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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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Special issue – Non-invasive vascular imaging
摘要： This special issue focusses on advances in non-invasive vascular imaging with some outstanding articles on cutting-edge imaging technologies and their clinical use. For many years, invasive catheter angiography with its attendant risks was the only method to obtain more detailed information on the vasculature than plain radiographs could provide, although only the outline of the lumen is visualised directly. Indeed, the risks of invasive angiography are such that they have had to be factored into risk assessment prior to embarking on imaging investigation. For example, the landmark NASCET trial of carotid endarterectomy was reported in terms of the number needed to both investigate and treat to provide bene?t in the secondary prevention of stroke since the investigation itself (invasive carotid arteriography) as well as the proposed surgical intervention could both cause precisely the morbidity/mortality that the strategy was intending to avoid, i.e., stroke. As such, a shift to non-invasive carotid imaging in this scenario if equally accurate would mean a lower number to treat for the same bene?t as the potential morbidity/mortality simply associated with investigation had been negated.
关键词： Non-invasive vascular imaging,angiography,CT,ultrasound,MRI
更新于2025-09-10 09:29:36
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Optical Coherence Tomography and the Development of Antiangiogenic Therapies in Neovascular Age-Related Macular Degeneration
摘要： To explain the pivotal role optical coherence tomography (OCT) imaging had in the development of antiangiogenic therapies for the treatment of neovascular age-related macular degeneration (nvAMD). A historical literature review was combined with personal perspectives from the introduction of OCT imaging and the early clinical use of vascular endothelial growth factor (VEGF) inhibitors. At the time that OCT emerged, the gold standard for imaging of nvAMD was fluorescein angiography (FA), a time-consuming, dye-based, invasive technique that provided en face images of the retina and was used to characterize leakage, perfusion status, and the types of macular neovascularization (MNV). In comparison, OCT imaging was a fast, safe, noninvasive technique that complemented FA imaging by providing cross-sectional images of the macula. OCT was able to visualize and quantify the macular fluid that was associated with the presence of excess VEGF, which was identified by intraretinal fluid, subretinal fluid, and fluid under the retinal pigment epithelium (RPE). Clinicians quickly appreciated the benefits of OCT imaging for following macular fluid after anti-VEGF therapy. By observing the qualitative and quantitative changes in macular fluid depicted by OCT imaging, clinicians were empowered to compare anti-VEGF drugs and move from fixed-dosing regimens to patient-specific dosing strategies requiring fewer injections. Optical coherence tomography imaging was adopted as a VEGF-meter, a method to detect excess VEGF, and evolved to become the gold standard imaging strategy for diagnosing nvAMD, assessing treatment responses to anti-VEGF drugs, deciding when to re-treat, and evaluating disease progression.
关键词： neovascularization,anti-vascular endothelial growth factor,exudation,optical coherence tomography,antiangiogenesis
更新于2025-09-10 09:29:36
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Retinal vascular tortuosity assessment: inter-intra expert analysis and correlation with computational measurements
摘要： Background: The retinal vascular tortuosity can be a potential indicator of relevant vascular and non-vascular diseases. However, the lack of a precise and standard guide for the tortuosity evaluation hinders its use for diagnostic and treatment purposes. This work aims to advance in the standardization of the retinal vascular tortuosity as a clinical biomarker with diagnostic potential, allowing, thereby, the validation of objective computational measurements on the basis of the entire spectrum of the expert knowledge. Methods: This paper describes a multi-expert validation process of the computational vascular tortuosity measurements of reference. A group of five experts, covering the different clinical profiles of an ophthalmological service, and a four-grade scale from non-tortuous to severe tortuosity as well as non-tortuous / tortuous and asymptomatic / symptomatic binary classifications are considered for the analysis of the the multi-expert validation procedure. The specialists rating process comprises two rounds involving all the experts and a joint round to establish consensual rates. The expert agreement is analyzed throughout the rating procedure and, then, the consensual rates are set as the reference to validate the prognostic performance of four computational tortuosity metrics of reference. Results: The Kappa indexes for the intra-rater agreement analysis were obtained between 0.35 and 0.83 whereas for the inter-rater agreement in the asymptomatic / symptomatic classification were between 0.22 and 0.76. The Area Under the Curve (AUC) for each expert against the consensual rates were placed between 0.61 and 0.83 whereas the prognostic performance of the best objective tortuosity metric was 0.80. Conclusions: There is a high inter and intra-rater variability, especially for the case of the four grade scale. The prognostic performance of the tortuosity measurements is close to the experts’ performance, especially for Grisan measurement. However, there is a gap between the automatic effectiveness and the expert perception given the lack of clinical criteria in the computational measurements.
