This study aims to analyze and discuss the current situation of quality control and quality management in medical imaging.Firstly,it defines the concepts of quality management and image quality,emphasizing the crucial...This study aims to analyze and discuss the current situation of quality control and quality management in medical imaging.Firstly,it defines the concepts of quality management and image quality,emphasizing the crucial role of the department's Quality and Safety Team in imaging quality management[1].Subsequently,it details the composition and responsibilities of the Quality and Safety Management Group,as well as the specific divisions of labor and tasks of the Quality Management Team.The effective implementation of comprehensive quality control in the imaging department is ensured through the"Seven-Star Sword"method,which encompasses total process control,organization-wide participation,and total quality control[2].Furthermore,the application of the PDCA(Plan-Do-Check-Act)cycle in quality management is explored,along with strategies to improve patient satisfaction by reducing the waiting time for imaging reports[3].Finally,the management of a key departmental medical quality control indicator—critical values—is analyzed,and improvement measures are proposed[4].This study underscores the importance of quality management in enhancing medical service quality and ensuring patient safety,and puts forward specific implementation strategies and improvement methods.展开更多
The conventional method of seismic data acquisition geometry design is based on the assumption of horizontal subsurface reflectors, which often is not suitable for complex structure. We start from a controlled illumin...The conventional method of seismic data acquisition geometry design is based on the assumption of horizontal subsurface reflectors, which often is not suitable for complex structure. We start from a controlled illumination analysis and put forward a method of seismic survey geometry design for target-oriented imaging. The method needs a velocity model obtained by a preliminary seismic interpretation. The one-way Fourier finite-difference wave propagator is used to extrapolate plane wave sources on the target layer to the surface. By analyzing the wave energy distribution at the surface extrapolated from the target layer, the shot or receiver locations needed for target layer imaging can be determined. Numerical tests using the SEG-EAGE salt model suggest that this method is useful for confirming the special seismic acquisition geometry layout for target-oriented imaging.展开更多
Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective tr...Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular(approximately 10% of tissue volume), interstitium(approximately 15%) and intracellular(approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types Ⅰ/Ⅲ collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis(e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy(hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging(MRI) has the ability to characterize tissue proton relaxation times(T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI(DE-MRI) and multi-detector computed tomography(DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary catheterization and possibility of tissue sampling error. Similar to delayed contrast enhancement, equilibrium contrast enhanced MRI/MDCT and T1 mapping is completely noninvasive and may play a specialized role in diagnosis of subclinical and other myocardial pathologies. DE-MRI and when T1-mapping demonstrated sub-epicardium, sub-endocardial and patchy mid-myocardial enhancement in myocarditis, Behcet's disease and sarcoidosis, respectively. Furthermore, recent studies showed that the combined technique of cine, T2-weighted and DE-MRI technique has high diagnostic accuracy for detecting myocarditis. When the tomographic techniques are coupled with myocardial perfusion and left ventricular function they can provide valuable information on the progression of myocardial pathologies and effectiveness of new therapies.展开更多
Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex...Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex and needs to trade off other aberration in traditional ways.Although metasurface offers an effective method to overcome these limits and results in well-engineered dispersion,off-axis dispersion control is still a challenging topic.In this paper,we design a single-layer metalens which is capable of focusing at three wavelengths(473 nm,532 nm,and 632 nm)with different incident angles(0°,-17°and 17°)into the same point.We also demonstrate that this metalens can provide an alternative for the bulky color synthetic prism in a 3-chips digital micromirror device(DMD)laser projection system.Through this approach,various off-axis dispersion controlling optical devices could be realized.展开更多
Chemical imaging(CI)possesses a strong ability of pharmaceutical analysis.Its great strength relies on the integration of traditional spectroscopy(one dimension)and imaging technique(two dimensions)to generate three-d...Chemical imaging(CI)possesses a strong ability of pharmaceutical analysis.Its great strength relies on the integration of traditional spectroscopy(one dimension)and imaging technique(two dimensions)to generate three-dimensional data hypercubes.Data pre-processing or processing methods are proposed to analyze vast data matrixes and thereby realizing different research objectives.In this review paper,various pharmaceutical applications of quality control over the past few years are summed up in two groups of final product test and industrial utilization.The scope of"quality control"here includes traditional analytical use,process understanding and manufactural control.Finally,two major challenges about undesirable sample geometry and lengthy acquisition time are discussed for prospective commercial or industrial application.展开更多
