Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible ligh...Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.展开更多
Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While suc...Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While such a computing paradigm can only employ a single photonic device as the nonlinear node for data processing,the performance highly relies on the fading memory provided by the delay feedback loop(FL),which sets a restriction on the extensibility of physical implementation,especially for highly integrated chips.Here,we present a simplified photonic scheme for more flexible parameter configurations leveraging the designed quasi-convolution coding(QC),which completely gets rid of the dependence on FL.Unlike delay-based TDRC,encoded data in QC-based RC(QRC)enables temporal feature extraction,facilitating augmented memory capabilities.Thus,our proposed QRC is enabled to deal with time-related tasks or sequential data without the implementation of FL.Furthermore,we can implement this hardware with a low-power,easily integrable vertical-cavity surface-emitting laser for high-performance parallel processing.We illustrate the concept validation through simulation and experimental comparison of QRC and TDRC,wherein the simpler-structured QRC outperforms across various benchmark tasks.Our results may underscore an auspicious solution for the hardware implementation of deep neural networks.展开更多
The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an ...The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.展开更多
BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significan...BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.展开更多
Caustic ingestion is a relatively rare but potentially catastrophic gastroentero-logical emergency.Upper gastrointestinal(GI)endoscopy is currently regarded as the gold standard modality not only to assess the depth a...Caustic ingestion is a relatively rare but potentially catastrophic gastroentero-logical emergency.Upper gastrointestinal(GI)endoscopy is currently regarded as the gold standard modality not only to assess the depth and the extension of GI caustic injury,but also to guide the appropriate treatment.Intriguingly,contrast-enhanced computed tomography(CECT)has recently emerged as a promising non-invasive and more accurate alternative to endoscopy in this setting.However,to date,evidence concerning the role of CECT as an alternative or complementary diagnostic tool to endoscopy in caustic ingestion is still limited.The aim of our review was to summarize and discuss the current evidence concerning the role of CECT in the emergency diagnosis of caustic ingestion and its value in assessing injury severity among non-pediatric patients.展开更多
Dual-energy CT(DECT)is an advancement in CT technology that allows for the acquisition of images at two different energy levels.Two main post-processing tools,which form the backbone of DECT,include material decomposi...Dual-energy CT(DECT)is an advancement in CT technology that allows for the acquisition of images at two different energy levels.Two main post-processing tools,which form the backbone of DECT,include material decomposition and virtual monoenergetic images.Material decomposition helps in the generation of virtual nonenhanced,iodine,pulmonary lung blood volume,lung vessel,automated bone removal,and renal stone characterization images.DECT offers a broad spectrum of clinical applications in pediatric imaging,including vascular,neurological,thoracic,abdominal,skeletal,and oncologic assessments.Additionally,it contributes to shorter scan times and enables the use of lower contrast media volumes while maintaining diagnostic image quality.This technique provides unique qualitative and quantitative information about the composition of the tissue,allowing differentiation of materials,including iodinated contrast agents.The radiation dose of DECT is equivalent to or lower than that of a singleenergy CT,adding to the advantages of DECT,especially in children who are more sensitive to the harmful effects of radiation.In this minireview we outlined the basic principles of the DECT technique and its post-processing techniques with emphasis on clinical applications in pediatric imaging.展开更多
