Luminal Area Research Articles

Nature‐Inspired Pressure Interactive Alternating Current Electroluminescent for Orientation Indication, Visual Sensing, and Remote Monitoring

AbstractMost current visual pressure sensing devices are greatly limited by less integrated functions. To address this issue, a multi‐dimensional pressure interactive visual monitoring device is proposed based on the temperature and humidity adaptive hydrogel. Specifically, this device is composed of a buffer grid layer that divides it into pressure sensing and luminous display areas. With a double network structure incorporated with a LiBr liquid, the pressure sensing area demonstrates great deformability, resilience, and self‐absorption. In a dynamic mode, the best pressure can be detected at high humidity and low temperature, displaying a range of up to 45 N and offering feedback at a minimum load of 0.25 N. Importantly, the performance of the device remains excellent even after the dynamic compression repeating over 1300 cycles. In static mode, MPI‐ACEL achieves a delay time of up to 390 min. Finally, it is anticipated that this multifunctional device will provide a new, flexible, and effective scheme for visual pressure sensing, environmental adaptive directional indication, and multi‐dimensional remote monitoring.

Retinal and Choroidal Changes Following Implantable Collamer Lens V4c Implantation in High Myopia Patients-A 1-Year Follow-Up Study.

This prospective study aimed to evaluate the impact of Visian Implantable Collamer Lens (ICL) V4c implantation on retinal and choroidal morphology in patients with high myopia. A total of 97 eyes from 52 high myopic patients who underwent ICL V4c implantation were followed up for 12 months. Preoperative and postoperative evaluations included comprehensive ophthalmic assessments and enhanced depth imaging optical coherence tomography (EDI-OCT) to analyze changes in central retinal thickness (CRT), retinal volume (CRV), choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), and choroidal vascular index (CVI). Repeated measures mixed-effects models were used for comparing pre- and postoperative measurement variables and exploring relationships among age, axial length (AL), spherical equivalent refraction (SER), and postoperative retinal and choroidal changes, with statistical significance set at p < 0.05. Follow-up assessments were conducted at various time points, with participation rates ranging from 21% to 98%. Baseline characteristics showed a median age of 26.7 years, -10.14 diopters of SER, and an AL of 27.44 mm. Throughout the 12-month follow-up, CRT and 3.0 mm CRV consistently increased compared to the baseline, with statistically significant rises observed at postoperative day 1, week 1, and month 12. Most ChT measurements, including subfoveal ChT, declined over the 12 months, except at postoperative 6 months. Horizontal and vertical TCA and LA values significantly increased throughout the follow-up, except for month 6. After surgery, both horizontal and vertical CVI parameters exhibited an increase compared to the baseline, with some changes reaching statistical significance. Correlation analysis performed by repeated measures mixed-effects models showed that no relationship was found between age, AL, and SER and changes in postoperative retinal parameters and CVI parameters. However, postoperative changes in ChT and choroidal area parameters showed a negative correlation with AL and a positive correlation with SER. Our research demonstrated that ICL V4c implantation resulted in noteworthy alterations in retinal and choroidal morphology over a 1-year follow-up period. Moreover, in patients with high myopia, individuals with longer AL and higher degrees of myopia exhibited more pronounced postoperative changes in the choroid and retina. Further studies with extended follow-up durations are necessary to comprehensively understand the long-term effects of ICL implantation on retinal and choroidal morphology and function.

Choroidal morphology and microvascular structure in eyes of patients with idiopathic normal pressure hydrocephalus before and after ventriculo-peritoneal shunt surgery

