Total Vascular Volume Research Articles

Vessel and Airway Characteristics in One-Year Computed Tomography-defined Rapid Emphysema Progression: SPIROMICS.

Rationale: Rates of emphysema progression vary in chronic obstructive pulmonary disease (COPD), and the relationships with vascular and airway pathophysiology remain unclear. Objectives: We sought to determine if indices of peripheral (segmental and beyond) pulmonary arterial dilation measured on computed tomography (CT) are associated with a 1-year index of emphysema (EI; percentage of voxels <-950 Hounsfield units) progression. Methods: Five hundred ninety-nine former and never-smokers (Global Initiative for Chronic Obstructive Lung Disease stages 0-3) were evaluated from the SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) cohort: rapid emphysema progressors (RPs; n = 188, 1-year ΔEI > 1%), nonprogressors (n = 301, 1-year ΔEI ± 0.5%), and never-smokers (n = 110). Segmental pulmonary arterial cross-sectional areas were standardized to associated airway luminal areas (segmental pulmonary artery-to-airway ratio [PAARseg]). Full-inspiratory CT scan-derived total (arteries and veins) pulmonary vascular volume (TPVV) was compared with small vessel volume (radius smaller than 0.75 mm). Ratios of airway to lung volume (an index of dysanapsis and COPD risk) were compared with ratios of TPVV to lung volume. Results: Compared with nonprogressors, RPs exhibited significantly larger PAARseg (0.73 ± 0.29 vs. 0.67 ± 0.23; P = 0.001), lower ratios of TPVV to lung volume (3.21 ± 0.42% vs. 3.48 ± 0.38%; P = 5.0 × 10-12), lower ratios of airway to lung volume (0.031 ± 0.003 vs. 0.034 ± 0.004; P = 6.1 × 10-13), and larger ratios of small vessel volume to TPVV (37.91 ± 4.26% vs. 35.53 ± 4.89%; P = 1.9 × 10-7). In adjusted analyses, an increment of 1 standard deviation in PAARseg was associated with a 98.4% higher rate of severe exacerbations (95% confidence interval, 29-206%; P = 0.002) and 79.3% higher odds of being in the RP group (95% confidence interval, 24-157%; P = 0.001). At 2-year follow-up, the CT-defined RP group demonstrated a significant decline in postbronchodilator percentage predicted forced expiratory volume in 1 second. Conclusions: Rapid one-year progression of emphysema was associated with indices indicative of higher peripheral pulmonary vascular resistance and a possible role played by pulmonary vascular-airway dysanapsis.

Abstract 18634: Quantification of Coronary Volume to Left Ventricular Mass Ratio Using CT Angiography

Introduction: Coronary volume to left ventricular mass ratio (V/M) is a promising parameter that can detect physiological imbalances between coronary vasculature and the supplied myocardium. However, the existing method that assesses the V/M using epicardial vascular volume based on coronary CT angiography (CCTA) is labor intensive and prone to variability due to its dependence on coronary vasculature visualization. Hypothesis: A new technique based on CCTA and its associated bolus tracking data enables an efficient semi-automated approach that can reproducibly measure the V/M with less variability compared to the existing manual approach. Methods: The V/M was assessed by both existing manual and the new semi-automated techniques in 6 Yorkshire swine (49.1 ± 9.0 kg). Using a 320-slice CT scanner, 9 pairs of repeated CT measurements were made (100 kVp; 200 mA) with a 5-minute delay between each acquisition. Contrast (0.5 mL/kg; 370 mgI/mL) and a diluted contrast/saline chaser (0.5 mL/kg; 30:70contrast/saline) were injected peripherally at 5mL/s. Bolus tracking and triggering were followed by a single scan acquired at the peak of the aortic enhancement. Using a first-pass analysis model, the bolus tracking and single volume scan data were used to derive the total vascular blood volume (mL). Standard myocardial segmentation was used for myocardial mass (g) measurement. The V/M was also calculated from CCTA using the manual technique, by segmenting coronary luminal volume and myocardial mass. The reproducibility of the V/M was assessed using regression analysis. The variability of the two techniques for determining normal V/M was quantified using the coefficient of variation. Results: The first ((V/M) 1 ) and second ((V/M) 2 ) measurements were related by (V/M) 2 = 1.039 (V/M) 1 + 0.002 (Pearson’s r = 0.90; RMSE = 0.01 mL/g). The coefficient of variation was 0.13 and 0.24 for the V/M calculated from the new semi-automated and existing manual techniques, respectively. Conclusion: A novel semi-automated technique can be used for quantification of V/M with low variability. This technique can potentially be used for early detection of physiological imbalances between coronary vasculature and the supplied myocardium following coronary artery disease.

