ISSN 1004-4140
CN 11-3017/P

2018 Vol. 27, No. 1

CT Theory
The Study of Seismic Tomography Forward Grid Based on 3D Layered Media Model
SONG Zhen-dong, JIANG Zheng-hong, WEI Cheng-wu, ZHANG Teng-fei, WANG Dan
2018, 27(1): 1-8. doi: 10.15953/j.1004-4140.2018.27.01.01
Abstract(466) PDF(12)
The seismic tomography technique is an important means to study the velocity structure of the strata, it is the method that combines the seismic wave travel or waveform data of the receiving point with the physical and mathematical model established to reconstruct the velocity structure of the strata. The accuracy of the forward modeling of tomography will directly affect goodness-of-fit of the reverse velocity relative to the true velocity of the stratum. Therefore, it is very important to find a higher precision forward modeling algorithm for tomography.Based on the three-dimensional layered medium, this paper will use the minimum traveltime ray tracing method by gridding model to conduct forward modeling research. In this paper, three grids of triangle, rectangle and hexagon will be used to parameterize the model, and then their forward results accuracy will be compared to summarize the optimal mesh division method for three-dimensional layered medium.
Forward Modeling of 2D First Arrival Traveltime Tomography Using Moser Method
HAN Pei-en, ZHANG Xue-qiang
2018, 27(1): 9-17. doi: 10.15953/j.1004-4140.2018.27.01.02
Abstract(405) PDF(21)
Seismic tomography is one of the main techniques exploring the inner structure and characteristics of the Earth. The focus of the paper is the use of Moser method in 2D first arrival wave travel time tomography. We used the basic principle of travel time tomography to improve the forward modeling of Moser shortest path method. Moreover, we proposed two ways to fix the existing problems in travel time and ray path calculation:1)using dynamic nodes to improve the precision of travel time calculation; 2) using multiple linked list hash to improve the efficiency of wave front nodes. By using the homogeneous medium model, we proved that the accuracy of the improved Moser method is much higher that of the original algorithm in forward modeling, with a relative error of 0.1% or less. Finally, we applied the improved Moser method to forward modeling calculation of Marmousi2 model. The resulted ray map agreed with the theoretical expectation, which proved the accuracy of improved Moser method.
Spectral CT
Study on Clinical Application of Dual-source CT for Differentiating Diagnosis between Renal Clear Cell Carcinoma and Non-clear Cell Carcinoma
LU Yan-yan, CHEN Hong-wei, BAO Jian, FANG Xiang-ming, ZOU Xin-nong, TANG Qun-feng
2018, 27(1): 19-25. doi: 10.15953/j.1004-4140.2018.27.01.03
Objective: To investigate the application of dual-source CT dual energy imaging technique in differential diagnosis of renal clear cell carcinoma and non-clear cell carcinoma. Methods: 68 cases of patients with suspected renal occupying lesions who received ultrasound, CT scan in our hospital from April 2015 to March 2017 were selected, all patients underwent dual-source CT scan. Comparative analysis of dual-source CT imaging features of renal clear cell carcinoma and non-clear cell carcinoma was taken, iodine concentration and NIC(normalized iodine concentration) of renal clear cell carcinoma and non clear cell carcinoma in corticomedullary phase and parenchyma phase, iodine concentration in different pathological grading and NIC of renal clear cell carcinoma were compared, sensitivity and specificity of differential diagnosis of dual source CT dual energy imaging technique used in diagnosing renal cell carcinoma and non clear cell carcinoma. Results: 32 cases who were confirmed by surgery and pathology had renal clear cell carcinoma and 17 cases had non clear cell carcinoma, after scanning of dual source CT dual energy imaging technique, the iodine concentration and NIC of patients with clear cell carcinoma in corticomedullary phase and parenchymal phase were higher than those of patients with non clear cell carcinoma, there was significant distance(P<0.05); Iodine concentration and NIC of low grade(grade I and II) renal clear cell carcinoma patients in corticomedullary phase and parenchyma phase were significantly higher than those of the high grade(grade III and IV), there was significant difference between the two groups(P<0.05). In addition, analysis of diagnostic sensitivity and specificity of dual source CT dual energy imaging technique used in diagnosing renal cell carcinoma and non clear cell carcinoma showed:when NIC value of 0.704 was set as a standard in parenchyma phase, the differential diagnostic sensitivity(84.6%) and specificity(76.7%) of renal clear cell carcinoma and non clear cell carcinoma were the highest. Conclusion: Dual source CT dual energy imaging technique can distinguish renal cell carcinoma and non clear cell carcinoma via iodine quantitative analysis technique, it has higher zero sensitivity and specificity, can provide basis for pathologic grading of renal clear cell carcinoma.
