BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.Th...BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.This study aimed to assess the diagnostic value of dual-layer spectral computed tomography(CT)-derived VMIs,in combination with multiplanar reformation(MPR)and evaluation of peritumoral fat stranding(PFS),for improving the accuracy of T staging in CRC.AIM To assess the diagnostic performance of dual-layer spectral CT(DLSCT)VMIs,particularly at low energy levels,and their integration with personalized MPR for preoperative T staging of CRC.METHODS In this retrospective study,157 patients with pathologically confirmed CRC(mean age:63.5±12.1 years)underwent DLSCT within 1 week before surgery.VMIs ranging from 40 keV to 70 keV(at 10 keV intervals)and conventional polyenergetic images(PEIs)were reconstructed.Objective image quality parameters,including image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR),were quantified,alongside subjective image quality scores using a 5-point Likert scale.Interobserver agreement was evaluated usingκstatistics.Taking histopathology as the reference standard,the diagnostic accuracy of T staging(T1-2 vs T3-4)was compared across PEIs and VMIs,both with and without MPR and PFS.RESULTS Low-keV VMIs(40-70 keV)demonstrated significantly higher SNR and CNR than PEIs(all P<0.001).Notably,40-keV VMIs achieved noise levels comparable to PEIs(8.17±3.63 vs 8.53±2.90;P=0.673).Subjective image quality peaked at 40-50 keV VMIs(Likert scores 4.85-4.88 vs 3.97 for PEIs;P<0.001),supported by excellent interobserver agreement(κ=0.812-0.913).The combination of 40-50 keV VMIs with MPR yielded the highest T staging accuracy(94.27%)compared to axial PEIs(70.7%),with a sensitivity and specificity of 83.87%and 96.83%,respectively(Youden index=0.81;P<0.05).While PFS enhanced staging accuracy on PEIs(up to 77.07%with MPR),it provided no significant additional benefit for VMIs.CONCLUSION DLSCT VMIs at 40-50 keV significantly enhanced image quality and improved preoperative T staging accuracy of CRC when combined with MPR.These findings underscored the clinical value of low-keV spectral imaging in tailoring individualized treatment strategies.展开更多
The optical diffraction effect imposes a radical obstacle preventing conventional optical microscopes from achieving an imaging resolution beyond the Abbe diffraction limit and thereby restricting their usage in a mul...The optical diffraction effect imposes a radical obstacle preventing conventional optical microscopes from achieving an imaging resolution beyond the Abbe diffraction limit and thereby restricting their usage in a multitude of nanoscale applications.Over the past decade,the optical microsphere nanoimaging technique has been demonstrated to be a cost-effective solution for overcoming the diffraction limit and has achieved an imaging resolution of up to about k6k8 in a real-time and label-free manner,making it highly competitive among numerous super-resolution imaging technologies.In this review,we summarize the underlying nano-imaging mechanisms of the microsphere nanoscope and key advancements aimed at imaging performance enhancement:first,to change the working environment or modify the peripheral hardware of a single microsphere nanoscope at the system level;second,to compose the microsphere compound lens;and third,to engineer the geometry or ingredients of microspheres.We also analyze challenges yet to be overcome in optical microsphere nano-imaging,followed by an outlook of this technique.展开更多
This paper proposes an automated detection framework for transmission facilities using a featureattention multi-scale robustness network(FAMSR-Net)with high-fidelity virtual images.The proposed framework exhibits thre...This paper proposes an automated detection framework for transmission facilities using a featureattention multi-scale robustness network(FAMSR-Net)with high-fidelity virtual images.The proposed framework exhibits three key characteristics.First,virtual images of the transmission facilities generated using StyleGAN2-ADA are co-trained with real images.This enables the neural network to learn various features of transmission facilities to improve the detection performance.Second,the convolutional block attention module is deployed in FAMSR-Net to effectively extract features from images and construct multi-dimensional feature maps,enabling the neural network to perform precise object detection in various environments.Third,an effective bounding box optimization method called Scylla-IoU is deployed on FAMSR-Net,considering the intersection over union,center point distance,angle,and shape of the bounding box.This enables the detection of power facilities of various sizes accurately.Extensive experiments demonstrated that FAMSRNet outperforms other neural networks in detecting power facilities.FAMSR-Net also achieved the highest detection accuracy when virtual images of the transmission facilities were co-trained in the training phase.The proposed framework is effective for the scheduled operation and maintenance of transmission facilities because an optical camera is currently the most promising tool for unmanned aerial vehicles.This ultimately contributes to improved inspection efficiency,reduced maintenance risks,and more reliable power delivery across extensive transmission facilities.展开更多
