The rapidly growing computational demands of artificial intelligence(AI)and complex optimization tasks are increasingly straining conventional electronic architectures,driving the search for novel,energy-efficient pro...The rapidly growing computational demands of artificial intelligence(AI)and complex optimization tasks are increasingly straining conventional electronic architectures,driving the search for novel,energy-efficient processing paradigms.Photonic computing,which harnesses the unique properties of light to perform computation,has emerged as a compelling alternative.This perspective highlights a key advancement:a versatile nonlinear optoelectronic engine based on integrated photodetectors and micro-ring modulators(PD+MRM).This engine enables crucial functionalities like nonlinear activation and signal relay,forming a core building block for monolithic photonic processors.Its application in integrating optical Ising machines for optimization and optical recurrent neural networks(RNNs)for AI has been examined recently.The PD+MRM unit’s inherent compactness,efficiency,and onchip reconfigurable nonlinearity address historical photonic computing challenges,signaling a shift towards more versatile and scalable monolithic photonic processors.展开更多
In the past decade,there has been tremendous progress in integrating chalcogenide phase-change materials(PCMs)on the silicon photonic platform for non-volatile memory to neuromorphic in-memory computing applications.I...In the past decade,there has been tremendous progress in integrating chalcogenide phase-change materials(PCMs)on the silicon photonic platform for non-volatile memory to neuromorphic in-memory computing applications.In particular,these non von Neumann computational elements and systems benefit from mass manufacturing of silicon photonic integrated circuits(PICs)on 8-inch wafers using a 130 nm complementary metal-oxide semiconductor line.Chip manufacturing based on deep-ultraviolet lithography and electron-beam lithography enables rapid prototyping of PICs,which can be integrated with high-quality PCMs based on the wafer-scale sputtering technique as a back-end-of-line process.In this article,we present an overview of recent advances in waveguide integrated PCM memory cells,functional devices,and neuromorphic systems,with an emphasis on fabrication and integration processes to attain state-of-the-art device performance.After a short overview of PCM based photonic devices,we discuss the materials properties of the functional layer as well as the progress on the light guiding layer,namely,the silicon and germanium waveguide platforms.Next,we discuss the cleanroom fabrication flow of waveguide devices integrated with thin films and nanowires,silicon waveguides and plasmonic microheaters for the electrothermal switching of PCMs and mixed-mode operation.Finally,the fabrication of photonic and photonic–electronic neuromorphic computing systems is reviewed.These systems consist of arrays of PCM memory elements for associative learning,matrix-vector multiplication,and pattern recognition.With large-scale integration,the neuromorphic photonic computing paradigm holds the promise to outperform digital electronic accelerators by taking the advantages of ultra-high bandwidth,high speed,and energy-efficient operation in running machine learning algorithms.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
Electroencephalography(EEG)analysis extracts critical information from brain signals,enabling brain disease diagnosis and providing fundamental support for brain–computer interfaces.However,performing an artificial i...Electroencephalography(EEG)analysis extracts critical information from brain signals,enabling brain disease diagnosis and providing fundamental support for brain–computer interfaces.However,performing an artificial intelligence analysis of EEG signals with high energy efficiency poses significant challenges for electronic processors on edge computing devices,especially with large neural network models.Herein,we propose an EEG opto-processor based on diffractive photonic computing units(DPUs)to process extracranial and intracranial EEG signals effectively and to detect epileptic seizures.The signals of the EEG channels within a second-time window are optically encoded as inputs to the constructed diffractive neural networks for classification,which monitors the brain state to identify symptoms of an epileptic seizure.We developed both free-space and integrated DPUs as edge computing systems and demonstrated their applications for real-time epileptic seizure detection using benchmark datasets,that is,the Children’s Hospital Boston(CHB)–Massachusetts Institute of Technology(MIT)extracranial and Epilepsy-iEEG-Multicenter intracranial EEG datasets,with excellent computing performance results.Along with the channel selection mechanism,both numerical evaluations and experimental results validated the sufficiently high classification accuracies of the proposed opto-processors for supervising clinical diagnosis.Our study opens a new research direction for utilizing photonic computing techniques to process large-scale EEG signals and promote broader applications.展开更多
With the development of the big data era,the need for computation power is dramatically growing,especially for solving partial differential equations(PDEs),because PDEs are often used to describe complex systems and p...With the development of the big data era,the need for computation power is dramatically growing,especially for solving partial differential equations(PDEs),because PDEs are often used to describe complex systems and phenomena in both science and engineering.However,it is still a great challenge for on-chip photonic solving of time-evolving PDEs because of the difficulties in big coefficient matrix photonic computing,high accuracy,and error accumulation.We overcome these challenges by realizing a microcomb-driven photonic chip and introducing time-division multiplexing and matrix partition techniques into PDE photonic solving,which can solve PDEs with a large coefficient matrix on a photonic chip with a limited size.Timeevolving PDEs,including the heat equation with the first order of time derivative,the wave equation with the second order of time derivative,and the nonlinear Burgers equation,are solved with an accuracy of up to 97%.Furthermore,the parallel solving of the Poisson equation and Laplace's equation is demonstrated experimentally on a single chip,with an accuracy of 95.9%and 95.8%,respectively.We offer a powerful photonic platform for solving PDEs,which takes a step forward in the application of photonic chips in mathematical problems and will promote the development of on-chip photonic computing.展开更多
AIM:To review the benefits of single photon emission computed tomography(SPECT)/computed tomography(CT)hybrid imaging for diagnosis of various endocrine disorders.METHODS:We performed MEDLINE and Pub Med searches usin...AIM:To review the benefits of single photon emission computed tomography(SPECT)/computed tomography(CT)hybrid imaging for diagnosis of various endocrine disorders.METHODS:We performed MEDLINE and Pub Med searches using the terms:"SPECT/CT";"functional anatomic mapping";"transmission emission tomography";"parathyroid adenoma";"thyroid cancer";"neuroendocrine tumor";"adrenal";"pheochromocytoma";"paraganglioma";in order to identify relevant articles published in English during the years 2003 to 2015.Reference lists from the articles were reviewed to identify additional pertinent articles.Retrieved manuscripts(case reports,reviews,meta-analyses and abstracts)concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.RESULTS:The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging,with seamless fusion of three-dimensional volume datasets.The usefulness of combining functional information to depict the biodistribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin,with anatomy derived from CT,has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function.The literature describes benefits of SPECT/CT for^(99m)Tc-sestamibi parathyroid scintigraphy and^(99m)Tc-pertechnetate thyroid scintigraphy,^(123)I-or^(131)I-radioiodine for staging of differentiated thyroid carcinoma,^(111)In-and^(99m)Tclabeled somatostatin receptor analogues for detection of neuroendocrine tumors,^(131)I-norcholesterol(NP-59)scans for assessment of adrenal cortical hyperfunction,and^(123)I-or^(131)I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.CONCLUSION:SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT,translating to improved diagnostic accuracy and meaningful impact on patient care.展开更多
