CT理论与应用研究

2013, 22(1): 10-14.

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2013, 22(1): 23-32.

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An Integrated Algorithm of Image Pre-processing and Post-processing in Thermal Neutron Computed Tomography(n-CT)

MI De-ling, ZHANG Ai-min, WEI Biao, FENG Peng, REN Yong

2013, 22(1): 15-24.

Abstract(1749) PDF(5)

Abstract:
As a kind of extremely important nuclear imaging technologies,thermal neutron CT imaging technology can carry out Non-destructive testing and Non-destructive evaluating of detected samples.Based on a series of factors that lead to image degradation in the thermal neutron CT imaging process and the discussion of that,we present an integrated processing solution and developed a set of analytical software which investigating the image Pre-processing and post-processing technology based on MATLAB GUI integrated processor.The results of the research show that,the solution can effectively improve the thermal neutron CT images quality.These not only provide reliable guarantee for Non-destructive testing and evaluating,but also provide some reference value for thermal neutron CT imaging technology.

Soft Soil Uniaxial Consolidation Experiment with CT

MAO Ling-tao, ZHAO Dan, YUAN Ze-xun, ZHOU Kai

2013, 22(1): 33-40.

Abstract(1373) PDF(1)

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In this paper,the marine sediment soft soil of Beigangchi Wharf in Tianjin Port was scanned by Computer Tomography(CT) in different load during uniaxial consolidation experiment.With the CT images,the soil characteristics during consolidation were analyzed.The results show that:with the pressure growth,the average grey value of the CT images increases gradually,which indicates that soil samples are compacted and the density increases.During consolidation,the pore-water pressure dissipation leads to the structure change in the soil,which makes different trends of CT image grey standard deviation for different kinds soil.Grey compression coefficient is introduced to evaluate the soil compressibility.According to the changes of grey compression coefficient,it is illustrated that the soft soil of Beigangchi Wharf in Tianjin Port has high compressibility.

Simulation Study on Pulse Compression by Bi-phase Coded Excitation with Carrier Modulation

WU He-zhen, LIU Zheng-yi

2013, 22(1): 41-51.

Abstract(1329) PDF(1)

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In order to introduce the digital encoded technology to the seismic detection,the author studied coded excitation digital simulation and grasped the rules and characters of coded excitation,which is based on the basic coded excitation principle.By modulation launching of coded excitation signal,the author also did simulation research on pulse compression of received signal.Furthermore,the author processed pulse compression with 13 bit signal excitation transducer with one to five units code element(by launching of 13 bit signal excitation transducer with one to five units code element).The author did the power spectrum analyses and analyzed the influence on different excitation signal and its pulse compression result by transducer.

TEM in Leimengou Molybdenum Ore Exploration Application Effect Analysis

HAN Jing-long

2013, 22(1): 53-60.

Abstract(1324) PDF(1)

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Leimengou molybdenum ore belongs to the breccia type molybdenum deposit,its occurrence,from inside to outside for breccia molybdenum ore-breccia-normal rock,ore body boundary is not clear,the surface is not exposed.Breccia and rock resistivity difference is apparent,geophysical prospecting method in the region has a physical property.Transient electromagnetic method in the area of application,obtained better result,established the geological geophysical model for rational arrangement of exploration engineering,provides the basis for molybdenum.This paper introduces the transient electromagnetic method based on the principle of thunder,molybdenum ore exploration as an example,the focus of the technique data processing,data interpretation,application effect and some technical problems in some analysis author.

Visibility Histogram Based Transfer Function for 3D Visualization of Heart

GU Chong, YANG Xin, YAO Li-ping, XUE Hai-hong, SUN Kun

2013, 22(1): 61-73.

Abstract(1534) PDF(1)

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Transfer function is an important tool for direct volume rendering of 3D visualization of heart. However, the complexity of heart structure makes the design of transfer function a difficult task. In this paper, we introduce visibility histogram based transfer function to display the cardiac dual source CT data. We first preprocess the cardiac dual source CT volume data and afterwards explore the transfer function based on visibility histogram. Furthermore, we propose the automatic method to design the transfer function. With these methods, users can highlight the region of interested and even observe more details of cardiac chamber. Finally, we accelerate the calculation and 3D rendering using the technology of CUDA, thus leading to the real-time dynamic display of three-dimensional volume data. The experiments show that the proposed method can effectively remove the ribs, pulmonary veins in cardiac dual source CT data, enhance the myocardial tissue, blood and some internal structures such as the aortic valve, which is of great importance for cardiologists in clinical diagnosis.

