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- 2015
- cardiovascular imaging
- coronary artery disease
- coronary calcium score
- atherosclerosis
- coronary CT angiography.
- Medical Imaging
- Università degli Studi di Napoli Federico II
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Targeting fluorescent nanodiamonds to vascular endothelial growth factor receptors in tumor
摘要： The increased expression of vascular endothelial growth factor (VEGF) and its receptors is associated with angiogenesis in a growing tumor, presenting potential targets for tumor-selective imaging by way of targeted tracers. Though fluorescent tracers are used for targeted in vivo imaging, the lack of photostability and biocompatibility of many current fluorophores hinder their use in several applications involving long-term, continuous imaging. To address these problems, fluorescent nanodiamonds (FNDs), which exhibit infinite photostability and excellent biocompatibility, were explored as fluorophores in tracers for targeting VEGF receptors in growing tumors. To explore FND utility for imaging tumor VEGF receptors, we used click-chemistry to conjugate multiple copies of an engineered single-chain version of VEGF site-specifically derivatized with trans-cyclooctene (scVEGF-TCO) to 140 nm FND. The resulting targeting conjugates, FND-scVEGF, were then tested for functional activity of the scVEGF moieties through biochemical and tissue culture experiments and for selective tumor uptake in Balb/c mice with induced 4T1 carcinoma. We found that FND-scVEGF conjugates retain high affinity to VEGF receptors in cell culture experiments and observed preferential accumulation of FND-scVEGF in tumors relative to untargeted FND. Microspectroscopy provided unambiguous determination of FND within tissue by way of the unique spectral shape of nitrogen-vacancy induced fluorescence. These results validate and invite the use of targeted FND for diagnostic imaging and encourage further optimization of FND for fluorescence brightness.
关键词： Vascular Endothelial Growth Factor,Oncology,Targeted Fluorescence Imaging,Nanodiamond,Angiogenesis
更新于2025-11-21 11:24:58
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An opsin 5–dopamine pathway mediates light-dependent vascular development in the eye
摘要： During mouse postnatal eye development, the embryonic hyaloid vascular network regresses from the vitreous as an adaption for high-acuity vision. This process occurs with precisely controlled timing. Here, we show that opsin 5 (OPN5; also known as neuropsin)-dependent retinal light responses regulate vascular development in the postnatal eye. In Opn5-null mice, hyaloid vessels regress precociously. We demonstrate that 380-nm light stimulation via OPN5 and VGAT (the vesicular GABA/glycine transporter) in retinal ganglion cells enhances the activity of inner retinal DAT (also known as SLC6A3; a dopamine reuptake transporter) and thus suppresses vitreal dopamine. In turn, dopamine acts directly on hyaloid vascular endothelial cells to suppress the activity of vascular endothelial growth factor receptor 2 (VEGFR2) and promote hyaloid vessel regression. With OPN5 loss of function, the vitreous dopamine level is elevated and results in premature hyaloid regression. These investigations identify violet light as a developmental timing cue that, via an OPN5–dopamine pathway, regulates optic axis clearance in preparation for visual function.
关键词： Hyaloid regression,Vascular development,Dopamine,VEGFR2,Light-dependent,Eye,Opsin 5,Retinal ganglion cells
更新于2025-11-21 11:20:42
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Non-Invasive Optical Guided Tumor Metastasis/Vessel Imaging by Using Lanthanide Nanoprobe with Enhanced Down-Shifting Emission beyond 1500 nm
摘要： Visualization of tumor vessels/metastasis and cerebrovascular architecture is vital important for analyzing pathological states of brain diseases and tumor's abnormal blood vessel to improve cancer diagnosis. In vivo fluorescence imaging using second near infrared emission beyond 1500 nm (NIR-IIb) is emerged as a next generation optical imaging method with significant improvement in imaging sensitivity and spatial resolution. Unfortunately, highly biocompatible probe capable of generating NIR-IIb emission with sufficient brightness and uniformed size is still scarce. Here, we have proposed the polyacrylic acid (PAA)-modified NaLnF4:40Gd/20Yb/2Er nanorods (Ln=Y, Yb, Lu, PAA-Ln-NRs) with enhanced downshifting NIR-IIb emission, high quantum yield (QY), relative narrow bandwidth (~160 nm) and high bio-compatibility via Ce3+ doping for high performance NIR-IIb bioimaging. The downshifting emission beyond 1500 nm is improved by 1.75~2.2 times with simultaneously suppressing the upconversion (UC) path in Y, Yb, and Lu hosts via Ce3+ doping. Moreover, compared with the traditionally used Y-based host, the QY of NIR-IIb emission in Lu-based probe in water is improved from 2.2% to 3.6%. The explored bright NIR-IIb emitted PAA-Lu-NRs were used for high sensitivity small tumor (~ 4 mm)/metastatic tiny tumor detection (~ 3 mm), tumor vessel visualization with high spatial resolution (41 μm) and brain vessel imaging. Therefore, our findings open up the opportunity of utilizing lanthanide based NIR-IIb probe with bright 1525 nm emission for in vivo optical-guided tumor vessel/metastasis and non-invasive brain vascular imaging.