A national analysis of vascular surgery resident operative experience in peripheral artery disease

BackgroundEndovascular and hybrid interventions have played an increasingly prominent role in the treatment of peripheral arterial disease (PAD) in the past decade. This shift has prompted concerns about the adequacy of open surgical training for current surgical residents. Moreover, the recent Best Surgical Therapy in Patients With Critical Limb Ischemia trial has further emphasized the importance of open surgical techniques in the treatment of peripheral arterial disease. The purpose of this study was to examine national temporal trends in peripheral operative volume among integrated vascular surgery residents. MethodsData was obtained from the Accreditation Council for Graduate Medical Education national data reports for integrated vascular surgery residents. Case volumes for surgeon chief or surgeon junior cases were collected from academic years 2012 to 2013 and 2021 to 2022. Trends in case-mix and volume were evaluated using linear regression analysis. ResultsThe mean total vascular operative volume increased from 851.2 to 914.3 cases among graduating chief residents, with an annual growth of 8.5 ± 1.7 cases/year (R2 = 0.77; P < .0001). Major vascular case volume also increased at a rate of 5.7 ± 1.2 cases/year (R2 = 0.74; P < .001). Among operative categories, peripheral cases were the most frequent (n = 232.2 [26.6%]) and demonstrated the greatest annual growth (+8.0 ± 0.8 cases/year, R2 = 0.93; P < .001). No changes were seen in volume of open peripheral cases, including suprainguinal bypass (+0.1 ± 0.2 cases/year; R2 = 0.08; P = .40) or femoropopliteal bypass procedures (−0.1 ± 0.2 cases/year; R2 = 0.17; P = .20). Infrapopliteal bypass (+0.4 ± 0.1 cases/year; R2 = 0.48; P = .006), iliac/femoral endarterectomy (+1.3 ± 0.2 cases/year; R2 = 0.82; P < .001), and leg thromboembolectomy (+0.4 ± 0.1 cases/year; R2 = 0.64; P < .001) all demonstrated annual growth. For endovascular peripheral cases, aortoiliac revascularization (+3.4 ± 0.3 cases/year; R2 = 0.94; P < .001), femoropopliteal revascularization (+5.4 ± 0.2 cases/year; R2 = 0.98; P < .001), and tibioperoneal revascularization (+2.0 ± 0.2 cases/year; R2 = 0.92; P < .001) all increased in volume. Lower extremity amputations, including above-knee amputation (+0.6 ± 0.2 cases/year; R2 = 0.65; P < .001) and below-knee amputation (+0.9 ± 0.2 cases/year; R2 = 0.72; P < .001) also demonstrated an increase in volume. ConclusionsCurrent graduating residents have higher open and endovascular case volumes for peripheral artery disease on a national level, despite the increasing popularity of endovascular techniques. Further studies are needed to identify how these trends may impact current vascular surgery milestones. These trends may also influence the rising interest in competency-based training programs.

Construction of a vascularized fascia-prosthesis compound model with axial pedicle for ear reconstruction surgery.

Background: To design a vascular pedicled fascia-prosthesis compound model that can be used for ear reconstruction surgery. Methods: A vascularized tissue engineering chamber model was constructed in New Zealand rabbits, and fresh tissues were obtained after 4weeks. The histomorphology and vascularization of the newly born tissue compound were analyzed and evaluated by tissue staining and Micro-CT scanning. Results: The neoplastic fibrous tissue formed in the vascularized tissue engineering chamber with the introduction of abdominal superficial vessels, similar to normal fascia, was superior to the control group in terms of vascularization, vascular density, total vascular volume, and total vascular volume/total tissue volume. Conclusion: In vivo, introducing abdominal superficial vessels in the tissue engineering chamber prepped for ear prosthesis may form a well-vascularized pedicled fascia-prosthesis compound that can be used for ear reconstruction.

Pulmonary Vascular Volume by Quantitative CT in Dyspneic Smokers with Minor Emphysema

Reduced lung diffusing capacity for carbon monoxide (DLCO) at rest and increased ventilation (⩒ E)-carbon dioxide output (⩒CO2) during exercise are frequent findings in dyspneic smokers with largely preserved FEV1. It remains unclear whether low DLCO and high ⩒ E-⩒CO2 are mere reflections of alveolar destruction (i.e. emphysema) or impaired pulmonary perfusion in non-emphysematous tissue contributes to these functional abnormalities. Sixty-four smokers (41 males, FEV1= 84 ± 13%predicted) underwent pulmonary function tests, an incremental exercise test, and quantitative chest computed tomography. Total pulmonary vascular volume (TPVV) was calculated for the entire segmented vascular tree (VIDA Vision™). Using the median % low attenuation area (-950 HU), participants were dichotomized into “Trace” or “Mild” emphysema (E), each group classified into preserved versus reduced DLCO. Within each emphysema subgroup, participants with abnormally low DLCO showed lower TPVV, higher ⩒ E-⩒CO2, and exertional dyspnea than those with preserved DLCO (p < 0.05). TPVV (r = 0.34; p = 0.01), but not emphysema (r = −0.05; p = 0.67), correlated with lower DLCO after adjusting for age and height. Despite lower emphysema burden, Trace-E participants with reduced DLCO had lower TPVV, higher dyspnea, and lower peak work rate than the Mild-E with preserved DLCO (p < 0.05). Interestingly, TPVV (but not emphysema) correlated inversely with both dyspnea-work rate (r = −0.36, p = 0.004) and dyspnea-⩒ E slopes (r = −0.40, p = 0.001). Reduced pulmonary vascular volume adjusted by emphysema extent is associated with low DLCO and heightened exertional ventilation in dyspneic smokers with minor emphysema. Impaired perfusion of non-emphysematous regions of the lungs has greater functional and clinical consequences than hitherto assumed in these subjects.

