ISSN 1004-4140
CN 11-3017/P

2010 Vol. 19, No. 3

CT Theory
On the 2D Fan-beam CT Reconstruction from Insufficient Projection Data
LIANG Wen-xuan, HU Guang-shu
2010, 19(3): 1-12.
Abstract(1456) PDF(2)
CT reconstruction from insufficient data is important in many medical and other applications.Recently to solve this under-determined problem,the Total Variation minimization method has regained popularity due to the newly-emerging compressed sensing theory.In this paper TV-minimization is extended to a more general framework for CT reconstuction from insufficient data.The framework proposed is also based on the compressed sensing theory,but is more flexible and amenable to various applications.Analysis and simulations are conducted for an initial special case and promising results are achieved.
Image Reconstruction in Tomosynthesis by Wavelet Galerkin Method
LU Xiao-qiang, BAI Gang-feng, SUN Yi
2010, 19(3): 13-23.
Abstract(1044) PDF(1)
In tomosynthesis,projection data are acquired from limited view angles,which is a severely ill-posed inverse problem.Based on the model of tomosynthesis,the system equation is presented.After regularizating the system equation,an adaptive wavelet Galerkin method is proposed to reconstruct images in tomosynthesis.The method combined the numerical simplicity of Galerkin method with the inherent scale multiplicity characteristic of wavelet which is more adaptable to the resolution of the reconstructed image.Compared to the ART reconstruction,the results demonstrate that the reconstruction strategy has comparable performance with the improvement of the convergence speed and the reduction of computational time.
A Set Method Simulation of Lower Level Discriminator in Small Animal PET Based on GATE Toolkits
WANG Yi, YANG Bo, WEI Qiang-lin, LIU Yi-bao
2010, 19(3): 25-32.
Abstract(1168) PDF(0)
Scattered coincidences could be harmful to the quality of the image reconstruction.The lower level discriminator can decrease the proportion of scattered coincidence counts.This paper is to validate the effect of the lower level discriminator on the coincidence counts.GATE(geant4 application for tomographic emission) was used to find the best value of the lower level discriminator by modeling the Eplus-166 PET scanner developed by IHEP(Institute of High Energy Physics) in China.It is found that the value of the threshold should be set properly due to the size of the creature to be scanned.Compared with the experiment data,to simulate PET with GATE is practicable.
Overview of Nonuniform Fast Fourier Transformation
XUE Hui, ZHANG Li, LIU Yi-nong
2010, 19(3): 33-46.
Abstract(1546) PDF(12)
Nonuniform fast Fourier transformation(NUFFT),as an efficient method for irregular sampling problem,is widely used in signal processing.This article gives a review of the history and development of NUFFT,followed by a detailed depiction of the general scheme of the algorithm.The newly improvements in the past few years is also discussed.Finally,it is shown that NUFFT performs well in CT reconstruction,such as Fourier reconstruction,iterative reconstruction and sparse sampling problems.
3D Velocity Structure in Shanxi Graben and Ordos from Two Plane Waves Method
LI Peng, ZHOU Shi-yong, CHEN Yong-shun, FENG Yong-ge, JIANG Ming-ming, TANG You-cai
2010, 19(3): 47-60.
Abstract(1183) PDF(1)
Using the broad-band seismic data of Peking University and CENC,taking the method of two plane waves tomography,we have obtain the phase velocities of Rayleigh wave and the 3D shear velocities in Ordos region.Through analyzing the results,we have found the phase velocities of Rayleigh wave in Shanxi graben and Weihe graben are lower.High velocity anomaly beneath moho has been observed in Ordos block,indicate that Ordos block is a stable craton,and its effect extend to 120km depth at least;in the depth between 70 and 120km of Shanxi graben and Weihe graben,shear velocities were lower than origin model,indicating that the substance there had plasticity and these region are strong activity,which is consistent with the activity of earthquake.
Industrical CT
Edge Detection in the Tire X-ray Detection
FENG Xia, HAO Zhen-ping, FENG Yan, SHI Chao
2010, 19(3): 61-66.
Abstract(1117) PDF(2)
By using of X-rays having radial tire quality test is an important subject,through image processing and matching have tire quality testing is a complex system,edge detection is an important basis of image analysis for the image segmentation,textural and shape feature extraction.Through Matlab experiments compared different edge detection methods found suitable edge detection method in radial tire quality testing.
Medical CT
MSCT and X-ray: The Comparison of Clinical Value in the Diagnosis of Lumbar Spondylolisthesis
FU Chuan-ming, CHEN Yi-jia, CHEN Xue-qiang, CHEN Lun-gang, ZOU Jian-hua, WU Wen-qiang
2010, 19(3): 67-73.