Complicated Fault Identification Study and Application
MA Jin-ping, FAN Hong-yao, SANG Shu-yun, WANG Qing-zhen, SHI Rui-qi
2018, 27(1): 27-34. doi: 10.15953/j.1004-4140.2018.27.01.04
Now more and more traps are faulted trap, so the fault recognition is very important. By project study we think that:1).The combine of coherence and sup retrace technique can make big faults more clear. 2).The attribute fusion of different curvature attributes can improve small faults identification. 3).The gradient vector technique can make fault image clearer. 4).This technique already has very good application in study area. 5. This technique can be applied in other similar area.
Application of Elastic Wave CT Technique on Detection of Fracture Zone in the Rock Mass of Dazu Stone Carvings
KONG De-tian, LI Gao, ZHENG Xu-hui, SHI Jin-shan
2018, 27(1): 35-44. doi: 10.15953/j.1004-4140.2018.27.01.05
Abstract(413) PDF(12)
Dazu Stone Carvings is one of important stone relics existent in China, which has significant historical and cultural values to this world, one of which had been once listed as "first protect engineering" of stone relics in China. Recently, a new round protecting engineering, including reinforcement of dangerous rock masses and seepage treatment of rock masses, is started by department of cultural relics protection. In order to determine situation of fracture zones developed in the rock masses of Dafowan in Mount Baodingshan, one spot of Dazu Stone Carvings, a detecting work based on cross-hole elastic wave CT technique is carried out on the position designated. The velocity imaging of rock mass between holes resulted from the detecting work clearly reveals the scales and space attitudes of fracture zones in the rock mass between holes. The reliability of the imaging result is demonstrated by the compatibility of the fracture zones with the tectonic stress field of regional geological structures, and the detecting result provides a reliable reference for the analysis of seepage and stability of Dafowan rock masses.
Industrical CT
An Iterative Algorithm with Simultaneously Updating the Spectrum and the Image of Dual Energy Computed Tomography
CHANG Shao-jie, MOU Xuan-qin
2018, 27(1): 45-54. doi: 10.15953/j.1004-4140.2018.27.01.06
Knowing the X-ray spectrum is important to dual energy computed tomography(DECT)reconstruction. Whereas the spectrum is not always available in practice. In addition, the reconstructed image of DECT is extremely sensitive to noise which demands special noise suppression strategy in reconstruction algorithm design. In this paper, we develop an iterative algorithm with simultaneously updating the spectrum and the image of DECT, which did not need the knowledge of the spectrum in advance. Namely, spectrum estimation and iterative reconstruction are incorporated in an iterative framework. The estimated spectrum and the reconstructed images are obtained simultaneously with the proposed algorithm. Two sets of simulation experiment with different phantoms were adopted for evaluation. In comparison with the initially estimated spectrum,experimental results validated that the proposed method can provide the accurate estimated spectrum. Besides, the quality of the reconstructed density images has been improved by this work at the same time.
