Measurement Of Wall Thickness Research Articles

Correlation of Fetal Anterior Abdominal Wall Thickness and Other Standard Biometric Ultrasound Measurements to Predict Fetal Macrosomia in Gestational Diabetes.

Gestational diabetes mellitus (GDM) is one of the most common medical conditions affecting pregnancy and significantly increasing the risk for maternal and perinatal complications. The aim of the present study is to study the correlation of fetal anterior abdominal wall thickness (FAAWT) and other standard fetal biometric parameters measured by ultrasound between 36 and 39 weeks of gestation with neonatal birth weight in pregnancies complicated by GDM. Prospective cohort study in a tertiary care center including 100 singleton pregnancies with GDM were subjected to ultrasound between 36 and 39 weeks of gestation. Standard fetal biometry (Biparietal diameter, Head Circumference, Abdominal circumference [AC], and Femur Length) and estimated fetal weight were calculated. FAAWT was measured at AC section and actual neonatal birth weights were recorded after delivery. Macrosomia was defined as an absolute birth weight more than 4000 g regardless of the gestational age. Statistical analysis was done and 95% confidence level was considered significant. Among 100 neonates, 16 were macrosomic (16%) and third trimester mean FAAWT was significantly higher in macrosomic babies (6.36 ± 0.5 mm) as compared to nonmacrosomic babies (5.54 ± 0.61 mm) (P < 0.0001). FAAWT >6 mm (Receiver operating characteristic curve derived) provided a sensitivity of 87.5%, specificity of 75%, positive predictive value of 40%, and negative predictive value (NPV) of 96.9% for prediction of macrosomia. While other standard fetal biometric parameters did not correlate well with actual birth weight in macrosomic neonates, only FAAWT was found to have statistically significant correlation (correlation coefficient of 0.626, P = 0.009). The FAAWT was the only sonographic parameter to have a significant correlation with neonatal birth weight in macrosomic neonates of GDM mothers. We found a high sensitivity (87.5%), specificity (75%), and NPV (96.9%) suggesting that FAAWT < 6 mm can rule out macrosomia in pregnancies with GDM.

The Impact of Cystic Fibrosis- and Noncystic Fibrosis-Bronchiectasis on Pulmonary Artery Wall Thickness and Right Heart Functions Assessed by Speckle-Tracking Echocardiography.

Right heart functions are affected in patients with bronchiectasis as a result of pulmonary hypertension induced by chronic hypoxemia. Pulmonary artery wall thickness has recently been introduced as a sign of intensive and prolonged inflammation. The aim of this study was to analyze right ventricular and right atrial functions and to mea-sure pulmonary artery wall thickness in patients with cystic fibrosis-bronch iecta sis in comparison to those with noncystic fibrosis-bronchiectasis and healthy individuals. We studied 36 patients with cystic fibrosis-bronchiectasis, 34 patients with noncystic fibrosis-bronchiectasis, and 32 age- and sex-matched control subjects. Lung function tests were performed. All subjects underwent comprehensive echocardiographic evaluation including conventional, tissue Doppler, speckle-tracking, and pulmonary artery wall thickness measurements. Right ventricular global longitudinal strain and global longitudinal right atrial strain during ventricular systole decreased in cystic fibrosis-bronchiectasis group compared with noncystic fibrosis-bronchiectasis and control groups (P <.001, both). Conversely, pulmonary artery wall thickness was increased in cystic fibrosis-bronchiectasis group in comparison to other groups (P <.001). Moreover, right ventricular global longitudinal strain was lower and pulmonary artery wall thickness was higher in patients with airflow obstruction (P <.001 and P =.025, respectively) than in those without. Only right ventricular global longitudinal strain was significantly correlated with pulmonary function test parameters. The negative effect of cystic fibrosis on right ventricular and right atrial functions was independent of age, gender, and disease duration. Our study showed that right ventricular and right atrial functions were deteriorated and pulmonary artery wall was thickened in cystic fibrosis-bronchiectasis patients more than noncystic fibrosis-bronchiectasis patients. Right ventricular global longitudinal strain detected subclinical right ventricular dysfunction and was associated with the severity of pulmonary disease.

電磁超音波共鳴法による腐食減肉試験片の肉厚計測精度向上のための信号処理法の検討

電磁超音波共鳴法による腐食減肉試験片の肉厚計測精度向上のための信号処理法の検討

Post-voided residual urine ratio as a predictor of bladder outlet obstruction in men with lower urinary tract symptoms: development of a clinical nomogram.