Photonic accelerators have emerged as promising alternatives to conventional electronic processors because they offer unique advantages such as high parallelism,low propagation loss,and in-propagation computation,maki...Photonic accelerators have emerged as promising alternatives to conventional electronic processors because they offer unique advantages such as high parallelism,low propagation loss,and in-propagation computation,making them well-suited for modern machine learning tasks that benefit from scalable parallelism.Fundamental mathematical operations including matrix-vector multiplication,convolution,and nonlinear activation functions are readily achieved with all-optical components.Due to the fixed hardware sizes,most kernel reutilization with photonics is based on the intermediate optical–electrical–optical conversion and storage.Yet,for a class of algorithms where signal recurrence is intrinsic,such truncation is suboptimal.The advancement in photonic material platforms with low loss and high integration density makes direct optical signal feedback with on-chip waveguides feasible.This development enables a specialized class of devices that we term integrated photonic recurrent processors(IPRPs).IPRPs uniquely accelerate computation by incorporating optical delay memory and bypassing the conventional single-pass photonic computing overheads.We explore algorithms with inherent recurrence and their implementation using integrated photonics.We also highlight potential applications for IPRPs and discuss how emerging material technologies may drive their advancement.With ongoing improvements in fabrication,integration,and control,IPRPs hold strong promise as compact,energy-efficient platforms for advancing optical computing.展开更多
Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighte...Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighteen age-matchednormal controls were studied with ^(99m)Tc-TRODAT-1 SPECT imaging.The regions of interests(ROIs)were drawn manually oncerebellum(CB),occipital cortex(OC)and three transverse plane slice-views of striatums,the semiquantitative BG(back-ground)/[(OC+CB)/2]were then calculated.Results:A lower uptake of ^(99m)Tc-TRODAT-1 in striatums were displayed inthirty-six out of thirty-eight PD patients by visual inspection,compared to controls.In twenty-four PD cases with HYS(Hoehn andYahr scale)stage Ⅰ,a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affectedlimbs than in the same regions of the controls,although the striatal uptake was bilaterally reduced.Using Spearman correlationanalysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions inthe PD group(P<0.05),a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05).However,analysis of variance(ANOVA)did not show any relationship between the decreasing uptake of ^(99m)Tc-TRODAT-1 andincreasing severity of PD patients,although the specific uptake of ^(99m)Tc-TRODAT-1 was continuously decreased in the striatumby visual inspection with the progress of PD from HYS stage Ⅰ to Ⅲ.Conclusion:^(99m)Tc-TRODAT-1 SPECT imaging may serve asa useful method for improving the correct diagnosis of PD.In assessing the role of ^(99m)Tc-TRODAT-1 SPECT in disease severity ofPD,UPDRS can offer a comprehensive index,although the Hoehn and Yahr assessment may be available in part.展开更多
The mechanism underlying body weight support treadmill training in elderly hemiplegic stroke patients is largely unknown. This study aimed to elucidate the changes of cortical blood flow in seven elderly patients with...The mechanism underlying body weight support treadmill training in elderly hemiplegic stroke patients is largely unknown. This study aimed to elucidate the changes of cortical blood flow in seven elderly patients with post-stroke hemiplegia before and after body weight support treadmill training by semi-quantitative analysis of regional cerebral blood flow assessed by single photon emission computed tomography. Body weight support treadmill training for 6 months was effective in improving cerebral blood flow and promoting the walking speed and balance recovery in elderly patients with post-stroke hemiplegia.展开更多
Rheumatoid arthritis(RA)is an autoimmune disease,which is associated with systemic and chronic inflammation of the joints,resulting in synovitis and pannus formation.For several decades,the assessment of RA has been l...Rheumatoid arthritis(RA)is an autoimmune disease,which is associated with systemic and chronic inflammation of the joints,resulting in synovitis and pannus formation.For several decades,the assessment of RA has been limited to conventional radiography,assisting in the diagnosis and monitoring of disease.Nevertheless,conventional radiography has poor sensitivity in the detection of the inflammatory process that happens in the initial stages of RA.In the past years,new drugs that significantly decrease the progression of RA have allowed a more efficient treatment.Nuclear Medicine provides functional assessment of physiological processes and therefore has significant potential for timely diagnosis and adequate follow-up of RA.Several single photon emission computed tomography(SPECT)and positron emission tomography(PET)radiopharmaceuti-cals have been developed and applied in this field.The use of hybrid imaging,which permits computed tomography(CT)and nuclear medicine data to be acquired and fused,has increased even more the diagnostic accuracy of Nuclear Medicine by providing anatomical localization in SPECT/CT and PET/CT studies.More recently,fusion of PET with magnetic resonance imaging(PET/MRI)was introduced in some centers and demonstrated great potential.In this article,we will review studies that have been published using Nuclear Medicine for RA and examine key topics in the area.展开更多
Hyperbranched polysulfonamine （HPSA） is a promising biomaterial due to its highly branched spherical architecture and efficient intracellular translocation. To realize the fianctionalization of HPSA, both N-succinim...Hyperbranched polysulfonamine （HPSA） is a promising biomaterial due to its highly branched spherical architecture and efficient intracellular translocation. To realize the fianctionalization of HPSA, both N-succinimidyl 3-（2- pyridyldithio） propionate （SPDP） for tethering the human-mouse chimeric monoclonal antibody CH12 and N-hydroxy succinimidyl S-acetylmercaptoacetyltriglycinate （NHS-MAG3） for labeling 188Re were sequentially grafted onto the primary amine terminals of HPSA via covalent linkages, attaining the SPDP-HPSA-MAG3 intermediate. In order to reserve the structural integrity of CH12, the fragment crystallizable （Fc） region was also processed by oxidation of oligosaccharide moieties with sodium periodate and then reacted with N-（κ-maleimidoundecanoic acid） hydrazide （KMUH）. After chelating 188Re with MAG3 group, the SPDP was reduced to PDP and connected onto the maleinimide group at the Fc region. As a result, both the epidermal growth factor receptor viii （EGFRvIII） targeted monoclonal antibody CH12 and the radionuclide 188Re were conjugated to the HPSA-based vehicles, forming the 188Re-labeled and CH12-tethered HPSA （CH12-HPSA- 188Re）. The molecular weight and in vitro stability of CH12-HPSA-188Re were evaluated by gel electrophoresis and paper chromatography. On one hand, the CH12-HPSA-188Re could specifically bind to the EGFRvlII-positive human hepatocarcinoma cells in vitro. On the other hand, it could also target at the tumor tissue of nude mice in vivo. Hence, the CH12-HPSA-188Re could effectively target at the human hepatocarcinoma and facilitate the tumor detection and targeted radioimmunotherapy.展开更多
