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Computed tomography-based nomogram of Siewert type Ⅱ/Ⅲ adenocarcinoma of esophagogastric junction to predict response to docetaxel, oxaliplatin and S-1
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作者 Chuan-Qinyuan Zhou Dan Gao +7 位作者 Yan Gui Ning-Pu Li Wen-Wen Guo Hai-Ying Zhou Rui Li Jing Chen Xiao-Ming Zhang Tian-Wu Chen 《World Journal of Radiology》 2024年第1期9-19,共11页
BACKGROUND Neoadjuvant chemotherapy(NAC)has become the standard care for advanced adenocarcinoma of esophagogastric junction(AEG),although a part of the patients cannot benefit from NAC.There are no models based on ba... BACKGROUND Neoadjuvant chemotherapy(NAC)has become the standard care for advanced adenocarcinoma of esophagogastric junction(AEG),although a part of the patients cannot benefit from NAC.There are no models based on baseline computed tomography(CT)to predict response of Siewert type II or III AEG to NAC with docetaxel,oxaliplatin and S-1(DOS).AIM To develop a CT-based nomogram to predict response of Siewert type II/III AEG to NAC with DOS.METHODS One hundred and twenty-eight consecutive patients with confirmed Siewert type II/III AEG underwent CT before and after three cycles of NAC with DOS,and were randomly and consecutively assigned to the training cohort(TC)(n=94)and the validation cohort(VC)(n=34).Therapeutic effect was assessed by disease-control rate and progressive disease according to the Response Evaluation Criteria in Solid Tumors(version 1.1)criteria.Possible prognostic factors associated with responses after DOS treatment including Siewert classification,gross tumor volume(GTV),and cT and cN stages were evaluated using pretherapeutic CT data in addition to sex and age.Univariate and multivariate analyses of CT and clinical features in the TC were performed to determine independent factors associated with response to DOS.A nomogram was established based on independent factors to predict the response.The predictive performance of the nomogram was evaluated by Concordance index(C-index),calibration and receiver operating characteristics curve in the TC and VC.RESULTS Univariate analysis showed that Siewert type(52/55 vs 29/39,P=0.005),pretherapeutic cT stage(57/62 vs 24/32,P=0.028),GTV(47.3±27.4 vs 73.2±54.3,P=0.040)were significantly associated with response to DOS in the TC.Multivariate analysis of the TC also showed that the pretherapeutic cT stage,GTV and Siewert type were independent predictive factors related to response to DOS(odds ratio=4.631,1.027 and 7.639,respectively;all P<0.05).The nomogram developed with these independent factors showed an excellent performance to predict response to DOS in the TC and VC(C-index:0.838 and 0.824),with area under the receiver operating characteristic curve of 0.838 and 0.824,respectively.The calibration curves showed that the practical and predicted response to DOS effectively coincided.CONCLUSION A novel nomogram developed with pretherapeutic cT stage,GTV and Siewert type predicted the response of Siewert type II/III AEG to NAC with DOS. 展开更多
关键词 Esophagogastric junction ADENOCARCINOMA Neoadjuvant chemotherapy RESPONSE Tomography x-ray computed Predictor
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Emerging role of computed tomography coronary angiography in evaluation of children with Kawasaki disease 被引量:1
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作者 Manphool Singhal Rakesh Kumar Pilania +2 位作者 Pankaj Gupta Nameirakpam Johnson Surjit Singh 《World Journal of Clinical Pediatrics》 2023年第3期97-106,共10页
Coronary artery abnormalities are the most important complications in children with Kawasaki disease(KD).Two-dimensional transthoracic echocardiography currently is the standard of care for initial evaluation and foll... Coronary artery abnormalities are the most important complications in children with Kawasaki disease(KD).Two-dimensional transthoracic echocardiography currently is the standard of care for initial evaluation and follow-up of children with KD.However,it has inherent limitations with regard to evaluation of mid and distal coronary arteries and,left circumflex artery and the poor acoustic window in older children often makes evaluation difficult in this age group.Catheter angiography(CA)is invasive,has high radiation exposure and fails to demonstrate abnormalities beyond lumen.The limitations of echocardiography and CA necessitate the use of an imaging modality that overcomes these problems.In recent years advances in computed tomography technology have enabled explicit evaluation of coronary arteries along their entire course including major branches with optimal and acceptable radiation exposure in children.Computed tomography coronary angiography(CTCA)can be performed during acute as well as convalescent phases of KD.It is likely that CTCA may soon be considered the reference standard imaging modality for evaluation of coronary arteries in children with KD. 展开更多
关键词 coronary artery abnormalities computed tomography coronary angiography 2D-echocardiography Kawasaki disease Imaging modality Acquired heart disease