OBJECTIVE By analysis and evaluation of the perfusion images and perfusion parameters of the rabbits with VX2 lung tumor, the association between the perfusion parameters and tumor angiogenesis of patients with squamo...OBJECTIVE By analysis and evaluation of the perfusion images and perfusion parameters of the rabbits with VX2 lung tumor, the association between the perfusion parameters and tumor angiogenesis of patients with squamous cell carcinoma of the lung has been studied in order to establish a non-invasive and effective way to detect tumor blood supply, which is be able to exhibit hemodynamic data in tumors during cancer treatments. METHODS Fifteen Netherlands rabbits inoculated with VX2 lung tumor （rabbit group） and 25 patients with squamous cell carcinoma of the lung （patient group） received a multi-slice spiral CT perfusion imaging test using the Netherlands PHILIPS Brilliance 16-slice spiral CT and a U.S. MEDRAD binocular highpressure syringe. Image postprocessing was done using the special perfusion software and EBW 4.0 Workstation. Perfusion volume （PV）, peak enhanced increment （PEI）, transit time peak （TTP）, and blood volume （BV） were measured and analyzed. RESULTS In the rabbit group, the values of the PV, PEI, TTP, and BV of the tumor margin were （53.89 ± 13.38） mL/（min.mL）, （45.71 ± 15.52） Hu, （39.29 ± 10.10） sec, and （31.45 ± 18.19） mL/100 g, respectively; these values of the tumor center were （36.57 ± 14.17） mL/（min.mL）, （28.64 ± 11.74） Hu, （39.00 ＋ 9.78） sec, and （19.76 ± 13.95） mL/100 g, respectively; the values of the muscles were （12.45± 4.38） mL/（min.mL）, （10.98 ± 5.03） Hu, （38.86 ± 10.04） sec, and （5.38 ±2.87） mL/100 g, respectively. The values of the relative perfusion volume （RPV）, relative peak enhanced increment （RPEI）, and relative blood volume （RBV） of the tumor margin were 4.38 ± 1.45, 3.96± 1.45, 9.99 ± 11.7, respectively; these values of the tumor center were 2.14 ± 1.08, 1.83±1.45, 4.17 ±3.39, respectively. The values of the PV, PEL BV of the tumor margin vs. the values of the muscles developed t-values, which were 15.028, 10.79, and 5.88, respectively （P ≤ 0.01）, with statistical significance; the values of the PV, PEI, BV of the tumor center vs. the values of the muscles produced t-values, which were 8.67, 7.49, and 4.55, respectively （P 〈 0.01）, with statistical significance. The values of the TTP of the tumor margin vs. TTP values of the muscles, and the TTP values of the tumor center vs. TTP values of the muscles developed t-values, which were 1.7 and 0.806, respectively （P ≥ 0.05）, without statistical significance. In the patient group, the values of the PV, PE, TTP, and BV of the tumor margin were （88.95 ± 30.89） mL/（min.mL）, （61.87 ± 27.31） Hu, （37.72 ± 12.53） sec, and （18.38 ± 7.2） mL/100 g, respectively; these values of the tumor center were （39.77 ± 18.29） mL/（min.mL）, （14.57 ± 8.1） Hu, （35.64 ± 12.41） sec, and （11.22 ± 6.02） mL/100 g, respectively; these values of the muscles were （12.45 ± 6.5） mL/（min.mL）, （6.14 ± 2.66） Hu, （35.68± 12.35） sec, and （2.23 ± 1.11） mL/100 g, respectively. The values of the RPV, RPEI, and RBV of the tumor margin were 8.05 ± 5.04, 8.87 ± 4.32, and 12.16 ± 8.49, respectively; these values of the tumor center were 2.39 ± 1.68, 2.97 ± 2.1, 3.53 ± 2.82, respectively. The values of the PV, PEI, BV of the tumor margin in the patient group vs. the values of the muscles produced t-values, which were 13.8, 10.85, and 12.22, respectively （P 〈 0.01）, with significant differences; these values of the tumor center vs. the values of the muscles developed t-values, which were 9.158, 6.26, 8.654, respectively （P 〈 0.01）, with significant differences. The TTP value of the tumor margin vs. that of the muscles produced t-value, which was 0.371, and the TTP value of the tumor center vs. that of the muscles developed t-value, which was 1 （P 〉 0.05）, without statistical difference. CONCLUSION CT perfusion imaging technics demonstrates directly dynamic changes of blood flow to tumors, which assists in identifying tumor growth and necrosis, therefore, this research provides an evidence-based guidelines for the treatment of human lung squamous cell carcinoma and has far-reaching clinical significance.展开更多
AIM To compare high definition white light endoscopy and bright narrow band imaging for colon polyps' detection rates. METHODS Patients were randomised to high definition white light endoscopy(HD-WLE) or the brigh...AIM To compare high definition white light endoscopy and bright narrow band imaging for colon polyps' detection rates. METHODS Patients were randomised to high definition white light endoscopy(HD-WLE) or the bright narrow band imaging(b NBI) during withdrawal of the colonoscope. Polyps identified in either mode were characterised using b NBI with dual focus(b NBI-DF) according to the Sano's classification. The primary outcome was to compare adenoma detection rates(ADRs) between the two arms. The secondary outcome was to assess the negative predictive value(NPV) in differentiating adenomas from hyperplastic polyps for diminutive rectosigmoid lesions.RESULTS A total of 1006 patients were randomised to HD-WLE(n = 511) or b NBI(n = 495). The mean of adenoma per patient was 1.62 and 1.84, respectively. The ADRs in b NBI and HD-WLE group were 37.4% and 39.3%, respectively. When adjusted for withdrawal time(OR = 1.19, 95%CI: 1.15-1.24, P < 0.001), the use of b NBI was associated with a reduced ADR(OR = 0.69, 95%CI: 0.52-0.92). Nine hundred and thirty three polyps(86%) in both arms were predicted with high confidence. The sensitivity(Sn), specificity(Sp), positive predictive value and NPV in differentiating adenomatous from non-adenomatous polyps of all sizes were 95.9%, 87.2%, 94.0% and 91.1% respectively. The NPV in differentiating an adenoma from hyperplastic polyp using b NBI-DF for diminutive rectal polyps was 91.0%.CONCLUSION ADRs did not differ between b NBI and HD-WLE, however HD-WLE had higher ADR after adjustment of withdrawal time. b NBI surpassed the PIVI threshold for diminutive polyps.展开更多
AIM To assess the utility of modified Sano′s(MS) vs thenarrow band imaging international colorectal endoscopic(NICE) classification in differentiating colorectal polyps.METHODS Patients undergoing colonoscopy between...AIM To assess the utility of modified Sano′s(MS) vs thenarrow band imaging international colorectal endoscopic(NICE) classification in differentiating colorectal polyps.METHODS Patients undergoing colonoscopy between 2013 and 2015 were enrolled in this trial.Based on the MS or the NICE classifications,patients were randomised for real-time endoscopic diagnosis.This was followed by biopsies,endoscopic or surgical resection.The endoscopic diagnosis was then compared to the final(blinded) histopathology.The primary endpoint was the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of differentiating neoplastic and non-neoplastic polyps(MSⅡ/Ⅱo/Ⅲa/Ⅲb vs I or NICE 1 vs 2/3).The secondary endpoints were "endoscopic resectability"(MSⅡ/Ⅱo/Ⅲa vs Ⅰ/Ⅲb or NICE 2 vs 1/3),NPV for diminutive distal adenomas and prediction of post-polypectomy surveillance intervals.RESULTS A total of 348 patients were evaluated.The Sn,Sp,PPV and NPV in differentiating neoplastic polyps from non-neoplastic polyps were,98.9%,85.7%,98.2% and 90.9% for MS;and 99.1%,57.7%,95.4% and 88.2% for NICE,respectively.The area under the receiver operating characteristic curve(AUC) for MS was 0.92(95%CI:0.86-0.98);and AUC for NICE was 0.78(95%CI:0.69,0.88).The Sn,Sp,PPV and NPV in predicting "endoscopic resectability" were 98.9%,86.1%,97.8% and 92.5% for MS;and 98.6%,66.7%,94.7% and 88.9% for NICE,respectively.The AUC for MS was 0.92(95%CI:0.87-0.98);and the AUC for NICE was 0.83(95%CI:0.75-0.90).The AUC values were statistically different for both comparisons(P = 0.0165 and P = 0.0420,respectively).The accuracy for diagnosis of sessile serrated adenoma/polyp(SSA/P) with high confidence utilizing MS classification was 93.2%.The differentiation of SSA/P from other lesions achieved Sp,Sn,PPV and NPV of 87.2%,91.5%,89.6% and 98.6%,respectively.The NPV for predicting adenomas in diminutive rectosigmoid polyps(n = 150) was 96.6% and 95% with MS and NICE respectively.The calculated accuracy of post-polypectomy surveillance for MS group was 98.2%(167 out of 170) and for NICE group was 92.1%(139 out of 151).CONCLUSION The MS classification outperformed the NICE classification in differentiating neoplastic polyps and predicting endoscopic resectability.Both classifications met ASGE PIVI thresholds.展开更多