BACKGROUND Irreversible transmural intestinal necrosis(ITIN)is associated with high mortality rates in patients with acute occlusive mesenteric ischemia(AOMI).Currently,there are not many studies on the use of dual en...BACKGROUND Irreversible transmural intestinal necrosis(ITIN)is associated with high mortality rates in patients with acute occlusive mesenteric ischemia(AOMI).Currently,there are not many studies on the use of dual energy computed tomography(DECT)for evaluating ITIN.AIM To evaluate the diagnostic value of DECT for ITIN in AOMI.METHODS The cases and computed tomography(CT)images of 102 patients with clinically diagnosed AOMI(including 48 ITIN)from January 2012 to January 2022 were retrospectively collected.The CT scans included both multidetector CT and DECT.The raw data from DECT portal-venous phase were reconstructed into 120 kVp mixed energy image,50 keV virtual monoenergetic imaging,and iodine map.Two radiologists independently completed the subjective visual assessment of CT signs related to AOMI.Objective parameters,including the attenuation of the normal and_(lesion)intestinal wall segment(CT50 keV_(lesion),CT_(50 keV normal/lesion))and iodine concentrations(IC_(lesion)and I_(Cnormal/lesion)),were quantified.Furthermore,multivariate logistic regression,receiver operating characteristic curves,and area under the curve(AUC)values were used to evaluate the subjective and objective indicators in predicting ITIN.RESULTS Regarding subjective signs,logistic regression analysis revealed reduced or absent bowel wall enhancement[odds ratio(OR)=5.576,95%confidence interval(CI):1.547-20.093],bowel dilation(OR=11.613,95%CI:3.790-35.586),and parenchymatous organ infarction(OR=4.727,95%CI:1.536-14.551)were independent risk factors for the ITIN.CT subjective signs had a high diagnostic efficacy for ITIN(AUC=0.853).The two DECT objective parameters also exhibited excellent diagnostic value for ITIN,with an AUC of 0.79,a cut-off value of CT50 keV normal/_(lesion)=2.81,and an AUC of 0.777 with a cut-off value of I_(Cnormal/lesion)=2.39.The Delong test showed that there was no significant difference in the efficacy of subjective CT signs and objective DECT parameters(P>0.05).Importantly,we observed that I_(Cnormal/lesion)combined with subjective signs(bowel dilation and parenchymatous organ infarction)had the highest predictive performance(AUC=0.894),sensitivity(100%),and specificity(70.83%),which was statistically different from the AUC of CT subjective signs(P=0.017).CONCLUSION I_(Cnormal/lesion)(DECT-based features)combined with CT subjective signs(bowel dilatation and parenchymatous organ infarction)showed favorable predictive performance for ITIN in AOMI,which may help clinicians develop timely treatment strategies.展开更多
Objective： The aim of our study was to make the qualitative and quantitative analysis to breast lesions using acoustic radiation force impulses （ARFI）, and assess the diagnostic value of ARFI for differentiation be...Objective： The aim of our study was to make the qualitative and quantitative analysis to breast lesions using acoustic radiation force impulses （ARFI）, and assess the diagnostic value of ARFI for differentiation between benign and malignant solid breast masses, meanwhile evaluate the influences of ARFI with breast imaging reporting and data system （BI-RADS） of suspicious masses. Methods： Seventy-five women with 86 breast lesions underwent conventional breast ultra- sound examination. Then B-mode BI-RADS features and assessments were recorded and standard breast US supplemented by ARFI elastographic examination were repeated. The data were recorded and analyzed as following： area ratio of breast lesion, the shear-wave velocity, the ratio of the shear-wave velocity between lesions and surrounding normal tissues, and according to the elastographic data reconsidered the BI-RADS category, all the results have been correlated with pathological results and make statistical evaluations of ARFI for differentiation between benign and malignant solid breast masses. Meantime our study has correlated the adjusted BI-RADS category of suspicious breast lesions with the pathological results and made assessment. Results： Thirty-eight patients were malignant breast carcinoma （31 invasive ductal carcinoma, 5 intraductal carcinoma in situ, 2 medullary carcinoma, 2 invasive Iobular carcinoma）, 48 patients were benign breast lesions （23 fibroadenoma, 12 benign nodular hyperplasia, 5 phyllodes tumor, 6 adenosis, 2 intraductal papilloma）. Underwent conventional breast ultrasound exam, 42 cases were BI-RADS category 3, 23 cases were BI-RADS category 4. When adding elastographic data, 46 cases were BI-RADS category 3 and 20 cases were BI-RADS category 4. Compared with pathological results showed for both the specificity of BIRADS features and the area under ROC curve has risen. Virtual touch tissue imaging （VTI） and virtual touch tissue quantification （VTQ） data showed the area ratio （AR） between elastographic lesions area and B-mode lesions area, SWV （maximal shear-wave velocity of lesions）, R-SWV （shear-wave velocity ratio between lesions and surrounding normal tissues） in benign breast lesions were lower than those in malignant lesions which has statistical significance and the cut-off point were 1.1,4.65 m/s, 5.18 respectively. Conclusion： The ARFI elastography can provide the reliable qualitative and quantitative analysis about hardness of breast lesions, supply the new BI-RADS category features to suspicious breast masses and serve as an effective diagnostic tool for differentiation between benign and malignant solid masses.展开更多
