Conventional fabrication methods lack the ability to control both macro- and micro-structures of generated scaffolds. Three-dimensional printing is a solid free-form fabrication method that provides novel ways to crea...Conventional fabrication methods lack the ability to control both macro- and micro-structures of generated scaffolds. Three-dimensional printing is a solid free-form fabrication method that provides novel ways to create customized scaffolds with high precision and accuracy. In this study, an electrically controlled cortical impactor was used to induce randomized brain tissue defects. The overall shape of scaffolds was designed using rat-specific anatomical data obtained from magnetic resonance imaging, and the internal structure was created by computer- aided design. As the result of limitations arising from insufficient resolution of the manufacturing process, we magnified the size of the cavity model prototype five-fold to successfully fabricate customized collagen-chitosan scaffolds using three-dimensional printing. Results demonstrated that scaffolds have three-dimensional porous structures, high porosity, highly specific surface areas, pore connectivity and good internal characteristics. Neural stem cells co-cultured with scaffolds showed good viability, indicating good biocompatibility and biodegradability. This technique may be a promising new strategy for regenerating complex damaged brain tissues, and helps pave the way toward personalized medicine.展开更多
The anatomic relationship of oral and maxillofacial region is very com-plex,due to the large number of sinuses,cavities and spaces,and also closely related to the brain.The diagnosis of oral and maxillofacial lesions ...The anatomic relationship of oral and maxillofacial region is very com-plex,due to the large number of sinuses,cavities and spaces,and also closely related to the brain.The diagnosis of oral and maxillofacial lesions usually depends on the imaging examination.The conventional imaging methods are common CT and X-ray plain films.In recent years,with the rapid development of medical science and technology,more intuitive and vivid three-dimensional images have been applied in the diagnosis and treatment of oral and maxillofacial diseases.Therefore,CT three-dimensional imaging technology has been widely used in clinical practice.This paper reviews this topic.展开更多
The high mortality rates of colon and rectal tumors have put forward an urgent need for rapid, sensitive, and accurate diagnosis. The polarization imaging technology, with the advantages of noninvasiveness, noncontact...The high mortality rates of colon and rectal tumors have put forward an urgent need for rapid, sensitive, and accurate diagnosis. The polarization imaging technology, with the advantages of noninvasiveness, noncontact, quantification, rapidity, and high sensitivity, is expected to be used for auxiliary diagnosis of colorectal cancer. Herein, the differences in colorectal tissues of four pathological types were studied using this powerful technology. Polarized light imaging combined with the Mueller matrix decomposition (MMPD) method was applied to extract structural features that may be related to colorectal tumors. It demonstrated that parameters δ and θ could reflect the structural differences of colorectal tumors. Preliminary simulated experiment results revealed that the parameter δ was related to the fiber density, and the parameter θ was related to the fiber angle. Then Tamura image texture analysis was used to quantitatively describe tissues of different pathological types, and the results showed that the coarseness, contrast, directionality, and roughness of the four groups were statistically different. Texture analysis based on the quantitative data of the four dimensions could be applied for the identification of benign and malignant colorectal tumors.展开更多
BACKGROUND Hepatobiliary surgery is complex and requires a thorough understanding of the liver’s anatomy,biliary system,and vasculature.Traditional imaging methods such as computed tomography(CT)and magnetic resonanc...BACKGROUND Hepatobiliary surgery is complex and requires a thorough understanding of the liver’s anatomy,biliary system,and vasculature.Traditional imaging methods such as computed tomography(CT)and magnetic resonance imaging(MRI),although helpful,fail to provide three-dimensional(3D)relationships of these structures,which are critical for planning and executing complicated surgeries.AIM To explore the use of 3D imaging and virtual surgical planning(VSP)technologies to improve surgical accuracy,reduce complications,and enhance patient recovery in hepatobiliary surgeries.METHODS A comprehensive review of studies published between 2017 and 2024 was conducted through PubMed,Scopus,Google Scholar,and Web of Science.Studies selected focused on 3D imaging and VSP applications in hepatobiliary surgery,assessing surgical precision,complications,and patient outcomes.Thirty studies,including randomized controlled trials,cohort studies,and case reports,were included in the final analysis.RESULTS Various 3D imaging modalities,including multidetector CT,MRI,and 3D rotational angiography,provide high-resolution views of the liver’s vascular and biliary anatomy.VSP allows surgeons to simulate complex surgeries,improving preoperative planning and reducing complications like bleeding and bile leaks.Several studies have demonstrated improved surgical precision,reduced complications,and faster recovery times when 3D imaging and VSP were used in complex surgeries.CONCLUSION 3D imaging and VSP technologies significantly enhance the accuracy and outcomes of hepatobiliary surgeries by providing individualized preoperative planning.While promising,further research,particularly randomized controlled trials,is needed to standardize protocols and evaluate long-term efficacy.展开更多
BACKGROUND Percutaneous transhepatic biliary drainage(PTBD)is one of the primary clinical treatment options for patients with obstructive jaundice.In recent years,PTBD assisted by three-dimensional(3D)reconstruction t...BACKGROUND Percutaneous transhepatic biliary drainage(PTBD)is one of the primary clinical treatment options for patients with obstructive jaundice.In recent years,PTBD assisted by three-dimensional(3D)reconstruction technology has been widely implemented,but its advantages over traditional methods remains inconclusive.Thus,a discussion is warranted.AIM To explore the safety and efficacy of 3D reconstruction technology-assisted PTBD.METHODS We systematically searched the databases including the Cochrane Library,PubMed,EMBASE,Web of Science and China National Knowledge Infrastructure.The search period extended from the establishment of each database to November,2024.We screened the literature according to predefined inclusion and exclusion criteria,assessed the quality of the studies,and extracted data.Meta-analysis was performed using Revman 5.4.1 software.RESULTS A total of 15 studies were included,involving 1434 patients.The results of the meta-analysis showed that compared with the traditional group,the overall post-operative complications rate in the 3D reconstruction technology group was significantly lower[odds ratio=0.25;95%confidence interval(CI):0.17-0.36,P<0.00001].The overall puncture success rate in the 3D reconstruction group was better than those in the traditional group(odds ratio=3.61;95%CI:1.98-6.55,P<0.0001).However,there was no significant difference between the two groups in the reduction levels of postoperative total bilirubin(mean difference=-1.38;95%CI:-3.29 to 0.53,P=0.16).Subgroup analysis were conducted on the surgery time according to guidance stages of the 3D reconstruction,3D reconstruction imaging modalities,and types of studies.The results were stable,with no significant changes observed.CONCLUSION 3D reconstruction technology significantly improves the puncture success rate and safety of PTBD.However,it has no significant advantage in bile drainage effectiveness.Continued research is warranted to further explore its clinical value and optimize its application.展开更多