Computed Tomography(CT)reconstruction is essential inmedical imaging and other engineering fields.However,blurring of the projection during CT imaging can lead to artifacts in the reconstructed images.Projection blur ...Computed Tomography(CT)reconstruction is essential inmedical imaging and other engineering fields.However,blurring of the projection during CT imaging can lead to artifacts in the reconstructed images.Projection blur combines factors such as larger ray sources,scattering and imaging system vibration.To address the problem,we propose DeblurTomo,a novel self-supervised learning-based deblurring and reconstruction algorithm that efficiently reconstructs sharp CT images from blurry input without needing external data and blur measurement.Specifically,we constructed a coordinate-based implicit neural representation reconstruction network,which can map the coordinates to the attenuation coefficient in the reconstructed space formore convenient ray representation.Then,wemodel the blur as aweighted sumof offset rays and design the RayCorrectionNetwork(RCN)andWeight ProposalNetwork(WPN)to fit these rays and their weights bymulti-view consistency and geometric information,thereby extending 2D deblurring to 3D space.In the training phase,we use the blurry input as the supervision signal to optimize the reconstruction network,the RCN,and the WPN simultaneously.Extensive experiments on the widely used synthetic dataset show that DeblurTomo performs superiorly on the limited-angle and sparse-view in the simulated blurred scenarios.Further experiments on real datasets demonstrate the superiority of our method in practical scenarios.展开更多
BACKGROUND Accurate identification of tumor invasion depth and lymph node(LN)involve-ment in patients with colon cancer(CC)is critical for guiding treatment strategies.However,the preoperative prediction of tumor inva...BACKGROUND Accurate identification of tumor invasion depth and lymph node(LN)involve-ment in patients with colon cancer(CC)is critical for guiding treatment strategies.However,the preoperative prediction of tumor invasion depth and LN metastasis in CC remains challenging.As the intestinal tumor develops,the fat density in the mesentery increases.METHODS Patients,who were diagnosed with CC and underwent surgery,were included and divided into the training and validation cohorts.CT-T values of the mesen-tery were extracted from the CT images.Cutoff points were determined using the receiver operating characteristic(ROC)curve,and the area under the ROC curve was employed to assess the performance of the CT-T value for tumor invasion depth and LN status prediction.RESULTS Cutoff values of 11.83 and 17.17 were identified to discriminate T1/2 vs T3/4 and N0 vs N1/2,respectively.With a cutoff CT-T value of 11.83,the total diagnostic accuracy for T stage was 83.1%(81.5%for the training cohort and 86.2%for the validation cohort).With a cutoff CT-T value of 17.17,the total diagnostic accuracy for N stage was 77.3%(75.8%for the training cohort and 80.1%for the validation cohort),which was higher than that of CT-reported LN metastasis.CONCLUSION In this study,we explored an efficient method for predicting preoperative T and N stages using the tumor-contributed CT value of the mesentery in CC,which displayed superior predictive accuracy.展开更多
BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are ne...BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size.展开更多
AIM:To describe the anatomic characteristics of the lacrimal sac and its adjacent bone structures and to provide surgical recommendations for endoscopic dacryocystorhinostomy(EN-DCR).METHODS:This retrospective compara...AIM:To describe the anatomic characteristics of the lacrimal sac and its adjacent bone structures and to provide surgical recommendations for endoscopic dacryocystorhinostomy(EN-DCR).METHODS:This retrospective comparative study involved 118 sides with complete nasolacrimal duct obstruction and 83 unaffected sides from 126 patients.Computed tomographic-dacryocystography(CT-DCG)scans were performed before lacrimal surgery,and image reconstruction was used to obtain continuous 0.75-mm axial,coronal,and segmental sections for review.The morphology of the lacrimal sac and its relationship with adjacent bony structures were determined for measurement,as well as the obstructed location.RESULTS:The height of the lacrimal sac was 12.99±2.10 mm in this study.The operculum of the middle turbinate(OMT)was located vertically in the lower third of the lacrimal sac.Horizontally,the junction between the maxillary bone and the lacrimal bone(MB-LB)was close to,mostly(60.2%)posterior to,the lacrimal sac.The uncinate process was more frequently attached to the lacrimal bones(75.1%).The obstructions were generally located around the entrance of the nasolacrimal duct(NLD).However,some were placed higher,with 7.63%blocked not lower than the OMT.There was a negative correlation between the diameter of the lacrimal sac and the level of obstruction(r=-0.35,P<0.01).CONCLUSION:In this study,the OMT and MB-LB can be served as the landmarks in EN-DCR.Partial uncinectomy should be performed in most cases.The obstructions were generally located around the entrance of the NLD,but some extreme individual variations strongly implies the importance of CT-DCG scanning before surgery.展开更多
