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18F?alfatide positron emission tomography may predict anti?angiogenic responses
摘要： As the crucial issue in the development of anti-angiogenic drugs is how to predict which patients will and will not benefit prior to the initiation of therapy, angiogenic 18F-alfatide positron emission computed tomography (PET) was assessed in the present study. Lung adenocarcinoma A549 (high angiogenesis) and prostate PC?3 (low angiogenesis) cell xenografted tumor-bearing mice underwent 18F-alfatide PET at baseline and following treatment with either an anti?angiogenic therapy or vehicle. The evaluation index for the inhibition of tumor growth in the individuals in the treated groups was represented by treatment/control (T/C) ratio (%). Anti?angiogenic responses were denoted by the changes in 18F-alfatide uptake in the same animal. The T/C ratio was lower in high-uptake tumors than in low?uptake tumors (P=0.001). A significant difference in the tumor volumes between the anti?angiogenic therapy group and the control group occurred earlier in the A549 model than in the PC?3 model. 18F-alfatide uptake decreased more for A549 tumors than for PC?3 tumors following anti?angiogenic therapy. In each treatment group, the degree of tumor response to anti?angiogenic therapy was associated well with the tumor uptake prior to treatment (P<0.05). These results indicated that 18F?alfatide PET may be a useful molecular imaging tool for individual selection prior to anti?angiogenic drug therapy.
关键词： 18F?alfatide positron emission tomography,heterogeneity,integrin αvβ3,response prediction,anti?angiogenic therapy
更新于2025-09-23 15:22:29
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A Quantum Field Approach for Advancing Optical Coherence Tomography Part I: First Order Correlations, Single Photon Interference, and Quantum Noise
摘要： Optical coherence tomography has become an important imaging technology in cardiology and ophthalmology, with other applications under investigations. Major advances in optical coherence tomography (OCT) imaging are likely to occur through a quantum field approach to the technology. In this paper, which is the first part in a series on the topic, the quantum basis of OCT first order correlations is expressed in terms of full field quantization. Specifically first order correlations are treated as the linear sum of single photon interferences along indistinguishable paths. Photons and the electromagnetic (EM) field are described in terms of quantum harmonic oscillators. While the author feels the study of quantum second order correlations will lead to greater paradigm shifts in the field, addressed in part II, advances from the study of quantum first order correlations are given. In particular, ranging errors are discussed (with remedies) from vacuum fluctuations through the detector port, photon counting errors, and position probability amplitude uncertainty. In addition, the principles of quantum field theory and first order correlations are needed for studying second order correlations in part II.
关键词： Plaque,Quantum mechanics,Interferometry,Ophthalmology,Noise,Vacuum,Cardiology,Arthritis,Optical coherence tomography
更新于2025-09-23 15:22:29
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Prediction models for different plaque morphology in non-significantly stenosed regions of saphenous vein grafts assessed with optical coherence tomography
摘要： Introduction: Coronary artery bypass grafting (CABG) is a method of choice in treatment of diffuse coronary artery disease (CAD), although it has some limitations such as late saphenous vein graft (SVG) patency loss, which occurs in one fifth of all conduits at 5 years. Since atherosclerosis in SVG has diffuse characteristics, it appears that significantly and non-significantly stenosed lesions may have an equal impact on worse prognosis. Aim: To assess non-significant lesions of SVG by the use of optical coherence tomography (OCT) and investigate the clinical and laboratory findings with the potential impact on plaque composition. Material and methods: Twenty-nine patients with 43 non-significant lesions were enrolled in the study. All variables were assessed using uni- and multivariable logistic regression analysis with each plaque morphology as a dependent variable. Odds ratio (OR) and 95% confidence interval (CI) were computed. Results: Plaque rupture (PRT) was independently associated with age (OR = 1.49, 95% CI: 1.09–2.04, p = 0.015) and lower rates of high-density lipoproteins (HDL) cholesterol (OR = 0.67, 95% CI: 0.49–0.92, p = 0.016). Intimal tearing or rupture (ITR) was related to reduced GFR (OR = 0.52, 95% CI: 0.38–0.72, p = 0.0004). Lipid-rich plaque (LRP) was associated with raised platelet count (PLT) (OR = 1.51, 95% CI: 1.16–1.96, p = 0.004) and increased frequency of smoking (OR = 1.45, 95% CI: 1.12–1.89, p = 0.007). Conclusions: Atherosclerosis of SVG is not restricted to significantly stenosed lesions. Plaque composition is independently associated with different types of clinical and laboratory findings, mostly recognized as risk factors of CAD.
