Dynamic enhanced computed tomography imaging findings of an inflammatory fibroid polyp with massive fibrosis in the stomach

Inflammatory fibroid polyp(IFP) is a rare benign lesion of the gastrointestinal tract. We report a case of computed tomography(CT) imaging finding of a gastric IFP with massive fibrosis. CT scans showed thickening of submucosal layer with overlying mucosal hyperenhancement in the gastric antrum. The submucosal layer showed increased enhancement on delayed phase imaging. An antrectomy with gastroduodenostomy was performed because gastric cancer was suspected, particularly signet ring cell carcinoma. The histopathological diagnosis was an IFP with massive fibrosis. The authors suggest that when the submucosal layer of the gastric wall is markedly thickened with delayed enhancement and preservation of the mucosal layer, an IFP with massive fibrosis should be considered in the differential diagnosis.

Ultrasonic Computed Tomography Imaging Method of Concrete Materials Based on Simulated Annealing Genetic Algorithm

Stability and accuracy of the imaging results are still unmet practical demands for ultrasonic computed tomography(CT)of concrete material.To address these issues,a CT technique based on simulated annealing genetic algorithm(SAGA)is presented in this work.Firstly,a natural weight matrix with clear physical meaning is introduced in the inverse algorithm and then a quadric broadening objective function is formed according to the propagation characteristics of ultrasound in concrete.After that,the simulated annealing(SA)searching is added to speed up the inverse process and to improve the convergence and stability of the algorithm.Finally,the optimal inverse imaging results have been achieved by variable ectopic adaptive genetic algorithm.The numerical simulation experiments have shown that the usage of the correct priori information and the excellent characteristic of SAGA in searching the global minimum value of the function have produced accurate and effective results with stable numerical values.The imaging resolution is improved and the imagining results reflecting the inner defections of the tested objects are more reliable and accurate.

Sparse Bayesian learning in ISAR tomography imaging

Inverse synthetic aperture radar(ISAR) imaging can be regarded as a narrow-band version of the computer aided tomography(CT). The traditional CT imaging algorithms for ISAR, including the polar format algorithm(PFA) and the convolution back projection algorithm(CBP), usually suffer from the problem of the high sidelobe and the low resolution. The ISAR tomography image reconstruction within a sparse Bayesian framework is concerned. Firstly, the sparse ISAR tomography imaging model is established in light of the CT imaging theory. Then, by using the compressed sensing(CS) principle, a high resolution ISAR image can be achieved with limited number of pulses. Since the performance of existing CS-based ISAR imaging algorithms is sensitive to the user parameter, this makes the existing algorithms inconvenient to be used in practice. It is well known that the Bayesian formalism of recover algorithm named sparse Bayesian learning(SBL) acts as an effective tool in regression and classification,which uses an efficient expectation maximization procedure to estimate the necessary parameters, and retains a preferable property of the l0-norm diversity measure. Motivated by that, a fully automated ISAR tomography imaging algorithm based on SBL is proposed.Experimental results based on simulated and electromagnetic(EM) data illustrate the effectiveness and the superiority of the proposed algorithm over the existing algorithms.

Optical coherence tomography enhanced depth imaging of chorioretinal folds in patients with orbital tumors

AIM:To characterize spectral-domain optical coherence tomography(SD-OCT)features of chorioretinal folds in orbital mass imaged using enhanced depth imaging(EDI).METHODS:Prospective observational case-control study was conducted in 20 eyes of 20 patients,the uninvolved eye served as a control.All the patients underwent clinical fundus photography,computed tomography,EDI SDOCT imaging before and after surgery.Two patients with cavernous hemangiomas underwent intratumoral injection of bleomycin A5;the remaining patients underwent tumor excision.Patients were followed 1 to 14mo following surgery(average follow up,5.8mo).RESULTS:Visual acuity prior to surgery ranged from 20/20 to 20/200.Following surgery,5 patients’visual acuity remained unchanged while the remaining 15 patients had a mean letter improvement of 10(range 4 to 26 letters).Photoreceptor inner/outer segment defects were found in 10 of 15 patients prior to surgery.Following surgical excision,photoreceptor inner/outer segment defects fully resolved in 8 of these 10 patients.CONCLUSION:Persistence of photoreceptor inner/outer segment defects caused by compression of the globe by an orbital mass can be associated with reduced visual prognosis.Our findings suggest that photoreceptor inner/outer segment defects on EDI SD-OCT could be an indicator for immediate surgical excision of an orbital mass causing choroidal compression.