The present study aims to investigate the choroidal morphology and microvascular structure in eyes of patients with idiopathic normal pressure hydrocephalus (iNPH) compared with the eyes of healthy age-matched individuals, and to assess the choroidal structure in eyes of iNPH patients before and after shunt surgery using Optical Coherence Tomography (OCT). The primary objective was to assess the choroidal morphology in eyes of iNPH patients before and after ventriculo-peritoneal (VP) surgery compared to age and sex-matched healthy individuals. The secondary objective was to compare the choroidal morphology of iNPH patients before and after a mean of 56 days from shunt surgery. Eighteen consecutive patients diagnosed with iNPH and 18 healthy controls were prospectively recruited between November 2021 and October 2022. Spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) was conducted before and within 4 months after shunt surgery. Images were binarized using the ImageJ software, and the choroidal vascular index (CVI) was calculated. Sub-foveal choroidal thickness (SFCT), total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were significantly increased in iNPH patients before surgery compared to the control group (p < 0.05). SFCT, TCA, and SCA were significantly increased in iNPH patients after surgery compared to the control group (p < 0.05). There were no differences in the CVI between iNPH patients and controls. No statistical differences in the choroidal structure were observed before and after VP shunt surgery (p > 0.05). In conclusion, the choroid was thicker in iNPH patients before and after VP shunt compared to age-matched healthy individuals. However, there were no difference in the choroidal microstructure in the eyes of iNPH patients before and after a mean of 3 months from VP shunt surgery.

Histomic and transcriptomic features of MRI-visible and invisible clinically significant prostate cancers are associated with prognosis.

Magnetic resonance imaging (MRI) is increasingly used to triage patients for prostate biopsy. However, 9% to 24% of clinically significant (cs) prostate cancers (PCas) are not visible in MRI. We aimed to identify histomic and transcriptomic determinants of MRI visibility and their association to metastasis, and PCa-specific death (PCSD). We studied 45 radical prostatectomy-treated patients with csPCa (grade group [GG]2-3), including 30 with MRI-visible and 15 with MRI-invisible lesions, and 18 men without PCa. First, histological composition was quantified. Next, transcriptomic profiling was performed using NanoString technology. MRI visibility-associated differentially expressed genes (DEGs) and Reactome pathways were identified. MRI visibility was classified using publicly available genes in MSK-IMPACT and Decipher, Oncotype DX, and Prolaris. Finally, DEGs and clinical parameters were used to classify metastasis and PCSD in an external cohort, which included 76 patients with metastatic GG2-4 PCa, and 84 baseline-matched controls without progression. Luminal area was lower in MRI-visible than invisible lesions and low luminal area was associated with short metastasis-free and PCa-specific survival. We identified 67 DEGs, eight of which were associated with survival. Cell division, inflammation and transcriptional regulation pathways were upregulated in MRI-visible csPCas. Genes in Decipher, Oncotype DX and MSK-IMPACT performed well in classifying MRI visibility (AUC = 0.86-0.94). DEGs improved classification of metastasis (AUC = 0.69) and PCSD (AUC = 0.68) over clinical parameters. Our data reveals that MRI-visible csPCas harbor more aggressive histomic and transcriptomic features than MRI-invisible csPCas. Thus, targeted biopsy of visible lesions may be sufficient for risk stratification in patients with a positive MRI.

Effects of hydroxychloroquine therapy on choroidal volume and choroidal vascularity index.

To determine changes in choroidal volume (CV) and choroidal vascularity index (CVI) in patients on hydroxychloroquine (HCQ) therapy. Retrospective analysis of patients on HCQ therapy. CV and CVI were assessed below the central foveal region on spectral-domain optical coherence tomography using an automatic denoising and localization algorithm. CV and CVI were compared with age-matched controls. Regression analyses were performed to generate associations between CV and CVI with demographics and HCQ treatment parameters. Associations were assessed using a generalized estimating equation model adjusted for intra-subject inter-eye correlations. A total of 137 adult patients (23 males and 114 females) were included. Mean age was 45.6 ± 13.7 years and most patients identified as Caucasian (79%). Total duration of HCQ therapy ranged from 3 months to 20 years. Daily HCQ intake varied from 150-600 mg (mean = 304 mg), while cumulative doses ranged from 18-2,800 g. At presentation, the median CV was 0.51 (IQR:0.356-0.747) mm, and median CVI was 0.559 (IQR:0.528-0.578). Increased cumulative HCQ dose was associated with decreased CV (p = 0.006). Compared to age-matched controls, CV, CVI, and luminal area were significantly lower in the study group (p = 0.0003, 0.0001, and 0.0002). In this study, we present a novel analysis of key biomarkers which predate the occurrence of HCQ retinopathy. Choroidal volume and vascularity index are significantly reduced in patients on HCQ therapy, especially at higher cumulative doses. These findings suggest new tools to guide medical decision-making for patients receiving HCQ therapy for rheumatologic diseases.

