Three-dimensional reconstruction and NURBS-based structured meshing of coronary arteries from the conventional X-ray angiography projection images

Despite its two-dimensional nature, X-ray angiography (XRA) has served as the gold standard imaging technique in the interventional cardiology for over five decades. Accordingly, demands for tools that could increase efficiency of the XRA procedure for the quantitative analysis of coronary arteries (CA) are constantly increasing. The aim of this study was to propose a novel procedure for three-dimensional modeling of CA from uncalibrated XRA projections. A comprehensive mathematical model of the image formation was developed and used with a robust genetic algorithm optimizer to determine the calibration parameters across XRA views. The frames correspondences between XRA acquisitions were found using a partial-matching approach. Using the same matching method, an efficient procedure for vessel centerline reconstruction was developed. Finally, the problem of meshing complex CA trees was simplified to independent reconstruction and meshing of connected branches using the proposed nonuniform rational B-spline (NURBS)-based method. Because it enables structured quadrilateral and hexahedral meshing, our method is suitable for the subsequent computational modelling of CA physiology (i.e. coronary blood flow, fractional flow reverse, virtual stenting and plaque progression). Extensive validations using digital, physical, and clinical datasets showed competitive performances and potential for further application on a wider scale

Group-wise similarity registration of point sets using Student’s t-mixture model for statistical shape models

A probabilistic group-wise similarity registration technique based on Student’s t-mixture model (TMM) and a multi-resolution extension of the same (mr-TMM) are proposed in this study, to robustly align shapes and establish valid correspondences, for the purpose of training statistical shape models (SSMs). Shape analysis across large cohorts requires automatic generation of the requisite training sets. Automated segmentation and landmarking of medical images often result in shapes with varying proportions of outliers and consequently require a robust method of alignment and correspondence estimation. Both TMM and mrTMM are validated by comparison with state-of-the-art registration algorithms based on Gaussian mixture models (GMMs), using both synthetic and clinical data. Four clinical data sets are used for validation: (a) 2D femoral heads ( 1000 samples generated from DXA images of healthy subjects); (b) control-hippocampi ( 50 samples generated from T1-weighted magnetic resonance (MR) images of healthy subjects); (c) MCI-hippocampi ( 28 samples generated from MR images of patients diagnosed with mild cognitive impairment); and (d) heart shapes comprising left and right ventricular endocardium and epicardium ( 30 samples generated from short-axis MR images of: 10 healthy subjects, 10 patients diagnosed with pulmonary hypertension and 10 diagnosed with hypertrophic cardiomyopathy). The proposed methods significantly outperformed the state-of-the-art in terms of registration accuracy in the experiments involving synthetic data, with mrTMM offering significant improvement over TMM. With the clinical data, both methods performed comparably to the state-of-the-art for the hippocampi and heart data sets, which contained few outliers. They outperformed the state-of-the-art for the femur data set, containing large proportions of outliers, in terms of alignment accuracy, and the quality of SSMs trained, quantified in terms of generalization, compactness and specificity

The effect of ticagrelor and clopidogrel on angiographic parameters according to diabetic status in patients with ST elevation myocardial infarction

Aim. We aimed to compare post-interventional angiographic outcomes of ticagrelor versus clopidogrel according to glycosylated hemoglobin (HbA1c) levels in patients with ST-elevation myocardial infarction.Material and methods. The study included a total of 532 patients, with 334 receiving ticagrelor (62,8%) and 198 clopidogrel (37,2%). Diabetic status of the patients was assessed with HbA1c. TIMI flow grade and TIMI frame count were calculated and compared between two groups.Results. TIMI flow grade 3 was higher and TFC was lower after percutaneous coronary intervention of the infarct-related artery in patients treated with ticagrelor compared to clopidogrel (89,2% vs. 73,7%; p< 0,001, 20 vs. 24; p< 0,001). There was a positive correlation between the increases in HbA1c and TFC levels in the whole group (r=0,225; p=0,004). In subgroup analysis, higher HbA1c levels did not affect TFC in patients using ticagrelor (r=-0,060; p=0,326 for patients with noreflow, r=-0,133; p=0,321 for patients with TIMI-3 flow). While level of HbA1c did not affect TFC in patients with TIMI-3 flow, the presence of post-procedural no-reflow caused worsening of TFC in patients using clopidogrel as HbA1c levels increased (r=0,374; p=0,005).Conclusion. Ticagrelor was found to be better in terms of angiographic parameters regardless of diabetes

Salt loading in canola oil fed SHRSP rats induces endothelial dysfunction

This study aimed to determine if 50 days of canola oil intake in the absence or presence of salt loading affects: (1) antioxidant and oxidative stress markers, (2) aortic mRNA of NADPH oxidase (NOX) subunits and superoxide dismutase (SOD) isoforms and (3) endothelial function in SHRSP rats. SHRSP rats were fed a diet containing 10 wt/wt% soybean oil or 10 wt/wt% canola oil, and given tap water or water containing 1% NaCl for 50 days. Without salt, canola oil significantly increased RBC SOD, plasma cholesterol and triglycerides, aortic p22phox, NOX2 and CuZn-SOD mRNA, and decreased RBC glutathione peroxidase activity. With salt, canola oil reduced RBC SOD and catalase activity, LDL-C, and p22phox mRNA compared with canola oil alone, whereas plasma malondialdehyde (MDA) was reduced and RBC MDA and LDL-C were higher. With salt, the canola oil group had significantly reduced endothelium-dependent vasodilating responses to ACh and contractile responses to norepinephrine compared with the canola oil group without salt and to the WKY rats. These results indicate that ingestion of canola oil increases O2 - generation, and that canola oil ingestion in combination with salt leads to endothelial dysfunction in the SHRSP model

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Are bioactive and free sex steroids associated with bone mineral density and bone turnover markers in middle aged men?

Aim: To investigate whether bioactive and free sex steroids are associated with bone mineral density (BMD) and bone turnover markers in middle aged men. Material and Methods: One hundred and fifteen out of 165 volunteers aged 35-65 years presenting to our outpatient clinic were included in the study. Serum albumin, total testosterone (T), total estradiol (E2), SHBG, osteocalcin (OC) and C-terminal telopeptide (CTx) levels were measured. Free and bioactive sex steroids, free androgen index (FAI) and free estrogen index (FEI) were calculated. BMD in the lumbar spine and the hip was measured in all participants and effects of sex steroids on BMD and bone turnover markers were investigated. Results: The mean age and the mean body mass index (BMI) in all participants were 52.4±7.8 years and 26.1±3.4 kg/m2 respectively. There was no significant difference in sex hormone levels and bone turnover markers between the individuals with osteoporosis and osteopenia and the individuals with normal BMD (p>0.05). There was a significant relation between age and FAI (r=-0.23, p=0.01), but there was no significant relation between age and bioactive and free sex steroids, FEI and SHBG. However, there was a positive correlation between BMI and bioactive E2 (r=0.35, p:0001), free E2 (r=0.29, p:0.002) and FEI (r=0.39, p=0.0001). After an adjustment for variables effective on BMD was made; no relation was found between BMD measures from the lumbar spine and the hip and serum bioactive sex steroids, free sex steroids, FAI, FEI and SHBG (p>0.05). However, there was a weak positive relation between serum bioactive T, FEI and OC, CTx levels (p=0.05). Conclusion: We think that bioactive and free sex steroids are not independent variables effective on BMD in the spine and the hip in middle aged men and that further studies are needed to elucidate the pathophysiology of idiopathic male osteoporosis