Quantitative analysis of high-resolution computed tomography features of idiopathic pulmonary fibrosis: a structure-function correlation study.

The quantitative analysis of high-resolution computed tomography (HRCT) is increasingly being used to quantify the severity and evaluate the prognosis of disease. Our aim was to quantify the HRCT features of idiopathic pulmonary fibrosis (IPF) and identify their association with pulmonary function tests. This was a retrospective, single-center, clinical research study. Patients with IPF were retrospectively included. Pulmonary segmentation was performed using the deep learning-based method. Radiologists manually segmented 4 findings of IPF, including honeycombing (HC), reticular pattern (RE), traction bronchiectasis (TRBR), and ground glass opacity (GGO). Pulmonary vessels were segmented with the automatic integration segmentation method. All segmentation results were quantified by the corresponding segmentation software. Correlations between the volume of the 4 findings on HRCT, volume of the lesions at different sites, pulmonary vascular-related parameters, and pulmonary function tests were analyzed. A total of 101 IPF patients (93 males) with a median age of 63 years [interquartile range (IQR), 58 to 68 years] were included in this study. Total lesion extent demonstrated a stronger negative correlation with diffusion capacity for carbon monoxide (DLco) compared to HC, RE, and TRBR [total lesion ratio, correlation coefficient (r) =-0.67, P<0.001; HC, r=-0.45, P<0.001; RE, r=-0.41, P<0.001; TRBR, r=-0.25, P<0.05, respectively]. Correlations with lung function were similar among various lesion sites with r from -0.38 to -0.61 (P<0.001). Pulmonary artery volume (PAV) displayed a slightly increased positive association with the DLco compared to total pulmonary vascular volume (PVV); for PAV, r=0.41 and P<0.001 and for total PVV, r=0.36 and P<0.001. Additionally, total lesion extent, HC, and RE indicated a negative relationship with vascular-related parameters, and the strength of the correlations was independent of lesion site. Quantitative analysis of HRCT features of IPF indicated a decline in function and an aggravation of vascular destruction with increasing lesion extent. Furthermore, a positive correlation between vascular-related parameters and pulmonary function was confirmed. This co-linearity indicated the potential of vascular-related parameters as new objective markers for evaluating the severity of IPF.

Lung vascular changes as biomarkers of severity in systemic sclerosis-associated interstitial lung disease.

It has recently become possible to assess lung vascular and parenchymal changes quantitatively in thoracic CT images using automated software tools. We investigated the vessel parameters of patients with SSc, quantified by CT imaging, and correlated them with interstitial lung disease (ILD) features. SSc patients undergoing standard of care pulmonary function testing and CT evaluation were retrospectively evaluated. CT images were analysed for ILD patterns and total pulmonary vascular volume (PVV) extents with Imbio lung texture analysis. Vascular analysis (volumes, numbers and densities of vessels, separating arteries and veins) was performed with an in-house developed software. A threshold of 5% ILD extent was chosen to define the presence of ILD, and commonly used cut-offs of lung function were adopted. A total of 79 patients [52 women, 40 ILD, mean age 56.2 (s.d. 14.2) years, total ILD extent 9.5 (10.7)%, PVV/lung volume % 2.8%] were enrolled. Vascular parameters for total and separated PVV significantly correlated with functional parameters and ILD pattern extents. SSc-associated ILD (SSc-ILD) patients presented with an increased number and volume of arterial vessels, in particular those between 2 and 4 mm of diameter, and with a higher density of arteries and veins of <6 mm in diameter. Considering radiological and functional criteria concomitantly, as well as the descriptive trends from the longitudinal evaluations, the normalized PVVs, vessel numbers and densities increased progressively with the increase/worsening of ILD extent and functional impairment. In SSc patients CT vessel parameters increase in parallel with ILD extent and functional impairment, and may represent a biomarker of SSc-ILD severity.

Maternal hemodynamics and computerized cardiotocography during labor with epidural analgesia

PurposeTo analyze the mechanisms involved in the fetal heart rate (FHR) abnormalities after the epidural analgesia in labor.MethodsA prospective unblinded single-center observational study on 55 term singleton pregnant women with spontaneous labor. All women recruited underwent serial bedside measurements of the main hemodynamic parameters using a non-invasive ultrasound system (USCOM-1A). Total vascular resistances (TVR), heart rate (HR), stroke volume (SV), cardiac output (CO) and arterial blood pressure were measured before epidural administration (T0), after 5 min 5 (T1) from epidural bolus and at the end of the first stage of labor (T2). FHR was continuously recorded through computerized cardiotocography before and after the procedure.ResultsThe starting CO was significantly higher in a subgroup of women with low TVR than in women with high-TVR group. After the bolus of epidural analgesia in the low-TVR group there was a significant reduction in CO and then increased again at the end of the first stage, in the high-TVR group the CO increased insignificantly after the anesthesia bolus, while it increased significantly in the remaining part of the first stage of labor. On the other hand, CO was inversely correlated with the number of decelerations detected on cCTG in the 1 hour after the epidural bolus while the short-term variation was significantly lower in the group with high-TVR.ConclusionMaternal hemodynamic status at the onset of labor can make a difference in fetal response to the administration of epidural analgesia.

