CT理论与应用研究

Repeatability Study on Non-rigid Registration for DCE-MRI Measurement of Solitary Pulmonary Nodule

ZHANG Mingzhu, FENG Feng, XIA Ganlin, CHEN Yufeng, FU Aiyan, SHI Donghui

2020, 29(1): 1-10. doi: 10.15953/j.1004-4140.2020.29.01.01

Abstract(495) PDF(9)

Abstract:
Objective:To investigate the repeatability before and after non-rigid registration in dynamic contrast-enhanced MRI quantitative analysis of solitary pulmonary nodules. Methods:Twenty-seven solitary pulmonary nodules underwent DCE-MRI examination on a 1.5 Tesla MR scanner. OmniKinetics software was applied with non-rigid registration of DCE-MRI. Two radiologists measured DCE-MRI quantitative parameters before and after the registration twice:capacity transfer constant (k^trans), rate constants (k_ep), extravascular extracellular space volume ratio (v_e), measured twice two weeks apart. The Bland-Altman analysis and Intraclass correlation coefficient (ICC) were used to assess the reproducibility of the quantitative parameters of inter- and intra-observer agreement. Result:The same reader measured twice, the value of ICC were 0.962 (k^trans), 0.736 (k_ep), 0.708 (v_e) before registration, and after were 0.983, 0.962, 0.834, respectively. After registration quantitative parameters were higher than before. After registration repeatability of k^trans, k_ep, v_e measurement (1.6%, 13.9%, 4.3%) better than before (4.8%, 33.5%, 9.6%). Between different readers, the value of ICC were 0.945 (k^trans), 0.760 (k_ep), 0.931 (v_e) before registration, and after were 0.988, 0.962, 0.976, after registration quantitative parameters were also higher than before. After registration repeatability of k^trans, k_ep, v_e measurement (1.8%, 13.7%, 13.1%) better than before (3.9%, 35.7%, 20.1%), respectively. Conclusion:Non-rigid registration technique can improve the repeatability of the measurement of solitary pulmonary nodule DCE-MRI quantitative parameters.

Application of Optimal Noise Reduction Smooth Model Based on EMD and EEMD in Seismic Waves

SI Youqiang, GUO Runhua, LI Mengru

2020, 29(1): 11-21. doi: 10.15953/j.1004-4140.2020.29.01.02

Abstract(381) PDF(7)

Abstract:
At present, seismic waves have a wide range of applications in geological structure detection and structural damage detection. There are various kinds of noise interference during the seismic wave acquisition process, which affects the data processing of the signal. In this paper, the optimal noise reduction model is established by EMD and EEMD algorithms. The noise reduction effect is analyzed and compared by low-pass filtering and band-pass filtering algorithms. The smooth models of the signal are also compared by taking different values for the smoothness coefficient α. In more detail, firstly, the basic principles of EMD and noise reduction smoothing model are introduced. The Gaussian white noise interference is then added via simulated Rayleigh wave; after that, the data is processed by the optimal noise reduction smooth model. Finally, the feasibility of the model is verified through the actual seismic wave. The results show that the EEMD model is effective in the practical application of seismic wave noise reduction.

Research on Intelligent Fracture Detection Technology and Its Application in Chengdao Burid Mountain

YU Shina, LI Shuai, GAO Xilong, ZHOU Hongke, WU Qunhu, HUANG Handong

2020, 29(1): 23-30. doi: 10.15953/j.1004-4140.2020.29.01.03

Abstract(267) PDF(7)

Abstract:
Fractures can destroy and preserve oil and gas reservoirs. The buried hill reservoir of Shengli Chengdao Ordovician is controlled by fractures and has strong heterogeneity. In this paper, with seismic edge detection as prior information and heuristic factor, ant body tracking is carried out on adaptive seismic coherence data body to fine detect cracks, which makes up for the defect of low resolution of single coherence body detection, and obtains the fracture detection results with higher coincidence degree with drilling and actual underground conditions. It plays a guiding role in oil and gas exploration in this area.