A semi-reference image quality assessment metric based on similarity measurement for synthesized virtual viewpoint image （VVI） in free-viewpoint television system （FFV） is proposed in this paper. The key point of ...A semi-reference image quality assessment metric based on similarity measurement for synthesized virtual viewpoint image （VVI） in free-viewpoint television system （FFV） is proposed in this paper. The key point of the proposed metric is taking resemblant information between VVI and its neighbor view images for quality assessment to make our metric to be extended to multi-semi-reference image quality assessment easily. The proposed metric first extracts impact factors from image features, then combines an image synthesis technique and similarity functions, in which, disparity information are taken into account for registering the resemblant regions. Experiments are divided into three phases. Phase I is to verify the validation of the proposed metric by taking impaired images and original reference into account. The experimental results show the agreement between evaluation scores and bio-characteristic of human visual system. Phase II shows the accordance with Phase I by taking neighbor view as reference. The proposed metric can be taken as a full reference one to evaluate the image quality even though the original reference is absent. Phase III is then performed to evaluate the quality of WI. Evaluation scores in the experimental results are able to evaluate the quality of VVI.展开更多
Objective：The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography （CT） virtual noncontrast （VNC） spectral imaging in a retrospective analysis.Methods：Forty hep...Objective：The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography （CT） virtual noncontrast （VNC） spectral imaging in a retrospective analysis.Methods：Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast （TNC） and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial,portal venous,and equilibrium phases.The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial （VNCa）,venous （VNCv）,and equilibrium （VNCe） phase by the material decomposition process using water and iodine as a base material pair.The image quality and the contrast-to-noise ratio （CNR） of metastasis of the four groups were compared with ANOVA analysis.The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chisquare test.Results：There were no significant differences in image quality among TNC,VNCa and VNCv images （P 〉 0.05）.The quality of VNCe images was significantly worse than that of other three groups （P 〈 0.05）.The mean CNR of metastasis in the TNC and VNCs images was 1.86,2.42,1.92,and 1.94,respectively; the mean CNR of metastasis in VNCa images was significantly higher than that in other three groups （P 〈 0.05）,while no statistically significant difference was observed among VNCv,VNCe and TNC images （P 〉 0.05）.The metastasis detection rate of the four nonenhanced groups with no statistically significant difference （P 〉 0.05）.Conclusions：The quality of VNCa and VNCv images is identical to that of TNC images,and the metastasis detection rate in VNC images is similar to that in TNC images.VNC images obtained from arterial phase show metastases more clearly.Thus,VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.展开更多
The correlations between shear wave velocity(SWV)calculated from virtual touch tissue imaging quantification(VTIQ)technique and histological prognostic factors of invasive ductal carcinoma was investigated.A total of ...The correlations between shear wave velocity(SWV)calculated from virtual touch tissue imaging quantification(VTIQ)technique and histological prognostic factors of invasive ductal carcinoma was investigated.A total of 76 breast tumors histologically confirmed as invasive ductal carcinomas were included in this study.SWV values were measured by VTIQ for each lesion preoperatively or prior to breast biopsy.The maximum values were recorded for statistical analysis.Medical records were reviewed to determine tumor size,histological grade,lymph node status and immunohistochemical results.Tumor subtypes were categorized as luminal A,luminal B,human epidermal growth factor receptor 2(HER2)positive and triple negative.The correlations between SWV and histological prognostic factors were analyzed.It was found that tumor size showed positive association with SWV(r=0.465,P<0.001).Larger tumors had significantly higher SWV than smaller ones(P=0.001).Histological grade 1 tumors had significantly lower SWV values than those with higher histological grade(P=0.015).The Ki67 expression,tumor subtypes and lymph node status showed no statistically significant correlations with SWV,although triple negative tumors and lymph node-positive tumors showed higher SWV values.It was concluded that tumor size was significantly associated with SWV.Higher histological grade was associated with increased SWV.There was no statistically significant correlations between SWV and other histological prognostic factors.展开更多
Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and u...Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.展开更多
Background The virtual reality （VR） system can provide the neurosurgeon to intuitively interact with and manipulate the three dimensional （3-D） image similarly to manipulate a real object.it was seldom reported th...Background The virtual reality （VR） system can provide the neurosurgeon to intuitively interact with and manipulate the three dimensional （3-D） image similarly to manipulate a real object.it was seldom reported that the system was used in diagnosis and treatment of cerebral aneurysms.This study aimed to investigate the application of VR system in diagnosis and therapeutic planning of cerebral aneurysms.Methods A total of 24 cases of cerebral aneurysms were enrolled in this study from 2006 to 2008, which diagnosed by 3-D digital subtraction angiography （3D-DSA） or VR-based computed tomography angiographies （CTA）.The VR system and 3D-DSA system were used to observe and measure aneurysms and the adjacent vessels.The data of observation and measurements were compared between VR image and 3D-DSA image.All the patients underwent surgical plan and simulated neurosurgical procedures in the VR system.Results There were 28 