It is not easy to reduce the metal artifacts of computed tomography images.However,the pixel values inside the metal artifact regions vary smoothly,while those on the borders of the metal and the bone regions vary sha...It is not easy to reduce the metal artifacts of computed tomography images.However,the pixel values inside the metal artifact regions vary smoothly,while those on the borders of the metal and the bone regions vary sharply.When the Canny operation by adaptive thresholding is conducted on the raw image,the almost continuous edges can be formed obviously on the borders of the metal and the bone regions,but this kind of information cannot be formed for the metal artifact regions.In this paper,by searching the closed areas formed by the border edges of the bone regions in the Canny image,the metal artifact regions,which are very difficult to discriminate only by intensity thresholding,can be excluded effectively.A novel prior image-based method is thus developed for metal artifact reduction.The experiments demonstrate that the proposed method can be realized easily and reduce the metal artifacts effectively even if multiple large metal objects exist simultaneously in the image.The method is suitable for the clinical application.展开更多
BACKGROUND:Previous studies have reported that early computed tomography(CT)findings significantly contribute to the outcomes of cardiac arrest(CA)patients.This study aims to evaluate the association between chest CT ...BACKGROUND:Previous studies have reported that early computed tomography(CT)findings significantly contribute to the outcomes of cardiac arrest(CA)patients.This study aims to evaluate the association between chest CT features and prognosis in CA patients treated with extracorporeal cardiopulmonary resuscitation(ECPR).METHODS:A retrospective observational study was conducted on adult CA patients treated with ECPR in a tertiary hospital between March 2015 and June 2023.All the patients underwent a wholebody CT scan within 1 h of ECPR.Data regarding demographic and clinical characteristics were collected from electronic medical records.The presence of gravity-dependent distribution and CT scores based on chest CT scans were determined for each patient.The primary outcome was 28-day survival.Receiver operating characteristic(ROC)curves were used to evaluate the ability of chest CT features(gravitydependent distribution and CT scores)to predict poor outcomes.The cut-off value of the CT score was determined.Kaplan-Meier curves were used to compare 28-day survival between the low-and high-CT score groups,which were classified using the estimated cut-off value.RESULTS:Among the 100 patients included,74 were non-survivors.The non-survivor patients showed a higher presence of gravity-dependent distribution and higher CT scores than survivors(P<0.05).Patients with gravity-dependent distribution had significantly higher CT scores than those with non-gravity-dependent distribution(P<0.05).The combination of CT score and gravity-dependent distribution predicted poor outcomes better than considering the features individually,demonstrating moderate performance(AUC:0.693,95%CI:0.568-0.801).According to the survival analysis,the risk of death increased as the CT score rose,with an estimated cut-off value of≥11(P=0.016).CONCLUSION:Chest CT features were associated with poor outcomes in CA patients following ECPR.展开更多
BACKGROUND Lymph node metastasis(LNM)is a key prognostic factor in pancreatic cancer(PC).Accurate preoperative prediction of LNM remains challenging.Radiomics offers a noninvasive method to extract quantitative imagin...BACKGROUND Lymph node metastasis(LNM)is a key prognostic factor in pancreatic cancer(PC).Accurate preoperative prediction of LNM remains challenging.Radiomics offers a noninvasive method to extract quantitative imaging features that may aid in predicting LNM.AIM To investigate the potential value of a computed tomography(CT)-based radiomics model in prediction of LNM in PC.METHODS A retrospective analysis was performed on 168 pathologically confirmed PC patients who underwent contrast-enhanced-CT.Among them,107 cases had no LNM,while 61 cases had confirmed LNM.These patients were randomly divided into a training cohort(n=135)and a validation cohort(n=33).A total of 792 radiomics features were extracted,comprising 396 features from the arterial phase and another 396 from the portal venous phase.The Minimum Redundancy Maximum