A Dual-energy Stationary CT System Based on Dual-plane Scanning Mode

JIN Xin, ZHANG Siyuan, LI Liang, CHEN Zhiqiang

2020, 29(1): 31-37. doi: 10.15953/j.1004-4140.2020.29.01.04

Abstract(667) PDF(29)

Abstract:
Stationary CT technique is a promising approach for baggage inspection due to its high scanning speed compared with traditional spiral-CT. The main challenges which current stationary CT system meets are the geometric calibration, image reconstruction from limited angle data and matching of dual-energy projection. In this paper, we presented a dual-energy stationary CT system based on dual-plane scanning mode. The multi-bean X-ray source of the system is made of carbon nanotube cathode, which enables fast switching of exposure sequence. The dual-plane scanning mode is applied in order to increase the cover angle of projection data and reduce artifacts. The attenuation information is collected by the dual-energy detector which enables materials decomposition and recognition. According to the experimental results of luggage, the stationary CT system presented in this paper enables three-dimensional imaging of luggage with high resolution and detailed material information, which indicates its potential in applications of baggage inspection.

A Retrospective Analysis of the Imaging Manifestations of Diabetic Charcot's Foot

WANG Shuo, LIU Huanning, WANG Jiangning, XIE Huimin, ZHENG Hailiang

2020, 29(1): 39-48. doi: 10.15953/j.1004-4140.2020.29.01.05

Abstract(281) PDF(4)

Abstract:
To investigate the imaging characteristics of diabetic Charcot foot and provide clinical basis for diagnosis. Materials and methods:the imaging findings of 16 cases of diabetic Charcot treated by surgery in our hospital between January 2016 and September 2019 were retrospectively analyzed. Results:There were local ulceration infection and effusion in 16 cases. X-ray manifestations described osteoporosis in 13 patients, bone destruction in 10 patients, bone hyperplasia in 6 patients, joint deformity in 12 patients (including foot joints), bone fracture in 1 patient, change in articular surface/joint space in 4 patients, and soft tissue swelling in 11 patients respectively. CT and MRI showed disorganized foot structure, abnormal bone morphology and poor joint alignment. MRI showed edema of bone marrow and soft tissue and abnormal fluid signal. CTA showed arteriovenous fistula of the lower leg. Conclusion:the imaging diagnosis of diabetic Charcot foot is mainly bone destruction and plasticity, and the early imaging manifestations are difficult to differentiate from other diseases, which should be based on clinical patients with diabetic peripheral neuropathy

Correlation of T2WI Characteristics with ADC Value and Ki-67 Expression in Young Women with Invasive Ductal Carcinoma

LV Xuefei, HU Shaoping

2020, 29(1): 49-54. doi: 10.15953/j.1004-4140.2020.29.01.06

Abstract(308) PDF(6)

Abstract:
Objective:To explore the correlation between the T2WI characteristics with ADC value and the expression of Ki-67 in young women with invasive breast cancer. Methods:Thirteen young patients (≤ 35 years old) admitted to our hospital from May 2018 to July 2019 were selected as study objects. The T2-weighted signal characteristics and apparent diffusion coefficient (ADC) values of the focus in the MRI scanning sequence were recorded in detail, and the percentage value of Ki-67 (activity of proliferating cells) was calculated by immunohis to chemistry. Results:The ADC value range of young women with invasive breast cancer was (0.78±0.08)×10^-3/mm², and the positive expression rate of Ki-67 detected was about 92%. In the focus, T2WI showed slightly higher signal and positive expression rate of Ki-67 were positively correlated, while ADC value was negatively correlated with Ki-67 within a certain range. The T2WI signal and the quantization value of ADC in the lesions were analyzed to be the factors influencing the positive expression of Ki-67. Conclusion:In young women with invasive breast cancer, the T2WI sequence signal features are mostly slightly high signal (84%) or equal (16%). With ADC value decreasing to a certain range (1×10^-3/mm²), Ki-67 presented a significant increase in positive expression. T2WI signal characteristics combined with ADC values have important reference value for diagnosis, clinical treatment selection and prognosis prediction of young female patients with invasive breast cancer.