BACKGROUND Anxiety is a common comorbidity in patients with Crohn’s disease(CD).Data on the imaging characteristics of brain microstructure and cerebral perfusion in CD with anxiety are limited.AIM To compare the ima...BACKGROUND Anxiety is a common comorbidity in patients with Crohn’s disease(CD).Data on the imaging characteristics of brain microstructure and cerebral perfusion in CD with anxiety are limited.AIM To compare the imaging characteristics of brain microstructure and cerebral perfusion among CD patients with or without anxiety and healthy individuals.METHODS This prospective comparative study enrolled consecutive patients with active CD and healthy individuals who visited the study hospital between January 2022 and January 2023.Anxiety was measured using the Hospital Anxiety and Depression Scale-Anxiety.The imaging characteristics of brain microstructure and cerebral perfusion were measured by diffusion kurtosis imaging and intravoxel incoherent motion.RESULTSA total of 57 participants were enrolled. Among the patients with active CD, 16 had anxiety. Compared withhealthy individuals, patients with active CD demonstrated significantly lower radial kurtosis values in the rightcerebellar region 6, lower axial kurtosis (AK) values in the right insula, left superior temporal gyrus, and rightthalamus, and higher slow and fast apparent diffusion coefficients (ADCslow and ADCfast) in the bilateral frontal lobe,bilateral temporal lobe, and bilateral insular lobe (all P < 0.05). Compared with patients with CD without anxiety,patients with CD and anxiety exhibited significantly higher ADCslow values in the left insular lobe and lower AKvalues in the right insula and right anterior cuneus (all P < 0.05).CONCLUSIONThere are variations in brain microstructure and perfusion among CD patients with/without anxiety and healthyindividuals, suggesting potential use in assessing anxiety-related changes in active CD.展开更多
BACKGROUND Liver imaging and transient elastography(TE)are both tools used to assess liver fibrosis and steatosis among people with hepatitis C virus(HCV)infection.However,the diagnostic accuracy of conventional imagi...BACKGROUND Liver imaging and transient elastography(TE)are both tools used to assess liver fibrosis and steatosis among people with hepatitis C virus(HCV)infection.However,the diagnostic accuracy of conventional imaging in detecting fibrosis and steatosis in this patient population remains unclear.AIM To investigate the correlation between steatosis and fibrosis and abnormal findings on liver imaging in patients with HCV.METHODS We conducted a retrospective cross-sectional analysis of patients with HCV at Grady Liver Clinic who had TE exams between 2018-2019.We analyzed the correlation of controlled attenuation parameter and liver stiffness measurement on TE and abnormal findings on liver imaging.Liver imaging findings(hepatic steatosis,increased echogenicity,cirrhosis,and chronic liver disease)were further evaluated for their diagnostic performance in detecting fibrosis(≥F2,≥F3,≥F4)and steatosis(≥S1,≥S2,≥S3).RESULTS Of 959 HCV patients who underwent TE,651 had liver imaging.Higher controlled attenuation parameter scores were observed in patients with abnormal liver findings(P=0.0050),hepatic steatosis(P<0.0001),and increased echogenicity(P<0.0001).Higher liver stiffness measurement values were also noted in those with abnormal liver(P<0.0001)and increased echogenicity(P=0.0026).Steatosis severity correlated with hepatic steatosis(r=0.195,P<0.001)and increased echogenicity(r=0.209,P<0.001).For fibrosis detection,abnormal liver imaging had moderate sensitivity(81.7%)and specificity(70.4%)for cirrhosis(≥F4),while cirrhosis on imaging had high specificity(99.2%)but low sensitivity(18.3%).Increased echogenicity showed high specificity(92.8%)but low sensitivity(20.9%)for steatosis detection.CONCLUSION Liver imaging detects advanced fibrosis and steatosis but lacks early-stage sensitivity.Integrating TE with imaging may improve evaluation in patients with HCV.展开更多
This paper describes the control software together with the operational hardware, which successfully realizes the operation of a new fully programmable imaging system with high spatial and temporal resolutions on the ...This paper describes the control software together with the operational hardware, which successfully realizes the operation of a new fully programmable imaging system with high spatial and temporal resolutions on the KT5D magnetic torus, for observing the visible l ight emission from the plasma discharge.展开更多
Single-cell imaging,a powerful analytical method to study single-cell behavior,such as gene expression and protein profiling,provides an essential basis for modern medical diagnosis.The coding and localization functio...Single-cell imaging,a powerful analytical method to study single-cell behavior,such as gene expression and protein profiling,provides an essential basis for modern medical diagnosis.The coding and localization function of microfluidic chips has been developed and applied in living single-cell imaging in recent years.Simultaneously,chip-based living single-cell imaging is also limited by complicated trapping steps,low cell utilization,and difficult high-resolution imaging.To solve these problems,an ultra-thin temperature-controllable microwell array chip(UTCMA chip)was designed to develop a living single-cell workstation in this study for continuous on-chip culture and real-time high-resolution imaging of living single cells.The chip-based on ultra-thin ITO glass is highly matched with an inverted microscope(or confocal microscope)with a high magnification objective(100×oil lens),and the temperature of the chip can be controlled by combining it with a home-made temperature control device.High-throughput single-cell patterning is realized in one step when the microwell array on the chip uses hydrophilic glass as the substrate and hydrophobic SU-8 photoresist as the wall.The cell utilization rate,single-cell capture rate,and microwell occupancy rate are all close to 100%in the microwell array.This method will be useful in rare single-cell research,extending its application in the biological and medical-related fields,such as early diagnosis of disease,personalized therapy,and research-based on single-cell analysis.展开更多