Differential predictability for high-risk plaque characteristics between fractional flow reserve and instantaneous wave-free ratio

To evaluate the differential associations of high-risk plaque characteristics (HRPC) with resting or hyperemic physiologic indexes (instantaneous wave-free ratio [iFR] or fractional flow reserve [FFR]), a total of 214 vessels from 127 patients with stable angina or acute coronary syndrome who underwent coronary computed tomography angiography (CCTA) and invasive physiologic assessment were investigated. HPRC were classified into quantitative (minimal luminal area < 4 mm2 or plaque burden ≥ 70%) and qualitative features (low attenuation plaque, positive remodeling, napkin ring sign, or spotty calcification). Vessels with FFR ≤ 0.80 or iFR ≤ 0.89 had significantly higher proportions of HRPC than those with FFR > 0.80 or iFR > 0.89, respectively. FFR was independently associated with both quantitative and qualitative HRPC, but iFR was only associated with quantitative HRPC. Both FFR and iFR were significantly associated with the presence of ≥ 3 HRPC, and FFR demonstrated higher discrimination ability than iFR (AUC 0.703 vs. 0.648, P = 0.045), which was predominantly driven by greater discriminating ability of FFR for quantitative HRPC (AUC 0.832 vs. 0.744, P = 0.005). In conclusion, both FFR and iFR were significantly associated with CCTA-derived HRPC. Compared with iFR, however, FFR was independently associated with the presence of qualitative HRPC and showed a higher predictive ability for the presence of ≥ 3 HRPC.

Choroidal vascularity index and submacular choroidal thickness in patients with Behçet disease assessed with enhanced-depth OCT

ObjectifExaminer les changements qui se produisent dans la choroïde grâce à l'indice de vascularisation choroïdienne (IVC) et à l’épaisseur choroïdienne (EC) en présence de maladie de Behçet (MB) avec ou sans atteinte oculaire. MéthodesOnt été inclus 68 patients présentant une MB oculaire, 40 patients présentant une MB sans atteinte oculaire et 40 sujets témoins en bonne santé. L'EC a été mesurée par tomographie par cohérence optique à l'imagerie à profondeur améliorée (EDI-OCT, pour enhanced-depth imaging optical coherence tomography; EC sous-fovéale à 1000 μm, EC nasale à 1000 μm et EC temporale). L'IVC (%) a été calculé en divisant l'aire luminale par l'aire choroïdienne sous-fovéale totale. RésultatsL'EC moyenne sous-fovéale (297 ± 68 µm), nasale (261 ± 66 µm) et temporale (272 ± 68 µm) dans les yeux présentant une MB oculaire et l'EC moyenne sous-fovéale (286 ± 31 µm), nasale (266 ± 29 µm) et temporale (269 ± 32 µm) dans les yeux présentant une MB sans atteinte oculaire étaient significativement moindres, comparativement aux mêmes zones chez les témoins en bonne santé (333 ± 69, 301 ± 75 et 312 ± 70 µm, respectivement). On a réalisé une autre analyse de sous-groupes (MB oculaire active, MB oculaire non active, MB sans atteinte oculaire et groupe témoin) ainsi que des comparaisons par paires. Or, l'IVC était significativement moins élevé dans les groupes MB oculaire active (64,3 ± 3,1) et MB oculaire non active (64,2 ± 4,5), comparativement au groupe témoin (67,2 ± 3,6; p = 0,026 et p < 0,001, respectivement). On n'a pas observé de différence significative entre le groupe MB sans atteinte oculaire (65,9 ± 3,4) et le groupe témoin (67,2 ± 3,6) au chapitre de l'IVC (p > 0,05). ConclusionsLa baisse de l'IVC en présence de MB oculaire laisse supposer que l'uvéite perturbe le système vasculaire choroïdien et la perfusion sanguine, tandis que l'inflammation générale dans la MB sans atteinte oculaire n'a aucun effet à cet égard. Qui plus est, c'est le caractère chronique de l'uvéite qui a des effets sur la choroïde plutôt que l'activité de la maladie en soi. La mesure de l'EC et de l'IVC représente peut-être un nouveau biomarqueur fiable du pronostic, qui permet d’évaluer le système vasculaire choroïdien et de surveiller la progression de la maladie en présence de MB oculaire grâce à l'EDI-OCT, une modalité d'imagerie non invasive. Cela dit, l'IVC ne semble pas constituer un biomarqueur permettant la surveillance de l'activité de la maladie ou de l'efficacité du traitement.