To confirm the correlation between post-void residual urine ratio (PVR-R) and BOO diagnosed by pressure-flow studies (PFS) in males with lower urinary tract symptoms (LUTS) and to develop a clinical nomogram. A consecutive series of patients aged 45years or older with non-neurogenic LUTS were prospectively enrolled. Patients underwent standard diagnostic assessment for BOO including International Prostatic Symptoms Score, uroflowmetry, urodynamic studies, suprapubic ultrasound of the prostate, and ultrasound measurements of the bladder wall thickness (BTW). PVR-R was defined as follows: PVR-R = (PVR/total Bladder Volume [BV]) × 100). Logistic regression analysis was used to investigate predictors of pathological bladder emptying (BOO) defined as Schafer > II. A nomogram to predict BOO based on the multivariable logistic regression model was then developed. Overall 335 patients were enrolled. Overall, 131/335 (40%) presented BOO on PFS. In a multivariable logistic age-adjusted regression model BWT (odds ratio [OR]: 2.21 per mm; 95% confidence interval [CI], 1.57-3.09; p = 0.001), PVR-R (OR: 1.02 per %; 95% CI, 1.01-1.03; p = 0.034) and prostate volume (OR: 0.97 per mL; 95% CI, 0.95-0.98; p = 0.001) were significant predictors for BOO. The model presented an accuracy of 0.82 and a clinical net benefit in the range of 10-90%. The present study confirms the important role of PVR-ratio in the prediction of BOO. For the first time, we present a clinical nomogram including PVR-ratio for the prediction of BOO.

Accuracy of Nodule Volume and Airway Wall Thickness Measurement Using Low-Dose Chest CT on a Photon-Counting Detector CT Scanner.

A comparison of high-resolution photon-counting detector computed tomography (PCD-CT) versus energy-integrating detector (EID) CT via a phantom study using low-dose chest CT to evaluate nodule volume and airway wall thickness quantification. Twelve solid and ground-glass lung nodule phantoms with 3 diameters (5 mm, 8 mm, and 10 mm) and 2 shapes (spherical and star-shaped) and 12 airway tube phantoms (wall thicknesses, 0.27-1.54 mm) were placed in an anthropomorphic chest phantom. The phantom was scanned with EID-CT and PCD-CT at 5 dose levels (CTDI vol = 0.1-0.8 mGy at Sn-100 kV, 7.35 mGy at 120 kV). All images were iteratively reconstructed using matched kernels for EID-CT and medium-sharp kernel (MK) PCD-CT and an ultra-sharp kernel (USK) PCD-CT kernel, and image noise at each dose level was quantified. Nodule volumes were measured using semiautomated segmentation software, and the accuracy was expressed as the percentage error between segmented and reference volumes. Airway wall thicknesses were measured, and the root-mean-square error across all tubes was evaluated. MK PCD-CT images had the lowest noise. At 0.1 mGy, the mean volume accuracy for the solid and ground-glass nodules was improved in USK PCD-CT (3.1% and 3.3% error) compared with MK PCD-CT (9.9% and 10.2% error) and EID-CT images (11.4% and 9.2% error), respectively. At 0.2 mGy and 0.8 mGy, the wall thickness root-mean-square error values were 0.42 mm and 0.41 mm for EID-CT, 0.54 mm and 0.49 mm for MK PCD-CT, and 0.23 mm and 0.16 mm for USK PCD-CT. USK PCD-CT provided more accurate lung nodule volume and airway wall thickness quantification at lower radiation dose compared with MK PCD-CT and EID-CT.

Measurement of Rectal Diameter and Anterior Wall Thickness by Ultrasonography in Children with Chronic Constipation.

