CT理论与应用研究

3-D Resistivity Inversion of a Vertical Line Source of Current

ZHU Tao, FENG Rui, XU Zhong-xin

2004, 13(2): 1-5.

Abstract(1559) PDF(0)

Abstract:
In monitoring water- or mud-injection of oil well by electrical method, the potential electrodes are placed on the surface and the corresponding current electrode is the steel case of oil well which is a vertical line source of current. The purpose of exploration is to reveal the flow direction and distribution of fluid through these observed data. 3-D resistivity inversion of a vertical line source of current and a method of constructing Jaccobian matrix are introduced in this paper. A preliminary result from a test oilfield is presented. An oil production well is taken as a vertical line source of current, around which 108 electrodes are placed evenly at 6 circles with 50 m space in radius. The medium true resistivity values of 5 horizontal layers ranging from 500 m to 2 000 m deep are obtained. The result shows that this method is effective to monitor the direction and distribution of fluid in a certain layer.

New progress of Magnetic Resonance Sounding (MRS)Method—A Record of Events of Taking Part in the 2nd MRs International Workshop

LI Zhen-yu, GAO Xiu-hua, PAN Yu-ling

2004, 13(2): 6-10.

Abstract(615) PDF(0)

Abstract:
Magnetic Resonance Sounding (MRS) is the only geophysical new method of directly detecting underground water at present. In this paper the main gains of taking part in the 2nd MRS international workshop are introduced, development and progress of hydroscope and applications of MRS method are considered. On the basis of the MRS successful application in the detection of underground water, using MRS method new progress has been made in slide monitoring of Three Gorges and archeology of the first Qin dynasty imperator mausoleum for the first time.

The Function of Geo-tomography for Disaster Reduction

GUO Lü-can, ZHAO Jing

2004, 13(2): 60-63.

Abstract(538) PDF(0)

Abstract:
Objective: To present a definition of geo-tomography, that is a discipline-branch concerned with the 2D or 3D display and quantitative analysis of the various structure earth-interior by its physical and chemical parameters. This term may be not so familiar in earth-science glossary, it embodies on the following sub-branches:seismic tomography, resistivity tomography, MRS tomography, fracture-plane imaging for seismic focus and image of GPR(ground penetrating radar). Above exploring method can be used to find potential active faults and seismogenic zones which are used to estimate seismic risk, get a reasonable prevention seismic intensity, and ensure safety of high buildings, big bridges, great dam and dikes(for flood disaster reduction).MRS serves in detecting groundwater and drought-resistant. Conclusion: The achievement of geo-tomography presents higher resolution image, serves for the monitoring for magma chamber in volcano regions,and mitigates eruption disaster. The earthquake prediction methods in the future would call for less dependence on past earthquake records and more reliance on improvements about seismogenesis process. The improvement of 3D image display of underground physical parameters (including velocity,density,temperature, elastic & viscosity parameters, absorbing quality factor Q-value etc.)should combine with MRS tomography image, for exploring underground material-transport and its dynamic process, getting higher resolution, that will provide higher quality forecast method, serving in estimating the seismic risk and the possibility of volcano eruption. mitigate the natural disaster.

Development of Accelerated CT Reconstruction Based on General Graphics Boards

CHEN Zhi-qiang, WANG Xu, ZHANG Li, XIAO Yong-shun

2004, 13(2): 11-20.

Abstract(660) PDF(4)

Abstract:
Objective: The technical application of general graphics boards in CT accelerated reconstruction is summarized. Methods: Introduce the current technique of graphics boards, and the principle of how their special structure operates in accelerating reconstruction. Results: Analyze the method and character in the use of graphics hardware to accelerate reconstruction. Conclusion: According to the latest technique of graphics boards, we introduce the way to improve the application of graphics boards in reconstruction,together with the prospect in this research.

Design and Implementation of Control System of the γ-Ray Security Inspection Device

SHEN Jian-hua, SHAO Li-kang, DING Hou-ben, WANG Hua, XU Xiao-ming, XU Ming-zhong

2004, 13(2): 21-23.

