ISSN 1004-4140
CN 11-3017/P

2005 Vol. 14, No. 4

Industrial CT
New Development of High Energy Industrial Computed Tomography (ICT)
CHEN Zhi-qiang, LI Liang, FENG Jian-chun
2005, 14(4): 1-4.
The new development of the research and industrialization for the high energy industrial CT(ICT) is introduced by Nuctech Company Limited.Some new achievements are discussed,including high-power linac accelerator,solid-state detector modules with high detection efficiency and fast reconstruction algorithm using rotating polar-coordinate backprojection.The successful research and industrialization advances the technology of Chinese high energy ICT,which makes china without our high energy ICT history and solves the problem of large workpiece nondestructive test.It is important to promote the technical level of high energy nondestructive test of our country.
Application of Morphology in X-ray Inspection Images
WANG Yue-hua, HAN Yan, CUI Qing-song
2005, 14(4): 5-9.
The purpose of this paper is to segment the image of the X-ray inspection.With the development of mathematical theory and the digital image processing technology,an effective segmentation method is introduced in the paper.It formulates and analyzes the advantages and disadvantages of traditional algorithms.The experiments show that this algorithm has good reality and gets the expected results.
CT Theory
Theory Analysis of Crack Defect in CT Image
AO Bo, ZHANG Ding-hua, ZHAO Xin-bo, XU Xia-gang
2005, 14(4): 10-16.
Due to the influence of other factors,it is difficult to analyze damage measurements of materials directly using CT image.In this paper,firstly,beginning from computing angle of mass attenuation coefficient of mixture.By analyzing the calculation principle of mass attenuation coefficient.Getting the other one equivalent expressing;The formula among density variations induced by microcracks.CT image value and volume percent of crack defects is obtained under service environment;finally obtained the formula between volume percent of crack defects and damage variable.This lay a theoretical foundation for material fatigue life prediction by using CT.
The Study on Methods of CT Image Enhancement
SUN Cun-jie, ZHANG Hong
2005, 14(4): 17-20.
The enhancement methods for CT Image were studied by means of the histogram equalization,median filtering and the wavelet transform..Experiment results indicate that the wavelet enhancement in this paper can reduce the amplification of noise and achieve an excellent balance between the enhancement of subtle image detail and the avoidance of noise amplification.The method was preceded with that of the histogram equalization and the median filtering.
Optimization of System Design for 64-slice Cone Beam Computed Tomography
Jiang Hsieh, Eugene Williams, Charlie Shaughnessy, Xiangyang Tang, Brian Grekowicz
2005, 14(4): 59-67.
The technology for x-ray computed tomography(CT) has experienced tremendous growth in recent years.Since the introduction of 4-slice helical scanners in 1998,rapid improvement has been made on CT scanners in terms of the volume coverage,spatial resolution,scan speed,and the number of slices.These advancements not only significantly impact clinical applications,but also bring huge challenges to the CT system design.Because of the complexity of the volumetric CT(VCT) system,various strategies have to be utilized in the design process.These methodologies include theoretical analysis,computer simulation for system performance prediction,bench-top experiments for analysis confirmation,automated image analysis tools for automatically evaluating image performance,and double-blind tests with human observers for parameter optimization.In this paper,we present some of the system design considerations and optimization processes for a 64-slice scanner.These design processes ensure the optimal performance of the cone beam CT scanner.Initial clinical feedback has demonstrated the effectiveness of our approach.
Papers on Medical CT
The Cerebralvascular Disease Diagnosis by using of 3D Reconstruction for MSCT Imaging
ZHU Qing-xiao, TONG Jing, GUO Xin-hua, LI Xue
2005, 14(4): 21-23.
Purpose: To evaluate the function of 3D Reconstruction for spiral CT imaging of cerebral-vascular disease. Method: The authors treated with 3D image reconstruction for 51 clinical cerebral patients after their brain enhanced CT scan and carry on the analysis,all examination using the GE Hispeed NX/I 2-slices CT scanner;transfer that image data to the work-station and carry on the 3D reconstruction.These images were examined by more than 2 radiological doctors,and analyzed. Results: In these 51 cerebral patients,there are cerebral normal 14 cases;pure-single variation 7 cases;others have the different degree cerebral-vascular changed to narrow(30 cases),Among them,the hybrid type narrow changed 12 cases;(more than two or contain two cerebral blood branch vessel narrow changed),the cerebral variation combined with cerebral vessel narrowing 5 cases,the cerebral one branch change to narrow down 13 cases. Conclusion: 3D image reconstruction for brain enhanced CT scan is an efficient examination method for cerebral-vascular diseases by using of spiral CT.
Feasibility of 16-slice helical CT Angiography with low dose Contrast Agent in the Lower Extremity
YAO Gang, SUN Jian-nan, LIU Ying, ZHANG Xiu-li, CHEN Xiu-mei
2005, 14(4): 24-28.
Objective To study the feasibility of 16-sice CT angiography with low dose contrast agent in the lower extremity. Materials and Methods Sixty-six patients with lower extremity 16-slice CT angiography were divided into 3 groups according to the dosage of contrast agent as follows:150ml,120ml,and 80ml.Each group was graded by using source image and MIP reconstruction for vascular delineation of lower extremity artery. Results The lower extremity artery in all groups were well delineated and there were also no significant difference statistically among the three groups on subjective graded scores.CT attenuation values in the artery were high,and with no significant difference among three roups. Conclusion It is feasible to use low dose contrast agent with 16-slice CT angiography in low extremity.