关键词： enhancement of downshifting emission,tiny metastatic tumor detection,tumor vascular imaging,rare-earth nanoprobes,brain vascular imaging
更新于2025-09-23 15:23:52
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Retinal vascular density evaluated by optical coherence tomography angiography in macular telangiectasia type 2
摘要： Purpose To evaluate the retinal and choroidal vascular changes through optical coherence tomography angiography (OCTA) in patients with macular telangiectasia type 2 (MacTel 2). Methods Our study included 20 patients (40 eyes) with MacTel 2, and age-matched and sex-matched 18 subjects (36 eyes) in the control group. Fundus color photographs, fundus autofluorescence, fundus fluorescein angiography, spectral-domain optical coherence tomography and OCTA were performed. Foveal vascular density and parafoveal vascular density (PFVD), and foveal retinal thickness and parafoveal retinal thickness, choroidal thickness (CT) and retinal ganglion cell–inner plexiform layer (GCIPL) were compared between MacTel 2 patients and normal age-matched controls. Results The retinal whole vascular density and PFVD of the deep plexus were significantly lower in patients with MacTel 2 than that of the control group (56.93% vs. 58.54%, p = 0.003; and 60.38% vs. 61.66%, p = 0.045). The foveal avascular zone (FAZ) of the deep plexus was significantly enlarged in patients with MacTel 2 than that of the control group (0.44 vs. 0.36, p = 0.009). There was a positive and statistically significant correlation between the FAZ of the superficial and deep plexus and CT in patients with MacTel 2. There was a positive and statistically significant correlation between retinal whole, parafoveal temporal quadrant vascular density of the superficial and deep plexus and GCIPL thickness in patients with MacTel 2. Conclusions Our study demonstrated that important retinal vascular density and FAZ changes in MacTel 2 occur in the deep capillary plexus of the retina.
关键词： Macular telangiectasia type 2,Vascular density,Choroidal thickness,Retinal ganglion cell–inner plexiform layer,Optical coherence tomography angiography
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow, Poland (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - A novel method to explore intrarenal arterial tree using micro-CT
摘要： The minimally invasive approach for renal surgeries, among others, requires preoperative determination of intrarenal arteries. Their proper identification based on standard preoperative CT images is still not a fully solved problem. Therefore, we decided to resolve this issue by providing a tree topology model using post-mortem kidneys. The number of vessels that compose intrarenal tree is so large, that it cannot by analyzed manually without the aid of image processing techniques. So that, the vessels has to be first depicted using an imaging technique that enables to provide superior resolution in comparison to standard CT scan. In this paper, we present a research on various injection materials enabling to fill the vascular beds in order to scan them using micro-CT and further reconstruct as a 3D model. The evaluated materials were chosen so that they are widely available and affordable. We compare them in terms of their ability to absorb ionizing radiation and penetrate vascular beds (density, viscosity), homogeneity, solidification rate, resistance to solvents and durability. We also present the technique of injecting kidney arteries with the use of the selected material - two-part epoxy adhesive with 10% iodine. In contrast to standard corrosive endocast preparation, in our case there is no need to remove soft parenchymal tissue which takes about two weeks using corrosive materials such as strong acids and bases. The proposed filling material enables to enhance vascular tree to such extend that micro-CT scans of the whole kidneys can be performed. This enables instantaneous substance injection and imaging without permanently destroying the soft tissue material. This approach can be used in various scenarios in which a filling material with the ability to increase radiation absorption is required and there is a need to maintain the integrity of the structure. To the best of our knowledge, this is the first such attempt. The obtained vascular trees by the means of micro-CT confirm the validity of the presented approach.