Medical CT
Comparative Study of 3.0 T MRI Preoperative Evaluation with Clinical Patholgic of Early-stage Cervical Carcinoma
XU Mei, GAO Yi-jun, WU Yan-li, LIU Chun-lan, HE Ping, WANG Jian, FAN Shu-ying, ZHOU Xiao-ling, LI Shu-hua, LIU Jing-wang
2018, 27(1): 55-61. doi: 10.15953/j.1004-4140.2018.27.01.07
Objective: To investigate the diagnostic value of 3.0 T MRI in preoperatively evaluation with early-stage cervical carcinoma. Methods: 20 patients with pathologically-confirmed early-stage cervical carcinoma were enrolled in this study. Both preoperative evaluation of 3.0 T MRI and clinical pathologic were performed in all the patients. The rates of diagnostic by 3.0 T MRI were statistically analyzed. Results: The preoperative MRI staging accuracy was 88.3%. The imaging of the tumor showed solid tumor with high intensity signal on T2WI(10/18) and low intensity signal On T1WI(14/18). In all patients, the tumers of 15 cases were earlier(4±2.1)s than myometrium. The time signal intensity curves of 13 cases were rapidly rised-slowly down. Conclusion: 3.0 T MRI has key value for early cervical cancer preoperation. It can help us to completely understand the situation of early stage cervical cancer and select the suitable treatment plan.
The Morphological Characteristics of Torn Vascular Intima Distinguishes True from False Lumen of Aortic Dissection
YUAN Xiao-jun, HAO Fen-e, ZHAO Lei, LIU Ai-shi
2018, 27(1): 63-69. doi: 10.15953/j.1004-4140.2018.27.01.08
Objective: To use the morphological characteristics of torn vascular intima to distinguishes true from false lumen of aortic dissection(AD). Methods: Totally 63 MSCTA data of aortic dissection was enrolled into retrospective analysis. On axial images of different segments of the aorta, the intersection angle was measured between torn vascular intima of aortic dissection and both joint point on arterial wall, the angle of true lumen included angle bisector(TLIAB) was calculated, the TLIAB's quadrant was ascertained, the numbers of TLIAB in different segments and different quadrants was statistically compared by using student's χ2 test. Results: The maximum number of TLIAB was 126 in different segments of aorta in 63 patients. There were significant differences in the number of TLIAB between different segments(χ2=63.87, P<0.05). There was no significant difference in the number of TLIAB between the same segments and different AD types. TLIAB was most common in the right anterior quadrant, most notably in the descending aortic arch; about 88.89% of the lumen in the right anterior and left anterior quadrant was the true lumen. Conclusion: It is a useful, simple and fast method to distinguish the true lumen from false lumen of aortic dissection according to the morphological characteristics of torn vascular intima.
Application of Low Dose CT Scanning in the Sacroiliac Joint of Adolescents
LIANG Zhen-hua, FANG Ting-song, HUANG Yu-jian, PAN Bang-sheng, LI Jun-hong
2018, 27(1): 71-76. doi: 10.15953/j.1004-4140.2018.27.01.09
Objective: To investigate the feasibility of low-dose CT scanning in the sacroiliac joint of adolescents and to determine its optimal parameters. Methods: With the application of PHILIPS 64-row 128-slice spiral CT scanner, a total of 150 adolescents aged 14~30 years(weight <75 kg and BMI <25) were selected in the study and then randomly divided into three groups. In the conventional dose group, the tube voltage was 120 k V and the tube current was 250 m As; low dose group A applied a tube voltage of 120 k V and tube current of 100 m As, and in low dose group B, the he tube voltage was 100 k V and the tube current was 100 m As. Sacroiliac joints among three groups were scanned. Volume CT dose index(CTDIvol) and dose length product(DLP) were recorded in the CT scanning patterns of the three groups. The image quality was independently scored and averaged by two physicians by using double blind method, scores were averaged. Rank-sum test and variance analysis were used for statistical analysis. Results: The image quality of the three groups could meet the diagnostic requirements, and there was no statistical significance(P>0.05). The radiation dose in low dose group B was significantly lower than that in conventional dose group, showing a significant difference(P<0.05). Conclusion: Low dose scanning technique using tube voltage of 100 k V and tube current of 100 m As can ensure the image quality, meet the diagnostic requirements and significantly reduce the patient's radiation dose.