Objective:To study the clinical value of Technetium-99m sestamibi myocardial perfusion single photon emission computed tomography(SPECT) in diabetes with suspected coronary artery diseases.Methods:Seventy-eight diabet...Objective:To study the clinical value of Technetium-99m sestamibi myocardial perfusion single photon emission computed tomography(SPECT) in diabetes with suspected coronary artery diseases.Methods:Seventy-eight diabetic patients complicated with cardiac symptoms or electrocardiogram(ECG) abnormalities and suspected coronary heart disease hospitalized in the department of endocrinology from January,2008 to December,2008 were investigated.Technetium-99m sestamibi myocardial perfusion SPECT was performed in all patients.Exercise stress test was done in 35 cases(group A).Adenosine stress test was done in 43 cases(group B).Results:The positive rates in the two groups were 54.29%(19/35) and 53.48%(23/43),respectively.There was no statistic difference between the 2 groups(P>0.05).The abnormality rates in male and female groups were 63.04% and 28.13%,respectively(P<0.01).Eighty-six segments of perfusion abnormality were detected in 38 positive patients.Four segments of fixed defect were found in 4 cases.Conclusion:As non-invasive method,myocardial perfusion SPECT can play an important role in the treatment of diabetes with suspected coronary artery disease.展开更多
ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography （18F-FDG PET） in the as-sessment of myocardial viability in patients with known coronary artery disease （CAD） whe...ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography （18F-FDG PET） in the as-sessment of myocardial viability in patients with known coronary artery disease （CAD） when compared to99mTc single photon emission computed tomography （SPECT） and echocardiography, with invasive coronary angiography as the gold standard.MethodsThirty patients with diagnosed CAD met the selection criteria, with 10 of them （9 men, mean age 59.5 ± 10.5 years） undergoing all of these imaging proce-dures consisting of SPECT and PET, echocardiography and invasive angiography. Diagnostic sensitivity of these less invasive modalities for detection of myocardial viability was compared to invasive coronary angiography. Inter- and intra-observer agreement was assessed for di-agnostic performance of SPECT and PET.ResultsOf all patients with proven CAD, 50% had triple vessel disease. Diagnostic sensitivity of SPECT, PET and echocardiography was 90%, 100% and 80% at patient-based assessment, respectively. Excellent agreement was achieved between inter-observer and intra-observer agreement of the diagnostic value of SPECT and PET in myocardial viability （k= 0.9）. Conclusion18F-FDG PET has high diagnostic value in the assessment of myocardial viability in patients with known CAD when com-pared to SPECT and echocardiography. Further studies based on a large cohort with incorporation of18F-FDG PET into patient management are warranted.展开更多
This study adapted a statistical probabilistic anatomical map of the brain for single photon emission computed tomography images of depressive end-stage renal disease patients.This research aimed to investigate the re...This study adapted a statistical probabilistic anatomical map of the brain for single photon emission computed tomography images of depressive end-stage renal disease patients.This research aimed to investigate the relationship between symptom clusters,disease severity,and cerebral blood flow.Twenty-seven patients(16 males,11 females)with stages 4 and 5 end-stage renal disease were enrolled,along with 25 healthy controls.All patients underwent depressive mood assessment and brain single photon emission computed tomography.The statistical probabilistic anatomical map images were used to calculate the brain single photon emission computed tomography counts.Asymmetric index was acquired and Pearson correlation analysis was performed to analyze the correlation between symptom factors,severity,and regional cerebral blood flow.The depression factors of the Hamilton Depression Rating Scale showed a negative correlation with cerebral blood flow in the left amygdale.The insomnia factor showed negative correlations with cerebral blood flow in the left amygdala,right superior frontal gyrus,right middle frontal gyrus,and left middle frontal gyrus.The anxiety factor showed a positive correlation with cerebral glucose metabolism in the cerebellar vermis and a negative correlation with cerebral glucose metabolism in the left globus pailidus,right inferior frontal gyrus,both temporal poles,and left parahippocampus.The overall depression severity(total scores of Hamilton Depression Rating Scale)was negatively correlated with the statistical probabilistic anatomical map results in the left amygdala and right inferior frontal gyrus.In conclusion,our results demonstrated that the disease severity and extent of cerebral blood flow quantified by a probabilistic brain atlas was related to various brain areas in terms of the overall severity and symptom factors in end-stage renal disease patients.展开更多
BACKGROUND Pancreatic neuroendocrine tumors(NETs)account for about 1%–2%of pancreatic tumors and about 8%of all NETs.Computed tomography(CT),magnetic resonance imaging,and endoscopic ultrasound are common imaging mod...BACKGROUND Pancreatic neuroendocrine tumors(NETs)account for about 1%–2%of pancreatic tumors and about 8%of all NETs.Computed tomography(CT),magnetic resonance imaging,and endoscopic ultrasound are common imaging modalities for the diagnosis of pancreatic NETs.Furthermore,somatostatin receptor imaging is of great value for diagnosing pancreatic NETs.Herein,we report the efficacy of technetium-99m methoxy-2-isobutylisonitrile(99mTc-MIBI)single photon emission CT(SPECT)/CT for detecting pancreatic NETs.CASE SUMMARY A 57-year-old woman presented to our hospital with a 1-d history of persistent upper abdominal distending pain.The distending pain in the upper abdomen was aggravated after eating,with nausea and retching.Routine blood test results showed a high neutrophil percentage,low leukomonocyte and monocyte percentages,and low leukomonocyte and eosinophil counts.Amylase,liver and kidney function,and tumor markers alpha-fetoprotein,carcinoembryonic antigen,and cancer antigen(CA)125,CA72-4,CA19-9,and CA153 were normal.Abdominal CT showed a mass,with multiple calcifications between the pancreas and the spleen.The boundary between the mass and the pancreas and spleen was poorly defined.Contrast-enhanced CT revealed that the upper abdominal mass was unevenly and gradually enhanced.99mTc-MIBI SPECT/CT revealed that a focal radioactive concentration,with mild radioactive concentration extending into the upper abdominal mass,was present at the pancreatic body and tail.The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET.CONCLUSION 99mTc-MIBI SPECT/CT appears to be a valuable tool for detecting pancreatic NETs.展开更多
BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has made it more challenging for patients to undergo yttrium-90(Y-90)radioembolization(RE).Same day Y-90 RE provides an opportunity to minimize logistical chal...BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has made it more challenging for patients to undergo yttrium-90(Y-90)radioembolization(RE).Same day Y-90 RE provides an opportunity to minimize logistical challenges and infection risk associated with COVID-19,thus improving patient access.AIM To describe the use of same day Y-90 RE with routine single photon emission computed tomography/computed tomography(SPECT/CT)in order to optimize therapy.METHODS All patients were selected for Y-90 RE through a multidisciplinary tumor board,and were screened and tested for COVID-19 infection per institutional protocol.A same day procedure was developed,consisting of angiography,imaging,and Y-90 resin particle delivery.Routine SPECT/CT after technetium-99m macroaggregated albumin(Tc-99m MAA)administration was performed for assessment of arterial supply,personalized dosimetry,and extrahepatic activity.Post-treatment Y-90 bremsstrahlung SPECT/CT was performed for confirmation of particle delivery,by utilization of energy windowing to limit signal from previously administered Tc-99m MAA particles.RESULTS A total of 14 patients underwent same day Y-90 RE between March and June 2020.Mean lung shunt fraction was 6.13%(range 3.5%-13.1%).Y-90 RE was performed for a single lesion in 7 patients,while the remaining 7 patients had treatment of multifocal lesions.The largest lesion measured 8.3 cm.All patients tolerated the procedure well and were discharged the same day.CONCLUSION Same day Y-90 RE with resin-based microspheres is feasible,and provides an opportunity to mitigate infection risk and logistical challenges associated with the COVID-19 pandemic and beyond.We recommend consideration of SPECT/CT,especially among patients with complex malignancies,for the potential to improve outcomes and eligibility of patients to undergo same day Y-90 RE.展开更多