Cardiovascular damage caused by cancer treatment has become an important cause of death for tumor survivors.With the recognition of cardiovascular diseases and cancer therapy-related cardiovascular toxicity(CTR-CVT)in...Cardiovascular damage caused by cancer treatment has become an important cause of death for tumor survivors.With the recognition of cardiovascular diseases and cancer therapy-related cardiovascular toxicity(CTR-CVT)in tumor patients,noninvasive imaging technologies play pivotal roles in the risk stratification,early diagnosis,monitoring and follow-up for CTR-CVT.In recent years,the field of cardio-oncology has witnessed continual updates in diagnostic and therapeutic strategies,with several pertinent guidelines and expert consensus documents issued in China and abroad.However,there remains a conspicuous absence of systematic guidance documents on the application of imaging techniques in the clinical practice of cardio-oncology.Therefore,the Chinese Anti-Cancer Association Society of Integrative Cardio-oncology,the Ultrasound Branch of the Chinese Medical Association,and the Chinese Society of Echocardiography convened experts to formulate the"Chinese guideline for the clinical application of noninvasive imaging technology in accessing cancer therapy-related cardiovascular toxicity".Building upon the systematic evaluation of guidelines and the latest evidence-based medical research in the field of cardio-oncology domestically and abroad,and in conjunction with data derived from evidence-based medical research in China,this guideline proposes noninvasive imaging examination methods and monitoring strategies for CTR-CVT,aiming to further standardize and guide the clinical practice of multidisciplinary physicians specializing in cardio-oncology in China.展开更多
The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the ...The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the integrated engineering technology of post-fracturing drilling,coring and monitoring of shale and the analysis of fracture source tracing,the evaluation of the fracture network after fracturing in the three-dimensional development of shale gas was conducted.The data of core fractures after fracturing indicate that three major types of fractures are formed after fracturing:natural fractures,hydraulic fractures,and fractures induced by external mechanical force,which are further classified into six subcategories:natural structural fractures,natural bedding fractures,hydraulic fractures,hydraulically activated fractures,drilling induced fractures,and fractures induced by core transportation.The forms of the artificial fracture network after fracturing are complex.Hydraulic fractures and hydraulically activated fractures interweave with each other,presenting eight forms of artificial fracture networks,among which the“一”-shaped fracture is the most common,accounting for approximately 70%of the total fractures.When the distance to the fractured wellbore is less than 35 m,the density of the artificial fracture network is relatively high;when it is 35–100 m,the density is lower;and when it is beyond 100 m,the density gradually increases.The results of the fracture tracing in the core sampling area confirm that the current fracturing technology can essentially achieve the differential transformation of the reservoir in the main area of Jiaoshiba block in Fuling.The three-layer three-dimensional development model can efficiently utilize shale gas reserves,although there is still room for improvement in the complexity and propagation uniformity of fractures.It is necessary to further optimize technologies such as close-cutting combined with temporary blocking and deflection within fractures or at fracture mouths,as well as limited flow perforation techniques,to promote the balanced initiation and extension of fractures.展开更多
Acute pancreatitis(AP)is a potentially life-threatening inflammatory disease of the pancreas,with clinical management determined by the severity of the disease.Diagnosis,severity prediction,and prognosis assessment of...Acute pancreatitis(AP)is a potentially life-threatening inflammatory disease of the pancreas,with clinical management determined by the severity of the disease.Diagnosis,severity prediction,and prognosis assessment of AP typically involve the use of imaging technologies,such as computed tomography,magnetic resonance imaging,and ultrasound,and scoring systems,including Ranson,Acute Physiology and Chronic Health Evaluation II,and Bedside Index for Severity in AP scores.Computed tomography is considered the gold standard imaging modality for AP due to its high sensitivity and specificity,while magnetic resonance imaging and ultrasound can provide additional information on biliary obstruction and vascular complications.Scoring systems utilize clinical and laboratory parameters to classify AP patients into mild,moderate,or severe categories,guiding treatment decisions,such as intensive care unit admission,early enteral feeding,and antibiotic use.Despite the central role of imaging technologies and scoring systems in AP management,these methods have limitations in terms of accuracy,reproducibility,practicality and economics.Recent advancements of artificial intelligence(AI)provide new opportunities to enhance their performance by analyzing vast amounts of clinical and imaging data.AI algorithms can analyze large amounts of clinical and imaging data,identify scoring system patterns,and predict the clinical course of disease.AI-based models have shown promising results in predicting the severity and mortality of AP,but further validation and standardization are required before widespread clinical application.In addition,understanding the correlation between these three technologies will aid in developing new methods that can accurately,sensitively,and specifically be used in the diagnosis,severity prediction,and prognosis assessment of AP through complementary advantages.展开更多
Perianal abscess is a common disease in anorectal surgery. If the diagnosis is not clear and the cure is thoroughly cleared, the recurrence and spread of anal fistula will cause life-long pain. Objective: To investiga...Perianal abscess is a common disease in anorectal surgery. If the diagnosis is not clear and the cure is thoroughly cleared, the recurrence and spread of anal fistula will cause life-long pain. Objective: To investigate the application of 3.0T MRI 3D CUBE T2WI lipid suppression sequence in the diagnosis of perianal abscess. Methods: Thirty-six patients with perianal abscess confirmed by operation were examined with 2D T2WI and 3D CUBE T2WI lipid suppression sequences before operation. Two imaging techniques were evaluated to show the types of perianal abscess, the number of abscesses, the number of internal orifices of abscess, and the number of fistula branches with anal fistula in abscess. Results: Among 36 cases of perianal abscess, there were 5 cases of anal subcutaneous abscess, 12 cases of ischiorectal space abscess (8 cases complicated with anal fistula), 6 cases of posterior anal space abscess, 5 cases of anal sphincter abscess (3 cases complicated with anal fistula), 2 cases of high intermuscular abscess, 2 cases of rectal submucosal abscess, 3 cases of complex abscess (3 cases complicated with anal fistula), 1 case of misdiagnosis, 2D T2WI lipid suppression sequence and 3D CUBE T2WI suppression. The accuracy of lipid sequence abscess typing was 80.6% (29/36) and 88.9% (32/36), respectively, with no significant difference (P > 0.05). Thirty-six patients were surgically diagnosed as having 32 internal orifices, 68.8% (22/32) and 93.8% (30/32) of 2D T2WI and 3D CUBE T2WI lipid-suppressing sequences, respectively, with significant difference (P Conclusion: 3D CUBE T2WI lipid suppression sequence is superior to 2D T2WI lipid suppression sequence in the classification of perianal abscess, the number of internal orifices of abscess and the number of fistula branches of abscess complicated with anal fistula. It can also determine the number of internal orifices of abscess complicated with anal fistula, the number of fistula branches, the shape of primary and branch fistula and the relationship among pelvic floor muscle tissues. It can provide more accurate images for preoperative and intraoperative clinical surgery.展开更多