关键词： Vascular tortuosity,Retinal circulation,Fundus images,Image analysis,Computer-aided diagnosis
更新于2025-09-10 09:29:36
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A Handheld Real-Time Photoacoustic Imaging System for Animal Neurological Disease Models: From Simulation to Realization
摘要： This article provides a guide to design and build a handheld, real-time photoacoustic (PA) imaging system from simulation to realization for animal neurological disease models. A pulsed laser and array-based ultrasound (US) platform were utilized to develop the system for evaluating vascular functions in rats with focal ischemia or subcutaneous tumors. To optimize the laser light delivery, ?nite element (FE)-based simulation models were developed to provide information regarding light propagation and PA wave generation in soft tissues. Besides, simulations were also conducted to evaluate the ideal imaging resolution of the US system. As a result, a PA C-scan image of a designed phantom in 1% Lipofundin was reconstructed with depth information. Performance of the handheld PA system was tested in an animal ischemia model, which revealed that cerebral blood volume (CBV) changes at the cortical surface could be monitored immediately after ischemia induction. Another experiment on subcutaneous tumors showed the anomalous distribution of the total hemoglobin concentration (HbT) and oxygen saturation (SO2), while 3D and maximum intensity projection (MIP) PA images of the subcutaneous tumors are also presented in this article. Overall, this system shows promise for monitoring disease progression in vascular functional impairments.
关键词： tumor,vascular function,stroke,photoacoustic imaging,neurological disease
更新于2025-09-10 09:29:36
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The potent small molecule integrin antagonist THR-687 is a promising next-generation therapy for retinal vascular disorders
摘要： Integrins are associated with various eye diseases such as diabetic retinopathy (DR) and wet age-related macular degeneration (AMD) and implicated in main pathologic disease hallmarks like neovascularization, inflammation, fibrosis and vascular leakage. Targeting integrins has the potential to attenuate these vision-threatening processes, independent of anti-vascular endothelial growth factor (VEGF) responsiveness. The current investigation characterized THR-687 as a novel pan RGD (arginylglycylaspartic acid) integrin receptor antagonist able to compete for binding with the natural ligand with nanomolar potency (e.g. αvβ3 (IC50 of 4.4±2.7 nM), αvβ5 (IC50 of 1.3±0.5 nM) and α5β1 (IC50 of 6.8±3.2 nM). THR-687 prevented the migration of human umbilical vein endothelial cells (HUVECs) into a cell-free area (IC50 of 258±113 nM) as well as vessel sprouting in an ex vivo mouse choroidal explant model (IC50 of 236±173 nM), and was able to induce the regression of pre-existing vascular sprouts. Moreover, combined intravitreal and intraperitoneal administration of THR-687 potently inhibited VEGF-induced leakage in the mouse retina. In addition, THR-687 injected intravitreally at 3 different dose levels (0.45 mg, 2.25 mg or 4.5 mg/eye) potently inhibited neovascularization-induced leakage in the cynomolgus laser-induced choroidal neovascularization (CNV) model. These data suggest that THR-687 is a promising drug candidate for the treatment of vision-threatening retinal vascular eye diseases such as DR and wet AMD.