关键词： coronary artery disease,optical coherence tomography,saphenous vein graft coronary artery bypass grafting
更新于2025-09-23 15:22:29
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Visual Acuity at Presentation in the Second Eye versus First Eye in Patients with Exudative Age-Related Macular Degeneration
摘要： Purpose: To assess the difference in best-corrected visual acuity (BCVA) at presentation between the first and second eye in patients with bilateral neovascular age-related macular degeneration (AMD). Methods: We reviewed the charts of all patients who had a clinical examination for neovascular AMD at the University Eye Clinic of Creteil in January 2013. We retrospectively analyzed demographic and clinical data for 264 patients. Results: In the fellow eye, choroidal neovascularization (CNV) developed in 75/264 patients (28.4%) with a time interval between the 2 events of 30.3 months (range 6-145). Data were available on 65 patients: 14/65 (21.5%) were asymptomatic, 24/65 (36.9%) had BCVA >20/40, whereas at the time of CNV diagnosis in the first eye, no patient was asymptomatic (p<0.0001), and 11/65 (16.9%) eyes had BCVA >20/40 (p<0.0001). The mean BCVA of the first affected eye was 0.68 (±0.41) logarithm of minimum angle of resolution (logMAR) and the mean BCVA for the second eye was 0.36 (±0.29) logMAR (p<0.0001). Conclusions: The BCVA at the time of diagnosis of CNV was higher in the second eye than in the first affected eye. This was possibly due to several factors including systematic bilateral examination in follow-up of unilateral exudative AMD that allowed detection of 20% of cases.
关键词： Patient management,Optical coherence tomography,Visual acuity,Age-related macular degeneration
更新于2025-09-23 15:22:29
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Combined use of Doppler OCT and en Face OCT Functions for Discrimination of an Aneurysm in the Lamina Cribrosa from a Disc Hemorrhage
摘要： purpose: In addition to retinal nerve fiber layer thickness measurements, the recently introduced AngioVue optical coherence tomography (OCT) offers corresponding layer-by-layer Doppler OCT and en face OCT functions, for simultaneous evaluation of perfusion and structure of the optic nerve head. We investigated the clinical usefulness of combined use of Doppler and en face Fourier-domain OCT functions of the AngioVue Fourier-domain OCT for discrimination of a disc hemorrhage and a disc hemorrhage–like atypical vessel structure located deep in the lamina cribrosa. Case report: We present our findings with AngioVue OCT on a disc hemorrhage and a spatially related retinal nerve fiber layer bundle defect in a glaucomatous eye (case 1). Both alterations were detected on en face OCT images without any Doppler OCT signal. We also report on an aneurysm suggestive for a disc hemorrhage on clinical examination and disc photography in a treated ocular hypertensive eye (case 2). The aneurysm was within the lamina cribrosa tissue at the border of the cup and the neuroretinal rim. This vascular structure produced strong Doppler signals but no structurally detectable signs on the en face OCT images. Conclusions: Combined evaluation of corresponding Doppler OCT and en face OCT images enables ophthalmologists to easily separate true disc hemorrhages from disc hemorrhage–like deep vascular structures. This is of clinical significance in preventing unnecessary intensification of pressure-lowering treatment in glaucoma.
关键词： Doppler optical coherence tomography,Aneurysm,AngioVue OCT,Optic disc hemorrhage,En face Fourier-domain OCT,Glaucoma progression
更新于2025-09-23 15:22:29
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Assessment of CT numbers in limited and medium field-of-view scans taken using Accuitomo 170 and Veraviewepocs 3De cone-beam computed tomography scanners
摘要： Purpose: To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. Materials and Methods: Tubes containing solutions with different concentrations of K2HPO4 were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT numbers of the K2HPO4 solutions were measured. The relationship between CT number and K2HPO4 concentration was examined by linear regression analyses. Then, the variation in CT number according to anatomic location was examined. Results: The relationship between K2HPO4 concentration and CT number was strongly linear. The slopes of the linear regressions for the limited FOVs were almost 2-fold lower than those for the medium FOVs. The absolute CT number differed between imaging protocols and anatomic locations. Conclusion: There is a strong linear relationship between X-ray attenuation and CT number. The specific imaging protocol and anatomic location of the object strongly influence this relationship.