A Method for Image Bipolar Detail Decomposition Based on the TV/L2 Model

WANG Lin-yuan, TONG Li, YAN Bin, HU Guo-en

2013, 22(1): 75-83.

Abstract(1263) PDF(1)

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The Total Variation (TV) minimization method based on TV/L2 model is affected by the regularized parameter in image decomposition, This paper suggests that when the value of the chosen regularized parameter is small and different from classic methods, the property of the decomposed image will have an important change. According to this, a new method for image bipolar detail decomposition based on the TV/L2 model is proposed in this paper. The new method can decompose an image into an approximate image and two detailed images with different properties, when the value of the regularized parameter is small. Applying the decomposition model to Printed Circuit Board (PCB) CT images, we found that by combining the information in the detailed images, an enhanced image with metallic artifacts being effectively reduced can be acquired.

Optimization of Filter Function in CT Image Reconstruction

HU Jun-jie, MA Chen-xin, YAN Bin

2013, 22(1): 85-92.

Abstract(1472) PDF(7)

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FBP is the most popular analytical algorithm used to reconstruct image in CT system.The filtering process before back projection plays an important role relate to the image reconstruction quality.Usually the filtering function is acquired by Ramp function multiplying a rectangular window;however the ideal rectangular window will lead to a rough reconstruction result because of Gibbs artifact.According to the theory of infinite series,the arithmetic average named Fejer-core can be abstained after the function is expanded to the form of part sum.The core function has superiority convergence property.So to avoid Gibbs phenomena,the paper advances an improvement filtering method.Experiment result shows that Gibbs is avoided when convolve the filtered projections with Fejer-core.So smooth image can be obtained.

Intravenous Leiomyomatosis with Inferior Vena Cava and Right Atrium Extension

LIANG Yu-ting, YANG Han-qing, KONG Ling, JIN Er-hu, HE Wen

2013, 22(1): 93-99.

Abstract(1250) PDF(3)

Abstract:
objective:Exploring the clinical,radiologic features of uterine intravenous leiomyomatosis(IVL) to promote awareness of the disease.Methods:3 cases of IVL with inferior vena cava and right atrium involvement were retrospectively analyzed.Results:Among the 3 patients,2 had previous hysteromyomectomy history,one is first onset.Two patients went to hospital because of lower extremity edema and nocturnal dyspnea,and one due to hydronephrosis.CT scan found huge abdominal and pelvic masses with lobulated surfaces and multiple nodular enhancements,meanwhile increased and widen pelvic veins were visualized with tumor thrombus formation and extending from the internal iliac vein into common iliac vein and then the inferior vena cava.In one case the tumor thrombus even spreads into the right atrium and causes liver congestion.Conclusion:IVL is a rare variant of uterine fibroids with different characteristics of incidence,imaging findings and course.The tumor may spread from pelvic veins upward to the inferior vena cava or even right atrium causing threat to patient's life.It is important to raise the awareness of IVL.

Application of 64-Slice Spiral CT Angiography in Uterine Arteriovenous Malformation

XIA Hong, YI Jian-hua, XU Yan, YANG Li, HE Yuan-li

2013, 22(1): 101-106.

Abstract(1239) PDF(1)

Abstract:
Objective:To explore the value of 64-slice spiral CT angiography in uterine arteriovenous malformation(UAVM).Methods:The image data of 64-slice spiral CT scanning was obtained from two patients with UAVM.Two-dimensional and three-dimensional reformation were performed in all cases including coronal multi planar reconstruction(MPR),maximum intensity projection(MIP),volume rendering(VR).Results:The 64-CTA reconstructed pelvis,common iliac arteries,the internal iliac arteries,the external arteries and their branches was clearly showed.The basic anatomic structure of UAVM was tumor-like dilatation of the vascular sac reconstructed images.The spatial relationship and illustrated feeding arteries and drainage veins could be fully illustrated.Conclusion:64-slice spiral CT angiography can accurately diagnose UAVM.It could provide clear and stereoscopic image data for clinical diagnosis and treatment.

The Value of High-Pressure Syringe Constant Speed Automatic Injection in Hysterosalpingography

ZHANG Fu-kang, MA Jun, LIU Qing-ping, ZHANG Li-yun

2013, 22(1): 107-113.