关键词： diabetic retinopathy,retinal vascular disorders,angiogenesis,THR-687,Integrin antagonist,wet age-related macular degeneration,vascular leakage
更新于2025-09-09 09:28:46
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Role of OCT Angiography in the Detection of Retinal Vascular and Macular Abnormalities in Subjects with Asteroid Hyalosis
摘要： Purpose: To study the role of Optical coherence tomography (OCT) Angiography (OCTA) in detecting retinal vascular and macular abnormalities as compared to Fundus Fluorescein Angiography (FFA) in subjects with Asteroid hyalosis (AH). Methods: In a prospective study, patients with AH underwent OCTA and FFA. AH graded as Grade 1 in 8 (optic disc, second order vessels visible), Grade 2 in 4 (optic disc, first-order vessels visible), Grade 3 in 11 (hazy view of optic disc) and Grade 4 (no view of fundus) in 2 eyes. Results: A total of 20 patients (25 eyes) with AH were included. In comparison to FFA, OCTA was able to similarly detect Diabetic Retinopathy changes such as Neovascularization, microaneurysms, capillary dropout, and foveal avascular zone extent in vascular occlusion in all grades of AH. Conclusion: OCTA, a noninvasive imaging tool, could detect various retinal vascular and macular abnormalities in patients with all grades of AH in comparison to FFA.
关键词： Fundus Fluorescein Angiography (FFA),macular abnormalities,OCT angiography (OCTA),asteroid hyalosis,retinal vascular abnormalities
更新于2025-09-09 09:28:46
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Imaging of Peripheral Vascular Malformations: Imaging Modalities Mini Review
摘要： Currently the major aim inperipheral vascular malformation (PVM) diagnosis, crucial for subsequent management and treatment, is to identify its hemodynamic characteristics. Other significant features that should be specified by a radiologist is the exact location of the anomaly, its size and morphology. Until recently the diagnostic methods available for comprehensive evaluation of malformations have been rather limited. Moreover, they were often associated with the necessity of exposing the patient to X-ray radiation and with invasive procedures, asfor example in angiography. The development of imaging techniques used in the diagnosis of vascular abnormalities in recent years, especially magnetic resonance imaging (MRI), has largely contributed to improved diagnostic value of the tests. In this article we review the currently available imaging modalities with particular consideration of magnetic resonance imaging and its capability to distinguish between high-flow and low-flow malformations.
关键词： Imaging,Low-flow and high-flow malformations,Magnetic resonance,Vascular malformation
更新于2025-09-09 09:28:46
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Effect of increasing heart rate on finger photoplethysmography fitness index (PPGF) in subjects with implanted cardiac pacemakers
摘要： Finger photoplethysmography (PPG) is a noninvasive method that measures blood volume changes in the finger. The PPG fitness index (PPGF) has been proposed as an index of vascular risk and vascular aging. The objectives of the study were to determine the effects of heart rate (HR) on the PPGF and to determine whether PPGF is influenced by blood pressure (BP) changes. Twenty subjects (78±8 years, 3 female) with permanent cardiac pacemakers or cardioverter defibrillators were prospectively recruited. HR was changed by pacing, in a random order from 60 to 100 bpm and in 10 bpm increments. At each paced HR, the PPGF was derived from a finger photoplethysmogram. Cardiac output (CO), stroke volume (SV) and total peripheral resistance (TPR) were derived from the finger arterial pressure waveform. Brachial blood pressure (BP) was measured by the oscillometric method. This study found that as HR was increased from 60 to 100 bpm, brachial diastolic BP, brachial mean BP and CO were significantly increased (p<0.01), whilst the PPGF and SV were significantly decreased (p<0.001). The effects of HR on the PPGF were influenced by BP, with a decreasing HR effect on the PPGF that resulted from a higher BP. In conclusion, HR was a significant confounder for PPGF and it must be taken into account in analyses of PPGF, when there are large changes or differences in the HR. The magnitude of this effect was BP dependent.