Relevance and Least Absolute Shrinkage and Selection Operator methods were used for feature selection and Radiomics model construction.The receiver operating characteristic curve was employed to assess the diagnostic potential of the model,and DeLong test was used to compare the area under the curve(AUC)values of the model.RESULTS Six radiomics features from the arterial phase and nine from the portal venous phase were selected.The Radscore model demonstrated strong predictive performance for LNM in both the training and test cohorts,with AUC values ranging from 0.86 to 0.94,sensitivity between 66.7% and 91.7%,specificity from 71.4% to 100.0%,accuracy between 78.8%and 91.1%,PPV ranging from 64.7% to 100.0%,and negative predictive value between 84.0% and 93.8%.No significant differences in AUC values were observed between the arterial and portal venous phases in either the training or test set.CONCLUSION The preoperative CT-based radiomics model exhibited robust predictive capability for identifying LNM in PC.展开更多
BACKGROUND Tumor deposits(TDs)are an independent predictor of poor prognosis in colorec-tal cancer(CRC)patients.Enhanced follow-up and treatment monitoring for TD+patients may improve survival rates and quality of lif...BACKGROUND Tumor deposits(TDs)are an independent predictor of poor prognosis in colorec-tal cancer(CRC)patients.Enhanced follow-up and treatment monitoring for TD+patients may improve survival rates and quality of life.However,the detection of TDs relies primarily on postoperative pathological examination,which may have a low detection rate due to sampling limitations.AIM To evaluate the spectral computed tomography(CT)parameters of primary tu-mors and the largest regional lymph nodes(LNs),to determine their value in predicting TDs in CRC.METHODS A retrospective analysis was conducted which included 121 patients with CRC whose complete spectral CT data were available.Patients were divided into the TDs+group and the TDs-group on the basis of their pathological results.Spectral CT parameters of the primary CRC lesion and the largest regional LNs were measured,including the normalized iodine concentration(NIC)in both the arte-rial and venous phases,and the LN-to-primary tumor ratio was calculated.Stati-stical methods were used to evaluate the diagnostic efficacy of each spectral para-meter.RESULTS Among the 121 CRC patients,33(27.2%)were confirmed to be TDs+.The risk of TDs positivity was greater in patients with positive LN metastasis,higher N stage and elevated carcinoembryonic antigen and cancer antigen 19-9 levels.The NIC(LNs in both the arterial and venous phases),NIC(primary tumors in the venous phase),and the LN-to-primary tumor ratio in both the arterial and venous phases were associated with TDs(P<0.05).In mul-tivariate logistic regression analysis,the arterial phase LN-to-primary tumor ratio was identified as an independent predictor of TDs,demonstrating the highest diagnostic performance(area under the curve:0.812,sensitivity:0.879,specificity:0.648,cutoff value:1.145).CONCLUSION The spectral CT parameters of the primary colorectal tumor and the largest regional LNs,especially the LN-to-primary tumor ratio,have significant clinical value in predicting TDs in CRC.展开更多
BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM T...BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM To evaluate the computed tomography characteristics of GS and provide insights into its accurate diagnosis.METHODS Twenty-three cases of GS confirmed between January 2011 and December 2023 were assessed clinically and radiologically.Imaging characteristics,including tumor location,size,contour,ulceration,growth pattern,enhancement degree and pattern,cystic change,calcification,and perigastric lymph nodes(PLNs),were reviewed by two experienced radiologists.RESULTS Our sample included 18 females and 5 males,with a median age of 54.7 years.A total of 39.1%of cases were asymptomatic.GSs appeared as oval and well-defined submucosal tumors,with exophytic(43.5%)or mixed(endoluminal+exophytic;43.5%)growth patterns.The tumors were primarily located in the gastric body(78.3%).Ulcerations were observed in 8 cases(34.5%),and PLNs were observed in 15 cases(65%).The average degree of enhancement was 48.3 Hounsfield units.Twenty cases(87%)showed peak enhancement in the delayed phase.Most GSs were homogeneous,while cystic change(13.0%)and calcification(17.4%)were rare.CONCLUSION GS predominantly showed gradual homogenous enhancement with peak enhancement in the delayed phase.PLNs around GS are helpful in differentiating GS from other gastric submucosal tumors.展开更多
文摘Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.