The recently introduced real-time three-dimensional color Doppler flow imaging （RT-3D CDFI） technique provides a quick and accurate calculation of regurgitant jet volume （RJV） and fraction. In order to evaluate RT...The recently introduced real-time three-dimensional color Doppler flow imaging （RT-3D CDFI） technique provides a quick and accurate calculation of regurgitant jet volume （RJV） and fraction. In order to evaluate RT-3D CDFI in the noninvasive assessment of aortic RJV and regurgitant jet fraction （RJF） in patients with isolated aortic regurgitation, real-time three-dimensional echocardiographic studies were performed on 23 patients with isolated aortic regurgitation to obtain LV end-diastolic volumes （LVEDV）, end-systolic volumes （LVESV） and RJV, and then RJF could be calculated. The regurgitant volume （RV） and regurgitant fraction （RF） calculated by two-dimensional pulsed Doppler （2D-PD） method served as reference values. The results showed that aortic RJV measured by the RT-3D CDFI method showed a good correlation with the 2D-PD measurements （r= 0.93, Y=0.89X＋ 3.9, SEE= 8.6 mL, P〈0.001 ）; the mean （SD） difference between the two methods was - 1.5 （9.8） mL. % RJF estimated by the RT-3D CDFI method was also correlated well with the values obtained by the 2D-PD method （r=0.88, Y=0.71X＋ 14.8, SEE= 6.4 %, P〈0. 001）; the mean （SD） difference between the two methods was -1.2 （7.9） %. It was suggested that the newly developed RT-3D CDFI technique was feasible in the majority of patients. In patients with eccentric aortic regurgitation, this new modality provides additional information to that obtained from the two-dimensional examination, which overcomes the inherent limitations of two-dimensional echocardiography by depicting the full extent of the jet trajectory. In addition, the RT-3D CDFI method is quick and accurate in calculating RJV and RJF.展开更多
Summary： This study sought to evaluate the contribution of two-dimensional ultrasound （2D-US） and three-dimensional skeletal imaging ultrasound （3D-SUIS） in the prenatal diagnosis of sirenomelia. Be- tween Septem...Summary： This study sought to evaluate the contribution of two-dimensional ultrasound （2D-US） and three-dimensional skeletal imaging ultrasound （3D-SUIS） in the prenatal diagnosis of sirenomelia. Be- tween September 2010 and April 2014, a prospective study was conducted in a single referral center using 3D-SU1S performed after 2D-US in 10 cases of sirenomelia. Diagnostic accuracy and detailed findings were compared with postnatal three-dimensional helical computed tomography （3D-HCT）, radiological findings and autopsy. Pregnancy was terminated in all 10 sirenomelia cases, including 9 singletons and I conjoined twin pregnancy, for a total of 5 males and 5 females. These cases of sirenomelia were deter- mined by autopsy and/or chromosomal examination. Initial 2D-US showed that there were 10 cases of oligohydranmios, bilateral renal agenesis, bladder agenesis, single umbilical artery, fusion of the lower limbs and spinal abnormalities; 8 cases of dipus or monopus; 2 cases of apus; and 8 cases of cardiac abnormalities. Subsequent 3D-SUIS showed that there were 9 cases of scoliosis, l0 cases of sacrococ- cygeal vertebra dysplasia, 3 cases of hemivertebra, 1 case of vertebral fusion, 3 cases of spina bifida, and 5 cases of rib abnormalities. 3D-SUIS identified significantly more skeletal abnormalities than did 2D-US, and its accuracy was 79.5% （70/88） compared with 3D-HCT and radiography. 3D-SUIS seems to be a useful complementary method to 2D-US and may improve the accuracy of identifying prenatal skeletal abnormalities related to sirenomelia.展开更多
Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent...Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.展开更多
Computed tomography has been proven to be useful for non-destructive inspection of structures and materials. We build a three-dimensional imaging system with the photonically generated incoherent noise source and the ...Computed tomography has been proven to be useful for non-destructive inspection of structures and materials. We build a three-dimensional imaging system with the photonically generated incoherent noise source and the Schottky barrier diode detector in the terahertz frequency band （90–140GHz）. Based on the computed tomography technique, the three-dimensional image of a ceramic sample is reconstructed successfully by stacking the slices at different heights. The imaging results not only indicate the ability of terahertz wave in the non-invasive sensing and non-destructive inspection applications, but also prove the effectiveness and superiority of the uni-traveling-carrier photodiode as a terahertz source in the imaging applications.展开更多
BACKGROUND Neurovascular compression(NVC) is the main cause of primary trigeminal neuralgia(TN) and hemifacial spasm(HFS). Microvascular decompression(MVD) is an effective surgical method for the treatment of TN and H...BACKGROUND Neurovascular compression(NVC) is the main cause of primary trigeminal neuralgia(TN) and hemifacial spasm(HFS). Microvascular decompression(MVD) is an effective surgical method for the treatment of TN and HFS caused by NVC. The judgement of NVC is a critical step in the preoperative evaluation of MVD, which is related to the effect of MVD treatment. Magnetic resonance imaging(MRI) technology has been used to detect NVC prior to MVD for several years. Among many MRI sequences, three-dimensional time-of-flight magnetic resonance angiography(3D TOF MRA) is the most widely used. However, 3D TOF MRA has some shortcomings in detecting NVC. Therefore, 3D TOF MRA combined with high resolution T2-weighted imaging(HR T2WI) is considered to be a more effective method to detect NVC.AIM To determine the value of 3D TOF MRA combined with HR T2WI in the judgment of NVC, and thus to assess its value in the preoperative evaluation of MVD.METHODS Related studies published from inception to September 2022 based on PubMed, Embase, Web of Science, and the Cochrane Library were retrieved. Studies that investigated 3D TOF MRA combined with HR T2WI to judge NVC in patients with TN or HFS were included according to the inclusion criteria. Studies without complete data or not relevant to the research topics were excluded. The Quality Assessment of Diagnostic Accuracy Studies checklist was used to assess the quality of included studies. The publication bias of the included literature was examined by Deeks’ test. An exact binomial rendition of the bivariate mixed-effects regression model was used to synthesize data. Data analysis was performed using the MIDAS module of statistical software Stata 16.0. Two independent investigators extracted patient and study characteristics, and discrepancies were resolved by consensus. Individual and pooled sensitivities and specificities were calculated. The I_(2) statistic and Q test were used to test heterogeneity. The study was registered on the website of PROSERO(registration No. CRD42022357158).RESULTS Our search identified 595 articles, of which 12(including 855 patients) fulfilled the inclusion criteria. Bivariate analysis showed that the pooled sensitivity and specificity of 3D TOF MRA combined with HR T2WI for detecting NVC were 0.96 [95% confidence interval(CI): 0.92-0.98] and 0.92(95%CI: 0.74-0.98), respectively. The pooled positive likelihood ratio was 12.4(95%CI: 3.2-47.8), pooled negative likelihood ratio was 0.04(95%CI: 0.02-0.09), and pooled diagnostic odds ratio was 283(95%CI: 50-1620). The area under the receiver operating characteristic curve was 0.98(95%CI: 0.97-0.99). The studies showed no substantial heterogeneity(I2 = 0, Q = 0.001 P = 0.50).CONCLUSION Our results suggest that 3D TOF MRA combined with HR T2WI has excellent sensitivity and specificity for judging NVC in patients with TN or HFS. This method can be used as an effective tool for preoperative evaluation of MVD.展开更多