Prediction of pulmonary hypertension using central-to-peripheral pulmonary vascular volume ratio on three-dimensional cardiothoracic CT in patients with congenital heart disease.

To evaluate whether the central-to-peripheral pulmonary vascular volume ratio measured using three-dimensional cardiothoracic CT can serve as a potential predictor of pulmonary hypertension (PH) in patients with congenital heart disease. Cardiothoracic CT was used to quantify right and left total, central, and peripheral pulmonary vascular volumes segmented based on a three-dimensional threshold-based approach in 60 patients with congenital heart disease (group with PH, n = 30; group without PH, n = 30). The CT-based central-to-peripheral pulmonary vascular volume ratios were correlated with the echocardiography-based maximum velocity of tricuspid regurgitation (TR Vmax) and systolic pulmonary arterial pressure (PAP) values. The diagnostic ability of the central-to-peripheral pulmonary vascular volume ratio to predict PH was analyzed. The central-to-peripheral pulmonary vascular volume ratios were significantly higher in the group with PH compared to the group without PH (1.6 ± 0.9 vs. 0.8 ± 0.3 for the right side, p < 0.001; 2.4 ± 2.2 vs. 1.0 ± 1.4 for the left side, p < 0.004). The right central-to-peripheral pulmonary volume ratios were significantly positively correlated with the TR Vmax and estimated systolic PAP values (R = 0.627 and 0.633, respectively; p < 0.001) in patients with and without PH, while the ratios were moderately correlated with the TR Vmax and estimated systolic PAP values (R = 0.431 and 0.435, respectively; p < 0.020) in the group with PH. The right and left central-to-peripheral pulmonary vascular volume ratios demonstrated a good diagnostic ability for predicting the presence of PH (area under the receiver-operating characteristic curve = 0.867, p < 0.001 and 0.859, p < 0.001 for the right and left, respectively). The CT-based central-to-peripheral pulmonary vascular volume ratio can be used to predict PH in patients with congenital heart disease.

In Vivo Imaging of Rat Vascularity with FDG-Labeled Erythrocytes.

Microvascular disease is frequently found in major pathologies affecting vital organs, such as the brain, heart, and kidneys. While imaging modalities, such as ultrasound, computed tomography, single photon emission computed tomography, and magnetic resonance imaging, are widely used to visualize vascular abnormalities, the ability to non-invasively assess an organ’s total vasculature, including microvasculature, is often limited or cumbersome. Previously, we have demonstrated proof of concept that non-invasive imaging of the total mouse vasculature can be achieved with 18F-fluorodeoxyglucose (18F-FDG)-labeled human erythrocytes and positron emission tomography/computerized tomography (PET/CT). In this work, we demonstrate that changes in the total vascular volume of the brain and left ventricular myocardium of normal rats can be seen after pharmacological vasodilation using 18F-FDG-labeled rat red blood cells (FDG RBCs) and microPET/CT imaging. FDG RBC PET imaging was also used to approximate the location of myocardial injury in a surgical myocardial infarction rat model. Finally, we show that FDG RBC PET imaging can detect relative differences in the degree of drug-induced intra-myocardial vasodilation between diabetic rats and normal controls. This FDG-labeled RBC PET imaging technique may thus be useful for assessing microvascular disease pathologies and characterizing pharmacological responses in the vascular bed of interest.

Assessing Fluid Intolerance with Doppler Ultrasonography: A Physiological Framework.

Ultrasonography is becoming the favored hemodynamic monitoring utensil of emergentologists, anesthesiologists and intensivists. While the roles of ultrasound grow and evolve, many clinical applications of ultrasound stem from qualitative, image-based protocols, especially for diagnosing and managing circulatory failure. Often, these algorithms imply or suggest treatment. For example, intravenous fluids are opted for or against based upon ultrasonographic signs of preload and estimation of the left ventricular ejection fraction. Though appealing, image-based algorithms skirt some foundational tenets of cardiac physiology; namely, (1) the relationship between cardiac filling and stroke volume varies considerably in the critically ill, (2) the correlation between cardiac filling and total vascular volume is poor and (3) the ejection fraction is not purely an appraisal of cardiac function but rather a measure of coupling between the ventricle and the arterial load. Therefore, management decisions could be enhanced by quantitative approaches, enabled by Doppler ultrasonography. Both fluid ‘responsiveness’ and ‘tolerance’ are evaluated by Doppler ultrasound, but the physiological relationship between these constructs is nebulous. Accordingly, it is argued that the link between them is founded upon the Frank–Starling–Sarnoff relationship and that this framework helps direct future ultrasound protocols, explains seemingly discordant findings and steers new routes of enquiry.

