Spectral CT
Medical CT
Review