aneurysms detected in VR system and 3D-DSA system.The VR system generated clear and vivid 3-D virtual images which clearly displayed the location and size of the aneurysms and their precise anatomical spatial relations to the parent arteries and skull.The location, size and shape of the aneurysms and their anatomical relationship with the adjacent vessels were similar between 3-D virtual image and 3D-DSA, but the spatial relationship between aneurysms and skull only been displayed by VR system.This VR system also could simulate simple surgical procedures and surgical environments.Conclusions The VR system can provide a highly effective way to provide precise imaging details as same as 3D-DSA system and assist the diagnosis of cerebral aneurysms with virtual 3-D data based on CTA.It significantly enhances the chosen therapeutic strategy of cerebral aneurysms.展开更多
High-repetition-rate(HRR) pulsed fiber lasers have attracted much attention in various fields. To effectively achieve HRR pulses in fiber lasers, dissipative four-wave-mixing mode-locking is a promising method. In thi...High-repetition-rate(HRR) pulsed fiber lasers have attracted much attention in various fields. To effectively achieve HRR pulses in fiber lasers, dissipative four-wave-mixing mode-locking is a promising method. In this work, we demonstrated an HRR pulsed fiber laser based on a virtually imaged phased array(VIPA), serving as a comb filter. Due to the high spectral resolution and low polarization sensitivity features of VIPA, the 30 GHz pulse with high quality and high stability could be obtained. In the experiments, both the single-waveband and dual-waveband HRR pulses were achieved. Such an HRR pulsed fiber laser could have potential applications in related fields, such as optical communications.展开更多
Virtual reality(VR)offers an artificial,computer generated simulation of a real life environment.It originated in the 1960 s and has evolved to provide increasing immersion,interactivity,imagination,and intelligence.B...Virtual reality(VR)offers an artificial,computer generated simulation of a real life environment.It originated in the 1960 s and has evolved to provide increasing immersion,interactivity,imagination,and intelligence.Because deep learning systems are able to represent and compose information at various levels in a deep hierarchical fashion,they can build very powerful models which leverage large quantities of visual media data.Intelligence of VR methods and applications has been significantly boosted by the recent developments in deep learning techniques.VR content creation and exploration relates to image and video analysis,synthesis and editing,so deep learning methods such as fully convolutional networks and general adversarial networks are widely employed,designed specifically to handle panoramic images and video and virtual 3 D scenes.This article surveys recent research that uses such deep learning methods for VR content creation and exploration.It considers the problems involved,and discusses possible future directions in this active and emerging research area.展开更多
We demonstrate a two-component detection of a coherent population trapping(CPT)resonance based on virtually imaged phased array(VIPA).After passing through a VIPA,the two coupling lights with different frequencies in ...We demonstrate a two-component detection of a coherent population trapping(CPT)resonance based on virtually imaged phased array(VIPA).After passing through a VIPA,the two coupling lights with different frequencies in the CPT experiment are separated in space and detected individually.The asymmetric lineshape is observed experimentally in the CPT signal for each component,and the comparison with the conventional detection is presented.The shift of the CPT resonant frequency is studied with both the two-component and one-component detections.Our scheme provides a convenient way to further study the CPT phenomenon for each frequency component.展开更多
Abstract.Similarity solution is investigated for the synchronous grouting of shield tunnel under the vertical non-axisymmetric displacement boundary condition in the paper.The synchronous grouting process of shield tu...Abstract.Similarity solution is investigated for the synchronous grouting of shield tunnel under the vertical non-axisymmetric displacement boundary condition in the paper.The synchronous grouting process of shield tunnel was simplified as the cylindrical expansion problem,which was based on the mechanism between the slurry and stratum of the synchronous grouting.The stress harmonic function on the horizontal and vertical ground surfaces is improved.Based on the virtual image technique,stress function solutions and Boussinesq’s solution,elastic solution under the vertical non-axisymmetric displacement boundary condition on the vertical surface was proposed for synchronous grouting problems of shield tunnel.In addition,the maximum grouting pressure was also obtained to control the vertical displacement of horizontal ground surface.The validity of the proposed approach was proved by the numerical method.It can be known fromthe parameter analysis that larger vertical displacement of the horizontal ground surface was induced by smaller tunnel depth,smaller tunnel excavation radius,shorter limb distance,larger expansion pressure and smaller elastic modulus of soils.展开更多
基金Supported by Jiangsu Province 333 Talent Key Industry Field Talent Project,No.[2022]21Key Scientific Research Program of Jiangsu Provincial Health Committee,No.ZD2021059+2 种基金Nantong Key Laboratory Project,No.[2020]163The Project of Nantong City Health Committee,No.MS2023027Young Medical Talents Fund of Health and Family Planning Commission of Nantong,No.QA2019006 and No.QNZ2023027.