Detecting early changes in choroidal vascularity and thickness using optical coherence tomography in patients with corneal crosslinking for keratoconus

AIM:To investigate changes in choroidal thickness and vascularity in keratoconus patients treated with corneal crosslinking.METHODS:This study evaluated 28 eyes of 22 patients with keratoconus who underwent corneal crosslinking.The choroidal thicknesses were evaluated on enhanced depth imaging optical coherence tomography at the preoperative and postoperative 3d,1,and 3mo.Choroidal thickness in the four cardinal quadrants and the fovea were evaluated.The choroidal vascularity index was also calculated.RESULTS:There was no significant difference in central choroidal thickness between the preoperative and postoperative 3d,1mo(P>0.05).There was a significant increase in the 3mo(P=0.034)and a significant decrease in the horizontal choroidal vascularity index on the postoperative 3d(P=0.014),there was no statistically significant change in vertical axes and other visits in horizontal sections(P>0.05).CONCLUSION:This study sheds light on choroidal changes in postoperative corneal crosslinking for keratoconus.While it suggests the procedure’s relative safety for submacular choroid,more extensive research is necessary to confirm these findings and their clinical significance.

Computed tomography vs liver stiffness measurement and magnetic resonance imaging in evaluating esophageal varices in cirrhotic patients:A systematic review and meta-analysis

BACKGROUND Computed tomography(CT),liver stiffness measurement(LSM),and magnetic resonance imaging(MRI)are non-invasive diagnostic methods for esophageal varices(EV)and for the prediction of high-bleeding-risk EV(HREV)in cirrhotic patients.However,the clinical use of these methods is controversial.AIM To evaluate the accuracy of LSM,CT,and MRI in diagnosing EV and predicting HREV in cirrhotic patients.METHODS We performed literature searches in multiple databases,including Pub Med,Embase,Cochrane,CNKI,and Wanfang databases,for articles that evaluated the accuracy of LSM,CT,and MRI as candidates for the diagnosis of EV and prediction of HREV in cirrhotic patients.Summary sensitivity and specificity,positive likelihood ratio and negative likelihood ratio,diagnostic odds ratio,and the areas under the summary receiver operating characteristic curves were analyzed.The quality of the articles was assessed using the quality assessment of diagnostic accuracy studies-2 tool.Heterogeneity was examined by Q-statistic test and I2 index,and sources of heterogeneity were explored using metaregression and subgroup analysis.Publication bias was evaluated using Deek’s funnel plot.All statistical analyses were conducted using Stata12.0,Meta Disc1.4,and Rev Man5.3.RESULTS Overall,18,17,and 7 relevant articles on the accuracy of LSM,CT,and MRI in evaluating EV and HREV were retrieved.A significant heterogeneity was observed in all analyses(P<0.05).The areas under the summary receiver operating characteristic curves of LSM,CT,and MRI in diagnosing EV and predicting HREV were 0.86(95%confidence interval[CI]:0.83-0.89),0.91(95%CI:0.88-0.93),and 0.86(95%CI:0.83-0.89),and 0.85(95%CI:0.81-0.88),0.94(95%CI:0.91-0.96),and 0.83(95%CI:0.79-0.86),respectively,with sensitivities of 0.84(95%CI:0.78-0.89),0.91(95%CI:0.87-0.94),and 0.81(95%CI:0.76-0.86),and 0.81(95%CI:0.75-0.86),0.88(95%CI:0.82-0.92),and 0.80(95%CI:0.72-0.86),and specificities of 0.71(95%CI:0.60-0.80),0.75(95%CI:0.68-0.82),and 0.82(95%CI:0.70-0.89),and 0.73(95%CI:0.66-0.80),0.87(95%CI:0.81-0.92),and 0.72(95%CI:0.62-0.80),respectively.The corresponding positive likelihood ratios were 2.91,3.67,and 4.44,and 3.04,6.90,and2.83;the negative likelihood ratios were 0.22,0.12,and 0.23,and 0.26,0.14,and 0.28;the diagnostic odds ratios were 13.01,30.98,and 19.58,and 11.93,49.99,and 10.00.CT scanner is the source of heterogeneity.There was no significant difference in diagnostic threshold effects(P>0.05)or publication bias(P>0.05).CONCLUSION Based on the meta-analysis of observational studies,it is suggested that CT imaging,a non-invasive diagnostic method,is the best choice for the diagnosis of EV and prediction of HREV in cirrhotic patients compared with LSM and MRI.