The COBRA II (COmplex Bifurcation lesions: RAndomized comparison of a fully bioresorbable modified-T stenting strategy versus bifurcation reconstruction with a dedicated self-expanding stent in combination with bioresorbable scaffolds) study: Final 5-year follow-up

BackgroundIn order to advocate further research in bioresorbable scaffold (BVS) technology we report the final 5-year outcomes of the COBRA II study, the only randomized controlled trial (RCT) performed to investigate the safety, feasibility, and performance of Absorb BVS (Abbott Vascular) in true coronary bifurcations. MethodsCOBRA II was a prospective single-center RCT. Fifteen patients with true coronary bifurcation lesions were randomized to bifurcation treatment with self-expanding biolimus-eluting Axxess bifurcation device (Biosensors International) combined with additional bioresorbable everolimus-eluting Absorb BVS in the bifurcation branches on (Axxess group) or to 2-stent mod-T stenting technique with Absorb BVS (mod-T group). Optical coherence tomography was performed post-procedure and at 30-months. The primary endpoint was change in minimal luminal area (MLA) on OCT from baseline to 30-months. ResultsFifteen patients with coronary bifurcation lesions were randomized to the Axxess group (n = 8) or Modified-T group (n = 7). At 30 months, MLAs were significantly smaller than post-procedure in the majority of bifurcation segments treated with BVS due to neointima formation, while MLAs in the proximal Axxess segment remained stable (primary endpoint).Five-year clinical follow-up was available for all patients. Only 1 major adverse cardiac event occurred; a patient underwent target lesion revascularization at 30 months in the Axxess group. There were no cases of cardiac death, spontaneous MI, or stent/scaffold thrombosis. ConclusionsIn this small RCT bifurcation study, BVS luminal dimensions were significantly smaller at 30 months, with acute strut discontinuities and late Intraluminal dismantling frequently observed, although acceptable clinical outcomes were noted at 5 years.

Modelling blood flow in coronary arteries: Newtonian or shear-thinning non-Newtonian rheology?

BackgroundThe combination of medical imaging and computational hemodynamics is a promising technology to diagnose/prognose coronary artery disease (CAD). However, the clinical translation of in silico hemodynamic models is still hampered by assumptions/idealizations that must be introduced in model-based strategies and that necessarily imply uncertainty. This study aims to provide a definite answer to the open question of how to properly model blood rheological properties in computational fluid dynamics (CFD) simulations of coronary hemodynamics. MethodsThe geometry of the right coronary artery (RCA) of 144 hemodynamically stable patients with different stenosis degree were reconstructed from angiography. On them, unsteady-state CFD simulations were carried out. On each reconstructed RCA two different simulation strategies were applied to account for blood rheological properties, implementing (i) a Newtonian (N) and (ii) a shear-thinning non-Newtonian (non-N) rheological model. Their impact was evaluated in terms of wall shear stress (WSS magnitude, multidirectionality, topological skeleton) and helical flow (strength, topology) profiles. Additionally, luminal surface areas (SAs) exposed to shear disturbances were identified and the co-localization of paired N and non-N SAs was quantified in terms of similarity index (SI). ResultsThe comparison between paired N vs. shear-thinning non-N simulations revealed remarkably similar profiles of WSS-based and helicity-based quantities, independent of the adopted blood rheology model and of the degree of stenosis of the vessel. Statistically, for each paired N and non-N hemodynamic quantity emerged negligible bias from Bland-Altman plots, and strong positive linear correlation (r > 0.94 for almost all the WSS-based quantities, r > 0.99 for helicity-based quantities). Moreover, a remarkable co-localization of N vs. non-N luminal SAs exposed to disturbed shear clearly emerged (SI distribution 0.95 [0.93, 0.97]). Helical flow topology resulted to be unaffected by blood rheological properties. ConclusionsThis study, performed on 288 angio-based CFD simulations on 144 RCA models presenting with different degrees of stenosis, suggests that the assumptions on blood rheology have negligible impact both on WSS and helical flow profiles associated with CAD, thus definitively answering to the question “is Newtonian assumption for blood rheology adequate in coronary hemodynamics simulations?”.