Abstract 10064: Pulmonary Hypertension in Patients with Connective Tissue Disease-associated Interstitial Lung Disease and Vascular Changes on Computed Tomography

Introduction: Pulmonary hypertension (PH) is a complication in patients with connective-tissue disease-associated interstitial lung disease (CTD-ILD) associated with mortality. In Idiopathic Pulmonary Fibrosis, increased vascular volume has been reported to be associated with poor outcomes. We sought to elicit whether similar changes could be observed in patients with CTD-ILD and pulmonary hypertension. Methods: We identified patients with a known diagnosis of CTD-ILD who had undergone chest CT, transthoracic echocardiography (TTE), and right heart catherization (RHC) using the Mass General Brigham Research Patient Data Repository (IRB #2018P000419). The electronic health records (EHR) were reviewed to confirm the diagnosis of CTD-ILD. A 3D reconstruction of the pulmonary vasculature using the Chest Imaging Platform ( www.chestimagingplatform.com ) to compute the total vascular volume was performed on thin sliced CT scans closest to the RHC. Vessels were separated into arterial and venous components using a deep learning approach. Statistical analysis was performed with R 4.01. Values are shown as medians and interquartile ranges and were compared using Wilcoxon Rank-Sum tests. Results: A total of 104 patients with CTD-ILD were identified: Pre-capillary PH (n=43), Isolated Post-capillary PH (n=9), Combined Pre- and Post-capillary PH (n=8), and PH Absent (n=44). There was no difference in patient age or lung volume by CT scan. On TTE, RVSP was elevated in PH (52 mmHg, IQR 41-64 mmHg vs 34 mm Hg, IQR 27-49 mmHg, p &lt; 0.0001), as was the arterial total vascular volume (118 mL, IQR 85-152 ml vs 100 mL, IQR 77-126 ml, p = 0.009) with no trend for significance for venous total vascular volume. Addition of total arterial volume remained a statistically significant predictor of presence of PH (p = 0.01) when added to logistic regression models predicting PH by TTE RVSP, with improvement in model AIC (106.1 to 97.9) and AUC (0.75 to 0.80) of the model. Conclusions: In this retrospective study of patients with CTD-ILD and available imaging and hemodynamics, patients with PH have increased arterial vascular volume compared to those without PH. Information derived from CT images routinely acquired in this population could be used to improve screening and phenotyping.

CT MEASURES OF INTRAPARENCHYMAL VASCULAR VOLUME IN COPD PATIENTS WITH AND WITHOUT PULMONARY HYPERTENSION

TOPIC: Pulmonary Vascular Disease TYPE: Original Investigations PURPOSE: Pulmonary hypertension (PH) is a significant contributing factor of overall morbidity and mortality in patients with COPD. Pruning in the form of loss of small vessel fractional volume has been shown to be associated with right heart disease and poor outcomes in COPD. In this investigation we sought to explore the relationship between this marker and the presence of precapillary pulmonary hypertension by hemodynamic measures. METHODS: We conducted a retrospective chart review study using the Research Patient Data Registry (RPDR) across patients in at Brigham and Women’s Hospital for patients with a diagnosis of Chronic Obstructive Pulmonary Disease (COPD) and measured FEV1/FVC of less than 70%. Patients with other forms of lung disease and risk factors for group 1 PH were excluded. Those patients with CT angiography within one year of right heart catheterization were further reviewed and we excluded those with poor image quality, pneumonia, significant fibrosis or lung collapse. All data collection was approved by the IRB at Mass General Brigham (IRB #2018P000419).We generated 3D models of the pulmonary vasculature using the Chest Imaging Platform (www.chestimagingplatform.org) and measured the total vascular volume (TBV), the volume of vessels with a cross sectional area <= 5 mm2 (BV5) and > 20mm2( BVg20); The small vessel fraction (aBV5/TBV) a marker of pruning, and the lung volume normalized arterial BVg20 (aBVg20/LV), a marker of proximal arterial enlargement were used for analysis. All data was analyzed using R version 4.0.1. Wilcoxon Rank-sum test and Spearman correlation were used for analysis and medians with IQR are reported. RESULTS: Of the Total Cohort (N=44), 17 had precapillary PH, 12 had PH associated with elevated wedge pressures and the remaining 15 did not meet diagnostic criteria for PH (mPAP > 20mmHg; PVR > 3 for precapillary, PAOP > 15mmHg for postcapillary). In the full cohort (N = 44), decrease in aBV5/TBV was associated with increase in mean PA pressure (R = -0.40, p = 0.007). We then restricted the analysis to those with less than 5% emphysema (N = 31). Here the aBV5/TBV was again negatively correlated with mean PA pressure (-0.6, p = 0.0004), but additionally aBVg20/LV was proportional to mean PA pressure (R = 0.46, p = 0.01).Within the group with less than 5% emphysema, those with precapillary PH had a lower aBV5/TBV (0.33[0.28-0.43] vs 0.46[0.46-0.55] p = 0.006, N = 13 and 7) than those without PH. There was no difference between age (66[62-80] vs 64[55-70], p = 0.34) and percent predicted FEV1 (53[48-69] vs 63[38-69] p>0.5). In those with > 5% emphysema (N = 13) there were no statistically significant correlations between aBV5/TBV and aBVg20/LV and mean PA pressure. CONCLUSIONS: In this retrospective study of COPD patients with CT angiography and hemodynamic assessment, decreased small arterial vascular fraction and proximal arterial volume increase was associated with increasing mPAP and was different between patients with precapillary PH versus those with no PH. The effect appears to be modulated by the presence of significant emphysema which independently may lead to loss of small vessel volume and additionally represents a specific sub-phenotype of COPD. CLINICAL IMPLICATIONS: Combining parenchymal and vascular phenotypic markers derived from CT imaging may help improve detection and phenotyping of PH in COPD. DISCLOSURES: No relevant relationships by Imama Ahmad, source=Web Response No relevant relationships by Sneha Lakshman, source=Web Response No relevant relationships by Pietro Nardelli, source=Web Response No relevant relationships by Farbod Rahaghi, source=Web Response Consultant relationship with Quantitative Imaging solutions Please note: 2016-2021 Added 05/03/2021 by Ruben San Jose Estepar, source=Web Response, value=Consulting fee Owner/Founder relationship with Quantitative Imaging Solutions Please note: 2015 Added 04/30/2021 by Raúl San José Estépar, source=Web Response, value=Ownership interest My spouse/partner as a Employee relationship with biogen Please note: >$100000 by George Washko, source=Web Response, value=Salary Owner/Founder relationship with Quantitative Imaging Solutions Please note: >$100000 by George Washko, source=Web Response, value=Ownership interest Advisory Committee Member relationship with Boehringer Ingelheim Please note: $1001 - $5000 by George Washko, source=Web Response, value=Consulting fee Consultant relationship with Vertex Please note: $5001 - $20000 by George Washko, source=Web Response, value=Consulting fee Advisory Committee Member relationship with PulmonX Please note: $1001 - $5000 by George Washko, source=Web Response, value=Consulting fee Advisory Committee Member relationship with CSL Behring Please note: $1001 - $5000 by George Washko, source=Web Response, value=Consulting fee Consultant relationship with Johnson and Johnson Please note: $5001 - $20000 by George Washko, source=Web Response, value=Consulting fee