With regard to problems in conventional synthetic aperture radar （SAR）, such as imaging distortion, beam limitation and failure in acquiring three-dimensional （3-D） information, a downward-looking 3-D imaging meth...With regard to problems in conventional synthetic aperture radar （SAR）, such as imaging distortion, beam limitation and failure in acquiring three-dimensional （3-D） information, a downward-looking 3-D imaging method based on frequency modulated continuous wave （FMCW） and digital beamforming （DBF） technology for airborne SAR is presented in this study. Downward-looking 3-D SAR signal model is established first, followed by introduction of virtual antenna optimization factor and discussion of equivalent-phase-center compensation. Then, compensation method is provided according to reside video phase （RVP） and slope term for FMCW SAR. As multiple receiving antennas are applied to downward-looking 3-D imaging SAR, range cell migration correction （RCMC） turns to be more complex, and corrective measures are proposed. In addition, DBF technology is applied in realizing cross-track resolution. Finally, to validate the proposed method, magnitude of slice, peak sidelobe ratio （PSLR）, integrated sidelobe ratio （ISLR） and two-dimensional （2-D） contour plot of impulse response function （IRF） of point target in three dimensions are demonstrated. Satisfactory performances are shown by simulation results.展开更多
By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emis...By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emissions(AE),joint response characteristics of the velocity field and AE during rock fracture were analyzed.Moreover,the localization effect of damage during rock fracture was explored by applying wave velocity imagings.The experimental result showed that the wave velocity imagings enable three-dimensional(3-D)visualization of the extent and spatial position of damage to the rock.A damaged zone has a low wave velocity and a zone where the low wave velocity is concentrated tends to correspond to a severely damaged zone.AE parameters and wave velocity imagings depict the changes in activity of cracks during rock fracture from temporal and spatial perspectives,respectively:the activity of cracks is strengthened,and the rate of AE events increases during rock fracture;correspondingly,the low-velocity zones are gradually aggregated and their area gradually increases.From the wave velocity imagings,the damaged zones in rock were divided into an initially damaged zone,a progressively damaged zone,and a fractured zone.During rock fracture,the progressively damaged zone and the fractured zone both develop around the initially damaged zone,showing a typical localization effect of the damage.By capturing the spatial development trends of the progressively damaged zone and fractured zone in wave velocity imagings,the development of microfractures can be predicted,exerting practical significance for determining the position of the main fracture.展开更多
Traditional laparoscopic liver cancer resection faces challenges,such as difficultiesin tumor localization and accurate marking of liver segments,as well as theinability to provide real-time intraoperative navigation....Traditional laparoscopic liver cancer resection faces challenges,such as difficultiesin tumor localization and accurate marking of liver segments,as well as theinability to provide real-time intraoperative navigation.This approach falls shortof meeting the demands for precise and anatomical liver resection.The introductionof fluorescence imaging technology,particularly indocyanine green,hasdemonstrated significant advantages in visualizing bile ducts,tumor localization,segment staining,microscopic lesion display,margin examination,and lymphnode visualization.This technology addresses the inherent limitations oftraditional laparoscopy,which lacks direct tactile feedback,and is increasinglybecoming the standard in laparoscopic procedures.Guided by fluorescenceimaging technology,laparoscopic liver cancer resection is poised to become thepredominant technique for liver tumor removal,enhancing the accuracy,safetyand efficiency of the procedure.展开更多
Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（C...Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.展开更多
A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method wit...A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method with scattering angle correction(CSS-BP-SC) can quickly perform the back-projection process of the Compton cone and can be used to precompute the list-mode maximum likelihood expectation maximization(LM-MLEM). A dedicated parallel architecture was designed for the graphics processing unit acceleration of the back-projection and iteration stage of the CSS-BP-SC-based LM-MLEM. The imaging results of the two-point source Monte Carlo(MC) simulation demonstrate that by analyzing the full width at half maximum along the three coordinate axes, the CSS-BP-SC-based LM-MLEM can obtain imaging results comparable to those of the traditional reconstruction algorithm, that is, the simple back-projection-based LM-MLEM. The imaging results of the mouse phantom MC simulation and experiment demonstrate that the reconstruction results obtained by the proposed method sufficiently coincide with the set radioactivity distribution, and the speed increased by more than 664 times compared to the traditional reconstruction algorithm in the mouse phantom experiment. The proposed method will further advance the imaging applications of Compton cameras.展开更多
We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into ...We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into real and virtual space. Experimental results show that the gap is reduced to 45% of that in a conventional integral imaging system with the same parameters.展开更多
基金supported by the National Natural Science Foundation of China,No.81301050,81401067,81271392,81471275,81541034the Natural Science Foundation of Tianjin City of China,No.14JCQNJC10200,15JCQNJC11100,16JCYBJC27600
文摘Conventional fabrication methods lack the ability to control both macro- and micro-structures of generated scaffolds. Three-dimensional printing is a solid free-form fabrication method that provides novel ways to create customized scaffolds with high precision and accuracy. In this study, an electrically controlled cortical impactor was used to induce randomized brain tissue defects. The overall shape of scaffolds was designed using rat-specific anatomical data obtained from magnetic resonance imaging, and the internal structure was created by computer- aided design. As the result of limitations arising from insufficient resolution of the manufacturing process, we magnified the size of the cavity model prototype five-fold to successfully fabricate customized collagen-chitosan scaffolds using three-dimensional printing. Results demonstrated that scaffolds have three-dimensional porous structures, high porosity, highly specific surface areas, pore connectivity and good internal characteristics. Neural stem cells co-cultured with scaffolds showed good viability, indicating good biocompatibility and biodegradability. This technique may be a promising new strategy for regenerating complex damaged brain tissues, and helps pave the way toward personalized medicine.