In addition to the tens of millions of medical doses consumed annually around the world,a vast number of nuclear magnetic resonance imaging(MRI)contrast agents are being deployed in MRI research and development,offeri...In addition to the tens of millions of medical doses consumed annually around the world,a vast number of nuclear magnetic resonance imaging(MRI)contrast agents are being deployed in MRI research and development,offering precise diagnostic information,targeting capabilities,and analyte sensing.Superparamagnetic iron oxide nanoparticles(SPIONs)are notable among these agents,providing effective and versatile MRI applications while also being heavy-metal-free,bioconjugatable,and theranostic.We designed and implemented a novel two-pronged computational and experimental strategy to meet the demand for the efficient and rigorous development of SPION-based MRI agents.Our MATLAB-based modeling simulation and magnetic characterization revealed that extremely small maghemite SPIONs in the 1-3 nm range possess significantly reduced transversal relaxation rates(R_(2))and are therefore preferred for positive(T_(1)-weighted)MRI.Moreover,X-ray diffraction and X-ray absorption fine structure analyses demonstrated that the diffraction pattern and radial distribution function of our SPIONs matched those of the targeted maghemite crystals.In addition,simulations of the X-ray near-edge structure spectra indicated that our synthesized SPIONs,even at 1 nm,maintained a spherical structure.Furthermore,in vitro and in vivo MRI investigations showed that our 1-nm SPIONs effectively highlighted whole-body blood vessels and major organs in mice and could be cleared through the kidney route to minimize potential post-imaging side effects.Overall,our innovative approach enabled a swift discovery of the desired SPION structure,followed by targeted synthesis,synchrotron radiation spectroscopic studies,and MRI evaluations.The efficient and rigorous development of our high-performance SPIONs can set the stage for a computational and experimental platform for the development of future MRI agents.展开更多
Pancreatic cancer(PC)remains one of the deadliest cancers worldwide,and has a poor,five-year survival rate of 5%.Although complete surgical resection is the only curative therapy for pancreatic cancer,less than20%of n...Pancreatic cancer(PC)remains one of the deadliest cancers worldwide,and has a poor,five-year survival rate of 5%.Although complete surgical resection is the only curative therapy for pancreatic cancer,less than20%of newly-diagnosed patients undergo surgical resection with a curative intent.Due to the lack of early symptoms and the tendency of pancreatic adenocarcinoma to invade adjacent structures or to metastasize at an early stage,many patients with pancreatic cancer already have advanced disease at the time of their diagnosis and,therefore,there is a high mortality rate.To improve the patient survival rate,early detection of PC is critical.The diagnosis of PC relies on computed tomography(CT)and/or magnetic resonance imaging(MRI)with magnetic resonance cholangiopancreatography(MRCP),or biopsy or fine-needle aspiration using endoscopic ultrasound(EUS).Although multi-detector row computed tomography currently has a major role in the evaluation of PC,MRI with MRCP facilitates better detection of tumors at an early stage by allowing a comprehensive analysis of the morphological changes of the pancreas parenchyma and pancreatic duct.The diagnosis could be improved using positron emission tomography techniques in special conditions in which CT and EUS are not completely diagnostic.It is essential for clinicians to understand the advantages and disadvantages of the various pancreatic imaging modalities in order to be able to make optimal treatment and management decisions.Our study investigates the current role and innovative techniques of pancreatic imaging focused on the detection of pancreatic cancer.展开更多
Methods of arc length control and visual image based weld detection for precision pulse TIG welding were investigated. With a particular all hardware circuit, arc voltage during peak current stage is sampled and inte...Methods of arc length control and visual image based weld detection for precision pulse TIG welding were investigated. With a particular all hardware circuit, arc voltage during peak current stage is sampled and integrated to indicate arc length, deviation of arc length and adjusting parameters are calculated and output to drive a step motor directly. According to the features of welding image grabbed with CCD camera, a special algorithm was developed to detect the central line of weld fast and accurately. Then an application system were established, whose static arc length error is ±0.1 mm with 20 A average current and 1 mm given arc length, static detection precision of weld is 0.01 mm , processing time of each image is less than 120 ms . Precision pulse TIG welding of some given thin stainless steel components with complicated curved surface was successfully realized.展开更多
In industrial flotation, froth layer plays an important role and reflects directly whether coal, air, water and reagents match each other properly or not and whether the quality of flotation is good or not. So the sup...In industrial flotation, froth layer plays an important role and reflects directly whether coal, air, water and reagents match each other properly or not and whether the quality of flotation is good or not. So the supervision and recognition of the state of froth layer is very important in the flotation process. The ash content of clean coal froth was predicted through extracting the features of images of flotation froth. The froth images were classified according to their structure. A control system of adding flotation reagents was established based on the LVQ neural net.展开更多
Choledochocele is a congenital abnormality of the biliary system,which characterized by a cystic dilatation of intramural segment of the distal common bile duct.Choledochocele manifests as cystic lesions in the duoden...Choledochocele is a congenital abnormality of the biliary system,which characterized by a cystic dilatation of intramural segment of the distal common bile duct.Choledochocele manifests as cystic lesions in the duodenal lumen and resembles duodenal duplication cysts in imaging.We reported a patient with choledochocele.Magnetic resonance cholangiopancreatography showed a thin-walled sac in the duodenal cavity and a fine tubular structure connecting with the end of the common bile duct.Magnetic resonance cholangiopancreatography is a noninvasive and convenient technique in the diagnosis of choledochocele.展开更多