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Seeing through Materials:X-Ray Imaging Using Computed Tomography
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作者 Yisheng Miao Chengpeng Xue +2 位作者 Xuelong Wu Zhongyao Li Junsheng Wang 《Journal of Beijing Institute of Technology》 EI CAS 2023年第4期494-516,共23页
X-ray computed tomography(XCT)has recently emerged as a powerful tool for characterizing the evolution of microstructure during phase transformation in three dimensional(3D)such as dendritic solidification of alloys.T... X-ray computed tomography(XCT)has recently emerged as a powerful tool for characterizing the evolution of microstructure during phase transformation in three dimensional(3D)such as dendritic solidification of alloys.This paper briefly reviews the recent advances in the in-situ observation of aluminium alloys,magnesium alloys and nickel-based superalloys during solidification using laboratory XCT and synchrotron X-ray sources.The focus is on the growth kinetics of dendrites,porosity and secondary phases.In addition,in-situ characterization during the loading and corrosion process is also discussed. 展开更多
关键词 x-ray computed tomography(XCT) SYNCHROTRON DENDRITE POROSITY ALLOYS
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Effects of combining multiple dose reduction techniques on coronary computed tomography angiography
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作者 Xiao-Lu Hu Pei-Kai Huang +2 位作者 Meng Zhang Jun Chen Meng-Qiang Xiao 《World Journal of Radiology》 2023年第2期32-41,共10页
BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awar... BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase.AIM To explore the value of multiple dose reduction techniques for CCTA.METHODS Consecutive normal and overweight patients were prospectively divided into two groups:Group A1,patients who received multiple dose reduction scans(n=82);and group A2,patients who received conventional scans(n=39).The scan parameters for group A1 were as follows:Isocentric scan,tube voltage=80 kV,and tube current control using 80%smart milliampere.The scan parameters for group A2 were as follows:Normal position,tube voltage=100 kV,and smart milliampere.RESULTS The average effective doses(EDs)for groups A1 and A2 were 1.13±0.35 and 3.36±1.30 mSv,respectively.There was a statistically significant difference in ED between the two groups(P<0.01).Furthermore,noise was significantly lower,and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1(P<0.01).Moreover,the subjective image quality(IQ)scores were excellent in both groups,in which there was no significant difference in subjective IQ score between the two groups(P=0.12).CONCLUSION Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis. 展开更多
关键词 Isocentric scanning coronary heart disease Dose reduction techniques coronary computed tomography angiography RADIATION
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Importance of computed tomography in posterior malleolar fractures:Added information to preoperative X-ray studies
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作者 NoéDe Marchi Neto Pietro Felice Tomazini Nesello +3 位作者 Jordanna Maria Bergamasco Marco Tulio Costa Ralph Walter Christian Nilson Roberto Severino 《World Journal of Orthopedics》 2023年第12期868-877,共10页
BACKGROUND Ankle fractures are common lesions of the lower limbs.Approximately 40%of ankle fractures affect the posterior malleolus(PM).Historically,PM osteosynthesis was recommended when PM size in X-ray images was g... BACKGROUND Ankle fractures are common lesions of the lower limbs.Approximately 40%of ankle fractures affect the posterior malleolus(PM).Historically,PM osteosynthesis was recommended when PM size in X-ray images was greater than 25%of the joint.Currently,computed tomography(CT)has been gaining traction in the preoperative evaluation of ankle fractures.AIM To elucidate the similarity in dimensions and to correlate PM size in X-ray images with the articular surface of the affected tibial plafond in the axial view on CT(AXCT)of a PM fracture.METHODS Eighty-one patients(mean age:39.4±13.5 years)were evaluated(54.3%were male).Two independent examiners measured PM size in profile X-ray images(PMXR)and sagittal CT(SAGCT)slices.The correlation of the measurements between the examiners and the difference in the PM fragment sizes between the two images were compared.Next,the PM size in PMXR was compared with the surface of the tibial plafond involved in the fracture in AXCT according to the Haraguchi classification.RESULTS The correlation rates between the examiners were 0.93 and 0.94 for PMXR and SAGCT,respectively(P<0.001).Fragments were 2.12%larger in SAGCT than in PMXR(P=0.018).In PMXR,there were 56 cases<25%and 25 cases≥25%.When PMXR was<25%,AXCT corresponded to 10.13%of the tibial plafond.When PMXR was≥25%,AXCT was 24.52%(P<0.001).According to the Haraguchi classification,fracture types I and II had similar PMXR measurements that were greater than those of type III.When analyzing AXCT,a significant difference was found between the three types,with II>I>III(P<0.001).CONCLUSION PM fractures show different sizes using X-ray or CT images.CT showed a larger PM in the sagittal plane and allowed the visualization of the real dimensions of the tibial plafond surface. 展开更多