Optical coherence tomography imaging of cranial meninges post brain injury in vivo

We report a new application of optical coherence tomography（OCT） to investigate the cranial meninges in an animal model of brain injury in vivo. The injury is induced in a mouse due to skull thinning, in which the repeated and excessive drilling exerts mechanical stress on the mouse brain through the skull, resulting in acute and mild brain injury. Transcranial OCT imaging reveals an interesting virtual space between the cranial meningeal layers post skull thinning, which is gradually closed within hours. The finding suggests a promise of OCT as an effective tool to monitor the mechanical trauma in the small animal model of brain injury.

Terahertz Three-Dimensional Imaging Based on Computed Tomography with Photonics-Based Noise Source

Computed tomography has been proven to be useful for non-destructive inspection of structures and materials. We build a three-dimensional imaging system with the photonically generated incoherent noise source and the Schottky barrier diode detector in the terahertz frequency band （90–140GHz）. Based on the computed tomography technique, the three-dimensional image of a ceramic sample is reconstructed successfully by stacking the slices at different heights. The imaging results not only indicate the ability of terahertz wave in the non-invasive sensing and non-destructive inspection applications, but also prove the effectiveness and superiority of the uni-traveling-carrier photodiode as a terahertz source in the imaging applications.

Optical coherence tomography with or without enhanced depth imaging for peripapillary retinal nerve fiber layer and choroidal thickness

AIM：To assess peripapillary retinal nerve fiber layer（RNFL）and choroidal thickness obtained with enhanced depth imaging（EDI）mode compared with those obtained without EDI mode using Heidelberg Spectralis optical coherence tomography（OCT）.METHODS：Fifty eyes of 25 normal healthy subjects and32 eyes of 20 patients with different eye diseases were included in the study.All subjects underwent 3.4 mm diameter peripapillary circular OCT scan centered on the optic disc using both the conventional and the EDI OCT protocols.The visualization of RNFL and choroidoscleral junction was assessed using an ordinal scoring scale.The paired t-test,intraclass correlation coefficient（ICC）,95%limits of agreement（LoA）,and Bland and Altman plots were used to test the agreement of measurements.RESULTS：The visibility score of RNFL obtained with and without EDI was of no significant difference（P=0.532）,the visualization of choroidoscleral junction was better using EDI protocol than conventional protocol（P〈0.001）.Peripapillary RNFL thickness obtained with EDI was slightly thicker than that obtained without EDI（103.25±9.42μm vs 101.87±8.78μm,P=0.010）.The ICC of the two protocols was excellent with the value of 0.867 to 0.924,the 95%LoA of global RNFL thickness was between-10.0 to 7.4μm.Peripapillary choroidal thickness obtained with EDI was slightly thinner than that obtained without EDI（147.23±51.04μm vs 150.90±51.84μm,P〈0.001）.The ICC was also excellent with the value of 0.960 to 0.987,the 95%LoA of global choroidal thickness was between-12.5 to 19.8μm.CONCLUSION：Peripapillary circular OCT scan with or without EDI mode shows comparable results in the measurement of peripapillary RNFL and choroidal thickness.

Comparison of Computed Tomography Imaging with Traditional Autopsy Results

The role of computed tomography(CT)images in forensic identification has been widely recognized.Such images can provide an important basis for identification of the cause of death in complicated and difficult cases,including falls from a height,drowning,explosion and gunshot cases,traffic accidents,and sudden death.However,few reports have focused on the application of CT images in cases of death caused by sharp object injuries.Therefore,the CT images and autopsy findings were compared in a case of death caused by sharp object injuries to the chest and abdomen,and the importance of CT images in cases of death from common sharp object injuries is herein discussed.