Pathologic Fracture Predicts for Poor Prognosis in Osteosarcoma for Recurrence and Amputation Based on X-ray
HAO Yun, HE Jin-peng
2018, 27(1): 77-84. doi: 10.15953/j.1004-4140.2018.27.01.10
Objective: The significance of pathologic fracture and prognosis for osteosarcoma is still controversial.The aim was to provide a Meta-analysis for pathologic fracture and prognostic features of osteosarcoma patients.Methods: A detailed search was made in MEDLINE, EMBASE and the Web of Knowledge for relevant original articles published in English; methodological quality of the included studies was also assessed. Two reviewers extracted data independently. Studies were pooled and odds ratio(ORs) with corresponding confidence intervals(CIs) were calculated. Results: Pool analysis of 1502 patients from 5 eligible studies was performed. Combined OR of pathologic fracture indicated that pathologic fracture was associated with local recurrence(n=1 018 in 4 studies; OR=1.83; 95% CI:1.06~3.15; P=0.03) and the limb salvage(n=1 502 in 5 studies; OR=1.84; 95%CI:1.25~2.72; P=0.002) but not with adequate margin(n=1 501 in 5 studies; OR=0.74; 95% CI:0.39~1.40;P=0.35) or histological response to neoadjuvant chemotherapy(n=1 420 in 4 studies; OR=0.41; 95% CI:0.98~2.05; P=0.07). Conclusion: The results of this Meta-analysis indicate that a higher risk of local recurrence and amputation were achieved in osteosarcoma patients with pathological fracture than those without pathological fracture. The pathologic fracture is a predictor of poor prognosis in osteosarcoma.
MRI Technique for Diagnosis of Cerebral Ischemic Foci and Evaluation of Alzheimer's Disease
ZHOU Li-jing
2018, 27(1): 85-91. doi: 10.15953/j.1004-4140.2018.27.01.11
Objective: To evaluate the application of MRI(magnetic resonance imaging) in the diagnosis of cerebral ischemic foci and brain atrophy and ischemic foci and the assessment of the risk of Alzheimer's disease(AD). Methods: 40 health people as group A, 40 patients with ischemic foci were group B, 40 patients with cerebral atrophy and ischemic foci and 40 AD patients were enrolled in our hospital from January 2016 to December 2016. All the cases were examiningd with MRI Diagnose and evaluate the differences in MRI images. Results: The ICA:PDV, R-ICA:MF of group C were significantly lower than those of group A and group B(P<0.05), ICA:PSV of group C was significantly lower than group B(P<0.05), but there were no significantly difference(P>0.05). The L-IJV:PDV of group C were significantly lower than in group A and group B(P<0.05). The MRI thickness of the four groups was significantly higher than that of the control group(P<0.05). The MRI thickness of the three groups was significantly higher than that of the control group(P<0.05), and the difference was statistically significant(P<0.05) Olfactory cortex(EC) and right hemisphere PCC linear trend were significantly different(P<0.05). Conclusion: Ischemic foci and brain atrophy are the result of different stages of brain tissue pathological changes.MRI diagnostic accuracy is higher, and the merge focal ischemic brain atrophy patients MRI images are similar to AD patients, and it can suggest the risk of AD, which has important clinical guiding value.