文摘BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.This study aimed to assess the diagnostic value of dual-layer spectral computed tomography(CT)-derived VMIs,in combination with multiplanar reformation(MPR)and evaluation of peritumoral fat stranding(PFS),for improving the accuracy of T staging in CRC.AIM To assess the diagnostic performance of dual-layer spectral CT(DLSCT)VMIs,particularly at low energy levels,and their integration with personalized MPR for preoperative T staging of CRC.METHODS In this retrospective study,157 patients with pathologically confirmed CRC(mean age:63.5±12.1 years)underwent DLSCT within 1 week before surgery.VMIs ranging from 40 keV to 70 keV(at 10 keV intervals)and conventional polyenergetic images(PEIs)were reconstructed.Objective image quality parameters,including image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR),were quantified,alongside subjective image quality scores using a 5-point Likert scale.Interobserver agreement was evaluated usingκstatistics.Taking histopathology as the reference standard,the diagnostic accuracy of T staging(T1-2 vs T3-4)was compared across PEIs and VMIs,both with and without MPR and PFS.RESULTS Low-keV VMIs(40-70 keV)demonstrated significantly higher SNR and CNR than PEIs(all P<0.001).Notably,40-keV VMIs achieved noise levels comparable to PEIs(8.17±3.63 vs 8.53±2.90;P=0.673).Subjective image quality peaked at 40-50 keV VMIs(Likert scores 4.85-4.88 vs 3.97 for PEIs;P<0.001),supported by excellent interobserver agreement(κ=0.812-0.913).The combination of 40-50 keV VMIs with MPR yielded the highest T staging accuracy(94.27%)compared to axial PEIs(70.7%),with a sensitivity and specificity of 83.87%and 96.83%,respectively(Youden index=0.81;P<0.05).While PFS enhanced staging accuracy on PEIs(up to 77.07%with MPR),it provided no significant additional benefit for VMIs.CONCLUSION DLSCT VMIs at 40-50 keV significantly enhanced image quality and improved preoperative T staging accuracy of CRC when combined with MPR.These findings underscored the clinical value of low-keV spectral imaging in tailoring individualized treatment strategies.
基金supported by Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province Human Resource Training Project(HRTP-[2022]-53).
文摘The optical diffraction effect imposes a radical obstacle preventing conventional optical microscopes from achieving an imaging resolution beyond the Abbe diffraction limit and thereby restricting their usage in a multitude of nanoscale applications.Over the past decade,the optical microsphere nanoimaging technique has been demonstrated to be a cost-effective solution for overcoming the diffraction limit and has achieved an imaging resolution of up to about k6k8 in a real-time and label-free manner,making it highly competitive among numerous super-resolution imaging technologies.In this review,we summarize the underlying nano-imaging mechanisms of the microsphere nanoscope and key advancements aimed at imaging performance enhancement:first,to change the working environment or modify the peripheral hardware of a single microsphere nanoscope at the system level;second,to compose the microsphere compound lens;and third,to engineer the geometry or ingredients of microspheres.We also analyze challenges yet to be overcome in optical microsphere nano-imaging,followed by an outlook of this technique.
基金supported by the Korea Electric Power Corporation(R22TA14,Development of Drone Systemfor Diagnosis of Porcelain Insulators in Overhead Transmission Lines)the National Fire Agency of Korea(RS-2024-00408270,Fire Hazard Analysis and Fire Safety Standards Development for Transportation and Storage Stage of Reuse Battery)the Ministry of the Interior and Safety of Korea(RS-2024-00408982,Development of Intelligent Fire Detection and Sprinkler Facility Technology Reflecting the Characteristics of Logistics Facilities).
文摘This paper proposes an automated detection framework for transmission facilities using a featureattention multi-scale robustness network(FAMSR-Net)with high-fidelity virtual images.The proposed framework exhibits three key characteristics.First,virtual images of the transmission facilities generated using StyleGAN2-ADA are co-trained with real images.This enables the neural network to learn various features of transmission facilities to improve the detection performance.Second,the convolutional block attention module is deployed in FAMSR-Net to effectively extract features from images and construct multi-dimensional feature maps,enabling the neural network to perform precise object detection in various environments.Third,an effective bounding box optimization method called Scylla-IoU is deployed on FAMSR-Net,considering the intersection over union,center point distance,angle,and shape of the bounding box.This enables the detection of power facilities of various sizes accurately.Extensive experiments demonstrated that FAMSRNet outperforms other neural networks in detecting power facilities.FAMSR-Net also achieved the highest detection accuracy when virtual images of the transmission facilities were co-trained in the training phase.The proposed framework is effective for the scheduled operation and maintenance of transmission facilities because an optical camera is currently the most promising tool for unmanned aerial vehicles.This ultimately contributes to improved inspection efficiency,reduced maintenance risks,and more reliable power delivery across extensive transmission facilities.