关键词： cast,micro-CT,3D vascular tree,minimally invasive surgery,contrast agents,ability to absorb ionizing radiation,kidney surgery,injection materials,kidney
更新于2025-09-23 15:23:52
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Comparison of fluorescein angiographic findings in type 1 and type 2 retinopathy of prematurity with intravitreal bevacizumab monotherapy and spontaneous regression
摘要： Purpose To investigate the extent of vascularization of the peripheral retina and vascular development patterns in patients with type 1 retinopathy of prematurity (ROP) treated with intravitreal injection of bevacizumab (IVB) and compare fluorescein angiography (FA) findings of them to those seen in patients with type 2 ROP who have recovered spontaneously. Methods Between May 2014 and September 2016, patients with type 1 ROP who had a single 0.025 ml (0.625 mg) IVB were evaluated as study group. On the other hand, type 2 ROP patients with stage 2 or stage 3 ROP in zone II without plus disease on indirect ophthalmoscopy were not treated and included as a control group. The progression of ROP and vascularization of retina were evaluated by FA under sedation analgesia in all patients. Results Sixty-two eyes of 31 premature infants were included in the study: 36 eyes/18 patients were treated for type 1 ROP and 26 eyes/13 patients were followed conservatively with the diagnoses of type 2 ROP. In the last FA examination among the study group, vascular terminal was in zone II in 8 eyes/4 patients (22.22%) and in zone III in 28 eyes/14 patients (77.78%). Vascular terminal was in zone III in all eyes of the control group (100%). We noted circumferential vessels in 12 eyes/8 patients (33.3%) and 7 eyes/5 patients (26.92%) in the study and control groups, respectively. Abnormal branching was noticed in 13 eyes/7 patients (46.42%) in the control group, whereas it was not detected in the study group. Arteriovenous shunts were noted in 1 eye of a patient in the study group and in 5 eyes/4 patients in the control group. In 6 eyes/3 patients among the study group, we performed laser photocoagulation to the avascular retina because of profound vascular leakage. Conclusion Peripheral vascular abnormalities probably occur as a result of ROP itself because similar FA findings were detected both in type 1 and type 2 ROP patients with or without treatment, although significantly less in IVB-treated group. Retinal vascularization usually reaches the farthermost limits with time even though it slows down in eyes treated with IVB, indicating the importance of a longer follow-up.
关键词： Fluorescein angiography,Bevacizumab,Peripheral vascular abnormalities,Retinopathy of prematurity
更新于2025-09-23 15:23:52
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Multimodal imaging in perifoveal exudative vascular anomalous complex with co-existent diabetic retinopathy
摘要： Perifoveal exudative vascular anomalous complex (PEVAC) is a recently described macular entity, which can be overlooked or confused with other retinal pathologies. On the basis of multimodal imaging features of 15 eyes with PEVAC, Sacconi et al.1 defined a PEVAC lesion as a unilateral, isolated, perifoveal, aneurysmal abnormality, occurring in otherwise healthy individuals, having characteristic angiographic and tomographic features and typically resistant to anti-vascular endothelial growth factor (anti-VEGF) therapy. Clinically, a PEVAC lesion is associated with intra-retinal fluid, haemorrhage and/or hard exudates. Querques et al.2 reported two cases of PEVAC and described the related angiographic and optical coherence tomography (OCT) features. In particular, there were no features of arterial hypertension, diabetes, or any other systemic or local vasculopathy, or signs of age-related macular degeneration. Multimodal imaging, in particular OCT-angiography along with OCT, fluorescein angiography and indocyanine angiography, have been used to provide a better understanding of the pathophysiological mechanisms of PEVAC. The purpose of this case report is to describe the imaging findings of a PEVAC lesion in a patient who had features of diabetic retinopathy.
关键词： aneurysm,perifoveal exudative vascular anomalous complex,diabetic retinopathy
更新于2025-09-23 15:22:29
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Effect of Anti-vascular Endothelial Growth Factor Antibody on the Survival of Cultured Retinal Ganglion Cells
摘要： Purpose: To investigate the effects of anti-vascular endothelial growth factor (VEGF) antibody on the survival of retinal ganglion cell (RGC)-5 cells differentiated with staurosporine under oxidative stress. Methods: We used real-time polymerase chain reaction and Western blot to confirm the expression of VEGF, VEGF receptor (VEGFR)-1 and VEGFR-2 in RGC-5 cells differentiated with staurosporine for 6 hours. The differentiated RGC-5 cells were treated with 800 μM hydrogen peroxide (H2O2) for 24 hours to induce oxidative stress. Then, the survival rate of RGC-5 was confirmed by lactate dehydrogenase assay at each concentration (0, 0.01, 0.1, and 1 mg) using bevacizumab as the anti-VEGF antibody. The expression of VEGF, VEGFR-1, and VEGFR-2 was confirmed using real-time polymerase chain reaction. Results: VEGF, VEGFR-1, and VEGFR-2 were all expressed in differentiated RGC-5 cells. When RGC-5 cells were simultaneously treated with bevacizumab and 800 μM H2O2, survival of RGC-5 decreased with bevacizumab concentration. VEGF expression in RGC-5 cells increased with increasing concentration of bevacizumab. Similar patterns were observed for VEGFR-1 and VEGFR-2, but the degree of increase was smaller than that for VEGF. Conclusions: When bevacizumab was administered to differentiated RGC-5 cells, the cell damage caused by oxidative stress increased. Therefore, given these in vitro study results, caution should be exercised with bevacizumab treatment.