Clinical Application of Low Tube Voltage Combined with Iterative Reconstruction in Lower Extremity Arterial CTA

ZHANG Jun, LIU Jiayi, LIANG Zhipeng

2020, 29(1): 55-60. doi: 10.15953/j.1004-4140.2020.29.01.07

Abstract(278) PDF(5)

Abstract:
Objective:To explore the application value of 80kV tube voltage combined with iterative reconstruction technology in CT angiography of lower extremity artery. Methods:40 patients were randomly divided into two groups. The parameters of scanning and injection were 80kV in the experimental group and 100kV in the control group. The radiation dose, contrast dose and image quality were compared between the two groups. Results:The effective radiation dose and contrast dose (95mL) of the control group were significantly higher than those of the experimental group, the difference was statistically significant (P<0.001); there was no statistical difference between the two groups in the CT value of vascular enhancement and the subjective score of image quality (P>0.05). Conclusion:The CT scanning technology of 80kV tube voltage combined with iterative reconstruction technology can significantly reduce the radiation dose and contrast agent dose on the premise of ensuring the image quality, which has important application and promotion value.

To Explore the Advantage of Gemstone CT Target Reconstruction in Displaying the Tissue Structure of Living Lung

CHEN Mailin, LIU Yuliang, LI Xiaoting, QI Liping, SUN Yingshi

2020, 29(1): 61-69. doi: 10.15953/j.1004-4140.2020.29.01.08

Abstract(305) PDF(8)

Abstract:
objective:to compare the image quality and the display of the structure of normal lung between lung CT targeted reconstruction (local small FOV thin layer CT imaging) and conventional lung CT. Methods:74 cases of subjects respectively routine pulmonary CT scan (5mm) and targeted reconstruction (FOV:20 cm, thickness:1.25mm). Two radiologists respectively determine normal lung CT imaging, targeted reconstruction image quality:pulmonary lobule structure, pulmonary vessels and bronchial branches display (grade 1~4) and judge the strength of confidence. The targeted reconstruction with 1.25-mm sections and small FOV showed more was used as the gold standard. and further determine the sensitivity of targeted reconstruction and conventional lung CT scan imaging (5mm), the consistency between two observers to make Kappa test. Results:Level 1 and 2 image quality of conventional lung CT scan and targeted reconstruction showed no significant statistical differences. Level 3 and level 4 image quality, targeted reconstruction is superior to the conventional lung CT scan, the differences between two observers was statistically significant (P<0.05); According to the targeted reconstruction imaging, Conventional pulmonary CT scan imaging (5mm) Level 3 image's sensitivity was 97.1%, 98.6%, respectively; Level 4 image's sensitivity was 80.8%, 85.3% respectively. And diagnostic confidence level increased significantly (P<0.05). Image quality judgment has a good consistency for targeted reconstruction, conventional lung CT between two observers (k=0.717, 0.746). Conclusion:Compared with conventional CT images, targeted reconstruction images can increase the normal display rate of pulmonary microstructure, the confidence of the judgment.

Guidance Value of MSCT in the Diagnosis and Clinical Treatment of GST

LI Yanju, LIU Xiaoxing, LIANG Shanshan, RAN Caihong, NNDA Zhuoma

2020, 29(1): 71-77. doi: 10.15953/j.1004-4140.2020.29.01.09

Abstract(228) PDF(5)

Abstract:
Objective:To analyze the guidance value of multi-slice spiral computed tomography (MSCT) in the diagnosis and clinical treatment of gastric stromal tumor (GST). Method:The clinical data of 56 patients with gastric stromal tumor admitted to our hospital from January 2018 to February 2019 were collected. The clinical data of patients were collected to evaluate the pathological risk of patients. The differences in MSCT images between patients with different pathological risks were analyzed, and the diagnostic accuracy of MSCT for GST was calculated. Results:Among the 56 patients, 11 patients (19.64%) had very low pathological risk, 18 patients (32.14%) had low risk, 14 patients (25.00%) had moderate risk, and 13 patients (23.21%) had high risk. There was no significant difference in the density of MSCT, the presence or absence of necrosis/ulcer in the tumor, the difference value of degree of of arteriovenous enhancement, the presence or absence of the intravascular and peritumoral vessels, and the pathological risk (P>0.05). There was a significant difference in peritumoral fat space, enhancement mode and pathological risk (P<0.05). Taking pathological biopsy as a control, the number of accurate diagnosis of GST by MSCT was 53 cases, and the diagnostic accuracy was 94.64%. Three cases were misdiagnosed as gastric cancer, and the misdiagnosis rate was 5.45%. Conclusion:MSCT has a high diagnostic accuracy for GST, which can effectively display the characteristics of GST images with different pathological risks, and can provide reliable imaging information for clinical operations.