基金National Natural Science Foundation of China(62171305,62405206,62004135,62001317,62111530301)Natural Science Foundation of Jiangsu Province(BK20240778,BK20241917)+3 种基金State Key Laboratory of Advanced Optical Communication Systems and Networks,China(2023GZKF08)China Postdoctoral Science Foundation(2024M752314)Postdoctoral Fellowship Program of CPSF(GZC20231883)Innovative and Entrepreneurial Talent Program of Jiangsu Province(JSSCRC2021527).
文摘Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While such a computing paradigm can only employ a single photonic device as the nonlinear node for data processing,the performance highly relies on the fading memory provided by the delay feedback loop(FL),which sets a restriction on the extensibility of physical implementation,especially for highly integrated chips.Here,we present a simplified photonic scheme for more flexible parameter configurations leveraging the designed quasi-convolution coding(QC),which completely gets rid of the dependence on FL.Unlike delay-based TDRC,encoded data in QC-based RC(QRC)enables temporal feature extraction,facilitating augmented memory capabilities.Thus,our proposed QRC is enabled to deal with time-related tasks or sequential data without the implementation of FL.Furthermore,we can implement this hardware with a low-power,easily integrable vertical-cavity surface-emitting laser for high-performance parallel processing.We illustrate the concept validation through simulation and experimental comparison of QRC and TDRC,wherein the simpler-structured QRC outperforms across various benchmark tasks.Our results may underscore an auspicious solution for the hardware implementation of deep neural networks.
基金Funded by Chinese National Natural Science Foundation of China(No.U2006224)。
文摘The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.
基金Supported by Natural Science Foundation of Anhui Medical University,No.2023xkj130.
文摘BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.
文摘Caustic ingestion is a relatively rare but potentially catastrophic gastroentero-logical emergency.Upper gastrointestinal(GI)endoscopy is currently regarded as the gold standard modality not only to assess the depth and the extension of GI caustic injury,but also to guide the appropriate treatment.Intriguingly,contrast-enhanced computed tomography(CECT)has recently emerged as a promising non-invasive and more accurate alternative to endoscopy in this setting.However,to date,evidence concerning the role of CECT as an alternative or complementary diagnostic tool to endoscopy in caustic ingestion is still limited.The aim of our review was to summarize and discuss the current evidence concerning the role of CECT in the emergency diagnosis of caustic ingestion and its value in assessing injury severity among non-pediatric patients.
文摘Dual-energy CT(DECT)is an advancement in CT technology that allows for the acquisition of images at two different energy levels.Two main post-processing tools,which form the backbone of DECT,include material decomposition and virtual monoenergetic images.Material decomposition helps in the generation of virtual nonenhanced,iodine,pulmonary lung blood volume,lung vessel,automated bone removal,and renal stone characterization images.DECT offers a broad spectrum of clinical applications in pediatric imaging,including vascular,neurological,thoracic,abdominal,skeletal,and oncologic assessments.Additionally,it contributes to shorter scan times and enables the use of lower contrast media volumes while maintaining diagnostic image quality.This technique provides unique qualitative and quantitative information about the composition of the tissue,allowing differentiation of materials,including iodinated contrast agents.The radiation dose of DECT is equivalent to or lower than that of a singleenergy CT,adding to the advantages of DECT,especially in children who are more sensitive to the harmful effects of radiation.In this minireview we outlined the basic principles of the DECT technique and its post-processing techniques with emphasis on clinical applications in pediatric imaging.
基金supported in part by the National Natural Science Foundation of China under Grants 62472434 and 62402171in part by the National Key Research and Development Program of China under Grant 2022YFF1203001+1 种基金in part by the Science and Technology Innovation Program of Hunan Province under Grant 2022RC3061in part by the Sci-Tech Innovation 2030 Agenda under Grant 2023ZD0508600.