Evaluation of the effect of sodium-glucose cotransporter-2 inhibitor treatment on choroidal vascular parameters in patients with type 2 diabetes mellitus

BackgroundTo evaluate the effect of sodium-glucose cotransporter-2 inhibitor treatment on choroidal vascular parameters in patients with type 2 diabetes mellitus (T2DM). MethodsTwenty eyes of 20 patients with T2DM without diabetic retinopathy and 20 eyes of 20 age- and sex-matched patients as the control group were included in the study. The patients were evaluated using enhanced depth imaging optic coherence tomography before treatment and at the third month of treatment. The choroidal images were binarized into luminal areas (LAs) and stromal areas (SAs). The choroidal vascularity index (CVI) was defined as the ratio of the LA to the total circumscribed choroid area (TCA). ResultsThe mean age of the patients was 56.65±8.41 years. The patients’ mean disease duration was 6.65±5.72 years, the mean HbA1c level was 8.89±1.62%, and the mean body mass index was 33.13±4.84 kg/m2. The subfoveal TCA, subfoveal LA, subfoveal SA, total TCA, total LA, and total SA values ​​of the patient group were found to be significantly lower than those of the control group (p = 0.006, p = 0.003, p = 0.028, p = 0.001, p = 0.001, and p = 0.006, respectively). There was a significant increase in the subfoveal TCA, subfoveal LA, subfoveal SA, subfoveal CVI, total TCA, total LA, and total SA values ​​after empagliflozin treatment compared to before empagliflozin treatment (p = 0.005, p = 0.003, p = 0.021, p = 0.032, p < 0.001, p < 0.001, and p = 0.001 respectively). ConclusionsEmpagliflozin provides an improvement in diabetic choroidal changes through its effect on choroidal vascularity parameters.

BRDF representation in response to the build orientation in 3D-printed digital materials

Additively manufactured (AM) parts still lack a thorough understanding of their optical properties, particularly surface texture and reflectance characteristics at different viewing angles. This study examines the reflectance properties of material jetting (MJT) parts using bidirectional reflectance distribution functions (BRDFs). The visual appearance of the MJT parts was analyzed using a gonio-spectrophotometer at 328 unique incidence and viewing geometries for seven different wedge angles for build orientation (BO) from 0° to 90° at 15° intervals. The redundancy analysis (RDA) and principal component analysis (PCA) were used to study BO and to determine the prominent measurement geometries. The results indicate higher BOs resulted in more color and texture variation and rougher surfaces, with Sq 4.21 μm vertical compared to 1.42 μm for horizontal BOs. Furthermore, it affected the visual representation and parametric estimation of BRDF, where significantly lower luminance, more diffuse reflection, and less hue distribution were observed for all CMYK resins printed at higher BOs. Accordingly, vertically printed surfaces showed a wider near-to-specular luminance area than other BOs. An analysis of the bidirectional reflectance property suggests that a gonio-spectrophotometer can be embedded in the printing process and quality assurance in AM as a computationally efficient model.

First-in-Human Drug-Eluting Balloon Treatment of Vulnerable Lipid-Rich Plaques: Rationale and Design of the DEBuT-LRP Study.

Patients with non-obstructive lipid-rich plaques (LRPs) on combined intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) are at high risk for future events. Local pre-emptive percutaneous treatment of LRPs with a paclitaxel-eluting drug-coated balloon (PE-DCB) may be a novel therapeutic strategy to prevent future adverse coronary events without leaving behind permanent coronary implants. In this pilot study, we aim to investigate the safety and feasibility of pre-emptive treatment with a PE-DCB of non-culprit non-obstructive LRPs by evaluating the change in maximum lipid core burden in a 4 mm segment (maxLCBImm4) after 9 months of follow up. Therefore, patients with non-ST-segment elevation acute coronary syndrome underwent 3-vessel IVUS-NIRS after treatment of the culprit lesion to identify additional non-obstructive non-culprit LRPs, which were subsequently treated with PE-DCB sized 1:1 to the lumen. We enrolled 45 patients of whom 20 patients (44%) with a non-culprit LRP were treated with PE-DCB. After 9 months, repeat coronary angiography with IVUS-NIRS will be performed. The primary endpoint at 9 months is the change in maxLCBImm4 in PE-DCB-treated LRPs. Secondary endpoints include clinical adverse events and IVUS-derived parameters such as plaque burden and luminal area. Clinical follow-up will continue until 1 year after enrollment. In conclusion, this first-in-human study will investigate the safety and feasibility of targeted pre-emptive PE-DCB treatment of LRPs to promote stabilization of vulnerable coronary plaque at risk for developing future adverse events.