Abstract(1423) PDF(1)

Abstract:
Objective:To investigate the value of high-pressure syringe constant speed automatic injection in hysterosalpingography(HSG).Methods:200 cases with infertility,were ivied into two groups including experimental group(n = 100) and control groups(n = 100) according to different injection methods of hysterosalpingography.The experimental group was underwent high-pressure syringe constant speed automatic injection,while the control group underwent traditional manual injection.Results:96 of 100(96%) in the experimental group can be observated dynamically the contrast agent flow into the uterus and the fallopian tube,and be made correct diagnosis.Only 6 of 100(6%) in the control group can be made correct diagnosis of unilateral or bilateral fallopian tubes obstruction.Other 96 cases in the control group cannot be observated dynamically the contrast agent flow into the uterus and the fallopian tube and cannot be made correct diagnosis.In the experimental group,medical personnel can be free from the radiation damage,while the medical personnel are unavoidable damage from the radiation damage.Conclusions:With the application of high pressure injector constant speed automatic injection,hysterosalpingography and injection therapy can be safer,more convenient,more effective state.It can improve the gynecological clinic level in this field and is suitable for clinical widespread application(especially in primary hospitals).

CT Image Feature Analysis of Pulmonary Sclerosing Hemangioma

WANG Ke-li, LI Meng-ying, LIU Guan-fu, LIU Xiao-feng, JIANG Yan, LI Zhi-yong

2013, 22(1): 115-120.

Abstract(1215) PDF(1)

Abstract:
objective: To study the CT feature of pulmonary sclerosing hemangioma (PSH), and improve the diagnosi's accuracy and differential diagnosis of PSH by CT scanning. Methods: The CT images of 18 PSHs confirmed operation and pathology were retrospectively analyzed, and 11 cases followed enhanced CT scanning. Result: It is very difficulty in preoperative diagnosis and main group of PSH is middle-aged women. Of those 18 cases, female were found in 17 cases (17/18, 94.44%), and patients aged in 43-70 years were found in 15 cases (15/18, 83.33%) and whose tumors were located in the left lower lung zone accounted for 50.00%. The tumors were round with clear edge (18/18, 100/%), were slightly lobulated (3/18), had punctate calcification (6/18, 33.33%), and had mediastinal lymph node (1/18). All cases were without cavity, pleural sag and metastasis, and vascular incisura. The CT values of observed cases were between 26-40 Hu. Among 11 cases followed enhanced CT scanning, 10 cases showed obvious enhancement and delay enhancement to a degree, and the CT values were increased over 46-60 Hu. Conclusion: The CT scanning is helpful for the diagnosis of PSH. Enhanced CT could be helpful to diagnosis,

Reduced Contrast Dose CTPA in the Feasibility Study

FU Chuan-ming, ZHANG Hai-bo, CHEN Lun-gang, XU Lin, WANG Kai-hua, WU De-hong

2013, 22(1): 121-127.

Abstract(1401) PDF(1)

Abstract:
Objective:by comparing the image quality,reduce the dosage of contrast agent in pulmonary CTA(CTPA) in clinical application.Materials and methods:using Siemens 64 rows of 128 layer spiral CT,60 cases of clinically suspected pulmonary embolism(PAE) were randomly divided into A,B,C 3 group(n = 20),group A:contrast agent 60 mL + 40 mL saline,group B:contrast agent 30 mL + 40 mL saline,group C:contrast agent 20 mL + 40 mL saline,the other scanning parameters were identical,the contrast agent tracking automatic triggering scanning.Will obtain the original data to the workstation,by 1imaging department deputy chief physician and chief technician,in the axial position measurement of pulmonary artery trunk,left,right pulmonary artery from the descending branch of right pulmonary vein and left,CT value,and the vascular enhancement degree,evaluation of recombinant vascular branches.Results:A,B,C 3 group in the pulmonary trunk,left,right pulmonary artery from the descending branch of the average CT values are:(513.20 Hu,504.34 Hu,509.54 Hu),(498.14 Hu,497.43 Hu,499.63 Hu),(486.31 Hu,489.45 Hu,491.49 Hu),the difference between the 3 groups was not statistically significant(P ＞ 0.05),3 groups of left,right pulmonary vein average CT values are:(235.41 Hu,176.31 Hu,119.91 Hu),(241.01 Hu,169.52 Hu,129.54 Hu),difference has statistics significance(P ＜ 0.05),between groups of pulmonary arteriovenous is statistically significant(P ＜ 0.01);recombinant lung vascular definition and branch vessels showed no significant differences(P ＞ 0.05).Conclusion:a small dose of contrast agent(20 mL/time) in CTPA is feasible,not only reduces the contrast agent(CM) on patients of potential hazards,and save the cost of examination.