Peripapillary choroidal thickness in Chinese children using enhanced depth imaging optical coherence tomography

AIM：To evaluate the peripapillary choroidal thickness（PPCT） in Chinese children,and to analyze the influencing factors.METHODS： PPCT was measured with enhanced depth imaging optical coherence tomography（EDI-OCT） in 70children（53 myopes and 17 non-myopes） aged 7 to 18 y,with spherical equivalent refractive errors between 0.50and-5.87 diopters（D）.Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc.PPCT was measured by EDI-OCT in six sectors： nasal（N）,superonasal（SN）,superotemporal（ST）,temporal（T）,inferotemporal（IT）and inferonasal（IN）,as well as global RNFL thickness（G）.RESULTS： The mean global PPCT was 165.49±33.76 μm.The temporal,inferonasal,inferotemporal PPCT were significantly thinner than the nasal,superonasal,superotemporal segments PPCT were significantly thinner in the myopic group at temporal,superotemporal and inferotemporal segments.The axial length was significantly associated with the average global（β=-0.419,P =0.014）,superonasal（β=-2.009,P=0.049） and inferonasal（β=-2.000,P=0.049） PPCT.The other factors（gender,age,SE） were not significantly associated with PPCT.CONCLUSION： PPCT was thinner in the myopic group at temporal,superotemporal and inferotemporal segments.The axial length was found to be negatively correlated to PPCT.We need more further studies about the relationship between PPCT and myopia.

New frontiers in focal therapy for prostate cancer:Prostate-specific membrane antigen positron emission tomography/magnetic resonance imaging

Imaging has a central role in the context of focal therapy(FT)for prostate cancer(PCa).Prostate-specific membrane antigen(PSMA)positron emission tomography/magnetic resonance imaging(PET/MRI)is a novel imaging modality that combines the morpho-functional information of MRI with the molecular characterization of PET.Some papers reported the potential advantages of PSMA PET/MRI in different clinical scenarios.Limited evidence on PSMA PET/MRI is available in the setting of FT.PSMA PET/MRI can be an effective imaging modality for detecting primary PCa and seems to provide accurate local staging of primary PCa.PSMA PET/MRI also shows high performance for restaging and detecting tumor recurrence.The higher soft-tissue contrast and the reduction of ionizing radiation are the main advantages reported in the literature compared to PET/computed tomography.PSMA PET/MRI could represent a turning point in the management of patients with PCa in the context of FT.Further studies are needed to confirm its applications in this specific clinical setting.

Coronary arterial bypass graft patency evaluated by multi-detector computed tomography and magnetic resonance imaging

The progression of atherosclerosis of the coronary artery does not stop after coronary arterial bypass grafting (CABG) surgery.……

Radiation Dose from CT-Scan of Childhood’s Head: Results of the First Ivorian Survey in a Single Study Site

Objectives: This study aims to evaluate the level of X-ray doses used in childhood’s head as Local Diagnostic Reference Levels (LDRLs) in computed tomography (CT) at a university hospital in Côte d’Ivoire. The Diagnostic Reference Level (DRL) have been set up and used to prevent unusually high radiation doses used in radiology departments and is therefore an optimization tool for practices and procedures in medical X-ray imaging for the radiation protection of patients. Methods: A prospective study of volume CT dose index (CTDIvol) and dose length product (DLP) was performed on images of childhood’s head obtained from a CT-scanner of 64 bars equipped with the tube current modulation capability and manufactured by Hitachi Medical System. 122 CT-scan data from 55 childhood’s head were analyzed. The scan data were stratified in four age groups: Results: The 75th percentile of CTDIvol and DLP (set as LDRL) obtained with respect to the stratified age groups are: 22.5 mGy and 452.5 mGy∙cm, 27.7 mGy and 690.6 mGy∙cm, 28 mGy and 722.4 mGy∙cm, 33.6 mGy and 736.8 mGy∙cm respectively. These outcome values increase with respect to the age of pediatric patients and are comparable to DRLs values obtained internationally. Conclusions: Obtaining good image quality while using low dose in children’s head computed tomography for radiation protection require to setup more surveys in Côte d’Ivoire for regional and national DRL. We proposed through this survey LDRLs in terms of CTDIvol and DLP, comparable to international DRLs values. This survey will be strengthened by additional surveys in order to obtain national DRLs for the radiation protection of the child patient in Côte d’Ivoire.