BACKGROUND Prostate cancer(PC)is one of the most common malignant tumors in men,and bone metastasis is one of its common complications,which seriously affects the quality of life and prognosis of patients.AIM To inves...BACKGROUND Prostate cancer(PC)is one of the most common malignant tumors in men,and bone metastasis is one of its common complications,which seriously affects the quality of life and prognosis of patients.AIM To investigate the diagnostic value of technetium-99m-methylene diphosphonate(99mTc-MDP)single photon emission computed tomography(SPECT)/CT imaging combined with the serum prostate-specific antigen(PSA)/free PSA ratio for PC bone metastasis(PCBM).METHODS One hundred patients with PC who visited the Hospital of Chengdu University of Traditional Chinese Medicine from January 2020 to January 2022 were recruited as the experimental(Exp)group,while 30 patients with benign prostatic lesions(BPLs)were recruited as the control(Ctrl)group.All patients underwent 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA testing.The SPECT/CT imaging results and serum PSA/fPSA ratios of patients were analyzed to evaluate their diagnostic values for PCBM.RESULTS The difference in general information of the patients was not obvious,showing comparability.The two methods showed no visible differences in negative predictive value and sensitivity for patients with PCBM,but had great differences in positive predictive value and specificity(P<0.05).The PSA/fPSA ratio of patients with PC in the Exp group was lower than those with BPLs,and patients with PCBM had a much lower PSA/fPSA ratio than those without PC(P<0.05).The results confirmed that the combined use of 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA ratio achieved a detection rate of 95%for PCBM.CONCLUSION The combination of 99mTc-MDP SPECT/CT and PSA/fPSA ratio is accurate and reliable for the diagnosis of PCBM,which provides an important reference for clinical practice.展开更多
Infective endocarditis is one of the leading life-threatening infections around the world.With the exponential growth in the field of transcatheter interventions and advances in specialized surgical techniques,the num...Infective endocarditis is one of the leading life-threatening infections around the world.With the exponential growth in the field of transcatheter interventions and advances in specialized surgical techniques,the number of prosthetic valves and cardiac implantable devices has significantly increased.This has led to a steep rise in the number of cases of prosthetic valve endocarditis(PVE)comprising up to 30%of all cases.Clinical guidelines rely on the use of the modified Duke criteria;however,the diagnostic sensitivity of the modified Duke criteria is reduced in the context of PVE.This is in part attributed to prosthesis related artifact which greatly affects the ability of echocardiography to detect early infective changes related to PVE in certain cases.There has been increasing recognition of the roles of complementary imaging modalities and updates in international society recommendations.Prompt diagnosis and treatment can prevent the devastating consequences of this condition.Imaging modalities such as cardiac computed tomography and 18-fluorodeoxyglucose positron emission tomography/computed tomography are diagnostic tools that provide a complementary role to echocardiography in aiding diagnosis,pre-operative planning,and treatment decisionmaking process in these challenging cases.Understanding the strengths and limitations of these adjuvant imaging modalities is crucial for the implementation of appropriate imaging modalities in clinical practice.展开更多
Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severit...Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increas-ingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography （PET） and single photon emission computed tomography （SPECT） has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging tech-niques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coro-nary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed.展开更多
BACKGROUND： Subthalamic nucleus deep brain stimulation （STN DBS） for Parkinson＇s disease （PD） has achieved good effects, but to date the mechanism of STN DBS remains poorly understood STN DBS may increase dopami...BACKGROUND： Subthalamic nucleus deep brain stimulation （STN DBS） for Parkinson＇s disease （PD） has achieved good effects, but to date the mechanism of STN DBS remains poorly understood STN DBS may increase dopamine levels or metabolic activity of the corpus striatum. OBJECTIVE： To validate the effects of STN DBS on dopamine metabolism and glucose metabolism in the corpus striatum of hemiparkinsonian monkeys using single photon emission computed tomography （SPECT） and position emission tomography （PET）. DESIGN, TIME AND SET＇rING： A controlled animal study was performed at the Neurosurgery Laboratory, Changhai Hospital of the Second Military Medical University of Chinese PLA between January 2004 and December 2007. METHODS： Hemiparkinsonism was induced in adult Rhesus Macaque monkeys, which exhibit similar characteristics of PD in humans, through unilateral internal carotid artery infusion of 1-methy-4-phenyl-1, 2, 3, 6-tetrahydropyrindine. Following model establishment, stimulation electrodes were implanted in the right STN, and chronic high-frequency stimulation （60 μs pulse width, 130 Hz frequency, and 1.5-2.0 V pressure） was performed. MAIN OUTCOME MEASURES： The changes in dopamine transporter （DAT）, D2 receptor （D2R）, and glucose metabolism in the corpus striatum following STN DBS were observed using SPECT and PET. RESULTS： SPECT examination showed that DAT specific binding in the right corpus striatum was increased at 3 months after DBS compared with prior to stimulation, and D2R specific binding in the right corpus striatum gradually decreased near levels on the left （non-electrode-implanted） side within 3 months after DBS. PET examination showed that the glucose metabolism in the right corpus striatum was markedly increased at 3 months after effective DBS. Hemiparkinsonism monkeys showed improved left limb rigidity, increased activities, and stable gait under chronic high-frequency stimulation. CONCLUSION： STN DBS increased striatal DAT, decreased D2R, and enhanced glucose metabolism, suggesting that chronic, high-frequency STN stimulation enhanced the metabolic activity of the corpus striatum, a mechanism for improving the PD symptoms of hemiparkinsonian monkeys.展开更多
文摘The rapidly growing computational demands of artificial intelligence(AI)and complex optimization tasks are increasingly straining conventional electronic architectures,driving the search for novel,energy-efficient processing paradigms.Photonic computing,which harnesses the unique properties of light to perform computation,has emerged as a compelling alternative.This perspective highlights a key advancement:a versatile nonlinear optoelectronic engine based on integrated photodetectors and micro-ring modulators(PD+MRM).This engine enables crucial functionalities like nonlinear activation and signal relay,forming a core building block for monolithic photonic processors.Its application in integrating optical Ising machines for optimization and optical recurrent neural networks(RNNs)for AI has been examined recently.The PD+MRM unit’s inherent compactness,efficiency,and onchip reconfigurable nonlinearity address historical photonic computing challenges,signaling a shift towards more versatile and scalable monolithic photonic processors.