关键词 Ankle fracture Posterior malleolar fracture computed tomography x-ray Posterior malleolus fracture Trimalleolar facture
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Coronary Artery Anomalies Detected by Multi-Detector Computed Tomography: A Single Centre Experience
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作者 Basma Hammad Eman El-sharkawy +6 位作者 Yasser Morsi Noha Shabaan Salah Eltahan Mohamed Elshafi Shady Abohashem Tanveer Mir Mostafa Elwany 《World Journal of Cardiovascular Diseases》 2023年第6期261-274,共14页
Background: Coronary artery anomalies (CAA) prevalence represents less than 1% of congenital heart diseases. It includes anomalies in origin, course, and termination. Its detection has been easier with advances i... Background: Coronary artery anomalies (CAA) prevalence represents less than 1% of congenital heart diseases. It includes anomalies in origin, course, and termination. Its detection has been easier with advances in imaging techniques using multi-detector computed tomography (MDCT). MDCT helps not only detection of the anomalous origin, but it allows delineation of the course and termination of the arteries, differentiation between benign and malignant courses, and guiding therapeutic interventions. Results: There were consecutive patients with a low-to-intermediate probability of coronary artery disease scanned with 128 MDCT. Each patient underwent a non-contrast prospective gating acquisition for coronary calcium scoring followed by contrast-enhanced helical retrospective gated scans for the detection of coronary artery origin, course, termination, and detection of concomitant atherosclerosis. We scanned 1000 patients with a mean age of 57.5 ± 8.3, and 68% were males. Thirty-two anomalies were noted (3.2%) including;nineteen (1.9%) anomalous origin from the opposite sinus, three (0.3%) anomalous left coronary arteries from the pulmonary artery (ALCAPA), one (0.1%) super dominant left anterior descending artery (LAD) giving origin to the posterior descending artery (PDA), three single coronary arteries (0.3%)in which the left main (LM) and right coronary arteries were originating with a common stem from the right coronary sinus (RCS)and the LM took a pre-pulmonic course. Along with six (0.6%) dual LAD including five (0.5%) patients with type I (short LAD and long diagonal), there was one (0.1%) type 4 with an extra LAD originating from the RCS with a pre-pulmonic course. Conclusions: MDCT allows easy detection of coronary anomalies with high spatial resolution and overcomes limitations in conventional invasive coronary angiography. Based on our study we recommend the use of MDCT as an efficient and feasible modality for the diagnosis of coronary anomalies once this pathology is clinically suspected. 展开更多
关键词 coronary Artery Anomalies Spatial Resolution Multi-Detector computed Tomography
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Radiation dose analysis of computed tomography coronary angiography in Children with Kawasaki disease
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作者 Mahesh Chandra Bhatt Manphool Singhal +4 位作者 Rakesh Kumar Pilania Subhash Chand Bansal Niranjan Khandelwal Pankaj Gupta Surjit Singh 《World Journal of Clinical Pediatrics》 2023年第4期230-236,共7页
BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data o... BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data on radiation dose in this group of children undergoing CTCA.AIM To audit the radiation dose of CTCA in children with KD.METHODS Study(December 2013-February 2018)was performed on dual source CT scanner using adaptive prospective electrocardiography-triggering.The dose length product(DLP in milligray-centimeters-mGy.cm)was recorded.Effective radiation dose(millisieverts-mSv)was calculated by applying appropriate age adjusted conversion factors as per recommendations of International Commission on Radiological Protection.Radiation dose was compared across the groups(0-1,1-5,5-10,and>10 years).RESULTS Eighty-five children(71 boys,14 girls)with KD underwent CTCA.The median age was 5 years(range,2 mo-11 years).Median DLP and effective dose was 21 mGy.cm,interquartile ranges(IQR)=15(13,28)and 0.83 mSv,IQR=0.33(0.68,1.01)respectively.Mean DLP increased significantly across the age groups.Mean effective dose in infants(0.63 mSv)was significantly lower than the other age groups(1-5 years 0.85 mSv,5-10 years 1.04 mSv,and>10 years 1.38 mSv)(P<0.05).There was no significant difference in the effective dose between the other groups of children.All the CTCA studies were of diagnostic quality.No child required a repeat examination.CONCLUSION CTCA is feasible with submillisievert radiation dose in most children with KD.Thus,CTCA has the potential to be an important adjunctive imaging modality in children with KD. 展开更多
关键词 computed tomography coronary angiography coronary artery abnormalities Dual source computed tomography Kawasaki disease Radiation exposure