Further Understanding of CT Features of the Femoral Neck Herniation Pits

LI Hong-jiang, ZHOU Yu-feng, XIA Gan-lin

2013, 22(1): 129-135.

Abstract(1229) PDF(3)

Abstract:
Objective:To improve the understanding of CT appearance of herniation pits of the femoral neck.Methods:The CT characteristics of 125 patients of herniation pits of the femoral neck were retrospectively analyzed.Results:During the 125 patients,lesions were only located in right femoral necks in 51 cases.33 cases of lesions only involved left femoral necks and 41 cases bilateral femoral necks were involved.218 lesions were determined during the 125 patients,including 72 solitary cases and 53 multiple cases.During the 218 lesions,121 were located in the right femoral necks and 97 in left.Lesions about 98% were located in the anterior lateral quadrant of base of femoral head and the near-end of femoral neck.The most of lesions were round or oval and all lesions were surrounded by thin clear sclerotic rims.39.4% of the lesions had crack-like cortical bone defects.The greatest diameter of the lesions was in the range of 0.3 cm to 3.0 cm.83.9% of the lesions were less than 10 mm in greatest diameter and 16.1% bigger than 10mm.CT appearance of the lesion showed that the soft-tissue density,fluid density and fat density were 17.9%,10.5% and 17.9% separately.During 6 months to 4 years follow-up study,it was found that most of the lesions without changes except that a little lesions increased in volume.Conclusions:Herniation pits of the femoral neck can be easier diagnosed by the multilayer spiral CT than by X-ray film.

Application Study of 256 Multidetector-Row Computed Tomography Enterography (MDCTE) in Small Bowel Diseases

DOU Ya-fang, TANG Ying, XIE Qian, ZHU Quan-dong, ZHU Rui-jiang, LIANG Zong-hui

2013, 22(1): 137-146.

Abstract(1202) PDF(1)

Abstract:
Purpose:To discuss the utility of MDCTE for evaluating diseases of the small bowel.Materials and methods:At our institution,118 patients(male 53;female 65;mean age 48.5 years) with symptoms of suspected small bowel diseases underwent 256-MDCTE.Pertinent MDCTE and histopathology reports were reviewed.The CT appearances characteristic of small-bowel tumor,inflammatory bowel disease and other conditions affecting the small bowel are described and illustrated in detail.Associated complications and extraenteric manifestations also are described.Results:Of 118 MDCTEs performed,the sensitivity,specificity,positive and negative predictive values and accuracy of visual assessment for small bowel disease were 78.87%(56/71),100%(47/47),100%(56/56),75.80%(47/62),and 87.29%((56 + 47)/118),respectively.Conclusion:Our results demonstrated that MDCTE with oral and intravenous contrast is useful in assessing small bowel diseases;however,further studies are needed to determine and validate the full diagnostic and clinical potential of bowel imaging at MDCTE.

CT Dynamic Analysis of Multiple Traumatic Pulmonary Pseudo-cysts

DING Zhang-qing, SUN Ying-ying, DING Ai-lan, ZHANG Yu-na, WANG Wen-sheng, WANG Chen

2013, 22(1): 147-154.

Abstract(897) PDF(1)

Abstract:
Objective:To investigate the CT findings and follow-up variation of multiple traumatic lung pseudo-cysts.Methods:The data of 30 cases of multiple traumatic pseudo lung cysts confirmed by clinical and imaging follow-up were retrospectively analyzed.Results:Most cases combined with pulmonary contusion,rib fractures,hemopneumothorax.Traumatic pseudocysts in all cases are multiple,an average of 4.6 lesions,size:4mm ×6 mm~13.5 cm × 6.2 cm.First CT examination from 1 hour to 5 days after trauma,and were followed up for 1 day to 15 months,with an average of 4.3 months.The first CT may show multiple simple hematoma,pulmonary contusion merging with multiple hematomas,pulmonary contusion merging with balloon cyst or liquid cyst,multiple airbags cyst or gas cyst.The hematomas lesions near pleural may appear airbag changes again due to hematoma rupture or delayed pneumothorax by rib fractures or other reasons.In the follow-up CT,the simple hematomas may contain with gas or without gas,the rest of the gas-containing lesions may become smaller and consolidation gradually,until completely absorbed or residual cicatricial band.Liquid cysts may be simple or complicated with halo sign.Gas-liquid cysts may appear wedge-shaped sign,silver bracelet sign,water in ball sign or the liquid in the cup sign,peanut shell sign,triangle flask sign and other signs.3 patients died after the CT examination within 2 hours,due to extensive pulmonary contusion and wet lung in 2 cases,liver and spleen bleeding in 1 case.The remaining cases received symptomatic treatment aimed at the accompanying;pulmonary pseudo-cysts were cured by conservative treatment.The absorption time of cysts was positively correlated with the length and size.Conclusion:CT can clearly show the forms,the evolution and the complications of the multiple traumatic lung pseudo-cysts,so it is the best imaging examination method for the diagnosis.