文摘Computed Tomography(CT)reconstruction is essential inmedical imaging and other engineering fields.However,blurring of the projection during CT imaging can lead to artifacts in the reconstructed images.Projection blur combines factors such as larger ray sources,scattering and imaging system vibration.To address the problem,we propose DeblurTomo,a novel self-supervised learning-based deblurring and reconstruction algorithm that efficiently reconstructs sharp CT images from blurry input without needing external data and blur measurement.Specifically,we constructed a coordinate-based implicit neural representation reconstruction network,which can map the coordinates to the attenuation coefficient in the reconstructed space formore convenient ray representation.Then,wemodel the blur as aweighted sumof offset rays and design the RayCorrectionNetwork(RCN)andWeight ProposalNetwork(WPN)to fit these rays and their weights bymulti-view consistency and geometric information,thereby extending 2D deblurring to 3D space.In the training phase,we use the blurry input as the supervision signal to optimize the reconstruction network,the RCN,and the WPN simultaneously.Extensive experiments on the widely used synthetic dataset show that DeblurTomo performs superiorly on the limited-angle and sparse-view in the simulated blurred scenarios.Further experiments on real datasets demonstrate the superiority of our method in practical scenarios.
基金Supported by National Natural Science Foundation of China,No.82303785and Medical Scientific Research Foundation of Guangdong Province,No.A2024096.
文摘BACKGROUND Accurate identification of tumor invasion depth and lymph node(LN)involve-ment in patients with colon cancer(CC)is critical for guiding treatment strategies.However,the preoperative prediction of tumor invasion depth and LN metastasis in CC remains challenging.As the intestinal tumor develops,the fat density in the mesentery increases.METHODS Patients,who were diagnosed with CC and underwent surgery,were included and divided into the training and validation cohorts.CT-T values of the mesen-tery were extracted from the CT images.Cutoff points were determined using the receiver operating characteristic(ROC)curve,and the area under the ROC curve was employed to assess the performance of the CT-T value for tumor invasion depth and LN status prediction.RESULTS Cutoff values of 11.83 and 17.17 were identified to discriminate T1/2 vs T3/4 and N0 vs N1/2,respectively.With a cutoff CT-T value of 11.83,the total diagnostic accuracy for T stage was 83.1%(81.5%for the training cohort and 86.2%for the validation cohort).With a cutoff CT-T value of 17.17,the total diagnostic accuracy for N stage was 77.3%(75.8%for the training cohort and 80.1%for the validation cohort),which was higher than that of CT-reported LN metastasis.CONCLUSION In this study,we explored an efficient method for predicting preoperative T and N stages using the tumor-contributed CT value of the mesentery in CC,which displayed superior predictive accuracy.
基金Supported by the 2022 Provincial Quality Engineering Project for Higher Education Institutions,No.2022sx031the 2023 Provincial Quality Engineering Project for Higher Education Institutions,No.2023jyxm1071.
文摘BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size.
基金Supported by the National Natural Science Foundation of China(No.81700807).
文摘AIM:To describe the anatomic characteristics of the lacrimal sac and its adjacent bone structures and to provide surgical recommendations for endoscopic dacryocystorhinostomy(EN-DCR).METHODS:This retrospective comparative study involved 118 sides with complete nasolacrimal duct obstruction and 83 unaffected sides from 126 patients.Computed tomographic-dacryocystography(CT-DCG)scans were performed before lacrimal surgery,and image reconstruction was used to obtain continuous 0.75-mm axial,coronal,and segmental sections for review.The morphology of the lacrimal sac and its relationship with adjacent bony structures were determined for measurement,as well as the obstructed location.RESULTS:The height of the lacrimal sac was 12.99±2.10 mm in this study.The operculum of the middle turbinate(OMT)was located vertically in the lower third of the lacrimal sac.Horizontally,the junction between the maxillary bone and the lacrimal bone(MB-LB)was close to,mostly(60.2%)posterior to,the lacrimal sac.The uncinate process was more frequently attached to the lacrimal bones(75.1%).The obstructions were generally located around the entrance of the nasolacrimal duct(NLD).However,some were placed higher,with 7.63%blocked not lower than the OMT.There was a negative correlation between the diameter of the lacrimal sac and the level of obstruction(r=-0.35,P<0.01).CONCLUSION:In this study,the OMT and MB-LB can be served as the landmarks in EN-DCR.Partial uncinectomy should be performed in most cases.The obstructions were generally located around the entrance of the NLD,but some extreme individual variations strongly implies the importance of CT-DCG scanning before surgery.