Measurement of rectal diameter by ultrasonography helps the clinician in the diagnosis of chronic constipation in children for whom rectal examination cannot be performed. The aim of the study is to determine the rectal diameter and anterior wall thickness values in constipated and healthy children and to evaluate the feasibility of ultrasonography in the diagnosis of functional constipation in children who refuse digital rectal examination. One hundred forty constipated and 164 healthy children participated in the study. All patients were divided into 4 subgroups according to their ages (≤3 years [group I], 3.1-6 years [group II], 6.1-12 years [group III], and >12 years [group IV]) and were referred to the radiology department. The measurement was made from above the symphysis pubis, under the ischial spine, and at the bladder neck. Anterior wall thickness measurement was performed. The measurements were recorded according to the presence or absence of fecal mass in the rectum. Constipated children with fecal mass positive group III was found to have significant difference in all of the planes in rectal diameter measurement. Rectum anterior wall thickness measurement was found to be higher in constipated patients with fecal mass (+) compared to the control. Its measurements in constipated patients in group II, group III, and group IV with no fecal mass were found to be statistically higher than the control group. The measurement of rectal diameter and anterior wall thickness by ultrasonography as a noninvasive method was per formed in children who did not want the digital rectal examination, and it may be useful in the diagnosis of constipation.

Failure analysis of the water-wall tube in once through Benson boiler

Failure analysis of a water wall tube of a once-through Benson boiler after 100,000 h of use of service is presented. A 15Mo3 material was used in the manufacture of the tube. In order to identify the root cause of the rupture, visual inspection, optical emission spectroscopy, microscopic examinations, mechanical strength measurements, and tube wall thickness measurements at various locations were performed on the failed tubes. Visual inspection revealed a fish mouth puncture opening with thin lips. As a result of optical spectroscopy, mechanical testing, and hardness measurements, the material was found to meet the requirements. Based on microstructure analysis, it appears that the pearlite spheroidized near the rupture site as a result of localized high temperatures. The failure mechanism of the tube was identified as a localized short-term overheating caused by high heat flux based on the results of all the tests and analyses conducted in this study.

Detection, Prognosis and Decision Support Tool for Offshore Wind Turbine Structures

Corrosion is the leading cause of failure for Offshore Wind Turbine (OWT) structures and it is characterized by a low probability of detection. With focus on uniform corrosion, we propose a corrosion detection and prognosis system coupled with a Decision Support Tool (DST) and a Graphical User Interface (GUI). By considering wall thickness measurements at different critical points along the wind turbine tower, the proposed corrosion detection and prognosis system—based on Kalman filtering, empirical corrosion models and reliability theory—estimates the Remaining Useful Life of the structure with regard to uniform corrosion. The DST provides a systematic approach for evaluating the results of the prognosis module together with economical information, to assess the different possible actions and their optimal timing. Focus is placed on the optimization of the decommissioning time of OWTs. The case of decommissioning is relevant as corrosion—especially in the splash zone of the tower—makes maintenance difficult and very costly, and corrosion inevitably leads to the end of life of the OWT structure. The proposed algorithms are illustrated with examples. The custom GUI facilitates the interpretation of results of the prognosis module and the economical optimization, and the interaction with the user for setting the different parameters and costs involved.

Wall thickness measurement and defect detection in ductile iron pipe structures using laser ultrasonic and improved variational mode decomposition

A reliable non-destructive evaluation technique that accurately assesses the wall thickness and slag inclusions of ductile iron pipes prior to annealing is crucial to reducing costs in subsequent operations. The rough outer layer of the produced ductile iron pipes leads to considerable background noise, limiting the probability of detection of laser ultrasonic testing equipment. In this study, an improved variational mode decomposition approach based on particle swarm optimization is suggested initially to increase the signal-to-noise ratio. This technique develops a fitness function suitable for processing ultrasound signals. A scanning laser ultrasound technique is designed for simultaneous measuring wall thickness and finding slag inclusions in ductile iron pipes based on excitation locations and flight time. A finite element analysis simulation model is established to assess the feasibility of this scanning method. This experiment is conducted on a 4.2 mm thick sample with slag inclusion defects and a 6.2 mm thick sample without slag inclusion flaws. Experimental results demonstrate that the developed denoising technique may enhance the average signal-to-noise ratio from 34.83 dB to 43.15 dB; the accuracies of thicknesses measurement for two ductile iron pipes are 96.90% and 99.52%, respectively, and the slag inclusion defects can be recognized by ultrasonic amplitude or energy distribution in different B-scan images. It has potential implications for in-service inspection of ductile iron pipe structures.

Role of cardiac magnetic resonance (CMR) in planning ventricular septal myomectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM).