Application of Gray-scale Texture Feature in the Diagnosis of Pulmonary Nodules on CT Imaging

XIANG Zi-yun, SHI Chang-zheng, ZHOU Jie, ZHAN Yong, LUO Liang-ping

2013, 22(1): 155-160.

Abstract(971) PDF(3)

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Objective:To explore the value of image texture analysis in the diagnosis of pulmonary nodules.Methods:104 cases of pulmonary nodules were collected,all of which were confirmed by pathology.The level set model was used to extract and segment the lung nodule automatically.The features of energy,contrast,correlation,homogeneity and entropy in pulmonary nodules were calculated by gray-level co-occurrence matrix,which were compared between the benign and malignant lung nodules.Results:The characteristics of energy,contrast,correlation,homogeneity and entropy have significant statistical difference between benign and malignant pulmonary nodules(P＜ 0.05).The means of energy,homogeneity,correlation in benign nodules are greater than that in malignant nodules while the means of contrast and entropy in benign nodules are less than that of malignant nodules.Conclusion:The texture characteristics in pulmonary benign nodules are gray relatively uniform,local texture regular,relatively little contrast in gray,while that in pulmonary malignant nodules are local texture tangle some,gray uneven distribution,marked gray contrast,so the image texture features have important value in the diagnosis of lung nodules.

Imaging Features of Solid Pseudopapillary Tumor of the Pancreas on Computed Tomography and Magnetic Resonance Imaging

LI Jing-ying, WANG Xiu-ling, WU Meng

2013, 22(1): 161-166.

Abstract(870) PDF(1)

Abstract:
Objective:To analyze the imaging features of solid pseudopapillary tumors(SPTP) of the pancreas on computed tomography(CT) and Magnetic Resonance Imaging(MRI).Method:Retrospectively analyze the image data of a total of 11 consecutive cases with surgically and pathologically confirmed SPTP of the Pancreas.Among them,7cases underwent unenhanced and enhanced CT scan,2 cases only enhanced CT,the other 2 cases at the same time enhanced CT,plain and contrast enhanced MRI.Results:8 cases of tumor in the pancreas head and neck,2 cases in the body,1 case in the tail.The lesions are round or oval,edge rules,clear boundaries;diameter 1.8~13.2 cm,an average of 8.0 cm.2 tumors was predominantly composed of cystic portions,8 tumors were composed of similar proportions of solid and cystic portions,and 1 tumors were mainly composed of solid potions.All tumors showed mixed density in CT pre-contrast scan,solid portions and capsule of the tumors were delayed enhanced in post-contrast scan,the arterial phase showed mild to moderate enhancement,the degree of enhancement of the portal venous phase high than the arterial phase but were lower than normal pancreatic tissue,the cystic part,calcification and hemorrhage were not enhanced.Tumors showed mixed signal on MRI.On T1WI mainly is iintensity;on T2WI mainly slightly high signal,on post-contrast scan,solid portions were uneven medium delayed enhancement.Conclusion:Pancreatic solid pseudopapillary tumor is a larger more commen in young women,CT and MRI manifestations of cystic and solid mixed with complete capsule,delayed enhanced gradually filling mass,recognizing the performance of its characteristic conducive to clinical make a correct diagnosis before surgery.

Adult Three Real Heart CT Enhanced Performance and Operation Pathology

ZHENG Qiao, ZOU Jian-hua

2013, 22(1): 167-172.

Abstract(1037) PDF(1)

Abstract:
Objective:To explore the adult three real heart CT enhanced performance and operation pathology,improve the diagnostic level.Methods:A retrospective analysis of 3 cases were confirmed by operation and pathology of three real heart clinic data and CT manifestation.Results:three real heart imaging findings typical,common on the left side of the three branch real heart and on the right side of the three real(right atrial diverticulum).The complete three real hearts is left atria fiber membrane will be the one divides into two,with a hole in the middle.On the right side of the three housing is connected show with right atrial cystic structure,strengthen the concentric real,visible diverticulum mouth.Conclusion:spiral CT enhancement scanning and post processing technology in three real heart diagnosis significantly,can guide the clinical operation.

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2013 Vol. 22, No. 1