Abstract(1042) PDF(0)
Objective: To evaluate the accuracy of MSCT and X-ray diagnosis of lumbar spondylolisthesis.Methods: 40 lumbar spondylolisthesis cases who received the operation after the plain X-ray film and MSCT examination.Contrast the degrees,positions and type of lumbar spondylolisthesis examined by X-ray film and MSCT with the operation result.Results: the operation result showed that 27 cases were true spondylolisthesis and 13 cases were false spondylolisthesis.Contrasted with the operation result,the accuracy of lumbar spondylolisthesis type and position examined by MSCT and X-ray is 100 %;predicted values of sensitivity specificity positive and negative results of the spondylolisthesis judged by plain X-ray film are 59.3 %,100 %,100 % and 54.2 % respectively.Predicted values of sensitivity specificity positive and negative result of the olisthy judged by MSCT are all 100 % in the four above-mention aspects.There is apparently statistical disparity between olisthy properties examined by X-ray and MSCT(P<0.01).Conclusion: Both X-ray and MSCT can examine the degrees and positions of lumbar spondylolisthesis accurately,and MSCT can judge the lumbar spondylolisthesis type more accurately than X-ray apparently.X-ray screening is still the basic method;MSCT can make a further definite diagnosis of the type and offer more valuable image information for clinical treatment.
Clinical Application of MR Angiography of Whole Lower Extremity Artery
ZHANG Yi, DENG Li-gang, JIN Er-hu, LIANG Yu-ting, GUAN Wei
2010, 19(3): 75-81.
Objective: To determine the role of three dimensional contrast-enhanced MR angiography(3D CE-MRA) in evaluating the peripheral arterial occlusive disease.Methods: 3D CE-MRA examinations of pelvic and whole lower extremity arteries were performed at 3.0 Tesla MR system in 43 symptomatic patients.Artificial subtraction of source images,reconstruction of maximum intensity projection(MIP) and pasting of three segments in the post-processing software were done step by step,and the vasculature trees of the whole pelvic and lower leg arteries with variable views were obtained.Results: 3D CE-MRA scanning and post-processing editing were successfully completed in 42 patients(98%),arterial vasculature was showed clearly and image was qualified for evaluating the disease.One examination failed due to poor cooperation and severe illness of the patient.Conclusion: 3D CE-MRA provided useful information in clinically diagnosing and managing the peripheral arterial occlusive disease.
On Using Low-does CT to Screen Primary Asymptomatic Lung Cancer
WANG Su, LI Zhong-kai, ZHANG Li-bo, MENG Song-wei, LI Peng, WANG Zhong-wei
2010, 19(3): 83-91.
Abstract(1146) PDF(0)
Objective: To utilize the method of low-does CT to reduce the exposure to X-ray,to reduce the radiation to the human body,to carry out the screening on primary asymptomatic lung cancer,to increases the screening rate,to realize the early diagnosis and treatment against disease and to increase the survival rate.It improves the situation that has been for a long time,in which the lung cancer attacks unnoticeably and is difficulty to be diagnosed.Method: To divide 500 cases having no symptom in the chest into two groups: smoking group and non-smoking group.Aided by employing the HRCT & Image Post-processing Technology in the local lesion,low-does scanning parameter was applied in increasing the screening rate of primary lung cancer.Result: 35 cases were confirmed to be carrying tubercle out of 500 cases,among which 6 cases were confirmed as lung cancer;7 cases as benign lesion(2 cases as hamartoma,2 cases as tuberculoma and 3 cases as inflammatory masses) while the remaining 22 cases were confirmed as negative tubercle.Besides,87 cases were confirmed as other types of lung disease(emphysema,bulla of lung,inflammation,obsolete tuberculosis,hydrothorax,pachynsis pleurae,etc.) and 378 cases are normal.The 6 lung cancer cases were given surgery,radiotherapy,chemotherapy,etc.respectively.Conclusion: The low-does CT,which can increase the screening rate and realize the early diagnosis and treatment against disease,is an effective method to detect primary asymptomatic lung cancer.
Solitary Fibrous Tumor: Computed Tomography and Pathological Analysis
BAI Yu-han, CHEN Jun, HUANG Ya-bing, MIAO Huan-ming, ZHA Yun-fei
2010, 19(3): 93-98.
Objective: To explore the CT manifestations and pathologic features of solitary fibrous tumor(SFT) so as to improve its diagnostic accuracy.Method: The clinical and CT signs and pathologic data of 3 patients with pathologically proved SFT were analyzed and the relative literatures were reviewed.Results: The patients with SFT were lacked of clinical symptoms or presented atypical symptoms due to the oppression of tumor.On CT images the lesion of three cases was large solid mass and the solid part of the mass was mild to apparent enhancement for two cases of the administration of contrast agent.SFT is the soft minors with well-defined margins and smooth contours.Conclusion: The value of CT diagnosis of SFT was limited.The diagnosis of SFT should be combined with history,clinical appearance.The final diagnosis of SFT was depended on the pathology and immunohistochemistry.
Imaging Diagnosis of Facial Nerve Neuroma
SHEN Li-hui, CHEN Xiao-bai, LI Bin
2010, 19(3): 99-106.