基金Supported by The Project of Nantong City Health Committee,No.MS2023027 and WKZL2018017The“333”Talent Funding Project of Jiangsu Province,No.BRA2020198+1 种基金The Project of Jiangsu Provincial Health Commission,No.ZD2021059The Youth Research Fund of Nantong Municipal Health Commission,No.QNZ2023027.
文摘BACKGROUND Irreversible transmural intestinal necrosis(ITIN)is associated with high mortality rates in patients with acute occlusive mesenteric ischemia(AOMI).Currently,there are not many studies on the use of dual energy computed tomography(DECT)for evaluating ITIN.AIM To evaluate the diagnostic value of DECT for ITIN in AOMI.METHODS The cases and computed tomography(CT)images of 102 patients with clinically diagnosed AOMI(including 48 ITIN)from January 2012 to January 2022 were retrospectively collected.The CT scans included both multidetector CT and DECT.The raw data from DECT portal-venous phase were reconstructed into 120 kVp mixed energy image,50 keV virtual monoenergetic imaging,and iodine map.Two radiologists independently completed the subjective visual assessment of CT signs related to AOMI.Objective parameters,including the attenuation of the normal and_(lesion)intestinal wall segment(CT50 keV_(lesion),CT_(50 keV normal/lesion))and iodine concentrations(IC_(lesion)and I_(Cnormal/lesion)),were quantified.Furthermore,multivariate logistic regression,receiver operating characteristic curves,and area under the curve(AUC)values were used to evaluate the subjective and objective indicators in predicting ITIN.RESULTS Regarding subjective signs,logistic regression analysis revealed reduced or absent bowel wall enhancement[odds ratio(OR)=5.576,95%confidence interval(CI):1.547-20.093],bowel dilation(OR=11.613,95%CI:3.790-35.586),and parenchymatous organ infarction(OR=4.727,95%CI:1.536-14.551)were independent risk factors for the ITIN.CT subjective signs had a high diagnostic efficacy for ITIN(AUC=0.853).The two DECT objective parameters also exhibited excellent diagnostic value for ITIN,with an AUC of 0.79,a cut-off value of CT50 keV normal/_(lesion)=2.81,and an AUC of 0.777 with a cut-off value of I_(Cnormal/lesion)=2.39.The Delong test showed that there was no significant difference in the efficacy of subjective CT signs and objective DECT parameters(P>0.05).Importantly,we observed that I_(Cnormal/lesion)combined with subjective signs(bowel dilation and parenchymatous organ infarction)had the highest predictive performance(AUC=0.894),sensitivity(100%),and specificity(70.83%),which was statistically different from the AUC of CT subjective signs(P=0.017).CONCLUSION I_(Cnormal/lesion)(DECT-based features)combined with CT subjective signs(bowel dilatation and parenchymatous organ infarction)showed favorable predictive performance for ITIN in AOMI,which may help clinicians develop timely treatment strategies.
文摘Objective： The aim of our study was to make the qualitative and quantitative analysis to breast lesions using acoustic radiation force impulses （ARFI）, and assess the diagnostic value of ARFI for differentiation between benign and malignant solid breast masses, meanwhile evaluate the influences of ARFI with breast imaging reporting and data system （BI-RADS） of suspicious masses. Methods： Seventy-five women with 86 breast lesions underwent conventional breast ultra- sound examination. Then B-mode BI-RADS features and assessments were recorded and standard breast US supplemented by ARFI elastographic examination were repeated. The data were recorded and analyzed as following： area ratio of breast lesion, the shear-wave velocity, the ratio of the shear-wave velocity between lesions and surrounding normal tissues, and according to the elastographic data reconsidered the BI-RADS category, all the results have been correlated with pathological results and make statistical evaluations of ARFI for differentiation between benign and malignant solid breast masses. Meantime our study has correlated the adjusted BI-RADS category of suspicious breast lesions with the pathological results and made assessment. Results： Thirty-eight patients were malignant breast carcinoma （31 invasive ductal carcinoma, 5 intraductal carcinoma in situ, 2 medullary carcinoma, 2 invasive Iobular carcinoma）, 48 patients were benign breast lesions （23 fibroadenoma, 12 benign nodular hyperplasia, 5 phyllodes tumor, 6 adenosis, 2 intraductal papilloma）. Underwent conventional breast ultrasound exam, 42 cases were BI-RADS category 3, 23 cases were BI-RADS category 4. When adding elastographic data, 46 cases were BI-RADS category 3 and 20 cases were BI-RADS category 4. Compared with pathological results showed for both the specificity of BIRADS features and the area under ROC curve has risen. Virtual touch tissue imaging （VTI） and virtual touch tissue quantification （VTQ） data showed the area ratio （AR） between elastographic lesions area and B-mode lesions area, SWV （maximal shear-wave velocity of lesions）, R-SWV （shear-wave velocity ratio between lesions and surrounding normal tissues） in benign breast lesions were lower than those in malignant lesions which has statistical significance and the cut-off point were 1.1,4.65 m/s, 5.18 respectively. Conclusion： The ARFI elastography can provide the reliable qualitative and quantitative analysis about hardness of breast lesions, supply the new BI-RADS category features to suspicious breast masses and serve as an effective diagnostic tool for differentiation between benign and malignant solid masses.