Comparison of the Choroid in Primary Open-angle and Angle-Closure Glaucoma Using Optical Coherence Tomography.

The current study highlights distinct choroidal alterations in primary open-angle and angle-closure glaucoma, underscoring the potential of choroidal vascularity index as a valuable indicator for understanding glaucoma pathogenesis. To evaluate choroidal structural changes in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) and healthy controls utilizing the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) by enhanced depth imaging optical coherence tomography (EDI-OCT). This study was cross-sectional. A total of 171 eyes of 171 subjects, comprising 69 eyes with untreated POAG, 58 eyes with untreated PACG and 44 healthy eyes, were enrolled in this study. SFCT, luminal area (LA), stromal area (SA) and total choroidal area (TCA) were measured on EDI-OCT scans. The CVI parameter is calculated as the proportion of LA to TCA. This study included 69 POAG patients with a mean age of 51.4±13.3 years, 58 PACG patients with a mean age of 57.0±7.3 years, and 44 healthy subjects with a mean age of 51.11±10.7 years. The CVI in the POAG and PACG groups was significantly lower than that in the control group (P = 0.001 and P = 0.005, respectively), however not significantly different between the two glaucoma groups (P = 1.000). POAG eyes had significantly lower LA than PACG and controls (P = 0.014 and P = 0.049, respectively), while PACG eyes had significantly greater SA than controls (P = 0.041). The CVI of POAG and PACG eyes was significantly lower than that of normal eyes. A reduced LA was observed mainly in eyes with POAG, and an increased SA was observed mainly in eyes with PACG. The role of the choroid may differ between POAG and PACG eyes.

Evaluation of peripapillary choroidal vascularity index in young smokers

Purpose: This retrospective study aimed to compare the peripapillary choroidal vascularity index (CVI) between young smokers who smoked less than 5 packs/year and non-smokers. Methods: The study included 52 smokers and 67 non-smokers, and comprehensive eye examinations were performed on all participants. Axial lengths (AL) were measured, and peripapillary enhanced depth imaging optical coherence tomography (EDI-OCT) images were obtained and evaluated using the Open Source ImageJ software. The CVI, total choroidal area (TCA), luminal area (LA), stromal area (SA), and retinal nerve fibre layer (RNFL) quadrants were compared between the two groups. Results: The mean age of the smokers was 23.76 ± 1.84 years, and for non-smokers, it was 23.98 ± 2.18 years. The mean peripapillary CVI for smokers was 0.65 ± 0.08, and for non-smokers, it was 0.67 ± 0.03. No statistically significant difference in CVI was observed between the two groups. However, statistically significant differences were found in the temporal inferior (TI), temporal superior (TS), nasal inferior (NI), and nasal superior (NS) quadrants of the RNFL between the two groups (p < 0.05). There was no correlation between the number of packs/year and CVI values in the smoking group (r = 0.031, p = 0.826). Conclusion: The study revealed no significant difference in CVI among young smokers who smoked less than 5 packs/year compared to non-smokers. However, there was a statistically significant decrease in the TI, TS, NI, and NS quadrants of the RNFL in early-age smokers.

Comparison of CT-derived Plaque Characteristic Index With CMR Perfusion for Ischemia Diagnosis in Stable CAD.

Coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) have been used to diagnose lesion-specific ischemia in patients with coronary artery disease. The aim of this study was to investigate the diagnostic performance of CCTA-derived plaque characteristic index compared with myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) derived from CMR perfusion in the assessment of lesion-specific ischemia. Between October 2020 and March 2022, consecutive patients with suspected or known coronary artery disease, who were clinically referred for invasive coronary angiography were prospectively enrolled. All participants sequentially underwent CCTA and CMR and invasive fractional flow reserve within 2 weeks. The diagnostic performance of CCTA-derived plaque characteristics, CMR perfusion-derived stress MBF, and MPR were compared. Lesions with fractional flow reserve ≤0.80 were considered to be hemodynamically significant stenosis. Nighty-two patients with 141 vessels were included in this study. Plaque length, minimum luminal area, plaque area, percent area stenosis, total atheroma volume, vessel volume, lipid-rich volume, spotty calcium, napkin-ring signs, stress MBF, and MPR in flow-limiting stenosis group were significantly different from nonflow-limiting group. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of lesion-specific ischemia diagnosis were 61.0%, 55.3%, 63.1%, 35.6%, and 79.3% for stress MBF, and 89.4%, 89.5%, 89.3%, 75.6%, 95.8% for MPR; meanwhile, 82.3%, 79.0%, 84.5%, 65.2%, and 91.6% for CCTA-derived plaque characteristic index. In our prospective study, CCTA-derived plaque characteristics and MPR derived from CMR performed well in diagnosing lesion-specific myocardial ischemia and were significantly better than stress MBF in stable coronary artery disease.

Effects of electron migration and adsorption on the suppression of negative corona discharge in nanoparticle transformer oil: experiments and simulations

SiO2 and TiO2 nanofluids (NFs for short) were prepared, and a series of DC corona discharge tests were carried out under needle-plate electrode on both NFs and base oil, using the luminous area and pulse current to characterize the negative corona discharge characteristics. The trap distribution characteristic as well as the mobilities of positive and negative ions of the two types of NFs and base oil were measured. A kind of new corona discharge simulation model was established, and the effects of shallow traps and electrons adsorbed by nanoparticles were considered in the simulation model. The corona discharge was simulated under the needle-plate electrode and the simulation results were compared with the corona discharge characteristics obtained from the tests. Furthermore, the effects of shallow trap and electron adsorbed by nanoparticles on space charge and electric field distribution as well as field ionization in transformer oil were analyzed respectively, revealing the mechanism that nanoparticles regulate the carrier migration process to suppress the negative corona discharge of transformer oil.

Short-term Effect of Strabismus Surgery on Choroidal Vasculature.

To investigate the effect of strabismus surgery on choroidal structure using the binarization method. Forty-two eyes of 27 patients who had surgery for horizontal strabismus were included in the study. Optical coherence tomography (OCT) images of the patients before the operation and at 1 day and 1 week after the operation were binarized. Total choroidal area (TCA), stromal area (SA), luminal area (LA), and choroidal vascularity index (CVI) were calculated and compared. The mean age of the patients was 16.7 ± 13.5 years; 12 were female, and 15 were male. The mean spherical equivalent was 0.125 ± 0.50 diopters (D). The mean axial length value was 23.3 ± 1.3 mm. Preoperative TCA was 599686 ± 113451, LA was 394259 ± 67259, SA was 209180 ± 47723, and CVI was 0.66 ± 0.02. At 1 day postoperatively, TCA was 615575 ± 103686, LA was 395364 ± 60314, SA was 218418 ± 45620, and CVI was 0.65 ± 0.02. At 1 week postoperatively, TCA was 610997 ± 110578, LA was 394002 ± 65186, SA was 214995 ± 46481, and CVI was 0.66 ± 0.04. A statistically significant decrease in CVI and increase in TCA and SA were observed on the first postoperative day; these changes were observed as returning to preoperative values at 1 week postoperatively. Strabismus surgery temporarily decreases the CVI by increasing the SA of the choroidal layer, possibly due to hemodynamic changes and/or inflammatory causes in the early period. [J Pediatr Ophthalmol Strabismus. 2024;61(2):114-119.].

Choroidal vascular changes in non-alcoholic fatty liver disease.