The anatomical organization of the corticopontocerebellar tract （CPCT） in the human brain remains poorly understood. The present study investigated probabilistic tractography of the CPCT in the human brain using dif...The anatomical organization of the corticopontocerebellar tract （CPCT） in the human brain remains poorly understood. The present study investigated probabilistic tractography of the CPCT in the human brain using diffusion tensor tractography with functional magnetic resonance imaging. CPCT data was obtained from 14 healthy subjects. CPCT images were obtained from functional magnetic resonance imaging and diffusion tensor tractography, revealing that the CPCT originated from the primary sensorimotor cortex and descended to the pontine nucleus through the corona radiata, the posterior limb of the internal capsule, and the cerebral peduncle. After crossing the pons through the transverse pontine fibers, the CPCT entered the cerebellum via the middle cerebral peduncle. However, some variation was detected in the midbrain （middle cerebral peduncle and/or medial lemniscus） and pons （ventral and/or dorsal transverse pontine fibers）. The CPCT was analyzed in 3 dimensions from the cerebral cortex to the cerebellum. These results could be informative for future studies of motor control in the human brain.展开更多
文摘This study aims to analyze and discuss the current situation of quality control and quality management in medical imaging.Firstly,it defines the concepts of quality management and image quality,emphasizing the crucial role of the department's Quality and Safety Team in imaging quality management[1].Subsequently,it details the composition and responsibilities of the Quality and Safety Management Group,as well as the specific divisions of labor and tasks of the Quality Management Team.The effective implementation of comprehensive quality control in the imaging department is ensured through the"Seven-Star Sword"method,which encompasses total process control,organization-wide participation,and total quality control[2].Furthermore,the application of the PDCA(Plan-Do-Check-Act)cycle in quality management is explored,along with strategies to improve patient satisfaction by reducing the waiting time for imaging reports[3].Finally,the management of a key departmental medical quality control indicator—critical values—is analyzed,and improvement measures are proposed[4].This study underscores the importance of quality management in enhancing medical service quality and ensuring patient safety,and puts forward specific implementation strategies and improvement methods.
文摘The conventional method of seismic data acquisition geometry design is based on the assumption of horizontal subsurface reflectors, which often is not suitable for complex structure. We start from a controlled illumination analysis and put forward a method of seismic survey geometry design for target-oriented imaging. The method needs a velocity model obtained by a preliminary seismic interpretation. The one-way Fourier finite-difference wave propagator is used to extrapolate plane wave sources on the target layer to the surface. By analyzing the wave energy distribution at the surface extrapolated from the target layer, the shot or receiver locations needed for target layer imaging can be determined. Numerical tests using the SEG-EAGE salt model suggest that this method is useful for confirming the special seismic acquisition geometry layout for target-oriented imaging.
文摘Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular(approximately 10% of tissue volume), interstitium(approximately 15%) and intracellular(approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types Ⅰ/Ⅲ collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis(e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy(hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging(MRI) has the ability to characterize tissue proton relaxation times(T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI(DE-MRI) and multi-detector computed tomography(DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary catheterization and possibility of tissue sampling error. Similar to delayed contrast enhancement, equilibrium contrast enhanced MRI/MDCT and T1 mapping is completely noninvasive and may play a specialized role in diagnosis of subclinical and other myocardial pathologies. DE-MRI and when T1-mapping demonstrated sub-epicardium, sub-endocardial and patchy mid-myocardial enhancement in myocarditis, Behcet's disease and sarcoidosis, respectively. Furthermore, recent studies showed that the combined technique of cine, T2-weighted and DE-MRI technique has high diagnostic accuracy for detecting myocarditis. When the tomographic techniques are coupled with myocardial perfusion and left ventricular function they can provide valuable information on the progression of myocardial pathologies and effectiveness of new therapies.
基金We acknowledge the financial support by the National Natural Science Foundation of China under contact Nos.61622508,61622509,and 61575201.
文摘Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex and needs to trade off other aberration in traditional ways.Although metasurface offers an effective method to overcome these limits and results in well-engineered dispersion,off-axis dispersion control is still a challenging topic.In this paper,we design a single-layer metalens which is capable of focusing at three wavelengths(473 nm,532 nm,and 632 nm)with different incident angles(0°,-17°and 17°)into the same point.We also demonstrate that this metalens can provide an alternative for the bulky color synthetic prism in a 3-chips digital micromirror device(DMD)laser projection system.Through this approach,various off-axis dispersion controlling optical devices could be realized.
文摘Chemical imaging(CI)possesses a strong ability of pharmaceutical analysis.Its great strength relies on the integration of traditional spectroscopy(one dimension)and imaging technique(two dimensions)to generate three-dimensional data hypercubes.Data pre-processing or processing methods are proposed to analyze vast data matrixes and thereby realizing different research objectives.In this review paper,various pharmaceutical applications of quality control over the past few years are summed up in two groups of final product test and industrial utilization.The scope of"quality control"here includes traditional analytical use,process understanding and manufactural control.Finally,two major challenges about undesirable sample geometry and lengthy acquisition time are discussed for prospective commercial or industrial application.