基金Supported by the National Natural Science Foundation of China (No. 60672073,60872094)the Program for New Century Excellent Talents in University (NCET-06-0537)the Natural Science Foundation of Ningbo (No. 2007A610037).
文摘A semi-reference image quality assessment metric based on similarity measurement for synthesized virtual viewpoint image （VVI） in free-viewpoint television system （FFV） is proposed in this paper. The key point of the proposed metric is taking resemblant information between VVI and its neighbor view images for quality assessment to make our metric to be extended to multi-semi-reference image quality assessment easily. The proposed metric first extracts impact factors from image features, then combines an image synthesis technique and similarity functions, in which, disparity information are taken into account for registering the resemblant regions. Experiments are divided into three phases. Phase I is to verify the validation of the proposed metric by taking impaired images and original reference into account. The experimental results show the agreement between evaluation scores and bio-characteristic of human visual system. Phase II shows the accordance with Phase I by taking neighbor view as reference. The proposed metric can be taken as a full reference one to evaluate the image quality even though the original reference is absent. Phase III is then performed to evaluate the quality of WI. Evaluation scores in the experimental results are able to evaluate the quality of VVI.
文摘Objective：The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography （CT） virtual noncontrast （VNC） spectral imaging in a retrospective analysis.Methods：Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast （TNC） and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial,portal venous,and equilibrium phases.The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial （VNCa）,venous （VNCv）,and equilibrium （VNCe） phase by the material decomposition process using water and iodine as a base material pair.The image quality and the contrast-to-noise ratio （CNR） of metastasis of the four groups were compared with ANOVA analysis.The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chisquare test.Results：There were no significant differences in image quality among TNC,VNCa and VNCv images （P 〉 0.05）.The quality of VNCe images was significantly worse than that of other three groups （P 〈 0.05）.The mean CNR of metastasis in the TNC and VNCs images was 1.86,2.42,1.92,and 1.94,respectively; the mean CNR of metastasis in VNCa images was significantly higher than that in other three groups （P 〈 0.05）,while no statistically significant difference was observed among VNCv,VNCe and TNC images （P 〉 0.05）.The metastasis detection rate of the four nonenhanced groups with no statistically significant difference （P 〉 0.05）.Conclusions：The quality of VNCa and VNCv images is identical to that of TNC images,and the metastasis detection rate in VNC images is similar to that in TNC images.VNC images obtained from arterial phase show metastases more clearly.Thus,VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.
基金grants from the Fundamental Research Funds for the Central Universities(No.2172015YGYL019)the Fundamental Research Funds for the Central Universities(No.2015LC021)+1 种基金National Natural Science Foundation of China(No.81000616)Hubei Key Laboratory of Molecular Imaging Research Funds(No.02.03.2015-149).
文摘The correlations between shear wave velocity(SWV)calculated from virtual touch tissue imaging quantification(VTIQ)technique and histological prognostic factors of invasive ductal carcinoma was investigated.A total of 76 breast tumors histologically confirmed as invasive ductal carcinomas were included in this study.SWV values were measured by VTIQ for each lesion preoperatively or prior to breast biopsy.The maximum values were recorded for statistical analysis.Medical records were reviewed to determine tumor size,histological grade,lymph node status and immunohistochemical results.Tumor subtypes were categorized as luminal A,luminal B,human epidermal growth factor receptor 2(HER2)positive and triple negative.The correlations between SWV and histological prognostic factors were analyzed.It was found that tumor size showed positive association with SWV(r=0.465,P<0.001).Larger tumors had significantly higher SWV than smaller ones(P=0.001).Histological grade 1 tumors had significantly lower SWV values than those with higher histological grade(P=0.015).The Ki67 expression,tumor subtypes and lymph node status showed no statistically significant correlations with SWV,although triple negative tumors and lymph node-positive tumors showed higher SWV values.It was concluded that tumor size was significantly associated with SWV.Higher histological grade was associated with increased SWV.There was no statistically significant correlations between SWV and other histological prognostic factors.
基金supported by grants from the Scientific Research Project of Hunan Health Commission in 2019(No.B2019071)the Scientific Research Project of Hunan Health Commission in 2020(No.B20200059).
文摘Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.