The Application Value of Chest Multi-slice Spiral CT in the Diagnosis of Mass in Dense Breast

MIAO Na, QI Xuhong, DU Changyue, CHEN Shiguang, BI Dongmei, WEN Zhiyong

2020, 29(1): 79-88. doi: 10.15953/j.1004-4140.2020.29.01.10

Abstract(256) PDF(6)

Abstract:
Objective:To evaluate the diagnostic value of chest multi-slice spiral CT in breast mass. Methods:Imaging data of preoperative chest MSCT and mammography in 72 patients with breast masses confirmed by surgical pathology were collected. There were 54 cases of malignant breast mass and 18 cases of benign breast mass. Patients were divided into non-dense group (23 cases) and dense group (49 cases) according to the types of breast glands. Taking pathological examination results as reference, the diagnostic efficiency of breast masses in chest MSCT and mammography was evaluated. Results:In the dense breast group, the diagnostic accuracy of chest MSCT for malignant mass was 89.19%, higher than that of mammography 67.57%, and the difference was statistically significant (P=0.024, χ²=5.103); the diagnostic accuracy of chest MSCT for benign mass was 75% higher than that of mammography 58.33%. In the non-dense breast group, the diagnostic accuracy of mammography for malignant mass was 94.12%, slightly higher than chest MSCT of 82.35%. The diagnostic accuracy of chest MSCT and mammography for all breast masses was 86.11% and 75%. The detection rate of chest MSCT for metastatic lymph nodes and chest metastases was better than that of mammography. Conclusion:Breast MSCT has high value in qualitative diagnosis of breast mass. Chest MSCT can provide more information and improve the diagnostic accuracy of dense breast mass than mammography.

CT Findings of Primary Mediastinal Yolk Sac Tumor

CHEN Kai, GUAN Yubao, LIUFU Yuling, ZHENG Wuxi, DENG Enxin, LIU Yuanming

2020, 29(1): 89-94. doi: 10.15953/j.1004-4140.2020.29.01.11

Abstract(129) PDF(7)

Abstract:
Objective:To improve the CT diagnostic accuracy of primary mediastinal yolk sac tumor. Methods:The clinical manifestations and CT features of 13 cases with primary mediastinal yolk sac tumor were analyzed retrospectively. Results:All the 13 patients were young males, aged 18-33 years old, with an average age of 25 years old. All the tumors were located in the anterior mediastinum, including 7 cases in the right anterior mediastinum, 2 cases in the left anterior mediastinum, and 4 cases in the anterior middle mediastinum. Seven of the 13 patients were tested for serum alpha-fetoprotein (AFP), all of which were higher than normal. In 12 cases, the diameter was greater than 8cm, 9 cases showed uneven enhancement after enhancement, and 4 cases showed uniform enhancement. Twelve cases were closely related to the great vessels, among which 6 cases obviously surrounded the adjacent great vessels. Pleural effusion was found in 6 cases, pericardial effusion in 3 cases. There were enlarged mediastinal lymph nodes in 3 cases. Conclusion:Primary mediastinal yolk sac tumor is more likely to occur in young men, often located in the anterior mediastinum, with a large lesion volume and multiple cystic necrotic areas. CT can clearly show the relationship between the lesion and adjacent blood vessels, and combined with AFP detection can help improve its diagnostic accuracy.

CT Diagnosis of Pulmonary Mucosa Associated Lymphoid Tissue Lymphomaes

LIN Guansheng, MA Zhoupeng, YU Qian, FU Wenbing

2020, 29(1): 95-101. doi: 10.15953/j.1004-4140.2020.29.01.12

Abstract(351) PDF(6)