The most common cause of death in nonalcoholic fatty liver disease (NAFLD) is cardiovascular disease. Choroidal microvascular structure in the eye may be a predictor of systemic vascular disease. We aimed to evaluate the effects of NAFLD on the choroidal microvascular structure using enhanced depth optical coherence tomography (EDI-OCT). This prospective study was conducted by evaluating a total of 96 patients, 52 with steatosis and 44 without steatosis. After anthropometric measurements and ultrasonography were performed in the Gastroenterology Clinic, venous blood samples were taken for biochemical examinations. Then, all patients underwent an eye examination by an ophthalmologist. Subfoveolar choroidal thickness (SFCT) values of the cases were measured with EDI-OCT. Choroid vascular index (CVI) measurements were obtained by dividing the subfoveal choroidal area in the EDI-OCT images into luminal and stromal areas using the image binarization technique (ImageJ). In statistical analysis, the chi-square test was used to compare categorical data, and the independent t-test and Mann-Whitney U test were used to compare quantitative data. The mean age of those with fatty liver was 41±15.7 years, and of those without fatty liver it was 46 ± 10.7 years. There was nostatistically significant difference between the groups in terms of age (p = 0.064). Body mass index (BMI), waist circumference (WC), glucose, uric acid, alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), total cholesterol (TC), ferritin, insulin, and Homestatic Model Assesment - Insuline Restistance (HOMA-IR) were statistically significantly higher in the NAFLD group. On the other hand, there was no statistically significant difference between the groups in terms of low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, and aspartate aminotransferase (AST) values. The mean SFCT was measured as 280.26 ± 23.68 microns in the NAFLD group, and 308.96 ± 18.57 microns in the control group. There was no statistically significant difference in SFCT between the groups (p = 0.077). CVI measurements were 0.63 and 0.65, respectively, and they were significantly lower in the group with NAFLD (p = 0.045). This is the first study in the literature to compare patients with and without ultrasonographic fatty liver in terms of choroidal vascular changes. We found that the choroidal vascular index decreased in NAFLD. This result proves that NAFLD causes changes at the microvascular level and is a multisystemic disease.

Endothelial structure contributes to heterogeneity in brain capillary diameter.

The high metabolic demand of brain tissue is supported by a constant supply of blood flow through dense microvascular networks. Capillaries are the smallest class of vessels in the brain and their lumens vary in diameter between ~2 and 5 μm. This diameter range plays a significant role in optimizing blood flow resistance, blood cell distribution, and oxygen extraction. The control of capillary diameter has largely been ascribed to pericyte contractility, but it remains unclear if the architecture of the endothelial wall also contributes to capillary diameter. Here, we use public, large-scale volume electron microscopy data from mouse cortex (MICrONS Explorer, Cortical mm3) to examine how endothelial cell number, endothelial cell thickness, and pericyte coverage relates to microvascular lumen size. We find that transitional vessels near the penetrating arteriole and ascending venule are composed of two to six interlocked endothelial cells, while the capillaries intervening these zones are composed of either one or two endothelial cells, with roughly equal proportions. The luminal area and diameter are on average slightly larger with capillary segments composed of two interlocked endothelial cells vs one endothelial cell. However, this difference is insufficient to explain the full range of capillary diameters seen in vivo. This suggests that both endothelial structure and other influences, including pericyte tone, contribute to the basal diameter and optimized perfusion of brain capillaries.

Relationships Between Choroidal Characteristics and Disease Activity in Acute Central Serous Chorioretinopathy

Purpose: To investigate choroidal characteristics during active and resolved (presence and absence of subretinal fluid, respectively) central serous chorioretinopathy (CSC), and to clarify their relationships with disease activity.Methods: The choroidal characteristics of 33 CSC and 35 age-matched control eyes were analyzed using optical coherence tomography (OCT). The CSC group included eyes with subretinal fluid at baseline. Horizontal OCT images passing through the macula, and data for age, sex, visual acuity, and refractive error, were acquired. The subretinal fluid height and subfoveal choroidal thickness were measured. The total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were measured using ImageJ software. The choroidal vascularity index (CVI) was defined as the ratio of LCA to TCA. The measurements were repeated after 5.6 months following complete absorption of the subretinal fluid. The choroidal characteristics were compared between the active and resolved phases.Results: The CSC group had significantly greater choroidal thickness, TCA, LCA, and CVI values compared to the control group. The choroidal thickness, TCA, LCA, and SCA were significantly reduced after resolution compared to active CSC. However., the decrease in SCA was greater than that in LCA, which led to a significant increase in CVI (68.6 ± 3.2 vs. 71.6 ± 3.0, &lt;i&gt;p&lt;/i&gt; &lt; 0.001) after CSC resolution.Conclusions: CVI measurements may allow estimation of CSC disease activity. TCA, LCA, SCA, and CVI changes may indicate whether the disease is active or resolved, and thus guide CSC treatment.