Abstract(1118) PDF(0)
Objective: To investigate the valve of diagnosis in imaging findings of facial nervetumors in the CT and MR.Methods: CT and MRI findings in 18 cases with pathologically-proved facial nerve neuromas were analyzed retrospectively.Results: All of 18 cases were detected(11/18 facial neuroma,5/18 facial neurofibroma and 2/18 facial hemangioma).Conclusions: HRCT and MRI are effective methods in detecting the lesions of f acial nerve.CT is better to demonstrate the osseous destruction in detail,and CE-MRI is easier to find small facial nerve lesions intracranially.Combined application of CT and MRI can improve the he diagnostic accuracy.
Clinical CT/MRI Analysis of Chronic Alcoholism Encephalopathy Caused by Alcohol Dependence
YU Hong-sheng, WU Ning-qiang, SHEN You-li
2010, 19(3): 107-116.
Objective: To analyze the clinical and imaging characteristics of chronic alcoholism encephalopathy(CAE) due to Alcohol dependence,to explore the clinical diagnosis value in the disease.Methods: A retrospective analysis of clinical and CT,MRI imaging data of 32 cases complete data in patients of CAE,its imaging features were concluded.Results: CAE is characterized by different degrees of nervous system damage(especially the central nervous system) and mental disorders;the brain damage mainly shows in CT,MRI: 27 cases of brain atrophy;7 cases of cerebral infarction;18 cases of white matter demyelization;3 cases of Wernicke's encephalopathy;1 cases of Marchiafava-Bignami disease;24 cases of multiple lesions coexist.Conclusion: a) It is the mainly pathological mechanisms in CAE occurred that alcohol use leading to brain vessels damage and nutrient metabolism disorder,brain tissue ischemia and hypoxia and nerve fiber demyelinationis.b) CAE imaging has its own characteristic,especially cerebellar vermis atrophy,Wernicke's encephalopathy and Marchiafava-Bignami disease is more characteristic,there were great significance in understanding the nature,scope and degree of brain damage by CT,MRI examination.It is an important basis in the clinical diagnosis,treatment and prognosis of evalulation.
CT Differentiation of Consolidative Bronchio-loalveolar Carcinoma and Pneumonia
HOU Rui, CHEN Xiao-bai, WANG Ren-gui, SUN Lei, ZHANG Chun-yan, DUAN Yong-li
2010, 19(3): 117-122.
Abstract(1214) PDF(1)
Objective: To investigate the value of CT image findings in differentiating diagnosis of bronchioloalveolar carcinoma(BAC) and pneumonia.Methods: Twenty-six patients of bronchioloalveolar carcinoma and thirty-six patients of pneumonia underwent chest scans with Siemens 16-slice CT.Image findings of consolidation,pseudocavitation,air bronchogram sign,leafless tree sign,crazy paving,ground-glass opacities,consolidation crossing lobe,bulging of fissure,atelectasis,CT angiogram sign,coexist nodule,lymph node,pleural effusion,pleural thickening were analysed.Results: Statistically significant(p<0.01) findings that were more often seen on CT scans of patients with consolidative BAC than on those of patients with pneumonia included low density of consolidation,pseudocavitation,leafless tree sign,crazy paving,ground-glass opacities,consolidation crossing lobe,bulging of fissure,CT angiogram sign,coexist nodule.Conclusion: CT may be helpful in differentiating consolidative BAC from pneumonia if image findings of low-density consolidation with pseudocavitation,leafless tree sign,crazy paving,ground-glass opacities,consolidation crossing lobe,bulging of fissure,CT angiogram sign,coexist nodule is shown on CT.
The Research of Comparision between Dual Source CT Air Enema Intestinal Examination and Capsule Endoscopy Small Bowel Examination
HUANG Yin-ping, SHEN Bi-xian, CHEN Sheng-ji, ZHOU Na, BAO Lian, CHEN Li-xing
2010, 19(3): 123-129.
Abstract(1274) PDF(0)
Objective: To evaluate the value of the dual source CT air enema intestinal examination in the diagnosis of small bowel diseases.Methods: 15 patients with suspected small bowel diseases underwent dual-source CT inspection before or after the capsule endoscopy within 3 days.Among them,8 males and 7 females,the oldest 42 years old,the youngest 23 years old.The major symptoms were abdominal pain in 10 cases,blood and pus stool in 4 cases,1 case of unexplained weight loss,the longest duration was 4 years and the shortest was 1 month.Results: Capsule endoscopy showed normal in 8 cases,dual-source CT examination were no exception.Dual-source CT diagnosed Crohn diseases in 4 cases,clinical diagnosis with capsule endoscopy were the same.Capsule endoscopy suspected tumors in 3 cases,but dual-source CT examination only found two positive cases,with diagnosis of benign and malignant,of which,confirmed by pathology,1 was jejunum stromal tumors,another was ileal adenocarcinoma.Only one case with 3cm size was suspected the tumor in capsule endoscopy,but in dual source CT was normal.Combined with MRI,and clinical history,the issue was proved to be false positive.Conclusion Dual source CT air enema intestinal examination could not only show the scope of the relationship with adjacent structures,and identify clinical inflammation and cancer lesions,and make the tumor differentiation of benign and malignant lesions.The examinations are also valuable for capsule endoscopy to confirm localization and scope of lesions,and rule out false positive.