Abstract(972) PDF(3)

Abstract:
The principle and design implementation of the γ-Ray security inspection device control system is detailedly presented.The system can be operated stably and respond rapidly, and has a good capability of anti-jamming.It has a preferable value of use.

Three Dimensions Reconstruction of CT Image by MATLAB

ZENG Zheng, DONG Fang-hua, CHEN Xiao, ZHOU Hong, ZHOU Jian-zhong

2004, 13(2): 24-29.

Abstract(1116) PDF(14)

Abstract:
Three dimensions reconstruction of CT image gives a intuitionistic image of body. It is convenient to observation and operation. But it is difficult to those people not major in computer. In order to solve this problem, how to reconstruct of CT image using image processing toolbox of MATLAB6.5 is discussed. MABLAB gives us a convenient method to reconstruct and acquires a good result. It can be mastered by anybody.

Digitized X-ray Imaging Technique

XI Yan-ping

2004, 13(2): 30-32.

Abstract(523) PDF(1)

Abstract:
X-ray technique is one of the most important and newest techniques in the medicine image area,this text briefly introduced X-ray the actuality of X-ray image technique,and expound The theory and stamps of Separate&direct X-ray image technique.

To Analysis The Chest X-ray Character of SARS

SONG Fu-jing, TONG Jing, JI Zhi-min, ZHANG Bo, JIANG Guo-lin, ZHANG Guang-ping

2004, 13(2): 33-36.

Abstract(597) PDF(0)

Abstract:
Objective To explore the X-ray characteristis of SARS. Methods To assay the chest X-ray and the CT images of SARS about 39 cases, who have been comfirmed diagnosis in clinical. Results Patches, styipes and ground-grass opactification were found on chest X-ray of SARS. Dynamic observation, the local changes fasting and wandering, ground-glass density and air-space opacities are present in CT images. Conclusions The X-ray and CT images of SARS have some characteristic. Couldn't diagnose only by these, but also combinate the epidemiologic, the clinical laboratory examinations and the X-ray examinations to synthetic diagnose.

Clinical Application of Multi-Slice CT Virtual Intravascular Endoscopy in Diagnosis of Arteriosclerosis

XIANG Zi-yun, ZHU Ping-xian

2004, 13(2): 37-42.

Abstract(603) PDF(0)

Abstract:
Objective To investigate manifestations of the multi-slice CT Virtual Intravascular Endoscopy (MSCT-VIE) in the arteriosclerosis and it's diagnostic value. Methods 40 cases in normal group and 24 cases of arteriosclerosis group were performed volume scan with SIEMENS Sensation 4 MSCT, Then the raw data was reconstructed with lowly kernel(kernel ≤ 30f) and thin slice (slice ≤ 3mm), and transmitted to CT 3D workstation, All images post process were performed by computed tomography virtual endoscopy (CT-VE), Multiplanar reconstructions(MPR), Maximum intensity projection(MIP) and volume reconstruction technique(VRT) software, The manifestations of lesions vessel of MSCT-VIE were analyzed and recorded. Result Among 64 cases, 24 cases of 78 lesions of calcifications, 24 cases with irregular inside wall and thicken of vessels; 21 cases with blood vessel stenosis; 15 cases of 48 lesions with atheromatous spot mass. conclusions the multi-slice CT Virtual Intravascular endoscopy was a valid method to diagnose arteriosclerosises, which was very rapid and noninvasive.

The Application of CT Original Data

LIU Qi-ze, LIU Guo-rui

2004, 13(2): 43-45.

Abstract(568) PDF(2)

Abstract:
Objective: The application of CT original data in the reconstruction was discussed in this article. Methods: The CT images of 10,000 patients, using PHILIPS TOMOSCAN.AV.EPPLUS CT machine, were taken into concern, and the scan positions were including lung, liver etc. More than 200 of them, which have some quality problems in their images, were discussed in this article and these problems were solved using the reconstruction of their original data. Results: The quality of the images were improved after the reconstruction of their original data. Conclusion: The reconstruction of CT original data can improve the quality of the CT images and will be helpful for diagnosis.