Abstract:
Objective:To investigate the CT manifestation of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma and improve the diagnostic level. Methods:The CT and clinical data of 7 cases of pulmonary MALT lymphomas proved by pathology were reviewed retrospectively. Results:There were 4 cases of multiple lesions and 3 cases of solitary lesion among 7 cases, 5 cases were pneumonic consolidation type and 2 cases were nodular/mass type. On unenhanced CT, all 5 cases of pneumonic consolidation type showed strip or patch consolidations of lung, and "air bronchograms sign" can be observed. Multiple ground glass nodules with clear margin were observed in 1 case; two cases of nodular/mass type showed intrapulmonary solitary mass with homogeneous density and clear boundary, and the maximum diameter was 32mm and 38mm respectively. "Air bronchograms sign" can be observed in 1 case. On enhanced CT, all 7 cases showed mild to moderate homogenous enhancement, and "blood vessel floating sign" can be observed in 5 cases. Multiple mediastinal lymphadenopathy can be observed in 1 case, a small amount of pleural effusion was observed in 2 cases and partial pleural thickening occurred in 2 cases. Conclusions:Most pulmonary MALT lymphomas manifested as multiple consolidation lesions. A few manifested as pulmonary nodule or mass, accompanied with "air bronchograms", "blood vessel floating sign" and mild to moderate enhancement. CT has important value for its diagnosis.

Imaging Analysis of Chondromyxoid Fibroma

YUAN Jianxiang, FANG Tingsong, PAN Derun, ZHANG Rui, SUN Yang

2020, 29(1): 103-110. doi: 10.15953/j.1004-4140.2020.29.01.13

Abstract(268) PDF(8)

Abstract:
Objective:To investigate the MRI, conventional radiography (CR) and CT characteristics of chondromyxoid fibroma (CMF). Methods:The study included 18 patients (12 females, 6 males; mean age 30 years; range 9 to 78 years). Diagnosis was made histopathologically in all patients. The CR (15), CT (8) and MRI (10) characteristics were summarized. Results:The lesions were located in femur (3), tibia (3), humerus (2), metacarpus (2), temporal bone (2), frontal bone (2), ulna (1), fibula (1), calcaneus (1), thoracic vertebra (1). Ten lesions were located in long bones, most of the lesions (10/18) were in the metaphysis, 2 lesions were in the epiphyseal, 1 lesion in the diaphyseal. 11 cases were round or oval, 4 cases were lobulated and multilocular, 3 cases were irregular, all of them showed different degrees expansion. All of the cases were demonstrated lytic lesions in CR and CT, 4 Cases(26.67%) were found calcification in CR, 6 cases(75%) were found calcification in CT. All cases showed hypointense to intermediate signal intensity on T1WI images. On T2WI images, all lesions were hyperintense:peripheral intermediate signal band with central hyperintense signal in 8 (80%) lesions, whereas diffusely hyperintense with heterogeneous pattern in two (20%). On contrast-enhanced T1WI images, peripheral nodular or arc enhancement was observed in 80% (8/10) and diffuse contrast enhancement was observed in 20% (2/10). Conclusion:CMF is a relatively rare primary bone tumor of cartilage, it has some imaging characteristics, its MRI signal and enhancement characteristics play an important role in the diagnosis and differential diagnosis. Imaging features can provide reference value for preoperative diagnosis of CMF.

Advance of CT Texture Feature Analysis in Diagnosis of Solitary Pulmonary Nodules

YAO Benbo, YU Jianqun

2020, 29(1): 111-118. doi: 10.15953/j.1004-4140.2020.29.01.14

Abstract(254) PDF(10)

Abstract:
Lung cancer is the most common malignant tumor in China. Chest CT scan can improve the detection and correct diagnosis of lung cancer. Early or asymptomatic lung cancer is mostly manifested as solitary pulmonary nodules, so the differential diagnosis of pulmonary nodules is very important. The diagnosis of pulmonary nodules on conventional CT images depended on their contour, shape and the characteristics of density, which is difficult to differential diagnosis in benign or malignant nodules, especial in ground glass nodule (GGN). However, computed tomography (CT) texture feature analysis is based on the quantification of internal gray scale features and other features, which provides a useful reference for the identification of benign and malignant solitary pulmonary nodules, prognosis judgment and gene mutation prediction. Thus texture analysis makes up for the deficiency of traditional CT quantitative evaluation. This paper summarizes the basic principle, method and workflow of CT texture feature analysis and its application in the diagnosis of solitary pulmonary nodules.

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2020 Vol. 29, No. 1