Clinical characteristics of peripapillary hyperreflective ovoid mass-like structures in myopic children

AIM:To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure(PHOMS)in myopic children and to investigate factors associated with PHOMS.METHODS:This retrospective observational study included 101 eyes of 101 children(age≤17y)with myopia.All included patients underwent comprehensive clinical examination.Optic nerve canal parameters,including disc diameter,optic nerve head(ONH)tilt angle,and border tissue angle were measured using serial enhanced-depth imaging spectral-domain optical coherence tomography(EDI-OCT).Based on the optic disc drusen consortium’s definition of PHOMS,eyes were classified as PHOMS group and non-PHOMS group.PHOMS was categorized according to height.RESULTS:Sixty-seven(66.3%)eyes were found with PHOMS.Small PHOMS could only be detected by optical coherence tomography(OCT).Medium PHOMS could be seen with blurred optic disc borders corresponding to OCT.The most frequent location of PHOMS was at the nasosuperior(91%,61 of 67 eyes)to ONH disc.The axial length and spherical equivalent were more myopic in the PHOMS group than in the non-PHOMS group(both P<0.001).ONH tilt angle was also significantly greater in PHOMS group than in non-PHOMS group[8.90(7.16-10.54)vs 3.93(3.09-5.25),P<0.001].Border tissue angle was significantly smaller in PHOMS group than in non-PHOMS group[29.70(20.90-43.81)vs 45.62(35.18-60.45),P<0.001].In the multivariable analysis,spherical equivalent(OR=3.246,95%CI=1.209-8.718,P=0.019)and ONH tilt angle(OR=3.275,95%CI=1.422-7.542,P=0.005)were significantly correlated with PHOMS.There was no disc diameter associated with PHOMS.In the linear regression analysis,border tissue angle was negatively associated with PHOMS height(β=-2.227,P<0.001).CONCLUSION:PHOMS is associated with optic disc tilt and optic disc nasal shift in myopia.Disc diameter is not a risk factor for PHOMS.The changes in ONH caused by axial elongation facilitated an understanding of the mechanism of PHOMS.

An algorithm for computed tomography image reconstruction from limited-view projections

With the development of the compressive sensing theory, the image reconstruction from the projections viewed in limited angles is one of the hot problems in the research of computed tomography technology. This paper develops an iterative algorithm for image reconstruction, which can fit the most cases. This method gives an image reconstruction flow with the difference image vector, which is based on the concept that the difference image vector between the reconstructed and the reference image is sparse enough. Then the l1-norm minimization method is used to reconstruct the difference vector to recover the image for flat subjects in limited angles. The algorithm has been tested with a thin planar phantom and a real object in limited-view projection data. Moreover, all the studies showed the satisfactory results in accuracy at a rather high reconstruction speed.

Optimization-based image reconstruction in x-ray computed tomography by sparsity exploitation of local continuity and nonlocal spatial self-similarity

The additional sparse prior of images has been the subject of much research in problems of sparse-view computed tomography（CT） reconstruction. A method employing the image gradient sparsity is often used to reduce the sampling rate and is shown to remove the unwanted artifacts while preserve sharp edges, but may cause blocky or patchy artifacts.To eliminate this drawback, we propose a novel sparsity exploitation-based model for CT image reconstruction. In the presented model, the sparse representation and sparsity exploitation of both gradient and nonlocal gradient are investigated.The new model is shown to offer the potential for better results by introducing a similarity prior information of the image structure. Then, an effective alternating direction minimization algorithm is developed to optimize the objective function with a robust convergence result. Qualitative and quantitative evaluations have been carried out both on the simulation and real data in terms of accuracy and resolution properties. The results indicate that the proposed method can be applied for achieving better image-quality potential with the theoretically expected detailed feature preservation.

A multifunctional nanoaggregate-based system for detection of rheumatoid arthritis via Optoacoustic/NIR-Ⅱ fluorescent imaging and therapy via inhibiting JAK-STAT/NF-κB/NLRP3 pathways

Rheumatoid arthritis(RA)is a debilitating autoimmune disease that causes chronic pain and serious complications,presenting a significant challenge to treat.Promising approaches for treating RA involve signaling pathways modulation and targeted therapy.To this end,a multifunctional nanosystem,TPC-U@HAT,has been designed for RA therapy,featuring multitargeting,dual-stimuli response,and on-demand drug release capabilities.TPC-U@HAT is composed of a probe/prodrug TPC,a JAK1 kinase inhibitor upadacitinib,and the drug carrier HAT.TPC is composed of an aggregation-induced emission(AIE)-active NIR-II chromophore TPY and an NF-κB/NLRP3 inhibitor caffeic acid phenethyl ester(CAPE),connected via boronic ester bond which serves as the reactive-oxygen-species-responsive linker.The carrier,HAT,is created by grafting bone-targeting alendronate and hydrophobic tocopheryl succinate onto hyaluronic acid chains,which can encapsulate TPC and upadacitinib to form TPC-U@HAT.Upon intravenous injection into mice,TPC-U@HAT accumulates at inflamed lesions of RA through both active and passive targeting,and the overexpressed hyaluronidase and H_(2)O_(2) therein cleave the hyaluronic acid polymer chains and boronate bonds,respectively.This generates an AIE-active chromophore for detection and therapeutic evaluation of RA via both optoacoustic imaging and NIR-II fluorescent imaging and concomitantly releases CAPE and upadacitinib to exert efficacious therapy by inhibiting NF-κB/NLRP3 and JAK-STAT pathways.