文摘OBJECTIVE By analysis and evaluation of the perfusion images and perfusion parameters of the rabbits with VX2 lung tumor, the association between the perfusion parameters and tumor angiogenesis of patients with squamous cell carcinoma of the lung has been studied in order to establish a non-invasive and effective way to detect tumor blood supply, which is be able to exhibit hemodynamic data in tumors during cancer treatments. METHODS Fifteen Netherlands rabbits inoculated with VX2 lung tumor （rabbit group） and 25 patients with squamous cell carcinoma of the lung （patient group） received a multi-slice spiral CT perfusion imaging test using the Netherlands PHILIPS Brilliance 16-slice spiral CT and a U.S. MEDRAD binocular highpressure syringe. Image postprocessing was done using the special perfusion software and EBW 4.0 Workstation. Perfusion volume （PV）, peak enhanced increment （PEI）, transit time peak （TTP）, and blood volume （BV） were measured and analyzed. RESULTS In the rabbit group, the values of the PV, PEI, TTP, and BV of the tumor margin were （53.89 ± 13.38） mL/（min.mL）, （45.71 ± 15.52） Hu, （39.29 ± 10.10） sec, and （31.45 ± 18.19） mL/100 g, respectively; these values of the tumor center were （36.57 ± 14.17） mL/（min.mL）, （28.64 ± 11.74） Hu, （39.00 ＋ 9.78） sec, and （19.76 ± 13.95） mL/100 g, respectively; the values of the muscles were （12.45± 4.38） mL/（min.mL）, （10.98 ± 5.03） Hu, （38.86 ± 10.04） sec, and （5.38 ±2.87） mL/100 g, respectively. The values of the relative perfusion volume （RPV）, relative peak enhanced increment （RPEI）, and relative blood volume （RBV） of the tumor margin were 4.38 ± 1.45, 3.96± 1.45, 9.99 ± 11.7, respectively; these values of the tumor center were 2.14 ± 1.08, 1.83±1.45, 4.17 ±3.39, respectively. The values of the PV, PEL BV of the tumor margin vs. the values of the muscles developed t-values, which were 15.028, 10.79, and 5.88, respectively （P ≤ 0.01）, with statistical significance; the values of the PV, PEI, BV of the tumor center vs. the values of the muscles produced t-values, which were 8.67, 7.49, and 4.55, respectively （P 〈 0.01）, with statistical significance. The values of the TTP of the tumor margin vs. TTP values of the muscles, and the TTP values of the tumor center vs. TTP values of the muscles developed t-values, which were 1.7 and 0.806, respectively （P ≥ 0.05）, without statistical significance. In the patient group, the values of the PV, PE, TTP, and BV of the tumor margin were （88.95 ± 30.89） mL/（min.mL）, （61.87 ± 27.31） Hu, （37.72 ± 12.53） sec, and （18.38 ± 7.2） mL/100 g, respectively; these values of the tumor center were （39.77 ± 18.29） mL/（min.mL）, （14.57 ± 8.1） Hu, （35.64 ± 12.41） sec, and （11.22 ± 6.02） mL/100 g, respectively; these values of the muscles were （12.45 ± 6.5） mL/（min.mL）, （6.14 ± 2.66） Hu, （35.68± 12.35） sec, and （2.23 ± 1.11） mL/100 g, respectively. The values of the RPV, RPEI, and RBV of the tumor margin were 8.05 ± 5.04, 8.87 ± 4.32, and 12.16 ± 8.49, respectively; these values of the tumor center were 2.39 ± 1.68, 2.97 ± 2.1, 3.53 ± 2.82, respectively. The values of the PV, PEI, BV of the tumor margin in the patient group vs. the values of the muscles produced t-values, which were 13.8, 10.85, and 12.22, respectively （P 〈 0.01）, with significant differences; these values of the tumor center vs. the values of the muscles developed t-values, which were 9.158, 6.26, 8.654, respectively （P 〈 0.01）, with significant differences. The TTP value of the tumor margin vs. that of the muscles produced t-value, which was 0.371, and the TTP value of the tumor center vs. that of the muscles developed t-value, which was 1 （P 〉 0.05）, without statistical difference. CONCLUSION CT perfusion imaging technics demonstrates directly dynamic changes of blood flow to tumors, which assists in identifying tumor growth and necrosis, therefore, this research provides an evidence-based guidelines for the treatment of human lung squamous cell carcinoma and has far-reaching clinical significance.
文摘AIM To compare high definition white light endoscopy and bright narrow band imaging for colon polyps' detection rates. METHODS Patients were randomised to high definition white light endoscopy(HD-WLE) or the bright narrow band imaging(b NBI) during withdrawal of the colonoscope. Polyps identified in either mode were characterised using b NBI with dual focus(b NBI-DF) according to the Sano's classification. The primary outcome was to compare adenoma detection rates(ADRs) between the two arms. The secondary outcome was to assess the negative predictive value(NPV) in differentiating adenomas from hyperplastic polyps for diminutive rectosigmoid lesions.RESULTS A total of 1006 patients were randomised to HD-WLE(n = 511) or b NBI(n = 495). The mean of adenoma per patient was 1.62 and 1.84, respectively. The ADRs in b NBI and HD-WLE group were 37.4% and 39.3%, respectively. When adjusted for withdrawal time(OR = 1.19, 95%CI: 1.15-1.24, P < 0.001), the use of b NBI was associated with a reduced ADR(OR = 0.69, 95%CI: 0.52-0.92). Nine hundred and thirty three polyps(86%) in both arms were predicted with high confidence. The sensitivity(Sn), specificity(Sp), positive predictive value and NPV in differentiating adenomatous from non-adenomatous polyps of all sizes were 95.9%, 87.2%, 94.0% and 91.1% respectively. The NPV in differentiating an adenoma from hyperplastic polyp using b NBI-DF for diminutive rectal polyps was 91.0%.CONCLUSION ADRs did not differ between b NBI and HD-WLE, however HD-WLE had higher ADR after adjustment of withdrawal time. b NBI surpassed the PIVI threshold for diminutive polyps.
文摘AIM To assess the utility of modified Sano′s(MS) vs thenarrow band imaging international colorectal endoscopic(NICE) classification in differentiating colorectal polyps.METHODS Patients undergoing colonoscopy between 2013 and 2015 were enrolled in this trial.Based on the MS or the NICE classifications,patients were randomised for real-time endoscopic diagnosis.This was followed by biopsies,endoscopic or surgical resection.The endoscopic diagnosis was then compared to the final(blinded) histopathology.The primary endpoint was the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of differentiating neoplastic and non-neoplastic polyps(MSⅡ/Ⅱo/Ⅲa/Ⅲb vs I or NICE 1 vs 2/3).The secondary endpoints were "endoscopic resectability"(MSⅡ/Ⅱo/Ⅲa vs Ⅰ/Ⅲb or NICE 2 vs 1/3),NPV for diminutive distal adenomas and prediction of post-polypectomy surveillance intervals.RESULTS A total of 348 patients were evaluated.The Sn,Sp,PPV and NPV in differentiating neoplastic polyps from non-neoplastic polyps were,98.9%,85.7%,98.2% and 90.9% for MS;and 99.1%,57.7%,95.4% and 88.2% for NICE,respectively.The area under the receiver operating characteristic curve(AUC) for MS was 0.92(95%CI:0.86-0.98);and AUC for NICE was 0.78(95%CI:0.69,0.88).The Sn,Sp,PPV and NPV in predicting "endoscopic resectability" were 98.9%,86.1%,97.8% and 92.5% for MS;and 98.6%,66.7%,94.7% and 88.9% for NICE,respectively.The AUC for MS was 0.92(95%CI:0.87-0.98);and the AUC for NICE was 0.83(95%CI:0.75-0.90).The AUC values were statistically different for both comparisons(P = 0.0165 and P = 0.0420,respectively).The accuracy for diagnosis of sessile serrated adenoma/polyp(SSA/P) with high confidence utilizing MS classification was 93.2%.The differentiation of SSA/P from other lesions achieved Sp,Sn,PPV and NPV of 87.2%,91.5%,89.6% and 98.6%,respectively.The NPV for predicting adenomas in diminutive rectosigmoid polyps(n = 150) was 96.6% and 95% with MS and NICE respectively.The calculated accuracy of post-polypectomy surveillance for MS group was 98.2%(167 out of 170) and for NICE group was 92.1%(139 out of 151).CONCLUSION The MS classification outperformed the NICE classification in differentiating neoplastic polyps and predicting endoscopic resectability.Both classifications met ASGE PIVI thresholds.