The Application of High Pressure Injector in CT Contrast Enhancement

ZHANG Yuan-fang, LIU Guo-rui, FANG Wen-hui, GUO Yue-lin, LI Yang-kang

2004, 13(2): 46-50.

Abstract(513) PDF(2)

Abstract:
Objective Discuss the application of high pressure injector in CT Contrast Enhancement. Methods 2338 patients underwent CT Contrast Enhancement using high pressure injector.300 patients underwent CT Contrast Enhancement by manual injection were also studied as contrast group. All the patients had negative iodin allergy test results before the examination. The inject speed is 2-3ml/s for adult,and it's 0.5-1.5 ml/s for neonates. The dose of contrast media is 50-80ml for adults; and it must be calculated by the weight for neonates. Results In high pressure injector group, 4 cases had severe allergic shock, which occupied 0.17%; 27 cases had moderate reaction, which occupied 1.2%; 56 cases had mild reaction, which occupied 2.4%; and 9 cases were failed to inject, which occupied 0.34%. In manual injection group, 1 case had allergic shock, which occupied 0.17%; 5 cases had mild reaction, which occupied 1.6; and displacement of contrast media didn't happen in any case. Conclusion With the increase of the inject speed of contrast media, the quality of the CT imagine will be improve, but the side effect will be improve too. So the inject speed must be seriously considered according to the age, examination position, and the situation of the patients.

Analysis on CT Misdiagnosis of Gallbladder Carcinoma

YI Dong-sheng, HE Yu-mei, WANG Hong-bing

2004, 13(2): 51-53.

Abstract(721) PDF(0)

Abstract:
Objective To analyse the CT misdiagnosed causes of gallbladder carcinoma. In order to improve diagnostic state. Methods 43 patients with the gallbladder carcinoma were examined by computed tomography (CT), 23 of them were misdiagnosed. The misdiagnosed causes were analysed and compared with CT images operation. Results: In the case of misdiagnosis they were diagnosed as acute and chronic cholecystitis in 5; gallbladder polyp in 1; bile duct carcinoma in porta in 2;bile duct carcinoma in 1; neoplasm of distal part of common bile duct or ampulla in 3; carcinoma of head of pancreas in 5;cholangitis in 1; jaundice of obstruction in 2; turgescence of gallbladder in 2; carcinoma of colon in 1. Conclusion: To be aware of CT characters of gallbladder carcinoma and the way of metastasis is useful to avoid misdiagnosis of the gallbladder carcinoma and to improve the diagnostic accuracy.

Correlation of CT Findings of Acute Pancreatitis with Changing of Serum and Urine Amykase

ZHOU Le-fu, XIANG Zi-yun

2004, 13(2): 54-56.

Abstract(544) PDF(0)

Abstract:
Objective: To evaluate the relationship between CT findings and the changing of serum and urine amylase in diagnosis of acute pancreatitis. Methods: 63 cases with acute pancreatitis were divided into five grades based on CT findings,and the CT grading relevant to the serum and urine amylase were analyzed. Results: The serum and urine amylase increase slightly or moderately in grading A, moderately in grade B, markedly in grade C, but tended to decrease in grade D, and decreased dramatically in grade E. Conclusion: CT examination is superior to the serum and urine amylase in evaluation of acute pancreatitis with B, C, D and E. But for grade A, accurate diagnosis should be made based on CT findings combined with the changing of serum and urine amylase.

Diagnostic Value of Conventional CT in Hyperacute Cerebral Infarction Compared with MR(DWI)

ZHU Jun, WANG Xiang

2004, 13(2): 57-59.

Abstract(536) PDF(0)

Abstract:
Objective To discuss the diagnostic value of conventional CT in hyperacute cerebral infarction. Method: The CT feature of 28 cases of hyperacute cerebral infarction were compared with their MR(including DWI) signs. Result: 24 cases showed hypodensity of lengtiform nucleus on conventional CT, while local brain swelling were found in 11 cases, hyperdense middle cerebral artery sign 6 cases. All cases were found abnormal on DWI. Conclusion: The conventional CT were of certain value for the diagnosis of hyperacute cerebral infarction.

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2004 Vol. 13, No. 2