基金the support of the National Natural Science Foundation of China(Grant No.62204201)。
文摘In the past decade,there has been tremendous progress in integrating chalcogenide phase-change materials(PCMs)on the silicon photonic platform for non-volatile memory to neuromorphic in-memory computing applications.In particular,these non von Neumann computational elements and systems benefit from mass manufacturing of silicon photonic integrated circuits(PICs)on 8-inch wafers using a 130 nm complementary metal-oxide semiconductor line.Chip manufacturing based on deep-ultraviolet lithography and electron-beam lithography enables rapid prototyping of PICs,which can be integrated with high-quality PCMs based on the wafer-scale sputtering technique as a back-end-of-line process.In this article,we present an overview of recent advances in waveguide integrated PCM memory cells,functional devices,and neuromorphic systems,with an emphasis on fabrication and integration processes to attain state-of-the-art device performance.After a short overview of PCM based photonic devices,we discuss the materials properties of the functional layer as well as the progress on the light guiding layer,namely,the silicon and germanium waveguide platforms.Next,we discuss the cleanroom fabrication flow of waveguide devices integrated with thin films and nanowires,silicon waveguides and plasmonic microheaters for the electrothermal switching of PCMs and mixed-mode operation.Finally,the fabrication of photonic and photonic–electronic neuromorphic computing systems is reviewed.These systems consist of arrays of PCM memory elements for associative learning,matrix-vector multiplication,and pattern recognition.With large-scale integration,the neuromorphic photonic computing paradigm holds the promise to outperform digital electronic accelerators by taking the advantages of ultra-high bandwidth,high speed,and energy-efficient operation in running machine learning algorithms.
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supported by the National Major Science and Technology Projects of China(2021ZD0109902 and 2020AA0105500)the National Natural Science Fundation of China(62275139 and 62088102)the Tsinghua University Initiative Scientific Research Program.
文摘Electroencephalography(EEG)analysis extracts critical information from brain signals,enabling brain disease diagnosis and providing fundamental support for brain–computer interfaces.However,performing an artificial intelligence analysis of EEG signals with high energy efficiency poses significant challenges for electronic processors on edge computing devices,especially with large neural network models.Herein,we propose an EEG opto-processor based on diffractive photonic computing units(DPUs)to process extracranial and intracranial EEG signals effectively and to detect epileptic seizures.The signals of the EEG channels within a second-time window are optically encoded as inputs to the constructed diffractive neural networks for classification,which monitors the brain state to identify symptoms of an epileptic seizure.We developed both free-space and integrated DPUs as edge computing systems and demonstrated their applications for real-time epileptic seizure detection using benchmark datasets,that is,the Children’s Hospital Boston(CHB)–Massachusetts Institute of Technology(MIT)extracranial and Epilepsy-iEEG-Multicenter intracranial EEG datasets,with excellent computing performance results.Along with the channel selection mechanism,both numerical evaluations and experimental results validated the sufficiently high classification accuracies of the proposed opto-processors for supervising clinical diagnosis.Our study opens a new research direction for utilizing photonic computing techniques to process large-scale EEG signals and promote broader applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.92150302 and 12274031)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301500)+1 种基金the Beijing Institute of Technology Research Fund Program for Teli Young Fellowsthe Beijing Institute of Technology Science and Technology Innovation Plan Innovative Talents Science and Technology Funding Special Plan(Grant No.2022CX01006)。
文摘With the development of the big data era,the need for computation power is dramatically growing,especially for solving partial differential equations(PDEs),because PDEs are often used to describe complex systems and phenomena in both science and engineering.However,it is still a great challenge for on-chip photonic solving of time-evolving PDEs because of the difficulties in big coefficient matrix photonic computing,high accuracy,and error accumulation.We overcome these challenges by realizing a microcomb-driven photonic chip and introducing time-division multiplexing and matrix partition techniques into PDE photonic solving,which can solve PDEs with a large coefficient matrix on a photonic chip with a limited size.Timeevolving PDEs,including the heat equation with the first order of time derivative,the wave equation with the second order of time derivative,and the nonlinear Burgers equation,are solved with an accuracy of up to 97%.Furthermore,the parallel solving of the Poisson equation and Laplace's equation is demonstrated experimentally on a single chip,with an accuracy of 95.9%and 95.8%,respectively.We offer a powerful photonic platform for solving PDEs,which takes a step forward in the application of photonic chips in mathematical problems and will promote the development of on-chip photonic computing.