文摘The anatomic relationship of oral and maxillofacial region is very com-plex,due to the large number of sinuses,cavities and spaces,and also closely related to the brain.The diagnosis of oral and maxillofacial lesions usually depends on the imaging examination.The conventional imaging methods are common CT and X-ray plain films.In recent years,with the rapid development of medical science and technology,more intuitive and vivid three-dimensional images have been applied in the diagnosis and treatment of oral and maxillofacial diseases.Therefore,CT three-dimensional imaging technology has been widely used in clinical practice.This paper reviews this topic.
文摘The high mortality rates of colon and rectal tumors have put forward an urgent need for rapid, sensitive, and accurate diagnosis. The polarization imaging technology, with the advantages of noninvasiveness, noncontact, quantification, rapidity, and high sensitivity, is expected to be used for auxiliary diagnosis of colorectal cancer. Herein, the differences in colorectal tissues of four pathological types were studied using this powerful technology. Polarized light imaging combined with the Mueller matrix decomposition (MMPD) method was applied to extract structural features that may be related to colorectal tumors. It demonstrated that parameters δ and θ could reflect the structural differences of colorectal tumors. Preliminary simulated experiment results revealed that the parameter δ was related to the fiber density, and the parameter θ was related to the fiber angle. Then Tamura image texture analysis was used to quantitatively describe tissues of different pathological types, and the results showed that the coarseness, contrast, directionality, and roughness of the four groups were statistically different. Texture analysis based on the quantitative data of the four dimensions could be applied for the identification of benign and malignant colorectal tumors.
文摘BACKGROUND Hepatobiliary surgery is complex and requires a thorough understanding of the liver’s anatomy,biliary system,and vasculature.Traditional imaging methods such as computed tomography(CT)and magnetic resonance imaging(MRI),although helpful,fail to provide three-dimensional(3D)relationships of these structures,which are critical for planning and executing complicated surgeries.AIM To explore the use of 3D imaging and virtual surgical planning(VSP)technologies to improve surgical accuracy,reduce complications,and enhance patient recovery in hepatobiliary surgeries.METHODS A comprehensive review of studies published between 2017 and 2024 was conducted through PubMed,Scopus,Google Scholar,and Web of Science.Studies selected focused on 3D imaging and VSP applications in hepatobiliary surgery,assessing surgical precision,complications,and patient outcomes.Thirty studies,including randomized controlled trials,cohort studies,and case reports,were included in the final analysis.RESULTS Various 3D imaging modalities,including multidetector CT,MRI,and 3D rotational angiography,provide high-resolution views of the liver’s vascular and biliary anatomy.VSP allows surgeons to simulate complex surgeries,improving preoperative planning and reducing complications like bleeding and bile leaks.Several studies have demonstrated improved surgical precision,reduced complications,and faster recovery times when 3D imaging and VSP were used in complex surgeries.CONCLUSION 3D imaging and VSP technologies significantly enhance the accuracy and outcomes of hepatobiliary surgeries by providing individualized preoperative planning.While promising,further research,particularly randomized controlled trials,is needed to standardize protocols and evaluate long-term efficacy.
基金Supported by the Natural Science Foundation of Fujian Province,No.2022J011442.
文摘BACKGROUND Percutaneous transhepatic biliary drainage(PTBD)is one of the primary clinical treatment options for patients with obstructive jaundice.In recent years,PTBD assisted by three-dimensional(3D)reconstruction technology has been widely implemented,but its advantages over traditional methods remains inconclusive.Thus,a discussion is warranted.AIM To explore the safety and efficacy of 3D reconstruction technology-assisted PTBD.METHODS We systematically searched the databases including the Cochrane Library,PubMed,EMBASE,Web of Science and China National Knowledge Infrastructure.The search period extended from the establishment of each database to November,2024.We screened the literature according to predefined inclusion and exclusion criteria,assessed the quality of the studies,and extracted data.Meta-analysis was performed using Revman 5.4.1 software.RESULTS A total of 15 studies were included,involving 1434 patients.The results of the meta-analysis showed that compared with the traditional group,the overall post-operative complications rate in the 3D reconstruction technology group was significantly lower[odds ratio=0.25;95%confidence interval(CI):0.17-0.36,P<0.00001].The overall puncture success rate in the 3D reconstruction group was better than those in the traditional group(odds ratio=3.61;95%CI:1.98-6.55,P<0.0001).However,there was no significant difference between the two groups in the reduction levels of postoperative total bilirubin(mean difference=-1.38;95%CI:-3.29 to 0.53,P=0.16).Subgroup analysis were conducted on the surgery time according to guidance stages of the 3D reconstruction,3D reconstruction imaging modalities,and types of studies.The results were stable,with no significant changes observed.CONCLUSION 3D reconstruction technology significantly improves the puncture success rate and safety of PTBD.However,it has no significant advantage in bile drainage effectiveness.Continued research is warranted to further explore its clinical value and optimize its application.