MRI Diagnosis of Cerebella Astrocytoma
XU Peng-jun, XU Yi-kai, DAI Lin
2005, 14(4): 29-32.
Objective To investigate the MRI finding of cerebella astrocytoma and to improve the diagnosis ability for this disease. Methods The MRI findings of 31 patients verified by surgery and pathology were analyzed retrospectively. Results Among 31 cases of cerebella astrocytoma,there were solid type in 7 case,tumor in cyst type 10 cases,cyst in tumor type 13 cases.In addition,1 case represected absolute cyst type.All cases were in company with obstructive hydrocephalas. Conclusion MRI findings of cerebella astrocytoma are characteristic and contrast-enhanced scan was helpful in detection of the lesion and characterization of the disease.The disease can be preoperatively diagnosed,but it should be differentiated from hemangioblastomas,medulloblastoma,ependymal tumor,metastasis.
Application of Multi-slice Spiral CT in the Diagnosis of Moyamoya Disease
LI Jiang-shan, LI Shao-dong, CHENG Guang-jun, XU Kai
2005, 14(4): 33-37.
Objective To evaluate the value of 16-slice Spiral CT angiography(M empirical study of SCTA) and reconstruction in the diagnosis and therapy of moyamoya disease. Material and methods 15 patiants with moyamoya disease were examined both with routine CT scanning and MSCTA,all performed Volume Rending(VR)、Maximum density projection(MIP) and Multiplanar reconstruction(MPR) with ADW4.2 software. Results In all cases CTA showed the stenosis or obstruction of arteria carotis interna(ICA) or proximum of Wills circle,abnormal vessel network in brain basal part.Including stenosis of bilateral ICA(6cases),one side ICA and posterior cerebral artery(1 case),one side middle cerebral artery(8 cases).The branch vessels could been evaluated with CTA images.VR was better on showing the stenosis of the vessels and its spatial relation with surrounding bone structure,MIP and MPR was better on showing abnormal vessel network in brain basal part and branch vessels. Conclusion With different reconstruction,MSCTA can display the abnormal vessels and spatial relation very well,and provide important reference for the therapy.
Diagnosis and Distinguishing Value Of Multislice CT In Fatty Liver of Limitation
ZHUO Guo-ran, SHI Yan, CUI Bing-di
2005, 14(4): 38-40.
Objective: To study the valave on diagnosis and distinguishing t diagnosis of the fatty liver of limitation. Methods: 43cases fatty liver of limitation were proved by puncture and treatment,the plain and enhanced CT was analysis their shape density and distribution。 Results: Most of the cases were distributed by the leaf and the part 44%、26%。In 43cases lights 9(21%),middle 23(56),heavy 11(23%),all diseases were sheet and the vessels shows clear whitout occupying-effection. Conclusion: Multislice CT is of great valave in the diagnosis and different diagnosis of the fatty liver of limitation
CT Diagnose Nasal Non-Hodgkin Lymphoma
LI Xiao-yang, MA Ju-wen, HU Wen-jian
2005, 14(4): 41-44.
Objective: To disicus CT value on the N-NHL. Methods: 7 cases of the N-NHL,male 5 cases,female 2 cases.all have done scaning of CT axis and coronal. Result: N-NHL display of CT: Tumour on the nasal cavity,bone destroy on the nosepiece,and the same display on the border upon frame. Conlusion: Tumour on the nasal cavity,bone destroy on the nosepiece and he border upon frame,N – NHLshould be hinted.
Geo-Tomography & Stereology
Multi-dimensional Stereological Methodology and Its Value in Geosciences
GUO Lü-can
2005, 14(4): 45-49.
Multi-dimensional Stereological Methodology is developed from the research in medical CT and MRI-scanner to display the computerized tomography images for human and animal body,which be used for research in anatomy physiology structure,pathologic characteristic,its theories and methods expansion and application in another science branches,such as the research for industry apparatus and underground structure...etc;Make use of the valid method to research the factors of paroxysm physiology structure,pathologic characteristic,these theories and techniques expensing to many branches;This work may develop the comprehensive predication method,refer to clinical CT application,combined to study the disease control factor,to distinguish the original paroxysm and expect following time-interval,find the precursor of the terminal disease,generalized as " multi-dimensional stereological predication method”,and deducing out a kind of the epistemological method.,which may be contributed to the research of earthquake's pregnancy(seismo-genic structure),and for the prediction of strong earthquake occurrence and volcano’s eruption estimation.
Advanced CT Information
New Advances of Multislice Spiral Computed Tomography
TONG Shuang-li
2005, 14(4): 50-53.
To discus the new advances in hardware and software technology of Multislice Spiral Computed Tomography(MSCT),to introduce clinic application of Multi-slice Spiral Computed Tomography in cardiac imaging,lung imaging,perfusion imaging,angiography imaging and emergency salvage.
The Meaning and Function of CT Science and Technology in Economy Development
GUO Xin-qu
2005, 14(4): 54-58.
Purpose: To elaborate the importance of CT science and technology play a important role in China economic development,summarize and analyze the relevant technique of CT in medical science,industry,geophysics and geology etc.examine realm of the application and the development present condition.Combining the technical new progress of Chinese CT industry in recent years have an important position in the domestic and international market. Conclusion: CT technology play an important role in development of Chinese economy;The industrial CT Technology of China is one of the advanced part in the world,play a competition role in that field.