文摘Background The virtual reality （VR） system can provide the neurosurgeon to intuitively interact with and manipulate the three dimensional （3-D） image similarly to manipulate a real object.it was seldom reported that the system was used in diagnosis and treatment of cerebral aneurysms.This study aimed to investigate the application of VR system in diagnosis and therapeutic planning of cerebral aneurysms.Methods A total of 24 cases of cerebral aneurysms were enrolled in this study from 2006 to 2008, which diagnosed by 3-D digital subtraction angiography （3D-DSA） or VR-based computed tomography angiographies （CTA）.The VR system and 3D-DSA system were used to observe and measure aneurysms and the adjacent vessels.The data of observation and measurements were compared between VR image and 3D-DSA image.All the patients underwent surgical plan and simulated neurosurgical procedures in the VR system.Results There were 28 aneurysms detected in VR system and 3D-DSA system.The VR system generated clear and vivid 3-D virtual images which clearly displayed the location and size of the aneurysms and their precise anatomical spatial relations to the parent arteries and skull.The location, size and shape of the aneurysms and their anatomical relationship with the adjacent vessels were similar between 3-D virtual image and 3D-DSA, but the spatial relationship between aneurysms and skull only been displayed by VR system.This VR system also could simulate simple surgical procedures and surgical environments.Conclusions The VR system can provide a highly effective way to provide precise imaging details as same as 3D-DSA system and assist the diagnosis of cerebral aneurysms with virtual 3-D data based on CTA.It significantly enhances the chosen therapeutic strategy of cerebral aneurysms.
基金supported in part by the National Natural Science Foundation of China(NSFC)(Nos.61805084,11974006,11874018 and 61875058)Science and Technology Program of Guangzhou(No.2019050001)+4 种基金Guangdong Key R&D Program(No.2018B090904003)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515010879)Foundation for Young Talents in Higher Education of Guangdong(No.2017KQNCX051)Scientific Research Foundation of Young Teacher of South China Normal University(No.17KJ09)Open Fund of the Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques(South China University of Technology,2019-2)
文摘High-repetition-rate(HRR) pulsed fiber lasers have attracted much attention in various fields. To effectively achieve HRR pulses in fiber lasers, dissipative four-wave-mixing mode-locking is a promising method. In this work, we demonstrated an HRR pulsed fiber laser based on a virtually imaged phased array(VIPA), serving as a comb filter. Due to the high spectral resolution and low polarization sensitivity features of VIPA, the 30 GHz pulse with high quality and high stability could be obtained. In the experiments, both the single-waveband and dual-waveband HRR pulses were achieved. Such an HRR pulsed fiber laser could have potential applications in related fields, such as optical communications.
基金supported by the National Natural Science Foundation of China(Grant Nos.61902012,61932003)supported by a Victoria Early-Career Research Excellence Award.
文摘Virtual reality(VR)offers an artificial,computer generated simulation of a real life environment.It originated in the 1960 s and has evolved to provide increasing immersion,interactivity,imagination,and intelligence.Because deep learning systems are able to represent and compose information at various levels in a deep hierarchical fashion,they can build very powerful models which leverage large quantities of visual media data.Intelligence of VR methods and applications has been significantly boosted by the recent developments in deep learning techniques.VR content creation and exploration relates to image and video analysis,synthesis and editing,so deep learning methods such as fully convolutional networks and general adversarial networks are widely employed,designed specifically to handle panoramic images and video and virtual 3 D scenes.This article surveys recent research that uses such deep learning methods for VR content creation and exploration.It considers the problems involved,and discusses possible future directions in this active and emerging research area.
基金supported by the National Natural Science Foundation of China(Nos.12005187 and 91536220)。
文摘We demonstrate a two-component detection of a coherent population trapping(CPT)resonance based on virtually imaged phased array(VIPA).After passing through a VIPA,the two coupling lights with different frequencies in the CPT experiment are separated in space and detected individually.The asymmetric lineshape is observed experimentally in the CPT signal for each component,and the comparison with the conventional detection is presented.The shift of the CPT resonant frequency is studied with both the two-component and one-component detections.Our scheme provides a convenient way to further study the CPT phenomenon for each frequency component.
基金The authors are grateful to the Traffic Technology Fund of Guizhou Province of China(No.2014-122-005)the National Natural Science Foundation of China(Grant No.51208523).
文摘Abstract.Similarity solution is investigated for the synchronous grouting of shield tunnel under the vertical non-axisymmetric displacement boundary condition in the paper.The synchronous grouting process of shield tunnel was simplified as the cylindrical expansion problem,which was based on the mechanism between the slurry and stratum of the synchronous grouting.The stress harmonic function on the horizontal and vertical ground surfaces is improved.Based on the virtual image technique,stress function solutions and Boussinesq’s solution,elastic solution under the vertical non-axisymmetric displacement boundary condition on the vertical surface was proposed for synchronous grouting problems of shield tunnel.In addition,the maximum grouting pressure was also obtained to control the vertical displacement of horizontal ground surface.The validity of the proposed approach was proved by the numerical method.It can be known fromthe parameter analysis that larger vertical displacement of the horizontal ground surface was induced by smaller tunnel depth,smaller tunnel excavation radius,shorter limb distance,larger expansion pressure and smaller elastic modulus of soils.