基金National Key Research and Development Program of China(2022YFC 3602400)Shanghai Municipal Health Commission“Top Priority Research Center”(2023-ZZ02021)+2 种基金Shanghai Public Health Key Discipline Construction Project(GWVI-11.1-26)Shanghai Academic/Technology Research Leader(21XD1432100)Key Research and Development Program of Shandong Province(2021SFGC0503)。
文摘Cardiovascular damage caused by cancer treatment has become an important cause of death for tumor survivors.With the recognition of cardiovascular diseases and cancer therapy-related cardiovascular toxicity(CTR-CVT)in tumor patients,noninvasive imaging technologies play pivotal roles in the risk stratification,early diagnosis,monitoring and follow-up for CTR-CVT.In recent years,the field of cardio-oncology has witnessed continual updates in diagnostic and therapeutic strategies,with several pertinent guidelines and expert consensus documents issued in China and abroad.However,there remains a conspicuous absence of systematic guidance documents on the application of imaging techniques in the clinical practice of cardio-oncology.Therefore,the Chinese Anti-Cancer Association Society of Integrative Cardio-oncology,the Ultrasound Branch of the Chinese Medical Association,and the Chinese Society of Echocardiography convened experts to formulate the"Chinese guideline for the clinical application of noninvasive imaging technology in accessing cancer therapy-related cardiovascular toxicity".Building upon the systematic evaluation of guidelines and the latest evidence-based medical research in the field of cardio-oncology domestically and abroad,and in conjunction with data derived from evidence-based medical research in China,this guideline proposes noninvasive imaging examination methods and monitoring strategies for CTR-CVT,aiming to further standardize and guide the clinical practice of multidisciplinary physicians specializing in cardio-oncology in China.
文摘The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the integrated engineering technology of post-fracturing drilling,coring and monitoring of shale and the analysis of fracture source tracing,the evaluation of the fracture network after fracturing in the three-dimensional development of shale gas was conducted.The data of core fractures after fracturing indicate that three major types of fractures are formed after fracturing:natural fractures,hydraulic fractures,and fractures induced by external mechanical force,which are further classified into six subcategories:natural structural fractures,natural bedding fractures,hydraulic fractures,hydraulically activated fractures,drilling induced fractures,and fractures induced by core transportation.The forms of the artificial fracture network after fracturing are complex.Hydraulic fractures and hydraulically activated fractures interweave with each other,presenting eight forms of artificial fracture networks,among which the“一”-shaped fracture is the most common,accounting for approximately 70%of the total fractures.When the distance to the fractured wellbore is less than 35 m,the density of the artificial fracture network is relatively high;when it is 35–100 m,the density is lower;and when it is beyond 100 m,the density gradually increases.The results of the fracture tracing in the core sampling area confirm that the current fracturing technology can essentially achieve the differential transformation of the reservoir in the main area of Jiaoshiba block in Fuling.The three-layer three-dimensional development model can efficiently utilize shale gas reserves,although there is still room for improvement in the complexity and propagation uniformity of fractures.It is necessary to further optimize technologies such as close-cutting combined with temporary blocking and deflection within fractures or at fracture mouths,as well as limited flow perforation techniques,to promote the balanced initiation and extension of fractures.
基金Fujian Provincial Health Technology Project,No.2020GGA079Natural Science Foundation of Fujian Province,No.2021J011380National Natural Science Foundation of China,No.62276146.
文摘Acute pancreatitis(AP)is a potentially life-threatening inflammatory disease of the pancreas,with clinical management determined by the severity of the disease.Diagnosis,severity prediction,and prognosis assessment of AP typically involve the use of imaging technologies,such as computed tomography,magnetic resonance imaging,and ultrasound,and scoring systems,including Ranson,Acute Physiology and Chronic Health Evaluation II,and Bedside Index for Severity in AP scores.Computed tomography is considered the gold standard imaging modality for AP due to its high sensitivity and specificity,while magnetic resonance imaging and ultrasound can provide additional information on biliary obstruction and vascular complications.Scoring systems utilize clinical and laboratory parameters to classify AP patients into mild,moderate,or severe categories,guiding treatment decisions,such as intensive care unit admission,early enteral feeding,and antibiotic use.Despite the central role of imaging technologies and scoring systems in AP management,these methods have limitations in terms of accuracy,reproducibility,practicality and economics.Recent advancements of artificial intelligence(AI)provide new opportunities to enhance their performance by analyzing vast amounts of clinical and imaging data.AI algorithms can analyze large amounts of clinical and imaging data,identify scoring system patterns,and predict the clinical course of disease.AI-based models have shown promising results in predicting the severity and mortality of AP,but further validation and standardization are required before widespread clinical application.In addition,understanding the correlation between these three technologies will aid in developing new methods that can accurately,sensitively,and specifically be used in the diagnosis,severity prediction,and prognosis assessment of AP through complementary advantages.
文摘Perianal abscess is a common disease in anorectal surgery. If the diagnosis is not clear and the cure is thoroughly cleared, the recurrence and spread of anal fistula will cause life-long pain. Objective: To investigate the application of 3.0T MRI 3D CUBE T2WI lipid suppression sequence in the diagnosis of perianal abscess. Methods: Thirty-six patients with perianal abscess confirmed by operation were examined with 2D T2WI and 3D CUBE T2WI lipid suppression sequences before operation. Two imaging techniques were evaluated to show the types of perianal abscess, the number of abscesses, the number of internal orifices of abscess, and the number of fistula branches with anal fistula in abscess. Results: Among 36 cases of perianal abscess, there were 5 cases of anal subcutaneous abscess, 12 cases of ischiorectal space abscess (8 cases complicated with anal fistula), 6 cases of posterior anal space abscess, 5 cases of anal sphincter abscess (3 cases complicated with anal fistula), 2 cases of high intermuscular abscess, 2 cases of rectal submucosal abscess, 3 cases of complex abscess (3 cases complicated with anal fistula), 1 case of misdiagnosis, 2D T2WI lipid suppression sequence and 3D CUBE T2WI suppression. The accuracy of lipid sequence abscess typing was 80.6% (29/36) and 88.9% (32/36), respectively, with no significant difference (P > 0.05). Thirty-six patients were surgically diagnosed as having 32 internal orifices, 68.8% (22/32) and 93.8% (30/32) of 2D T2WI and 3D CUBE T2WI lipid-suppressing sequences, respectively, with significant difference (P Conclusion: 3D CUBE T2WI lipid suppression sequence is superior to 2D T2WI lipid suppression sequence in the classification of perianal abscess, the number of internal orifices of abscess and the number of fistula branches of abscess complicated with anal fistula. It can also determine the number of internal orifices of abscess complicated with anal fistula, the number of fistula branches, the shape of primary and branch fistula and the relationship among pelvic floor muscle tissues. It can provide more accurate images for preoperative and intraoperative clinical surgery.