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Can visceral fat parameters based on computed tomography be used to predict occult peritoneal metastasis in gastric cancer? 被引量:3
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作者 Li-Ming Li Lei-Yu Feng +4 位作者 Chen-Chen Liu Wen-Peng Huang Yang Yu Peng-Yun Cheng Jian-Bo Gao 《World Journal of Gastroenterology》 SCIE CAS 2023年第15期2310-2321,共12页
BACKGROUND The preoperative prediction of peritoneal metastasis(PM)in gastric cancer would prevent unnecessary surgery and promptly indicate an appropriate treatment plan.AIM To explore the predictive value of viscera... BACKGROUND The preoperative prediction of peritoneal metastasis(PM)in gastric cancer would prevent unnecessary surgery and promptly indicate an appropriate treatment plan.AIM To explore the predictive value of visceral fat(VF)parameters obtained from preoperative computed tomography(CT)images for occult PM and to develop an individualized model for predicting occult PM in patients with gastric carcinoma(GC).METHODS A total of 128 confirmed GC cases(84 male and 44 female patients)that underwent CT scans were analyzed and categorized into PM-positive(n=43)and PM-negative(n=85)groups.The clinical characteristics and VF parameters of two regions of interest(ROIs)were collected.Univariate and stratified analyses based on VF volume were performed to screen for predictive characteristics for occult PM.Prediction models with and without VF parameters were established by multivariable logistic regression analysis.RESULTS The mean attenuations of VF_(ROI 1)and VF_(ROI 2)varied significantly between the PM-positive and PMnegative groups(P=0.044 and 0.001,respectively).The areas under the receiver operating characteristic curves(AUCs)of VF_(ROI 1)and VF_(ROI 2)were 0.599 and 0.657,respectively.The mean attenuation of VF_(ROI 2)was included in the final prediction combined model,but not an independent risk factor of PM(P=0.068).No significant difference was observed between the models with and without mean attenuation of VF(AUC:0.749 vs 0.730,P=0.339).CONCLUSION The mean attenuation of VF is a potential auxiliary parameter for predicting occult PM in patients with GC. 展开更多
关键词 Gastric carcinoma Peritoneal metastasis Visceral fat Tomography x-ray computed Prediction Individualized model
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Coronary computed tomography angiography in coronary artery disease 被引量:6
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作者 Kwan-Hoong Ng 《World Journal of Cardiology》 CAS 2011年第9期303-310,共8页
AIM: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.METHODS: A search of articl... AIM: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.METHODS: A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from f ive main radiology journals namely, Radiology, American Journal of Roentgenology, European Radiology, European Journal of Radiology and British Journal of Radiology. Analysis of the references was focused on the research directions of coronary CT angiography with regard to the type of studies in terms of diagnostic value, application of dose-reduction strategies and resultant effective radiation doses with use of these techniques.RESULTS: One hundred and forty two studies were identified which met the selection criteria and were included in the analysis. 64-slice CT (single source anddual-source CT) dominated 78% of the coronary CT angiography studies. Prior to 2007, research was focused on the diagnostic value of coronary CT angiography, but since 2008 more attention has been paid to radiation dose reduction. Radiation dose was reported in 64 studies, representing 45% of total studies published in the f ive radiology journals. Various dose-saving strategies have been implemented and prospective electrocardiography-triggering and high pitch techniques were found to be the most effective approaches for radiation dose reduction, with the corresponding mean effective dose being 3.5 ± 1.9 mSv and 1.7 ± 0.6 mSv, respectively.CONCLUSION: This review shows that the current research in coronary CT angiography has shifted from the previous focus on diagnostic accuracy in CAD to more emphasis on radiation dose reduction. 展开更多
关键词 coronary ARTERY disease Diagnostic value MULTISLICE computed tomography Radiation DOSE Risk
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Feasibility and accuracy of coronary imaging in elderly patients using the 64-row multi-detector computed tomography: a correlation study with conventional coronary angiography 被引量:4
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作者 Chee Khoon LIEW Sze Piaw CHIN +6 位作者 Tiong Kiam ONG Seyfarth Tobias Yean Yip FONG Choon Kiat ANG Houng Bang LIEW Rapaee ANNUAR Kui Hian SIM 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2006年第1期9-14,共6页