关键词： Image Processing, Computer-Assisted,Imaging, Three-Dimensional,Cone-Beam Computed Tomography
更新于2025-09-23 15:22:29
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Effect of object position in the field of view and application of a metal artifact reduction algorithm on the detection of vertical root fractures on cone-beam computed tomography scans: An <i>in vitro</i> study
摘要： Purpose: To assess the effects of object position in the field of view (FOV) and application of a metal artifact reduction (MAR) algorithm on the diagnostic accuracy of cone-beam computed tomography (CBCT) for the detection of vertical root fractures (VRFs). Materials and Methods: Sixty human single-canal premolars received root canal treatment. VRFs were induced in 30 endodontically treated teeth. The teeth were then divided into 4 groups, with 2 groups receiving metal posts and the remaining 2 only having an empty post space. The roots from different groups were mounted in a phantom made of cow rib bone, and CBCT scans were obtained for the 4 different groups. Three observers evaluated the images independently. Results: The highest frequency of correct diagnoses of VRFs was obtained with the object positioned centrally in the FOV, using the MAR algorithm. Peripheral positioning of the object without the MAR algorithm yielded the highest sensitivity for the first observer (66.7%). For the second and third observers, a central position improved sensitivity, with or without the MAR algorithm. In the presence of metal posts, central positioning of the object in the FOV significantly increased the diagnostic sensitivity and accuracy compared to peripheral positioning. Conclusion: Diagnostic accuracy was higher with central positioning than with peripheral positioning, irrespective of whether the MAR algorithm was applied. However, the effect of the MAR algorithm was more significant with central positioning than with peripheral positioning of the object in the FOV. The clinical experience and expertise of the observers may serve as a confounder in this respect.
关键词： Cone-Beam Computed Tomography,Artifact,Diagnosis,Tooth Fracture
更新于2025-09-23 15:22:29
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Effect of Refractive Status and Axial Length on Peripapillary Retinal Nerve Fibre Layer Thickness: An Analysis Using 3D OCT
摘要： Background: Accurate measurement of retinal nerve fiber layer (RNFL) is now possible with the high resolution optical coherence tomography (OCT). Effect of refractive status of the eye on RNFL thickness may be relevant in the diagnosis of glaucoma and other optic nerve diseases. Aim: To assess the RNFL thickness and compare its correlation with refractive status and axial length of the eye. Material and Methods: Three hundred eyes of 150 patients were included in this study, who underwent RNFL analysis using TOPCON 3D OCT 2000. Analysis of variance has been used to find the significance of study parameters between the study groups. Results: The study showed that refractive status/axial length affected the peripapillary RNFL thickness significantly. Conclusion: The study suggests that the diagnostic accuracy of OCT may be improved by considering refractive status and axial length of the eye when RNFL is measured.
关键词： Optical coherence tomography,Refractive error
更新于2025-09-23 15:22:29
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Enhanced depth imaging optical coherence tomography of choroidal osteoma with secondary neovascular membranes: report of two cases
摘要： We report enhanced depth imaging optical coherence tomography (EDI-OCT) features based on clinical and imaging data from two newly diagnosed cases of choroidal osteoma presenting with recent visual loss secondary to choroidal neovascular membranes. The features described in the two cases, compression of the choriocapillaris and disorganization of the medium and large vessel layers, are consistent with those of previous reports. We noticed a sponge-like pattern previously reported, but it was subtle. Both lesions had multiple intralesional layers and a typical intrinsic transparency with visibility of the sclerochoroidal junction.
关键词： Choroid neoplasms,Choroidal neovascularization,Osteoma,Tomography, optical coherence
更新于2025-09-23 15:22:29
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Targeted nanoparticles for multimodal imaging of the receptor for advanced glycation end-products
摘要： The receptor for advanced glycation end-products (RAGE) is implicated in multiple disease states such as cancer, diabetes and neurodegenerative disorders, and RAGE inhibitors are being explored as potential new therapies in such cases. Despite the known role RAGE plays in these conditions, there remains an urgent need for a molecular imaging agent that can accurately quantify RAGE levels in vivo, aid in validation of RAGE as a biomarker and/or therapeutic target, and support development of new RAGE inhibitors. This editorial highlights a multimodal nanoparticle-based imaging agent targeted at RAGE that was recently developed by Konopka and colleagues (Theranostics 2018; 8(18):5012-5024. doi:10.7150/thno.24791).
关键词： receptor for advanced glycation end-products,positron emission tomography,multimodal imaging
更新于2025-09-23 15:22:29