Establishment of FAP-overexpressing Cells for FAP-targeted Theranostics

Objective Fibroblast activation protein(FAP)has been widely studied and exploited for its clinical applications.One of the difficulties in interpreting reports of FAP-targeted theranostics is due to the lack of accurate controls,making the results less specific and less confirmative.This study aimed to establish a pair of cell lines,in which one highly expresses FAP(HT1080-hFAP)and the other has no detectable FAP(HT1080-vec)as control,to accurately evaluate the specificity of the FAP-targeted theranostics in vitro and in vivo.Methods The cell lines of the experimental group(HT1080-hFAP)and no-load group(HT1080-vec)were obtained by molecular construction of the recombinant plasmid pIRES-hFAP.The expression of hFAP in HT1080 cells was detected by PCR,Western blotting and flow cytometry.CCK-8,Matrigel transwell invasion assay,scratch test,flow cytometry and immunofluorescence were used to verify the physiological function of FAP.The activities of human dipeptidyl peptidase(DPP)and human endopeptidase(EP)were detected by ELISA in HT1080-hFAP cells.PET imaging was performed in bilateral tumor-bearing nude mice models to evaluate the specificity of FAP.Results RT-PCR and Western blotting demonstrated the mRNA and protein expression of hFAP in HT1080-hFAP cells but not in HT1080-vec cells.Flow cytometry confirmed that nearly 95%of the HT1080-hFAP cells were FAP positive.The engineered hFAP on HT1080 cells had its ability to retain enzymatic activities and a variety of biological functions,including internalization,proliferation-,migration-,and invasion-promoting activities.The HT1080-hFAP xenografted tumors in nude mice bound and took up^(68)GA-FAPI-04 with superior selectivity.High image contrast and tumor-organ ratio were obtained by PET imaging.The HT1080-hFAP tumor retained the radiotracer for at least 60 min.Conclusion This pair of HT1080 cell lines was successfully established,making it feasible for accurate evaluation and visualization of therapeutic and diagnostic agents targeting the hFAP.

Computed tomography and photoacoustic imaging guided photodynamic therapy against breast cancer based on mesoporous platinum with insitu oxygen generation ability

Photodynamic therapy(PDT)has been widely used in cancer treatment.However,hypoxia in most solid tumors seriously restricts the efficacy of PDT.To improve the hypoxic microenvironment,we designed a novel mesoporous platinum(mPt)nanoplatform to catalyze hydrogen peroxide(H2 O2)within the tumor cells in situ without an extra enzyme.During the fabrication,the carboxy terminus of the photosensitizer chlorin e6(Ce6)was connected to the amino terminus of the bifunctional mercaptoaminopolyglycol(SH-PEG-NH2)by a condensation reaction,and then PEG-Ce6 was modified onto the mPt moiety via the mercapto terminal of SH-PEG-NH2.Material,cellular and animal experiments demonstrated that Pt@PEG-Ce6 catalyzed H2 O2 to produce oxygen(O2)and that Ce6 transformed O2 to generate reactive oxygen species(ROS)upon laser irradiation.The Pt@PEG-Ce6 nanoplatform with uniform diameter presented good biocompatibility and efficient tumor accumulation.Due to the high atomic number and good near-infrared absorption for Pt,this Pt@PEG-Ce6 nanoplatform showed computed tomography(CT)and photoacoustic(PA)dual-mode imaging ability,thus providing an important tool for monitoring the tumor hypoxic microenvironment.Moreover,the Pt@PEG-Ce6 nanoplatform reduced the expression of hypoxia-inducible factor-la(HIF-1α)and programmed death-1(PD-1)in tumors,discussing the relationship between hypoxia,PD-1,and PDT for the first time.