文摘AIM:To review the benefits of single photon emission computed tomography(SPECT)/computed tomography(CT)hybrid imaging for diagnosis of various endocrine disorders.METHODS:We performed MEDLINE and Pub Med searches using the terms:"SPECT/CT";"functional anatomic mapping";"transmission emission tomography";"parathyroid adenoma";"thyroid cancer";"neuroendocrine tumor";"adrenal";"pheochromocytoma";"paraganglioma";in order to identify relevant articles published in English during the years 2003 to 2015.Reference lists from the articles were reviewed to identify additional pertinent articles.Retrieved manuscripts(case reports,reviews,meta-analyses and abstracts)concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.RESULTS:The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging,with seamless fusion of three-dimensional volume datasets.The usefulness of combining functional information to depict the biodistribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin,with anatomy derived from CT,has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function.The literature describes benefits of SPECT/CT for^(99m)Tc-sestamibi parathyroid scintigraphy and^(99m)Tc-pertechnetate thyroid scintigraphy,^(123)I-or^(131)I-radioiodine for staging of differentiated thyroid carcinoma,^(111)In-and^(99m)Tclabeled somatostatin receptor analogues for detection of neuroendocrine tumors,^(131)I-norcholesterol(NP-59)scans for assessment of adrenal cortical hyperfunction,and^(123)I-or^(131)I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.CONCLUSION:SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT,translating to improved diagnostic accuracy and meaningful impact on patient care.
基金supported by the European Union’s Horizon 2020 research and innovation program project INSPIRE(Grant No.101017088)the UK Engineering and Physical Sciences Research Council,project QUDOS(Grant No.EP/T028475/1).
文摘Photonic accelerators have emerged as promising alternatives to conventional electronic processors because they offer unique advantages such as high parallelism,low propagation loss,and in-propagation computation,making them well-suited for modern machine learning tasks that benefit from scalable parallelism.Fundamental mathematical operations including matrix-vector multiplication,convolution,and nonlinear activation functions are readily achieved with all-optical components.Due to the fixed hardware sizes,most kernel reutilization with photonics is based on the intermediate optical–electrical–optical conversion and storage.Yet,for a class of algorithms where signal recurrence is intrinsic,such truncation is suboptimal.The advancement in photonic material platforms with low loss and high integration density makes direct optical signal feedback with on-chip waveguides feasible.This development enables a specialized class of devices that we term integrated photonic recurrent processors(IPRPs).IPRPs uniquely accelerate computation by incorporating optical delay memory and bypassing the conventional single-pass photonic computing overheads.We explore algorithms with inherent recurrence and their implementation using integrated photonics.We also highlight potential applications for IPRPs and discuss how emerging material technologies may drive their advancement.With ongoing improvements in fabrication,integration,and control,IPRPs hold strong promise as compact,energy-efficient platforms for advancing optical computing.
文摘Objective:To investigate the role of ^(99m)Tc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathicParkinson's disease(PD).Methods:Thirty-eight patients with primary,tentative diagnosis of PD and eighteen age-matchednormal controls were studied with ^(99m)Tc-TRODAT-1 SPECT imaging.The regions of interests(ROIs)were drawn manually oncerebellum(CB),occipital cortex(OC)and three transverse plane slice-views of striatums,the semiquantitative BG(back-ground)/[(OC+CB)/2]were then calculated.Results:A lower uptake of ^(99m)Tc-TRODAT-1 in striatums were displayed inthirty-six out of thirty-eight PD patients by visual inspection,compared to controls.In twenty-four PD cases with HYS(Hoehn andYahr scale)stage Ⅰ,a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affectedlimbs than in the same regions of the controls,although the striatal uptake was bilaterally reduced.Using Spearman correlationanalysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions inthe PD group(P<0.05),a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05).However,analysis of variance(ANOVA)did not show any relationship between the decreasing uptake of ^(99m)Tc-TRODAT-1 andincreasing severity of PD patients,although the specific uptake of ^(99m)Tc-TRODAT-1 was continuously decreased in the striatumby visual inspection with the progress of PD from HYS stage Ⅰ to Ⅲ.Conclusion:^(99m)Tc-TRODAT-1 SPECT imaging may serve asa useful method for improving the correct diagnosis of PD.In assessing the role of ^(99m)Tc-TRODAT-1 SPECT in disease severity ofPD,UPDRS can offer a comprehensive index,although the Hoehn and Yahr assessment may be available in part.
文摘The mechanism underlying body weight support treadmill training in elderly hemiplegic stroke patients is largely unknown. This study aimed to elucidate the changes of cortical blood flow in seven elderly patients with post-stroke hemiplegia before and after body weight support treadmill training by semi-quantitative analysis of regional cerebral blood flow assessed by single photon emission computed tomography. Body weight support treadmill training for 6 months was effective in improving cerebral blood flow and promoting the walking speed and balance recovery in elderly patients with post-stroke hemiplegia.
文摘Rheumatoid arthritis(RA)is an autoimmune disease,which is associated with systemic and chronic inflammation of the joints,resulting in synovitis and pannus formation.For several decades,the assessment of RA has been limited to conventional radiography,assisting in the diagnosis and monitoring of disease.Nevertheless,conventional radiography has poor sensitivity in the detection of the inflammatory process that happens in the initial stages of RA.In the past years,new drugs that significantly decrease the progression of RA have allowed a more efficient treatment.Nuclear Medicine provides functional assessment of physiological processes and therefore has significant potential for timely diagnosis and adequate follow-up of RA.Several single photon emission computed tomography(SPECT)and positron emission tomography(PET)radiopharmaceuti-cals have been developed and applied in this field.The use of hybrid imaging,which permits computed tomography(CT)and nuclear medicine data to be acquired and fused,has increased even more the diagnostic accuracy of Nuclear Medicine by providing anatomical localization in SPECT/CT and PET/CT studies.More recently,fusion of PET with magnetic resonance imaging(PET/MRI)was introduced in some centers and demonstrated great potential.In this article,we will review studies that have been published using Nuclear Medicine for RA and examine key topics in the area.
基金financially supported by the National Natural Science Foundation of China (Nos.20974062,30700175)National Basic Research Program (Nos.2009CB930400,2012CB821500)China National Funds for Distinguished Young Scientists (No.21025417)
文摘Hyperbranched polysulfonamine （HPSA） is a promising biomaterial due to its highly branched spherical architecture and efficient intracellular translocation. To realize the fianctionalization of HPSA, both N-succinimidyl 3-（2- pyridyldithio） propionate （SPDP） for tethering the human-mouse chimeric monoclonal antibody CH12 and N-hydroxy succinimidyl S-acetylmercaptoacetyltriglycinate （NHS-MAG3） for labeling 188Re were sequentially grafted onto the primary amine terminals of HPSA via covalent linkages, attaining the SPDP-HPSA-MAG3 intermediate. In order to reserve the structural integrity of CH12, the fragment crystallizable （Fc） region was also processed by oxidation of oligosaccharide moieties with sodium periodate and then reacted with N-（κ-maleimidoundecanoic acid） hydrazide （KMUH）. After chelating 188Re with MAG3 group, the SPDP was reduced to PDP and connected onto the maleinimide group at the Fc region. As a result, both the epidermal growth factor receptor viii （EGFRvIII） targeted monoclonal antibody CH12 and the radionuclide 188Re were conjugated to the HPSA-based vehicles, forming the 188Re-labeled and CH12-tethered HPSA （CH12-HPSA- 188Re）. The molecular weight and in vitro stability of CH12-HPSA-188Re were evaluated by gel electrophoresis and paper chromatography. On one hand, the CH12-HPSA-188Re could specifically bind to the EGFRvlII-positive human hepatocarcinoma cells in vitro. On the other hand, it could also target at the tumor tissue of nude mice in vivo. Hence, the CH12-HPSA-188Re could effectively target at the human hepatocarcinoma and facilitate the tumor detection and targeted radioimmunotherapy.