关键词： Oxidative stress,RGC-5,Retinal ganglion cell,Anti-vascular endothelial growth factor,Bevacizumab
更新于2025-09-23 15:22:29
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In Vivo 3D Imaging of Retinal Neovascularization Using Multimodal Photoacoustic Microscopy and Optical Coherence Tomography Imaging
摘要： The pathological process of neovascularization of the retina plays a critical role in causing vision loss in several diseases, including diabetes, retinal vein occlusion, and sickle cell disease. Retinal neovascularization can lead to vitreous hemorrhage and retinal detachment, yet the pathological process of neovascularization is a complex phenomenon under active investigation. Understanding and monitoring retinal neovascularization is critically important in clinical ophthalmology. This study describes a novel multimodal ocular imaging system which combines photoacoustic microscopy (PAM) and a spectral domain optical coherence tomography (SD-OCT) to improve the visualization of retinal neovascularization (RNV), their depth, and the surrounding anatomy in living rabbits. RNV was induced in New Zealand rabbits by intravitreal injection of vascular endothelial growth factor (VEGF). The retinal vasculature before and after injection at various times was monitored and evaluated using multimodal imaging including color fundus photography, fluorescein angiography (FA), OCT, and PAM. In vivo experiments demonstrate that PAM imaging distinctly characterized the location as well as the morphology of individual RNV with high contrast at a safe laser energy of 80 nJ. SD-OCT was used to identify a cross-sectional structure of RNV. In addition, dynamic changes in the retinal morphology and retinal neovascularization were observed at day 4, 5, 6, 7, 9, 11, 14, 28, and day 35 after VEGF injection. PAM demonstrated high-resolution optical absorption of hemoglobin and vascular imaging of the retina and choroid with increased depth of penetration. With the current multimodal imaging system, RNV can be easily visualized in both 2D and 3D angiography. This multimodal ocular imaging system provides improved characterization of the microvasculature in a safe manner in larger rabbit eyes.
关键词： PAM,VEGF,multimodal imaging,optical coherence tomography,photoacoustic microscopy,retinal neovascularization,vascular endothelial growth factor,OCT
更新于2025-09-23 15:22:29
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Arterial Stiffness Assessment by Shear Wave Elastography and Ultrafast Pulse Wave Imaging: Comparison with Reference Techniques in Normotensives and Hypertensives
摘要： Shear wave elastography and ultrafast imaging of the carotid artery pulse wave were performed in 27 normotensive participants and 29 age- and sex-matched patients with essential hypertension, and compared with reference techniques: carotid–femoral pulse wave velocity (cfPWV) determined via arterial tonometry and carotid stiffness (carPWV) determined via echotracking. Shear wave speed in the carotid anterior (a-SWS) and posterior (p-SWS) walls were assessed throughout the cardiac cycle. Ultrafast PWV was measured in early systole (ufPWV-FW) and in end-systole (dicrotic notch, ufPWV-DN). Shear wave speed in the carotid anterior appeared to be the best candidate to evaluate arterial stiffness from ultrafast imaging. In univariate analysis, a-SWS was associated with carPWV (r = 0.56, p = 0.003) and carotid-to-femoral PWV (r = 0.66, p < 0.001). In multivariate analysis, a-SWS was independently associated with age (R2 = 0.14, p = 0.02) and blood pressure (R2 = 0.21, p = 0.004). Moreover, a-SWS increased with blood pressure throughout the cardiac cycle and did not differ between normotensive participants and patients with essential hypertension when compared at similar blood pressures.
关键词： Hypertension,Vascular ultrasound,Arterial stiffness,Pulse wave velocity,Shear wave elastography,Ultrafast imaging,Echotracking
更新于2025-09-23 15:22:29