Background Elderly patients generally have higher occurrence of coronary calcification, increased heart rate and difficulty with prolonged breath-holding. The aim of our study was to investigate the feasibility and ac... Background Elderly patients generally have higher occurrence of coronary calcification, increased heart rate and difficulty with prolonged breath-holding. The aim of our study was to investigate the feasibility and accuracy of using 64-row multi-detector computed tomography (MDCT) in the assessment of coronary artery stenoses in elderly patients. Methods One hundred and fifty two patients with suspected or known coronary artery disease were divided into 4 groups according to their age (Group A: 40-49 years,n=34; Group B: 50-59 years, n=57; Group C: 60-69 years, n=48; Group D: 70 years and above; n=13). Coronary CT angiography (CTA) using a 64-row MDCT was performed and the findings were compared with that of conventional coronary angiography (CCA).Using axial images, multi-planar reconstructions (MPR) and maximum intensity projections (MIP), coronary segments of lumen diameter = 1.5mm were analyzed for the presence of significant stenosis (= 50% ). Results Percentages of poor image quality from coronary CTA preventing reliable correlations with CCA were 21%, 14%, 19% and 62% in Groups A to D respectively. Patients in Group D had significantly higher calcium scores compared with the other groups (P<0.001). In patients where CTA images were of acceptable quality, percentages of accurate correlations with CCA were 89.8%, 93.4%, 86.6% and 78.0% for Groups A to D respectively.There were no significant difference in serum creatinine, heart rate and contrast volume between the 4 groups. Conclusions The 64-row MDCT coronary angiography was less accurate and feasible for patients aged 70 years or above due to heavy coronary calcification and inability to perform a satisfactory breath-hold. However, a high diagnostic accuracy with the MDCT is possible in patients aged less than 70 years. 展开更多
关键词 computed tomography ANGIOGRAPHY coronary ARTERY disease ELDERLY
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Comparison of 16 slice multi-detector computed tomography and breath hold 3D magnetic resonance angiography in the detection of coronary stenosis 被引量:2
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作者 Xin LIU Zulong CAI Youquan CAI Shaohong ZHAO Ningyu AN Yuangui GAO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2006年第1期24-28,共5页
Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting sig... Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (> 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeedl6)and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16× 1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1.7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256× 192). Mean heart rate was 63 ± 5.8 bpm and β-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale.Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2.Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83 %, 84 %, 49 %, 97 % and 63 %, 90 %, 55 %, 93 %, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value,which is useful for excluding coronary stenosis in symptomatic patients. 展开更多
关键词 computed TOMOGRAPHY magnetic resonance imaging coronary ARTERY disease ANGIOGRAPHY
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Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles 被引量:8
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作者 Bao-hua Yang Ai-xiang Wu +2 位作者 Guillermo A.Narsilio Xiu-xiu Miao Shu-yue Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第9期965-973,共9页
Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle,... Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle, a cylindrical copper oxide ore sample (I center dot 4.6 mm x 5.6 mm) was scanned using high-resolution X-ray computed tomography (HRXCT), a nondestructive imaging technology, at a spatial resolution of 4.85 mu m. Combined with three-dimensional (3D) image analysis techniques, the main mineral phases and pore space were segmented and the volume fraction of each phase was calculated. In addition, the mass fraction of each mineral phase was estimated and the result was validated with that obtained using traditional techniques. Furthermore, the pore phase features, including the pore size distribution, pore surface area, pore fractal dimension, pore centerline, and the pore connectivity, were investigated quantitatively. The pore space analysis results indicate that the pore size distribution closely fits a log-normal distribution and that the pore space morphology is complicated, with a large surface area and low connectivity. This study demonstrates that the combination of HRXCT and 3D image analysis is an effective tool for acquiring 3D mineralogical and pore structural data. 展开更多
关键词 high-resolution x-ray computed tomography 3D image analysis ore particles mineral dissemination pore space
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Microstructure Evolution of Sandstone Cemented by Microbe Cement Using X-ray Computed Tomography 被引量:4
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作者 RONG Hui QIAN Chunxiang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第6期1134-1139,共6页