Comparative Analysis of MSCT Features and Pathology of Ground-glass Nodules of Lung Adenocarcinomas
WANG Hui, LIU Hong, HUANG Hai-dong, ZHAO Rui
2018, 27(1): 93-99. doi: 10.15953/j.1004-4140.2018.27.01.12
Abstract(457) PDF(11)
Objective: To explore the Multi-slice CT(MSCT) manifestations and pathological basis of ground-glass nodules of lung adenocarcinomas, so as to improve the accuracy of the diagnosis of benign and malignant diseases. Methods: the CT data of 21 ground-glass nodules(GGNs) lesions proved to be lung adenocarcinoma by pathology were analyzed retrospectively, and included analysis of tumor size, nature, interface of tumor and lung,edge, vacuole sign, pleural indentation sign, bronchi and blood vessels through the tumor imaging features. The pathological findings were divided into two groups:preinvasion lesions and invasive lesions, and the CT features of the two groups were compared. Results: preinvasive lesions were 14, of which 13 were smaller than 2.0 cm in length-diameter, 10 were pure ground-glass nodules(p GGNs), 9 interface of tumor and lung were clear and smooth, 8 edges appeared lobular sign and 3 edges showed spicule sign; Invasive lesions were 7, of which 4 length-diameter were greater than 2.0 cm, 5 were mixed ground-glass nodules(m GGNs), 7 interface of tumor and lung were clear and coarse, 6 edges showed lobulation, 6 edges burred spiculation, 4 edge display spinous protuberance; In addition, vacuole sign, pleural indentation sign, bronchi and blood vessels through the tumor in walking and morphologic changes are more common in the invasve lesions. Conclusion: MSCT showed ground-glass nodules of lung cancer have certain characteristics. The probability of invasive lesions is obviously increased when GGNs have larger size, a mixed density, clear and coarse interface of tumor and lung, or when the CT signs, such as deep vacuole sign, lobular sign, spicule sign, spinous protuberant sign, the abnormal changes of bronchi and blood vessels through the tumor.
The Value of Multi-slice Helical CT in the Diagnosis of Different Subtypes of Renal Cell Carcinoma
SUN Xin, WANG Zhi-tao, ZHANG Yu, CUI Wen-jing, WANG Jian-hua
2018, 27(1): 101-106. doi: 10.15953/j.1004-4140.2018.27.01.13
Objective: To evaluate MSCT features in the diagnosis of renal cell carcinoma. Methods: MSCT appearance of 44 cases with renal cell carcinoma confirmed by surgery and pathology was retrospectively analyzed. The density of the lesion and the adjacent normal renal cortex were calculated in unenhanced and enhanced phases respectively. The ratios of lesion/renal cortex enhancement were calculated for three phases. Results: CT attenuation in unenhanced scan was not statistically different between three subtypes. In cortical, nephrographic and delayed phase, CT attenuation and the ratios of lesion/renal cortex enhancement of clear cell carcinoma were higher than that of papillary and chromophobe renal cells respectively(P value was 0.000 in different phase). There was no statistically significant difference between CT attenuation of papillary carcinoma and that of chromophobe cell carcinoma in different enhanced phase(P value was 0.376, 0.315, 0.382 respectively). However, the ratios of lesion/renal cortex enhancement of chromophobe renal cells were higher than that of papillary renal cells carcinoma in cortical, nephrographic and delayed phase respectively(P value was 0.046, 0.031, 0.048 respectively). Conclusion: Dynamic enhanced CT scan is good for differentiating clear cell carcinoma from other subtypes, but it is hard to discriminate between atypical papillary carcinoma and chromophobe carcinoma.