关键词： blood pressure,vascular aging,photoplethysmography,heart rate,PPG fitness index
更新于2025-09-09 09:28:46
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Analysis of Foveal Microvascular Structures Using Optical Coherence Tomography Angiography in Age-stratified Healthy Koreans
摘要： Purpose: To evaluate foveal avascular zone (FAZ) microvascular structural changes in healthy Korean subjects stratified by age using optical coherence tomography angiography (OCTA). Methods: Eighty eyes of 43 healthy volunteer subjects who had 20/20 or better best corrected visual acuity without other ocular or systemic disease except vitreous floaters and dry eye syndrome were enrolled and stratified by age group. To measure FAZ size and vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP), OCTA (DRI OCT Triton, Swept Source OCT, Topcon, Tokyo, Japan) scans were performed over fovea-centered 3 × 3 mm2 regions, and then compared with central macular thickness (CMT) and subfoveal choroidal thickness. Results: Mean age of the participants was 46.4 ± 16.1 (20–78). The SCP and DCP FAZ sizes were 0.32 ± 0.11 mm2 and 0.41 ± 0.14 mm2, respectively. There was a significant difference by age group (p < 0.001, p < 0.001), respectively. The FAZ VD for SCP and DCP was 28.96 ± 3.05% and 33.15 ± 3.64%, respectively. There was no difference between age groups (p = 0.118, p = 0.637). Univariate and multiple linear regression analysis showed that the FAZ size of SCP and DCP was significantly correlated with age (p = 0.039, p = 0.002) and CMT (p = 0.007, p = 0.013), respectively. The SCP and DCP FAZ size were positively correlated with age (R2 = 0.279, p < 0.001, R2 = 0.344, p < 0.001), and negatively correlated with CMT (R2 = 0.354, p < 0.001, R2 = 0.285, p < 0.001), respectively. Conclusions: The FAZ size of SCP and DCP increased with age and were negatively correlated with CMT. These results suggest that consideration of age and CMT is important when performing the clinical evaluation of FAZ size in healthy subjects.
关键词： Healthy subjects,Foveal avascular zone,Vascular density,Age,Optical coherence tomography angiography
更新于2025-09-09 09:28:46
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A single-arm, investigator-initiated study of the efficacy, safety, and tolerability of intravitreal aflibercept injection in subjects with exudative age-related macular degeneration previously treated with ranibizumab or bevacizumab (ASSESS study): 12-month analysis
摘要： In subjects with active exudative age-related macular degeneration, treating with a fixed intravitreal aflibercept injection dosing regimen for 12 months demonstrated improved anatomic and vision endpoints from baseline. Purpose: Switching therapies in neovascular age-related macular degeneration (AMD) may offer an advantage for some patients. This study evaluates the efficacy of intravitreal aflibercept injection (IAI) in subjects previously treated with ranibizumab and/or bevacizumab. Methods: Subjects (n=26) were given monthly 2 mg of IAI for 3 months, followed by 2 mg once in every 2 months for up to 12 months. The mean absolute change from baseline in central subfield thickness (CST) measured by optical coherence tomography and the mean change from baseline in best-corrected visual acuity (BCVA) early treatment in diabetic retinopathy study (ETDRS) letter score were obtained. Additionally, the percentage of subjects who gained or lost $15 letters of vision and the percentage of subjects who are 20/40 or better or 20/200 or worse were evaluated. Results: There was a mean decrease in CST of ?50.3 μm (P,0.001) and a mean increase in ETDRS BCVA of +9.2 letters (P,0.001). Twenty-seven percent of subjects experienced a $15-letter improvement in visual acuity, and no subject lost $3 lines of vision from baseline. Fifty percent of subjects were 20/40 or better, and 11.5% of subjects were 20/200 or worse at month 12. Conclusion: Fixed IAI dosing regimen for 12 months demonstrated improved anatomic and vision endpoints in subjects with active exudative AMD.
关键词： bevacizumab,aflibercept,vascular endothelial growth factors,ranibizumab,age-related macular degeneration
更新于2025-09-09 09:28:46