The bio-sandstone, which was cemented by microbe cement, was firstly prepared, and then the microstructure evolution process was studied by X-ray computed tomography (X-CT) technique. The experimental results indica... The bio-sandstone, which was cemented by microbe cement, was firstly prepared, and then the microstructure evolution process was studied by X-ray computed tomography (X-CT) technique. The experimental results indicate that the microstructure of bio-sandstone becomes dense with the development of age. The evolution of inner structure at different positions is different due to the different contents of microbial induced precipitation calcite. Besides, the increase rate of microbial induced precipitation calcite gradually decreases because of the reduction of microbe absorption content with the decreasing pore size in bio-sandstone. 展开更多
关键词 microbe cement bio-sandstone microstructure evolution x-ray computed tomography CALCITE
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Effects of dry-wet cycles on three-dimensional pore structure and permeability characteristics of granite residual soil using X-ray micro computed tomography 被引量:13
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作者 Ran An Lingwei Kong +1 位作者 Xianwei Zhang Chengsheng Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第3期851-860,共10页
Due to seasonal climate alterations,the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles.The X-ray micro computed tomography(micro-CT)acted as a nondestructive to... Due to seasonal climate alterations,the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles.The X-ray micro computed tomography(micro-CT)acted as a nondestructive tool for characterizing the microstructure of soil samples exposed to a range of damage levels induced by dry-wet cycles.Subsequently,the variations of pore distribution and permeability due to drywet cycling effects were revealed based on three-dimensional(3D)pore distribution analysis and seepage simulations.According to the results,granite residual soils could be separated into four different components,namely,pores,clay,quartz,and hematite,from micro-CT images.The reconstructed 3D pore models dynamically demonstrated the expanding and connecting patterns of pore structures during drywet cycles.The values of porosity and connectivity are positively correlated with the number of dry-wet cycles,which were expressed by exponential and linear functions,respectively.The pore volume probability distribution curves of granite residual soil coincide with the χ^(2)distribution curve,which verifies the effectiveness of the assumption of χ^(2)distribution probability.The pore volume distribution curves suggest that the pores in soils were divided into four types based on their volumes,i.e.micropores,mesopores,macropores,and cracks.From a quantitative and visual perspective,considerable small pores are gradually transformed into cracks with a large volume and a high connectivity.Under the action of dry-wet cycles,the number of seepage flow streamlines which contribute to water permeation in seepage simulation increases distinctly,as well as the permeability and hydraulic conductivity.The calculated hydraulic conductivity is comparable with measured ones with an acceptable error margin in general,verifying the accuracy of seepage simulations based on micro-CT results. 展开更多
关键词 Granite residual soil Dry-wet cycle x-ray micro computed tomography(micro-CT) Three-dimensional(3D)pore distribution Seepage simulations PERMEABILITY
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Coronary artery disease in Chinese adults with type 2 diabetes mellitus estimated by electron beam computed tomography and electron beam computed tomography angiography 被引量:1
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作者 Chen Huang Minwen Zheng Xiaoming Wang Jianyuan Gao Hua Meng Liping Wu Rong Li Hui Su Hua Zhang Ronghuai Zhang 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2007年第3期155-161,共7页
Objective To assess the prevalence and risk of coronary artery disease(CAD) in Chinese adults with type 2 diabetes mellitus(T2DM) using electron beam computed tomography(EBCT) and EBCT angiography(EBCTA) . Methods:Nin... Objective To assess the prevalence and risk of coronary artery disease(CAD) in Chinese adults with type 2 diabetes mellitus(T2DM) using electron beam computed tomography(EBCT) and EBCT angiography(EBCTA) . Methods:Ninety-four cases were enrolled in this study including diabetes(n=28) ,impaired glucose tolerance(IGT,n=30) ,coronary heart disease(CHD,n=11) ,and control(n=25) . Cardiac EBCT plain scanning and EBCTA were performed on all of these subjects to evaluate coronary artery calcifica-tion(CAC) scores,and number of segments of stenosed coronary arteries. Both CAC and/or coronary artery stenosis were defined as patients with coronary artery lesions(CAL) . Results CAC scores were not different with the control,diabetes,IGT,or CHD(P>0.05) groups. Compared to control(0.520±1.295) ,more stenosed coronary arteries segments(P<0.05) were detected in diabetes(2.964± 1.915) ,IGT(2.200±2.024) ,and CHD(2.273±1.679) . Number of stenosed artery segments were correlated with age(r=0.215,P=0.019) ,postprandial glucose(r=0.224,P=0.015) ,total cholesterol(r=0.323,P=0.000) ,and duration of diabetes(r=0.208,P=0.004) . The incidences of CAL in diabetes(96.43%) ,IGT(93.33%) ,and CHD(90.91%) was substantially higher than that in normal control(56.00%,P<0.01) . The odds ratio of CAL associated with having diabetes was estimated to be 7.514(95% CI:1.885-63.778) . Conclusions Coronary artery lesions are prevalent in Chinese adults with type 2 diabetes,implying a high CAD risk. EBCTA holds potential in depicting the details of CAL and can be used to track the progression of CAD in diabetes patients. 展开更多