Magnetic Resonance Imaging Assessment of Pulmonary Vascularity in Infants with Congenital Diaphragmatic Hernia: A Novel Tool for Direct Assessment of Severity of Pulmonary Hypertension and Hypoplasia

To assess the feasibility of magnetic resonance imaging (MRI) for postnatal assessment of pulmonary vascularity in infants with congenital diaphragmatic hernia (CDH). Infants with prenatally diagnosed CDH (n=24) received postnatal pulmonary MRI. Infants with nonpulmonary birth defects served as controls (n=5). Semiautomatic segmentation was performed to obtain total vascular volume using time of flight images to assess vascularity. Average vascular density (vascular volume/lung volume) in control infants was 0.23±0.06mm3/mm3 compared with 0.18±0.06mm3/mm3 in infants with CDH is (P=.09). When stratified further based on CDH severity, the difference between control infants and moderate CDH group was statistically significant. (0.23mm3/mm3 vs 0.15mm3/mm3, P=.01). Ipsilateral vascular density on MRI in infants with CDH significantly correlated with the prenatal pulmonary hypertensive index (P=.0004, Spearman R=+0.87) and with number of days on mechanical ventilation (P=.04, Spearman R=-0.44), total days on inhaled nitric oxide (P=.02, Spearman R=-0.47), use of epoprostenol for acute pulmonary hypertension (PH) (0.14mm3/mm3 vs 0.20mm3/mm3, P=.005), and use of sildenafil for chronic PH (0.15mm3/mm3 vs 0.19mm3/mm3, P=.03). Our results suggest that postnatal pulmonary vascularity assessed by MRI strongly correlates with prenatal and postnatal markers of PH severity and that pulmonary vascularity may serve as a direct measure of pulmonary vascular hypoplasia in infants with CDH.

USING AND MODELIZATION OF THE LAW OF EHERGY UNDER THE PATHOLOGY OF BLOOD FLOW IN THE CONSTRUCTION OF ELASTIC VARIABLE MODELS FOR BLOOD VESSEL WALLS

This article describes a mathematical model of the circulatory system for the cardiovascular system and provides a basicframework for the mathematical representation of cumulative medical parameters such as total vascular area,blood volume, self-regulation, and effects on the upper and inner heart. In mathematical terms, linear dependencies, differential,integral and differential equations are used.

Ambient air pollution exposure and radiographic pulmonary vascular volumes.