Evaluation of Alveolar Bone Changes in Chronic Periodontitis Before and After Sequence of Periodontal Treatment by CBCT
OUYANG Yu-ling, ZHU Yi-qing, LIU Yong-jing, ZHANG Wei, FANG Shun, BO Wen-jie
2018, 27(1): 107-114. doi: 10.15953/j.1004-4140.2018.27.01.14
Objective: To compare change in PD(periodontal probing), CAL(clinical attachment loss) and ABD(alveolar bone density) between the initial therapy and initial therapy flap surgery groups from baseline to end of follow-up(6 months). Methods: Patients with severe chronic periodontitis were observed in the initial therapy group(20) and the initial therapy flap surgery group(20). Totally 40 patients were followed up for 6 months after both treatment.Outcomes for PD, CAL and ABD for each tooth were collected at two time points(baseline and 6 months after treatment). Descriptive analysis was used to summarize the demographic characteristics. A mixed-model ANCOVA will be conducted, controlling for covariates of baseline outcome value, age, sex and alcohol intake, to evaluate the treatment difference between the initial therapy group and initial therapy flap surgery group in change from baseline of the outcomes. Results: A total of 145 teeth(72 in the initial therapy group, and 73 in the initial therapy flap & surgery group) were evaluated. Teeth that received the initial therapy flap surgery group performed better in change from baseline of PD than teeth that received the initial therapy group(-1.25 vs.-2.00, P<0.001). There is no statistical significance treatment difference in change from baseline of CAL between two groups. Teeth that received the initial therapy flap surgery group performed better in change from baseline of BMD than teeth that received the initial therapy group(0.027 vs. 0.059, P<0.001). Conclusion: There may be substantial benefits for patients who received the initial therapy flap surgery group than the initial therapy group only. CBCT could be used in evaluation of alveolar bone changes in the Sequence of periodontal treatment of chronic periodontitis
3D CT Value Analysis of Ground Glass Shadow and Coelentereous Growth in Stage Ⅰ Invasive Lung Adenocarcinoma
LIU Li-wei, ZHANG Long-jiang, QIAN Bin
2018, 27(1): 115-121. doi: 10.15953/j.1004-4140.2018.27.01.15
Objective: To investigate the relationship between ground glass opacity and the pathologic climax-like growth in patients with stage I invasive lung adenocarcinoma by three-dimensional CT. Methods: A total of 168 patients with stage inⅠ vasive pulmonary adenocarcinoma who were treated from June 2013 to June 2017 were selected. The components of ground glass in stage Ⅰinvasive lung adenocarcinoma were calculated by three-dimensional CT quantitative analysis software and the largest radial line measurement ratio, semi-quantitative assessment of the invasive growth of the adherent adenocarcinoma composition, and the correlation between the two. Results: The proportion of ground glass components was(0.21±0.18), the percentage of ground glass components was(0.44±0.36), the semi-quantitative analysis of pathological sections the ratio was(0.29±0.24). There was a positive correlation between the proportion of ground glass components and the proportion of climax-like growth components(r=0.634 and 0.598, P=0.000) by three-dimensional CT quantitative analysis and maximum diameter line analysis. The ratio of ground glass to the ratio of ground-glass components measured by the maximum diameter method was 3.8%. Outside the 95% confidence interval, the three-dimensional CT value was 4.4%. There was no significant difference between the two methods(P>0.05). Conclusion: The three-dimensional quantitative analysis of stage I invasive lung adenocarcinoma patients with ground-glass components and climax-like growth component has a significant correlation, which has a significant clinical significance in the diagnosis of secondary pathology, and compared to the maximum diameter method is more comprehensive reflect the stage I invasive lung adenocarcinoma of the tumor status.
Status Analysis of Geophysical Exploration for Shale Oil and Gas in Guangxi Province
LI Jing-he, YANG Jun, MENG Shu-jun
2018, 27(1): 123-136. doi: 10.15953/j.1004-4140.2018.27.01.16
Based on the important foundation investigations for shale gas exploration in 13 th Five Year Plan of China, the geophysical surveys for shale oil and gas in Yunnan, Guizhou and Guangxi provinces are implemented in order. However, there are few research work considered the geophysical explorations for shale oil and gas in Guangxi province. It also is the main challenge to implement the suitable geophysical technologies effectively for the above goals in foundation investigations of south China in 13 th Five Year Plan. With the geology comparability of Guangxi province and its peripheral areas for shale oil and gas exploration, the status analysis of geophysical exploration is given for the peripheral areas of Guangxi province. It is aimed at obtaining the wide applications of geophysical technologies for shale oil and gas exploration. Then some suggestions are given from the above analysis of geophysical exploration for shale oil and gas in Guangxi province. Moreover, the wide applications of 2D seismic exploration, the priority development of 2.5 D electromagnetic method, systemic testing of geophysical property and the application of hybrid geophysical survey are concluded by learning from the applications of geophysical exploration for shale oil and gas in peripheral areas of Guangxi province.