文摘Objective:To study the clinical value of Technetium-99m sestamibi myocardial perfusion single photon emission computed tomography(SPECT) in diabetes with suspected coronary artery diseases.Methods:Seventy-eight diabetic patients complicated with cardiac symptoms or electrocardiogram(ECG) abnormalities and suspected coronary heart disease hospitalized in the department of endocrinology from January,2008 to December,2008 were investigated.Technetium-99m sestamibi myocardial perfusion SPECT was performed in all patients.Exercise stress test was done in 35 cases(group A).Adenosine stress test was done in 43 cases(group B).Results:The positive rates in the two groups were 54.29%(19/35) and 53.48%(23/43),respectively.There was no statistic difference between the 2 groups(P>0.05).The abnormality rates in male and female groups were 63.04% and 28.13%,respectively(P<0.01).Eighty-six segments of perfusion abnormality were detected in 38 positive patients.Four segments of fixed defect were found in 4 cases.Conclusion:As non-invasive method,myocardial perfusion SPECT can play an important role in the treatment of diabetes with suspected coronary artery disease.
文摘ObjectiveTo investigate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography （18F-FDG PET） in the as-sessment of myocardial viability in patients with known coronary artery disease （CAD） when compared to99mTc single photon emission computed tomography （SPECT） and echocardiography, with invasive coronary angiography as the gold standard.MethodsThirty patients with diagnosed CAD met the selection criteria, with 10 of them （9 men, mean age 59.5 ± 10.5 years） undergoing all of these imaging proce-dures consisting of SPECT and PET, echocardiography and invasive angiography. Diagnostic sensitivity of these less invasive modalities for detection of myocardial viability was compared to invasive coronary angiography. Inter- and intra-observer agreement was assessed for di-agnostic performance of SPECT and PET.ResultsOf all patients with proven CAD, 50% had triple vessel disease. Diagnostic sensitivity of SPECT, PET and echocardiography was 90%, 100% and 80% at patient-based assessment, respectively. Excellent agreement was achieved between inter-observer and intra-observer agreement of the diagnostic value of SPECT and PET in myocardial viability （k= 0.9）. Conclusion18F-FDG PET has high diagnostic value in the assessment of myocardial viability in patients with known CAD when com-pared to SPECT and echocardiography. Further studies based on a large cohort with incorporation of18F-FDG PET into patient management are warranted.
基金support of the Pusan National University Research Grant for 2 years
文摘This study adapted a statistical probabilistic anatomical map of the brain for single photon emission computed tomography images of depressive end-stage renal disease patients.This research aimed to investigate the relationship between symptom clusters,disease severity,and cerebral blood flow.Twenty-seven patients(16 males,11 females)with stages 4 and 5 end-stage renal disease were enrolled,along with 25 healthy controls.All patients underwent depressive mood assessment and brain single photon emission computed tomography.The statistical probabilistic anatomical map images were used to calculate the brain single photon emission computed tomography counts.Asymmetric index was acquired and Pearson correlation analysis was performed to analyze the correlation between symptom factors,severity,and regional cerebral blood flow.The depression factors of the Hamilton Depression Rating Scale showed a negative correlation with cerebral blood flow in the left amygdale.The insomnia factor showed negative correlations with cerebral blood flow in the left amygdala,right superior frontal gyrus,right middle frontal gyrus,and left middle frontal gyrus.The anxiety factor showed a positive correlation with cerebral glucose metabolism in the cerebellar vermis and a negative correlation with cerebral glucose metabolism in the left globus pailidus,right inferior frontal gyrus,both temporal poles,and left parahippocampus.The overall depression severity(total scores of Hamilton Depression Rating Scale)was negatively correlated with the statistical probabilistic anatomical map results in the left amygdala and right inferior frontal gyrus.In conclusion,our results demonstrated that the disease severity and extent of cerebral blood flow quantified by a probabilistic brain atlas was related to various brain areas in terms of the overall severity and symptom factors in end-stage renal disease patients.
文摘BACKGROUND Pancreatic neuroendocrine tumors(NETs)account for about 1%–2%of pancreatic tumors and about 8%of all NETs.Computed tomography(CT),magnetic resonance imaging,and endoscopic ultrasound are common imaging modalities for the diagnosis of pancreatic NETs.Furthermore,somatostatin receptor imaging is of great value for diagnosing pancreatic NETs.Herein,we report the efficacy of technetium-99m methoxy-2-isobutylisonitrile(99mTc-MIBI)single photon emission CT(SPECT)/CT for detecting pancreatic NETs.CASE SUMMARY A 57-year-old woman presented to our hospital with a 1-d history of persistent upper abdominal distending pain.The distending pain in the upper abdomen was aggravated after eating,with nausea and retching.Routine blood test results showed a high neutrophil percentage,low leukomonocyte and monocyte percentages,and low leukomonocyte and eosinophil counts.Amylase,liver and kidney function,and tumor markers alpha-fetoprotein,carcinoembryonic antigen,and cancer antigen(CA)125,CA72-4,CA19-9,and CA153 were normal.Abdominal CT showed a mass,with multiple calcifications between the pancreas and the spleen.The boundary between the mass and the pancreas and spleen was poorly defined.Contrast-enhanced CT revealed that the upper abdominal mass was unevenly and gradually enhanced.99mTc-MIBI SPECT/CT revealed that a focal radioactive concentration,with mild radioactive concentration extending into the upper abdominal mass,was present at the pancreatic body and tail.The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET.CONCLUSION 99mTc-MIBI SPECT/CT appears to be a valuable tool for detecting pancreatic NETs.