基金Ethics Committee of Affiliated Changzhou Second People’s Hospital of Nanjing Medical University(approval number KY039-01).
文摘BACKGROUND Anxiety is a common comorbidity in patients with Crohn’s disease(CD).Data on the imaging characteristics of brain microstructure and cerebral perfusion in CD with anxiety are limited.AIM To compare the imaging characteristics of brain microstructure and cerebral perfusion among CD patients with or without anxiety and healthy individuals.METHODS This prospective comparative study enrolled consecutive patients with active CD and healthy individuals who visited the study hospital between January 2022 and January 2023.Anxiety was measured using the Hospital Anxiety and Depression Scale-Anxiety.The imaging characteristics of brain microstructure and cerebral perfusion were measured by diffusion kurtosis imaging and intravoxel incoherent motion.RESULTSA total of 57 participants were enrolled. Among the patients with active CD, 16 had anxiety. Compared withhealthy individuals, patients with active CD demonstrated significantly lower radial kurtosis values in the rightcerebellar region 6, lower axial kurtosis (AK) values in the right insula, left superior temporal gyrus, and rightthalamus, and higher slow and fast apparent diffusion coefficients (ADCslow and ADCfast) in the bilateral frontal lobe,bilateral temporal lobe, and bilateral insular lobe (all P < 0.05). Compared with patients with CD without anxiety,patients with CD and anxiety exhibited significantly higher ADCslow values in the left insular lobe and lower AKvalues in the right insula and right anterior cuneus (all P < 0.05).CONCLUSIONThere are variations in brain microstructure and perfusion among CD patients with/without anxiety and healthyindividuals, suggesting potential use in assessing anxiety-related changes in active CD.
文摘BACKGROUND Liver imaging and transient elastography(TE)are both tools used to assess liver fibrosis and steatosis among people with hepatitis C virus(HCV)infection.However,the diagnostic accuracy of conventional imaging in detecting fibrosis and steatosis in this patient population remains unclear.AIM To investigate the correlation between steatosis and fibrosis and abnormal findings on liver imaging in patients with HCV.METHODS We conducted a retrospective cross-sectional analysis of patients with HCV at Grady Liver Clinic who had TE exams between 2018-2019.We analyzed the correlation of controlled attenuation parameter and liver stiffness measurement on TE and abnormal findings on liver imaging.Liver imaging findings(hepatic steatosis,increased echogenicity,cirrhosis,and chronic liver disease)were further evaluated for their diagnostic performance in detecting fibrosis(≥F2,≥F3,≥F4)and steatosis(≥S1,≥S2,≥S3).RESULTS Of 959 HCV patients who underwent TE,651 had liver imaging.Higher controlled attenuation parameter scores were observed in patients with abnormal liver findings(P=0.0050),hepatic steatosis(P<0.0001),and increased echogenicity(P<0.0001).Higher liver stiffness measurement values were also noted in those with abnormal liver(P<0.0001)and increased echogenicity(P=0.0026).Steatosis severity correlated with hepatic steatosis(r=0.195,P<0.001)and increased echogenicity(r=0.209,P<0.001).For fibrosis detection,abnormal liver imaging had moderate sensitivity(81.7%)and specificity(70.4%)for cirrhosis(≥F4),while cirrhosis on imaging had high specificity(99.2%)but low sensitivity(18.3%).Increased echogenicity showed high specificity(92.8%)but low sensitivity(20.9%)for steatosis detection.CONCLUSION Liver imaging detects advanced fibrosis and steatosis but lacks early-stage sensitivity.Integrating TE with imaging may improve evaluation in patients with HCV.
基金The project supported by Chinese National Science Foundation (Nos. 10335060, 10235010) and Creative Project Grants of ChineseAcademy of Science
文摘This paper describes the control software together with the operational hardware, which successfully realizes the operation of a new fully programmable imaging system with high spatial and temporal resolutions on the KT5D magnetic torus, for observing the visible l ight emission from the plasma discharge.
基金supported by the National Natural Science Foundation of China(Nos.21625501,21936001)the Beijing Outstanding Young Scientist Program(No.BJJWZYJH01201910005017).
文摘Single-cell imaging,a powerful analytical method to study single-cell behavior,such as gene expression and protein profiling,provides an essential basis for modern medical diagnosis.The coding and localization function of microfluidic chips has been developed and applied in living single-cell imaging in recent years.Simultaneously,chip-based living single-cell imaging is also limited by complicated trapping steps,low cell utilization,and difficult high-resolution imaging.To solve these problems,an ultra-thin temperature-controllable microwell array chip(UTCMA chip)was designed to develop a living single-cell workstation in this study for continuous on-chip culture and real-time high-resolution imaging of living single cells.The chip-based on ultra-thin ITO glass is highly matched with an inverted microscope(or confocal microscope)with a high magnification objective(100×oil lens),and the temperature of the chip can be controlled by combining it with a home-made temperature control device.High-throughput single-cell patterning is realized in one step when the microwell array on the chip uses hydrophilic glass as the substrate and hydrophobic SU-8 photoresist as the wall.The cell utilization rate,single-cell capture rate,and microwell occupancy rate are all close to 100%in the microwell array.This method will be useful in rare single-cell research,extending its application in the biological and medical-related fields,such as early diagnosis of disease,personalized therapy,and research-based on single-cell analysis.