文摘It is not easy to reduce the metal artifacts of computed tomography images.However,the pixel values inside the metal artifact regions vary smoothly,while those on the borders of the metal and the bone regions vary sharply.When the Canny operation by adaptive thresholding is conducted on the raw image,the almost continuous edges can be formed obviously on the borders of the metal and the bone regions,but this kind of information cannot be formed for the metal artifact regions.In this paper,by searching the closed areas formed by the border edges of the bone regions in the Canny image,the metal artifact regions,which are very difficult to discriminate only by intensity thresholding,can be excluded effectively.A novel prior image-based method is thus developed for metal artifact reduction.The experiments demonstrate that the proposed method can be realized easily and reduce the metal artifacts effectively even if multiple large metal objects exist simultaneously in the image.The method is suitable for the clinical application.
基金approved by the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University(2020-SR-226).
文摘BACKGROUND:Previous studies have reported that early computed tomography(CT)findings significantly contribute to the outcomes of cardiac arrest(CA)patients.This study aims to evaluate the association between chest CT features and prognosis in CA patients treated with extracorporeal cardiopulmonary resuscitation(ECPR).METHODS:A retrospective observational study was conducted on adult CA patients treated with ECPR in a tertiary hospital between March 2015 and June 2023.All the patients underwent a wholebody CT scan within 1 h of ECPR.Data regarding demographic and clinical characteristics were collected from electronic medical records.The presence of gravity-dependent distribution and CT scores based on chest CT scans were determined for each patient.The primary outcome was 28-day survival.Receiver operating characteristic(ROC)curves were used to evaluate the ability of chest CT features(gravitydependent distribution and CT scores)to predict poor outcomes.The cut-off value of the CT score was determined.Kaplan-Meier curves were used to compare 28-day survival between the low-and high-CT score groups,which were classified using the estimated cut-off value.RESULTS:Among the 100 patients included,74 were non-survivors.The non-survivor patients showed a higher presence of gravity-dependent distribution and higher CT scores than survivors(P<0.05).Patients with gravity-dependent distribution had significantly higher CT scores than those with non-gravity-dependent distribution(P<0.05).The combination of CT score and gravity-dependent distribution predicted poor outcomes better than considering the features individually,demonstrating moderate performance(AUC:0.693,95%CI:0.568-0.801).According to the survival analysis,the risk of death increased as the CT score rose,with an estimated cut-off value of≥11(P=0.016).CONCLUSION:Chest CT features were associated with poor outcomes in CA patients following ECPR.
基金Supported by National Natural Science foundation of China,No.82202135,No.82371919,No.82372017,and No.82171925China Postdoctoral Science Foundation,No.2023M741808+4 种基金Young Elite Scientists Sponsorship Program by China Association of Chinese Medicine,No.2024-QNRC2-B16Jiangsu Provincial Key Research and Development Program,No.BE2023789Young Elite Scientists Sponsorship Program by Jiangsu Association for Science and Technology,No.JSTJ-2023-WJ027Project funded by Nanjing Postdoctoral Science Foundation,Natural Science Foundation of Nanjing University of Chinese Medicine,No.XZR2023036Foundation of Excellent Young Doctor of Jiangsu Province Hospital of Chinese Medicine,No.2023QB0112.