文摘BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has made it more challenging for patients to undergo yttrium-90(Y-90)radioembolization(RE).Same day Y-90 RE provides an opportunity to minimize logistical challenges and infection risk associated with COVID-19,thus improving patient access.AIM To describe the use of same day Y-90 RE with routine single photon emission computed tomography/computed tomography(SPECT/CT)in order to optimize therapy.METHODS All patients were selected for Y-90 RE through a multidisciplinary tumor board,and were screened and tested for COVID-19 infection per institutional protocol.A same day procedure was developed,consisting of angiography,imaging,and Y-90 resin particle delivery.Routine SPECT/CT after technetium-99m macroaggregated albumin(Tc-99m MAA)administration was performed for assessment of arterial supply,personalized dosimetry,and extrahepatic activity.Post-treatment Y-90 bremsstrahlung SPECT/CT was performed for confirmation of particle delivery,by utilization of energy windowing to limit signal from previously administered Tc-99m MAA particles.RESULTS A total of 14 patients underwent same day Y-90 RE between March and June 2020.Mean lung shunt fraction was 6.13%(range 3.5%-13.1%).Y-90 RE was performed for a single lesion in 7 patients,while the remaining 7 patients had treatment of multifocal lesions.The largest lesion measured 8.3 cm.All patients tolerated the procedure well and were discharged the same day.CONCLUSION Same day Y-90 RE with resin-based microspheres is feasible,and provides an opportunity to mitigate infection risk and logistical challenges associated with the COVID-19 pandemic and beyond.We recommend consideration of SPECT/CT,especially among patients with complex malignancies,for the potential to improve outcomes and eligibility of patients to undergo same day Y-90 RE.
文摘BACKGROUND Prostate cancer(PC)is one of the most common malignant tumors in men,and bone metastasis is one of its common complications,which seriously affects the quality of life and prognosis of patients.AIM To investigate the diagnostic value of technetium-99m-methylene diphosphonate(99mTc-MDP)single photon emission computed tomography(SPECT)/CT imaging combined with the serum prostate-specific antigen(PSA)/free PSA ratio for PC bone metastasis(PCBM).METHODS One hundred patients with PC who visited the Hospital of Chengdu University of Traditional Chinese Medicine from January 2020 to January 2022 were recruited as the experimental(Exp)group,while 30 patients with benign prostatic lesions(BPLs)were recruited as the control(Ctrl)group.All patients underwent 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA testing.The SPECT/CT imaging results and serum PSA/fPSA ratios of patients were analyzed to evaluate their diagnostic values for PCBM.RESULTS The difference in general information of the patients was not obvious,showing comparability.The two methods showed no visible differences in negative predictive value and sensitivity for patients with PCBM,but had great differences in positive predictive value and specificity(P<0.05).The PSA/fPSA ratio of patients with PC in the Exp group was lower than those with BPLs,and patients with PCBM had a much lower PSA/fPSA ratio than those without PC(P<0.05).The results confirmed that the combined use of 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA ratio achieved a detection rate of 95%for PCBM.CONCLUSION The combination of 99mTc-MDP SPECT/CT and PSA/fPSA ratio is accurate and reliable for the diagnosis of PCBM,which provides an important reference for clinical practice.
文摘Infective endocarditis is one of the leading life-threatening infections around the world.With the exponential growth in the field of transcatheter interventions and advances in specialized surgical techniques,the number of prosthetic valves and cardiac implantable devices has significantly increased.This has led to a steep rise in the number of cases of prosthetic valve endocarditis(PVE)comprising up to 30%of all cases.Clinical guidelines rely on the use of the modified Duke criteria;however,the diagnostic sensitivity of the modified Duke criteria is reduced in the context of PVE.This is in part attributed to prosthesis related artifact which greatly affects the ability of echocardiography to detect early infective changes related to PVE in certain cases.There has been increasing recognition of the roles of complementary imaging modalities and updates in international society recommendations.Prompt diagnosis and treatment can prevent the devastating consequences of this condition.Imaging modalities such as cardiac computed tomography and 18-fluorodeoxyglucose positron emission tomography/computed tomography are diagnostic tools that provide a complementary role to echocardiography in aiding diagnosis,pre-operative planning,and treatment decisionmaking process in these challenging cases.Understanding the strengths and limitations of these adjuvant imaging modalities is crucial for the implementation of appropriate imaging modalities in clinical practice.
文摘Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increas-ingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography （PET） and single photon emission computed tomography （SPECT） has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging tech-niques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coro-nary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed.
基金the National Natural Science Foundation of China,No.30471776
文摘BACKGROUND： Subthalamic nucleus deep brain stimulation （STN DBS） for Parkinson＇s disease （PD） has achieved good effects, but to date the mechanism of STN DBS remains poorly understood STN DBS may increase dopamine levels or metabolic activity of the corpus striatum. OBJECTIVE： To validate the effects of STN DBS on dopamine metabolism and glucose metabolism in the corpus striatum of hemiparkinsonian monkeys using single photon emission computed tomography （SPECT） and position emission tomography （PET）. DESIGN, TIME AND SET＇rING： A controlled animal study was performed at the Neurosurgery Laboratory, Changhai Hospital of the Second Military Medical University of Chinese PLA between January 2004 and December 2007. METHODS： Hemiparkinsonism was induced in adult Rhesus Macaque monkeys, which exhibit similar characteristics of PD in humans, through unilateral internal carotid artery infusion of 1-methy-4-phenyl-1, 2, 3, 6-tetrahydropyrindine. Following model establishment, stimulation electrodes were implanted in the right STN, and chronic high-frequency stimulation （60 μs pulse width, 130 Hz frequency, and 1.5-2.0 V pressure） was performed. MAIN OUTCOME MEASURES： The changes in dopamine transporter （DAT）, D2 receptor （D2R）, and glucose metabolism in the corpus striatum following STN DBS were observed using SPECT and PET. RESULTS： SPECT examination showed that DAT specific binding in the right corpus striatum was increased at 3 months after DBS compared with prior to stimulation, and D2R specific binding in the right corpus striatum gradually decreased near levels on the left （non-electrode-implanted） side within 3 months after DBS. PET examination showed that the glucose metabolism in the right corpus striatum was markedly increased at 3 months after effective DBS. Hemiparkinsonism monkeys showed improved left limb rigidity, increased activities, and stable gait under chronic high-frequency stimulation. CONCLUSION： STN DBS increased striatal DAT, decreased D2R, and enhanced glucose metabolism, suggesting that chronic, high-frequency STN stimulation enhanced the metabolic activity of the corpus striatum, a mechanism for improving the PD symptoms of hemiparkinsonian monkeys.