文摘The recently introduced real-time three-dimensional color Doppler flow imaging （RT-3D CDFI） technique provides a quick and accurate calculation of regurgitant jet volume （RJV） and fraction. In order to evaluate RT-3D CDFI in the noninvasive assessment of aortic RJV and regurgitant jet fraction （RJF） in patients with isolated aortic regurgitation, real-time three-dimensional echocardiographic studies were performed on 23 patients with isolated aortic regurgitation to obtain LV end-diastolic volumes （LVEDV）, end-systolic volumes （LVESV） and RJV, and then RJF could be calculated. The regurgitant volume （RV） and regurgitant fraction （RF） calculated by two-dimensional pulsed Doppler （2D-PD） method served as reference values. The results showed that aortic RJV measured by the RT-3D CDFI method showed a good correlation with the 2D-PD measurements （r= 0.93, Y=0.89X＋ 3.9, SEE= 8.6 mL, P〈0.001 ）; the mean （SD） difference between the two methods was - 1.5 （9.8） mL. % RJF estimated by the RT-3D CDFI method was also correlated well with the values obtained by the 2D-PD method （r=0.88, Y=0.71X＋ 14.8, SEE= 6.4 %, P〈0. 001）; the mean （SD） difference between the two methods was -1.2 （7.9） %. It was suggested that the newly developed RT-3D CDFI technique was feasible in the majority of patients. In patients with eccentric aortic regurgitation, this new modality provides additional information to that obtained from the two-dimensional examination, which overcomes the inherent limitations of two-dimensional echocardiography by depicting the full extent of the jet trajectory. In addition, the RT-3D CDFI method is quick and accurate in calculating RJV and RJF.
文摘Summary： This study sought to evaluate the contribution of two-dimensional ultrasound （2D-US） and three-dimensional skeletal imaging ultrasound （3D-SUIS） in the prenatal diagnosis of sirenomelia. Be- tween September 2010 and April 2014, a prospective study was conducted in a single referral center using 3D-SU1S performed after 2D-US in 10 cases of sirenomelia. Diagnostic accuracy and detailed findings were compared with postnatal three-dimensional helical computed tomography （3D-HCT）, radiological findings and autopsy. Pregnancy was terminated in all 10 sirenomelia cases, including 9 singletons and I conjoined twin pregnancy, for a total of 5 males and 5 females. These cases of sirenomelia were deter- mined by autopsy and/or chromosomal examination. Initial 2D-US showed that there were 10 cases of oligohydranmios, bilateral renal agenesis, bladder agenesis, single umbilical artery, fusion of the lower limbs and spinal abnormalities; 8 cases of dipus or monopus; 2 cases of apus; and 8 cases of cardiac abnormalities. Subsequent 3D-SUIS showed that there were 9 cases of scoliosis, l0 cases of sacrococ- cygeal vertebra dysplasia, 3 cases of hemivertebra, 1 case of vertebral fusion, 3 cases of spina bifida, and 5 cases of rib abnormalities. 3D-SUIS identified significantly more skeletal abnormalities than did 2D-US, and its accuracy was 79.5% （70/88） compared with 3D-HCT and radiography. 3D-SUIS seems to be a useful complementary method to 2D-US and may improve the accuracy of identifying prenatal skeletal abnormalities related to sirenomelia.
基金the support of the National Natural Science Foundation of China(Grant Nos.42207199,52179113,42272333)Zhejiang Postdoctoral Scientific Research Project(Grant Nos.ZJ2022155,ZJ2022156)。
文摘Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.
基金Supported by the Hundred Talents Program of Chinese Academy of Sciencesthe National Basic Research Program of China under Grant No 2014CB339803+2 种基金the Major National Development Project of Scientific Instrument and Equipment under Grant No2011YQ150021the National Natural Science Foundation of China under Grant Nos 61575214,61574155,61404149 and 61404150the Shanghai Municipal Commission of Science and Technology under Grant Nos 14530711300,15560722000 and 15ZR1447500
文摘Computed tomography has been proven to be useful for non-destructive inspection of structures and materials. We build a three-dimensional imaging system with the photonically generated incoherent noise source and the Schottky barrier diode detector in the terahertz frequency band （90–140GHz）. Based on the computed tomography technique, the three-dimensional image of a ceramic sample is reconstructed successfully by stacking the slices at different heights. The imaging results not only indicate the ability of terahertz wave in the non-invasive sensing and non-destructive inspection applications, but also prove the effectiveness and superiority of the uni-traveling-carrier photodiode as a terahertz source in the imaging applications.
基金Supported by the Key Research and Development Plan of Shaanxi Province,No.2021SF-298.
文摘BACKGROUND Neurovascular compression(NVC) is the main cause of primary trigeminal neuralgia(TN) and hemifacial spasm(HFS). Microvascular decompression(MVD) is an effective surgical method for the treatment of TN and HFS caused by NVC. The judgement of NVC is a critical step in the preoperative evaluation of MVD, which is related to the effect of MVD treatment. Magnetic resonance imaging(MRI) technology has been used to detect NVC prior to MVD for several years. Among many MRI sequences, three-dimensional time-of-flight magnetic resonance angiography(3D TOF MRA) is the most widely used. However, 3D TOF MRA has some shortcomings in detecting NVC. Therefore, 3D TOF MRA combined with high resolution T2-weighted imaging(HR T2WI) is considered to be a more effective method to detect NVC.AIM To determine the value of 3D TOF MRA combined with HR T2WI in the judgment of NVC, and thus to assess its value in the preoperative evaluation of MVD.METHODS Related studies published from inception to September 2022 based on PubMed, Embase, Web of Science, and the Cochrane Library were retrieved. Studies that investigated 3D TOF MRA combined with HR T2WI to judge NVC in patients with TN or HFS were included according to the inclusion criteria. Studies without complete data or not relevant to the research topics were excluded. The Quality Assessment of Diagnostic Accuracy Studies checklist was used to assess the quality of included studies. The publication bias of the included literature was examined by Deeks’ test. An exact binomial rendition of the bivariate mixed-effects regression model was used to synthesize data. Data analysis was performed using the MIDAS module of statistical software Stata 16.0. Two independent investigators extracted patient and study characteristics, and discrepancies were resolved by consensus. Individual and pooled sensitivities and specificities were calculated. The I_(2) statistic and Q test were used to test heterogeneity. The study was registered on the website of PROSERO(registration No. CRD42022357158).RESULTS Our search identified 595 articles, of which 12(including 855 patients) fulfilled the inclusion criteria. Bivariate analysis showed that the pooled sensitivity and specificity of 3D TOF MRA combined with HR T2WI for detecting NVC were 0.96 [95% confidence interval(CI): 0.92-0.98] and 0.92(95%CI: 0.74-0.98), respectively. The pooled positive likelihood ratio was 12.4(95%CI: 3.2-47.8), pooled negative likelihood ratio was 0.04(95%CI: 0.02-0.09), and pooled diagnostic odds ratio was 283(95%CI: 50-1620). The area under the receiver operating characteristic curve was 0.98(95%CI: 0.97-0.99). The studies showed no substantial heterogeneity(I2 = 0, Q = 0.001 P = 0.50).CONCLUSION Our results suggest that 3D TOF MRA combined with HR T2WI has excellent sensitivity and specificity for judging NVC in patients with TN or HFS. This method can be used as an effective tool for preoperative evaluation of MVD.