文摘BACKGROUND Lymph node metastasis(LNM)is a key prognostic factor in pancreatic cancer(PC).Accurate preoperative prediction of LNM remains challenging.Radiomics offers a noninvasive method to extract quantitative imaging features that may aid in predicting LNM.AIM To investigate the potential value of a computed tomography(CT)-based radiomics model in prediction of LNM in PC.METHODS A retrospective analysis was performed on 168 pathologically confirmed PC patients who underwent contrast-enhanced-CT.Among them,107 cases had no LNM,while 61 cases had confirmed LNM.These patients were randomly divided into a training cohort(n=135)and a validation cohort(n=33).A total of 792 radiomics features were extracted,comprising 396 features from the arterial phase and another 396 from the portal venous phase.The Minimum Redundancy Maximum Relevance and Least Absolute Shrinkage and Selection Operator methods were used for feature selection and Radiomics model construction.The receiver operating characteristic curve was employed to assess the diagnostic potential of the model,and DeLong test was used to compare the area under the curve(AUC)values of the model.RESULTS Six radiomics features from the arterial phase and nine from the portal venous phase were selected.The Radscore model demonstrated strong predictive performance for LNM in both the training and test cohorts,with AUC values ranging from 0.86 to 0.94,sensitivity between 66.7% and 91.7%,specificity from 71.4% to 100.0%,accuracy between 78.8%and 91.1%,PPV ranging from 64.7% to 100.0%,and negative predictive value between 84.0% and 93.8%.No significant differences in AUC values were observed between the arterial and portal venous phases in either the training or test set.CONCLUSION The preoperative CT-based radiomics model exhibited robust predictive capability for identifying LNM in PC.
文摘BACKGROUND Tumor deposits(TDs)are an independent predictor of poor prognosis in colorec-tal cancer(CRC)patients.Enhanced follow-up and treatment monitoring for TD+patients may improve survival rates and quality of life.However,the detection of TDs relies primarily on postoperative pathological examination,which may have a low detection rate due to sampling limitations.AIM To evaluate the spectral computed tomography(CT)parameters of primary tu-mors and the largest regional lymph nodes(LNs),to determine their value in predicting TDs in CRC.METHODS A retrospective analysis was conducted which included 121 patients with CRC whose complete spectral CT data were available.Patients were divided into the TDs+group and the TDs-group on the basis of their pathological results.Spectral CT parameters of the primary CRC lesion and the largest regional LNs were measured,including the normalized iodine concentration(NIC)in both the arte-rial and venous phases,and the LN-to-primary tumor ratio was calculated.Stati-stical methods were used to evaluate the diagnostic efficacy of each spectral para-meter.RESULTS Among the 121 CRC patients,33(27.2%)were confirmed to be TDs+.The risk of TDs positivity was greater in patients with positive LN metastasis,higher N stage and elevated carcinoembryonic antigen and cancer antigen 19-9 levels.The NIC(LNs in both the arterial and venous phases),NIC(primary tumors in the venous phase),and the LN-to-primary tumor ratio in both the arterial and venous phases were associated with TDs(P<0.05).In mul-tivariate logistic regression analysis,the arterial phase LN-to-primary tumor ratio was identified as an independent predictor of TDs,demonstrating the highest diagnostic performance(area under the curve:0.812,sensitivity:0.879,specificity:0.648,cutoff value:1.145).CONCLUSION The spectral CT parameters of the primary colorectal tumor and the largest regional LNs,especially the LN-to-primary tumor ratio,have significant clinical value in predicting TDs in CRC.
基金Supported by the National Natural Science Foundation of China,No.82101985.
文摘BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM To evaluate the computed tomography characteristics of GS and provide insights into its accurate diagnosis.METHODS Twenty-three cases of GS confirmed between January 2011 and December 2023 were assessed clinically and radiologically.Imaging characteristics,including tumor location,size,contour,ulceration,growth pattern,enhancement degree and pattern,cystic change,calcification,and perigastric lymph nodes(PLNs),were reviewed by two experienced radiologists.RESULTS Our sample included 18 females and 5 males,with a median age of 54.7 years.A total of 39.1%of cases were asymptomatic.GSs appeared as oval and well-defined submucosal tumors,with exophytic(43.5%)or mixed(endoluminal+exophytic;43.5%)growth patterns.The tumors were primarily located in the gastric body(78.3%).Ulcerations were observed in 8 cases(34.5%),and PLNs were observed in 15 cases(65%).The average degree of enhancement was 48.3 Hounsfield units.Twenty cases(87%)showed peak enhancement in the delayed phase.Most GSs were homogeneous,while cystic change(13.0%)and calcification(17.4%)were rare.CONCLUSION GS predominantly showed gradual homogenous enhancement with peak enhancement in the delayed phase.PLNs around GS are helpful in differentiating GS from other gastric submucosal tumors.