基金supported by start-up funds from the laboratory of H.WFaculty Sponsored Student Research Awards(FSSRA)from the Department of Chemistry and Biochemistry in the College of Science and Mathematics at California State University,Fresno。
文摘In addition to the tens of millions of medical doses consumed annually around the world,a vast number of nuclear magnetic resonance imaging(MRI)contrast agents are being deployed in MRI research and development,offering precise diagnostic information,targeting capabilities,and analyte sensing.Superparamagnetic iron oxide nanoparticles(SPIONs)are notable among these agents,providing effective and versatile MRI applications while also being heavy-metal-free,bioconjugatable,and theranostic.We designed and implemented a novel two-pronged computational and experimental strategy to meet the demand for the efficient and rigorous development of SPION-based MRI agents.Our MATLAB-based modeling simulation and magnetic characterization revealed that extremely small maghemite SPIONs in the 1-3 nm range possess significantly reduced transversal relaxation rates(R_(2))and are therefore preferred for positive(T_(1)-weighted)MRI.Moreover,X-ray diffraction and X-ray absorption fine structure analyses demonstrated that the diffraction pattern and radial distribution function of our SPIONs matched those of the targeted maghemite crystals.In addition,simulations of the X-ray near-edge structure spectra indicated that our synthesized SPIONs,even at 1 nm,maintained a spherical structure.Furthermore,in vitro and in vivo MRI investigations showed that our 1-nm SPIONs effectively highlighted whole-body blood vessels and major organs in mice and could be cleared through the kidney route to minimize potential post-imaging side effects.Overall,our innovative approach enabled a swift discovery of the desired SPION structure,followed by targeted synthesis,synchrotron radiation spectroscopic studies,and MRI evaluations.The efficient and rigorous development of our high-performance SPIONs can set the stage for a computational and experimental platform for the development of future MRI agents.
文摘Pancreatic cancer(PC)remains one of the deadliest cancers worldwide,and has a poor,five-year survival rate of 5%.Although complete surgical resection is the only curative therapy for pancreatic cancer,less than20%of newly-diagnosed patients undergo surgical resection with a curative intent.Due to the lack of early symptoms and the tendency of pancreatic adenocarcinoma to invade adjacent structures or to metastasize at an early stage,many patients with pancreatic cancer already have advanced disease at the time of their diagnosis and,therefore,there is a high mortality rate.To improve the patient survival rate,early detection of PC is critical.The diagnosis of PC relies on computed tomography(CT)and/or magnetic resonance imaging(MRI)with magnetic resonance cholangiopancreatography(MRCP),or biopsy or fine-needle aspiration using endoscopic ultrasound(EUS).Although multi-detector row computed tomography currently has a major role in the evaluation of PC,MRI with MRCP facilitates better detection of tumors at an early stage by allowing a comprehensive analysis of the morphological changes of the pancreas parenchyma and pancreatic duct.The diagnosis could be improved using positron emission tomography techniques in special conditions in which CT and EUS are not completely diagnostic.It is essential for clinicians to understand the advantages and disadvantages of the various pancreatic imaging modalities in order to be able to make optimal treatment and management decisions.Our study investigates the current role and innovative techniques of pancreatic imaging focused on the detection of pancreatic cancer.
文摘Methods of arc length control and visual image based weld detection for precision pulse TIG welding were investigated. With a particular all hardware circuit, arc voltage during peak current stage is sampled and integrated to indicate arc length, deviation of arc length and adjusting parameters are calculated and output to drive a step motor directly. According to the features of welding image grabbed with CCD camera, a special algorithm was developed to detect the central line of weld fast and accurately. Then an application system were established, whose static arc length error is ±0.1 mm with 20 A average current and 1 mm given arc length, static detection precision of weld is 0.01 mm , processing time of each image is less than 120 ms . Precision pulse TIG welding of some given thin stainless steel components with complicated curved surface was successfully realized.
基金Supported by the Nation’s Natural Science Foundation(5 99740 3 2 )
文摘In industrial flotation, froth layer plays an important role and reflects directly whether coal, air, water and reagents match each other properly or not and whether the quality of flotation is good or not. So the supervision and recognition of the state of froth layer is very important in the flotation process. The ash content of clean coal froth was predicted through extracting the features of images of flotation froth. The froth images were classified according to their structure. A control system of adding flotation reagents was established based on the LVQ neural net.
文摘Choledochocele is a congenital abnormality of the biliary system,which characterized by a cystic dilatation of intramural segment of the distal common bile duct.Choledochocele manifests as cystic lesions in the duodenal lumen and resembles duodenal duplication cysts in imaging.We reported a patient with choledochocele.Magnetic resonance cholangiopancreatography showed a thin-walled sac in the duodenal cavity and a fine tubular structure connecting with the end of the common bile duct.Magnetic resonance cholangiopancreatography is a noninvasive and convenient technique in the diagnosis of choledochocele.
基金the National Research Foundation of Korea Grant funded by the Korean Government,No. KRF-2008-314-E00173
文摘The anatomical organization of the corticopontocerebellar tract （CPCT） in the human brain remains poorly understood. The present study investigated probabilistic tractography of the CPCT in the human brain using diffusion tensor tractography with functional magnetic resonance imaging. CPCT data was obtained from 14 healthy subjects. CPCT images were obtained from functional magnetic resonance imaging and diffusion tensor tractography, revealing that the CPCT originated from the primary sensorimotor cortex and descended to the pontine nucleus through the corona radiata, the posterior limb of the internal capsule, and the cerebral peduncle. After crossing the pons through the transverse pontine fibers, the CPCT entered the cerebellum via the middle cerebral peduncle. However, some variation was detected in the midbrain （middle cerebral peduncle and/or medial lemniscus） and pons （ventral and/or dorsal transverse pontine fibers）. The CPCT was analyzed in 3 dimensions from the cerebral cortex to the cerebellum. These results could be informative for future studies of motor control in the human brain.