文摘With regard to problems in conventional synthetic aperture radar （SAR）, such as imaging distortion, beam limitation and failure in acquiring three-dimensional （3-D） information, a downward-looking 3-D imaging method based on frequency modulated continuous wave （FMCW） and digital beamforming （DBF） technology for airborne SAR is presented in this study. Downward-looking 3-D SAR signal model is established first, followed by introduction of virtual antenna optimization factor and discussion of equivalent-phase-center compensation. Then, compensation method is provided according to reside video phase （RVP） and slope term for FMCW SAR. As multiple receiving antennas are applied to downward-looking 3-D imaging SAR, range cell migration correction （RCMC） turns to be more complex, and corrective measures are proposed. In addition, DBF technology is applied in realizing cross-track resolution. Finally, to validate the proposed method, magnitude of slice, peak sidelobe ratio （PSLR）, integrated sidelobe ratio （ISLR） and two-dimensional （2-D） contour plot of impulse response function （IRF） of point target in three dimensions are demonstrated. Satisfactory performances are shown by simulation results.
基金Projects(51774138,51804122,51904105)supported by the National Natural Science Foundation of ChinaProjects(E2021209148,E2021209052)supported by the Natural Science Foundation of Hebei Province,China。
文摘By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emissions(AE),joint response characteristics of the velocity field and AE during rock fracture were analyzed.Moreover,the localization effect of damage during rock fracture was explored by applying wave velocity imagings.The experimental result showed that the wave velocity imagings enable three-dimensional(3-D)visualization of the extent and spatial position of damage to the rock.A damaged zone has a low wave velocity and a zone where the low wave velocity is concentrated tends to correspond to a severely damaged zone.AE parameters and wave velocity imagings depict the changes in activity of cracks during rock fracture from temporal and spatial perspectives,respectively:the activity of cracks is strengthened,and the rate of AE events increases during rock fracture;correspondingly,the low-velocity zones are gradually aggregated and their area gradually increases.From the wave velocity imagings,the damaged zones in rock were divided into an initially damaged zone,a progressively damaged zone,and a fractured zone.During rock fracture,the progressively damaged zone and the fractured zone both develop around the initially damaged zone,showing a typical localization effect of the damage.By capturing the spatial development trends of the progressively damaged zone and fractured zone in wave velocity imagings,the development of microfractures can be predicted,exerting practical significance for determining the position of the main fracture.
文摘Traditional laparoscopic liver cancer resection faces challenges,such as difficultiesin tumor localization and accurate marking of liver segments,as well as theinability to provide real-time intraoperative navigation.This approach falls shortof meeting the demands for precise and anatomical liver resection.The introductionof fluorescence imaging technology,particularly indocyanine green,hasdemonstrated significant advantages in visualizing bile ducts,tumor localization,segment staining,microscopic lesion display,margin examination,and lymphnode visualization.This technology addresses the inherent limitations oftraditional laparoscopy,which lacks direct tactile feedback,and is increasinglybecoming the standard in laparoscopic procedures.Guided by fluorescenceimaging technology,laparoscopic liver cancer resection is poised to become thepredominant technique for liver tumor removal,enhancing the accuracy,safetyand efficiency of the procedure.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11774095,11722431 and 11621404the Shanghai Basic Research Project under Grant No 18JC1412200+2 种基金the National Key R&D Program of China under Grant No2016YFB0400904the Program of Introducing Talents of Discipline to Universities under Grant No B12024the Shanghai International Cooperation Project under Grant No 16520710600
文摘Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.
基金supported by the National Natural Science Foundation of China (No. 12220101005)Natural Science Foundation of Jiangsu Province (No. BK20220132)+2 种基金Primary Research and Development Plan of Jiangsu Province (No. BE2019002-3)Fundamental Research Funds for Central Universities (No. NG2022004)the Foundation of the Graduate Innovation Center in NUAA (No. xcxjh20210613)。
文摘A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method with scattering angle correction(CSS-BP-SC) can quickly perform the back-projection process of the Compton cone and can be used to precompute the list-mode maximum likelihood expectation maximization(LM-MLEM). A dedicated parallel architecture was designed for the graphics processing unit acceleration of the back-projection and iteration stage of the CSS-BP-SC-based LM-MLEM. The imaging results of the two-point source Monte Carlo(MC) simulation demonstrate that by analyzing the full width at half maximum along the three coordinate axes, the CSS-BP-SC-based LM-MLEM can obtain imaging results comparable to those of the traditional reconstruction algorithm, that is, the simple back-projection-based LM-MLEM. The imaging results of the mouse phantom MC simulation and experiment demonstrate that the reconstruction results obtained by the proposed method sufficiently coincide with the set radioactivity distribution, and the speed increased by more than 664 times compared to the traditional reconstruction algorithm in the mouse phantom experiment. The proposed method will further advance the imaging applications of Compton cameras.
基金Project supported by the National Basic Research Program of China (Grant No. 2010CB327702)
文摘We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into real and virtual space. Experimental results show that the gap is reduced to 45% of that in a conventional integral imaging system with the same parameters.