关键词 diabetes coronary ARTERY CALCIFICATION coronary ARTERY STENOSIS ELECTRON-BEAM computed tomography (EBCT)
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Myocardial bridging analysis by coronary computed tomographic angiography in a Saudi population 被引量:1
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作者 Ragab Hani Donkol Zizi Saad 《World Journal of Cardiology》 CAS 2013年第11期434-441,共8页
AIM: To assess the incidence, location, morphology and clinical association of myocardial bridging in a Saudi population using coronary computed tomographic angiography(CCTA). METHODS: A total of 350 CCTA of Saudi pat... AIM: To assess the incidence, location, morphology and clinical association of myocardial bridging in a Saudi population using coronary computed tomographic angiography(CCTA). METHODS: A total of 350 CCTA of Saudi patients were included in this study(236 men, 114 women) with a mean age of 56.3 years. All patients were examined for appropriateness criteria of CCTA indications(typical chest pain, recent onset cardiomyopathy, left bundle branch block, etc.). The scans were retrospectively reviewed for the presence of myocardial bridging and any other pathological association. RESULTS: Myocardial bridging was found in 89 of 350(22.5%) patients. Most of the intramuscular segments were of the superficial type and found in the mid left anterior descending(LAD)(24.6%), followed by distal LAD(3.7%), diagonal branches(2%), ramus intermedius artery(1.4%) and obtuse marginal artery(0.8%). No myocardial bridging was detected in the right coronary or circumflex arteries. No significant differences were found between males and females(P = 0.14). Coronary artery atherosclerosis was found in 51 of 89(57.3%) patients with MB. Atherosclerotic plaques were not detected in the intramuscular or distal segment of bridging arteries. Dynamic compression was observed in 35(94.5%) patients with full encasement. No evidence of myocardial hypoperfusion was found in the territories supplied by the bridging arteries. CONCLUSION: CCTA is excellent in analyzing myocardial bridging in a Saudi population and the results are comparable to other populations. However, finding the real incidence may need a large multicenter study. 展开更多
关键词 coronary heart disease Myocardial bridging coronary computed tomographic ANGIOGRAPHY coronary ARTERIES ANATOMY coronary atherosclerosis
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Review of X-ray and computed tomography scan findings with a promising role of point of care ultrasound in COVID-19 pandemic 被引量:5
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作者 Darshan Gandhi Kriti Ahuja +4 位作者 Hemal Grover Pranav Sharma Shantanu Solanki Nishant Gupta Love Patel 《World Journal of Radiology》 CAS 2020年第9期195-203,共9页
As healthcare professionals continue to combat the coronavirus disease 2019(COVID-19)infection worldwide,there is an increasing interest in the role of imaging and the relevance of various modalities.Since imaging not... As healthcare professionals continue to combat the coronavirus disease 2019(COVID-19)infection worldwide,there is an increasing interest in the role of imaging and the relevance of various modalities.Since imaging not only helps assess the disease at the time of diagnosis but also aids evaluation of response to management,it is critical to examine the role of different modalities currently in use,such as baseline X-rays and computed tomography scans carefully.In this article,we will draw attention to the critical findings for the radiologist.Further,we will look at point of care ultrasound,an increasingly a popular tool in diagnostic medicine,as a component of COVID-19 management. 展开更多
关键词 x-ray computed tomography Point of care ultrasound COVID-19 CORONAVIRUS WUHAN
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Coronary plaque imaging by coronary computed tomography angiography 被引量:1
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作者 Akira Sato 《World Journal of Radiology》 CAS 2014年第5期148-159,共12页
Coronary computed tomography angiography(CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coron... Coronary computed tomography angiography(CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease(CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice. 展开更多
关键词 coronary computed tomography ANGIOGRAPHY coronary PLAQUE VULNERABLE PLAQUE Clinical OUTCOME