Among 2428 Framingham Heart Study participants who underwent chest computed tomography (CT) between 2008 and 2011, pulmonary vascular volumes were calculated by image analysis, including the total vascular volume and small vessel volume (cross-sectional area <5 mm2; BV5 defined as small vessel volume). Using spatiotemporal models and participant home address, we assigned 1-year (2008) and 5-year (2004-2008) average concentrations of fine particulate matter (PM2.5), elemental carbon (EC), and ground-level ozone (O3), and distance to major roadway. We examined associations of 1- and 5-year exposures, and distance to road, with CT vascular volumes using multivariable linear regression models. There was a consistent negative association of higher O3 with lower small vessel volumes, which persisted after adjustment for distance to road. Per interquartile range (IQR) of 2008 O3, BV5 was 0.34 mL lower (95% confidence intervals [CI], -0.61 to -0.06; P = 0.02), with similar results for 5-year exposure. One-year EC exposure and closer proximity to road were weakly associated with small vessel volumes; BV5 was 0.18 mL higher per IQR of 2008 EC (95% CI, -0.05 to 0.42; P = 0.13) and 0.40 mL higher per IQR closer proximity to road (95% CI: -0.10 to 0.89; P = 0.12). PM2.5 was not associated with small vascular volumes; BV5 was 0.26 mL lower per IQR of 2008 PM2.5 (95% CI: -0.68 to 0.16; P = 0.22). Among community-dwelling adults living in the northeastern United States, higher exposure to O3 was associated with lower small pulmonary vessel volumes on CT.

User of angiotensin-converting-enzyme inhibitor and/or angiotensin II receptor blocker might be associated with vascular calcification in predialysis chronic kidney disease patients: a retrospective single-center observational study

BackgroundVascular calcification is a prominent feature in chronic kidney disease (CKD) and diabetes mellitus. A recent report suggests that angiotensin II is protective to vascular calcification. Therefore, we investigated the relationship between vascular calcification and use of angiotensin-converting-enzyme inhibitor (ACEI) and/or angiotensin II receptor blocker (ARB) from a cross-sectional view.MethodsA total of 121 predialysis CKD patients (age 71 ± 12 y; male 72; estimated glomerular filtration rate (eGFR) 20.2 (11.8 - 40.3) mL/min/1.73 m2) who underwent thoracoabdominal plain computed tomography scan were included in this study. The total vascular calcification volume (Calc) was calculated with a three-dimensional imaging software and standardized by body surface area (BSA). The relevance between log [Calc/BSA] and ACEI/ARB use was investigated by multivariate linear regression analyses with or without a time-duration factor of ACEI/ARB use.ResultsThe Calc/BSA was 5.62 (2.01 - 12.7) mL/m2 in 121 patients. In multivariate analyses adjusted with age, sex, ACEI/ARB and log [eGFR], ACEI/ARB use is significantly and positively associated with log [Calc/BSA] (β = 0.2781, p = 0.0007). Even after the adjustment by age, sex, log [eGFR], phosphate, diabetes mellitus, systolic blood pressure, warfarin, hypertension, dyslipidemia, low-density lipoprotein cholesterol, diuretics and ACEI/ARB, ACEI/ARB use is significantly and positively associated with log [Calc/BSA] (β = 0.1677, p = 0.0487). When 90 patients whose time-duration of ACEI/ARB use was clear in medical records were studied, a multivariate analysis adjusted with age, sex, log [eGFR], and ACEI/ARB duration factors showed that the longer use of ACEI/ARB more than 2 years was significantly, independently and positively associated with log [Calc/BSA] (β = 0.2864, p = 0.0060).ConclusionsACEI/ARB user was associated with vascular calcification in predialysis patients with low eGFR. Prospective studies with larger numbers of patients or more in vitro studies are needed to confirm whether this phenomenon is due to the use of ACEI/ARB itself, the underlying disease condition or the prescription bias.

Micro-anatomic alterations of the placenta in a non-human primate model of gestational protein-restriction

ObjectivesMaternal protein malnutrition is associated with impaired fetal growth, and lifetime consequences for the offspring. Our group has previously developed a model of protein-restriction in the non-human primate, which was associated with fetal growth restriction, stillbirth, decreased placental perfusion, and evidence of fetal hypoxia, suggesting perturbed vascular development. Our objective was to histologically characterize the micro-anatomic alterations associated with adverse pregnancy outcomes taking an approach that permits investigation of the 3D vascular structure and surrounding histology without the requirement for 3D vascular casting or relying on 2D stereology which both have methodological limitations.MethodsRhesus macaques were assigned in the pre-gestational period to a control diet that contained 26% protein, or study diet containing 13% protein (50% PR diet). Placental tissue was collected at delivery and processed using a clarification, immunohistochemistry, and confocal microscopy protocol published previously by our group. Three dimensional reconstructions and quantitative assessment of the vascular micro-anatomy was performed using analysis software (Imaris®) and statistical analysis accounted for maternal and fetal confounders.ResultsIn unadjusted analysis, when comparing those pregnancies on a 50% PR diet (n = 4) with those on a control diet (n = 4), protein-restriction diet was associated with decreased maternal pre-pregnancy weight (difference of -1.975kg, 95% CI -3.267 to -0.6826). When controlling for maternal pre-pregnancy weight, fetal sex, and latency from tissue collection to imaging, a gestational protein-restriction diet was associated with decreases in total vascular length, total vascular surface area, total vascular volume, and vascular density.ConclusionIn this pilot study, a gestational protein-restriction diet altered the placental micro-vasculature with decreased vascular caliber and density, which may be related to the observed adverse pregnancy outcomes and perturbed placental perfusion previously demonstrated in this model.