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Kernel crack characteristics for X-ray computed microtomography(μCT)and their relationship with the breakage rate of maize varieties 被引量:2
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作者 DONG Peng-fei XIE Rui-zhi +6 位作者 WANG Ke-ru MING Bo HOU Peng HOU Jun-feng XUE Jun LI Chao-hai LI Shao-kun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第11期2680-2689,共10页
The most significant problem of maize grain mechanical harvesting quality in China at present is the high grain breakage rate(BR).BR is often the key characteristic that is measured to select hybrids desirable for mec... The most significant problem of maize grain mechanical harvesting quality in China at present is the high grain breakage rate(BR).BR is often the key characteristic that is measured to select hybrids desirable for mechanical grain harvesting.However,conventional BR evaluation and measurement methods have challenges and limitations.Microstructural crack parameters evaluation of maize kernel is of great importance to BR.In this connection,X-ray computed microtomography(μ-CT)has proven to be a quite useful method for the assessment of microstructure,as it provides important microstructural parameters,such as object volume,surface,surface/volume ratio,number of closed pores,and others.X-ray computed microtomography is a non-destructive technique that enables the reuse of samples already measured and also yields bidimensional(2D)cross-sectional images of the sample as well as volume rendering.In this paper,six different maize hybrid genotypes are used as materials,and the BR of the maize kernels of each variety is tested in the field mechanical grain harvesting,and the BR is used as an index for evaluating the breakage resistance of the variety.The crack characteristic parameters of kernel were detected by X-ray micro-computed tomography,and the relationship between the BR and the kernel crack characteristics was analyzed by stepwise regression analysis.Establishing a relationship between crack characteristic parameters and BR of maize is vital for judging breakage resistance.The results of stepwise multiple linear regression(MLR)showed that the crack characteristics of the object surface,number of closed pores,surface of closed pores,and closed porosity percent were significantly correlated to the BR of field mechanical grain harvesting,with the standard partial regression coefficients of–0.998,–0.988,–0.999,and–0.998,respectively.The R2 of this model was 0.999.Results validation showed that the Stepwise MLR Model could well predict the BR of maize based on these four variables. 展开更多
关键词 breakage rate kernel crack MAIZE MICROSTRUCTURE x-ray computed microtomography
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Pancreatic neuroendocrine tumor detected by technetium-99m methoxy-2-isobutylisonitrile single photon emission computed tomography/computed tomography:A case report
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作者 Chang-Jiang Liu Hua-Jun Yang +1 位作者 Yan-Chun Peng De-Yu Huang 《World Journal of Clinical Cases》 SCIE 2023年第12期2825-2831,共7页
BACKGROUND Pancreatic neuroendocrine tumors(NETs)account for about 1%–2%of pancreatic tumors and about 8%of all NETs.Computed tomography(CT),magnetic resonance imaging,and endoscopic ultrasound are common imaging mod... BACKGROUND Pancreatic neuroendocrine tumors(NETs)account for about 1%–2%of pancreatic tumors and about 8%of all NETs.Computed tomography(CT),magnetic resonance imaging,and endoscopic ultrasound are common imaging modalities for the diagnosis of pancreatic NETs.Furthermore,somatostatin receptor imaging is of great value for diagnosing pancreatic NETs.Herein,we report the efficacy of technetium-99m methoxy-2-isobutylisonitrile(99mTc-MIBI)single photon emission CT(SPECT)/CT for detecting pancreatic NETs.CASE SUMMARY A 57-year-old woman presented to our hospital with a 1-d history of persistent upper abdominal distending pain.The distending pain in the upper abdomen was aggravated after eating,with nausea and retching.Routine blood test results showed a high neutrophil percentage,low leukomonocyte and monocyte percentages,and low leukomonocyte and eosinophil counts.Amylase,liver and kidney function,and tumor markers alpha-fetoprotein,carcinoembryonic antigen,and cancer antigen(CA)125,CA72-4,CA19-9,and CA153 were normal.Abdominal CT showed a mass,with multiple calcifications between the pancreas and the spleen.The boundary between the mass and the pancreas and spleen was poorly defined.Contrast-enhanced CT revealed that the upper abdominal mass was unevenly and gradually enhanced.99mTc-MIBI SPECT/CT revealed that a focal radioactive concentration,with mild radioactive concentration extending into the upper abdominal mass,was present at the pancreatic body and tail.The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET.CONCLUSION 99mTc-MIBI SPECT/CT appears to be a valuable tool for detecting pancreatic NETs. 展开更多
关键词 Neuroendocrine tumors PANCREAS Tc-99m-Methoxy-2-isobutylisonitrile Single photon emission computed tomography x-ray computed tomography Case report
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