SAT0553 QUANTITATIVE ANALYSIS OF IMAGING FEATURES AT CHEST CT OF PULMONARY ARTERIAL AND VENOUS COMPONENTS IN SYSTEMIC SCLEROSIS-INTERSTITIAL LUNG DISEASE (SSc-ILD).

Background:Interstitial lung disease (ILD) and pulmonary arterial hypertension carry a negative impact on SSc prognosis. Chest CT is the gold standard in assessing ILD and helps in evaluating associated vascular involvement.Objectives:As qualitative analysis of CT scans is limited by low reproducibility and time constraints, we aimed at evaluating parenchymal and vascular features in SSc-ILD by quantitative analysis (QA) of CT scans and testing the relationship with clinical-functional data.Methods:We prospectively enrolled 80 patients who underwent PFTs and chest CT scan spirometry gated at TLC on the same day. Clinical, lung functional and diffusion data, as well as disability indexes were collected. CT images were analyzed by a computational platform for texture analysis of ILD patterns (CALIPER), through Imbio LTA. It quantified the extent of normal pattern (NP %), ground glass opacities (GG %), reticulation (RET %), honeycombing (HC %), total ILD extent (ILD EXT %) and hyperlucent (HL %). Low density areas, representing emphysematous area, were also quantified (LDA %). For lung vessel analysis, a software program developed by the Ludwig Boltzmann Institute for Lung Vascular Research was used. This software determined total, arterial, and venous vascular volumes (TV, AV, VV), and relative volumes (TV%, AV%, VV%), as well as density and number for total, arterial and venous vessels.Results:43/80 patients/CT scans were eligible for both software analyses, while 36/43 for arterial and venous separation. TV% and total vessel density were correlated positively with mRSS and negatively with %FVC (r=-0.537 and r=-0.382) and %TLC (r=-0.511 and r=-0.648), while vessel tortuosity correlated positively with %DLco. This was confirmed when separately analyzing arterial vessels, while VV% negatively correlated with %FVC, %TLC and %DLco. There was a positive correlation between %ILD patterns and %vascular volumes, being significant for TV%-AV%, total vessels and arterial density. Conversely, %ILD patterns were negatively correlated with VV and number of veins detected, despite positive correlation between VV% and ILD_EXT%. When clustering patients according to %FVC and %DLco with 80% normal cutoff, %FVC allowed clustering according to significantly different ILD patterns extents and vascular features, while %DLCO for vascular features only. Moreover, the consecutive addition of functional impairment and worsening of ILD (from both normal %FVC and %Dlco, to %DLco impairment only to both %FVC and %Dlco impairment), there was a significant increase in %TV, % AV and %VV, with the exception of decrease in %VV and venous density in patients with double impairment versus DLco single impairment.Conclusion:This is the first study showing in SSc a direct correlation between ILD and the increase in lung vascular volume, which is characterized by increase in arterial volume and density and reduction in venous volume and number. These results might be explained by the reduction of pulmonary volume due to fibrosis. However, also a para-physiological mechanism of redistribution of blood flow in lung areas, less involved by ILD, might be considered. Further studies on lung vessel quantification and distribution are ongoing.Disclosure of Interests:Cosimo Bruni Speakers bureau: Actelion, Eli Lilly, Mariaelena Occhipinti Consultant of: Imbio, Gianna Camiciottoli: None declared, Maurizio Bartolucci: None declared, Michael Pienn: None declared, Gemma Lepri: None declared, Alessio Fabbrizzi: None declared, Alessandra Tottoli: None declared, Giuglia Ciardi: None declared, Dilia Giuggioli: None declared, Giovanna CUOMO: None declared, Francesco Masini: None declared, Horst Olschewski: None declared, Federico Lavorini: None declared, Linda Calistri: None declared, Marco Matucci-Cerinic Grant/research support from: Actelion, MSD, Bristol-Myers Squibb, Speakers bureau: Acetelion, Lilly, Boehringer Ingelheim

Hyperglycemia compromises Rat Cortical Bone by Increasing Osteocyte Lacunar Density and Decreasing Vascular Canal Volume

Uncontrolled diabetes is associated with increased risk of bony fractures. However, the mechanisms have yet to be understood. Using high-resolution synchrotron micro-CT, we calculated the changes in the microstructure of femoral cortices of streptozotocin-induced hyperglycemic (STZ) Wistar Albino rats and tested the mechanical properties of the mineralized matrix by nanoindentation. Total lacunar volume of femoral cortices increased in STZ group due to a 9% increase in lacunar density. However, total vascular canal volume decreased in STZ group due to a remarkable decrease in vascular canal diameter (7 ± 0.3 vs. 8.5 ± 0.4 µm). Osteocytic territorial matrix volume was less in the STZ group (14,908 ± 689 µm3) compared with healthy controls (16,367 ± 391 µm3). In conclusion, hyperglycemia increased cellularity and lacunar density, decreased osteocyte territorial matrix, and reduced vascular girth, in addition to decreasing matrix mechanical properties in the STZ group when compared with euglycemic controls.