Septal myectomy is currently the gold standard treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). The procedure needs to be tailored and performed in a personalized fashion, taking into consideration the anatomic and physiologic heterogeneity of this disease. The extent and location of surgical myectomy will depend on the location of the hypertrophy, with the goal of widening the outflow tract and improve the function of the mitral valve. CMR helps to identify hypertrophy not well visualized by TTE, providing more accurate wall thickness measurements and differentiating HOCM from other causes of LV hypertrophy. CMR also helps identify an abnormal attachment of papillary muscle to the MV or to the septal myocardium and mitral valve pathology. A collaborative approach with cardiac surgeons, radiologists and cardiologists will optimize preoperative planning to improve the success for surgical myectomy.

The flutemetamol analogue cyano-flutemetamol detects myocardial AL and ATTR amyloid deposits: a post-mortem histofluorescence analysis

Background [18F]flutemetamol is a PET radioligand used to image brain amyloid, but its detection of myocardial amyloid is not well-characterized. This histological study characterized binding of fluorescently labeled flutemetamol (cyano-flutemetamol) to amyloid deposits in myocardium. Methods Myocardial tissue was obtained post-mortem from 29 subjects with cardiac amyloidosis including transthyretin wild-type (ATTRwt), hereditary/variant transthyretin (ATTRv) and immunoglobulin light-chain (AL) types, and from 10 cardiac amyloid-free controls. Most subjects had antemortem electrocardiography, echocardiography, SPECT and cardiac MRI. Cyano-flutemetamol labeling patterns and integrated density values were evaluated relative to fluorescent derivatives of Congo red (X-34) and Pittsburgh compound-B (cyano-PiB). Results Cyano-flutemetamol labeling was not detectable in control subjects. In subjects with cardiac amyloidosis, cyano-flutemetamol labeling matched X-34- and cyano-PiB-labeled, and transthyretin- or lambda light chain-immunoreactive, amyloid deposits and was prevented by formic acid pre-treatment of myocardial sections. Cyano-flutemetamol mean fluorescence intensity, when adjusted for X-34 signal, was higher in the ATTRwt than the AL group. Cyano-flutemetamol integrated density correlated strongly with echocardiography measures of ventricular septal thickness and posterior wall thickness, and with heart mass. Conclusion The high selectivity of cyano-flutemetamol binding to myocardial amyloid supports the diagnostic utility of [18F]flutemetamol PET imaging in patients with ATTR and AL types of cardiac amyloidosis.

Abstract 11330: Association of Left Ventricular Wall Stress and Incident Heart Failure in Elderly Community Dwelling Individuals

Introduction: Greater left ventricular (LV) wall stress is associated with adverse outcomes among patients with prevalent heart failure (HF). Less is known about the association between LV wall stress and risk of incident HF in community dwelling individuals. Methods: Using data from the NHLBI Biologic Specimen and Data Repository Information Coordinating Center, we studied 4,601 participants of the Atherosclerosis Risk in Communities study without prevalent HF who underwent echocardiography at visit 5 (2011-2013). LV end systolic and diastolic wall stress (LVESWS, LVEDWS) were calculated from chamber and wall thickness measures, E/e’ as a surrogate for LV end diastolic pressure, and systemic blood pressure. Incident HF was assessed by cohort surveillance for hospitalized HF through December 31, 2016. The relationship between LVESWS and LVEDWS was examined by Spearman rank correlation. The association between wall stress and risk of incident HF was tested in Cox regression adjusted for demographics, traditional CV risk factors, prevalent CAD and atrial fibrillation, as well as creatinine, NT-proBNP, troponin, triglycerides, C-reactive protein, LV ejection fraction, and LV mass. Results: The cohort was elderly (median age 75 years), predominantly female (58%), with 18% of individuals identifying as black. Median LVESWS and LVEDWS were 48.8 (IQR: 39.3, 60.1) and 18.9 (IQR: 15.8, 22.5) kdynes/cm2, respectively. LVESWS and LVEDWS were modestly correlated (rho = 0.30, p &lt;0.001). Over a median follow-up of 4.6 years, 156 individuals developed incident HF. In multivariable Cox regression mutually adjusted for LVEDWS and LVESWS, each 1-unit increase in LVEDWS significantly associated with an increased risk of incident HF (HR: 1.03; 95% CI 1.01 - 1.06) (Figure), while LVESWS did not (HR: 1.00; 95% CI 0.99-1.01). Conclusions: Among community dwelling elderly individuals, greater non-invasively measured LVEDWS is associated with an increased risk for incident HF.

MR Multitasking-based multi-dimensional assessment of cardiovascular system (MT-MACS) with extended spatial coverage and water-fat separation.

To extend the MR MultiTasking-based Multidimensional Assessment of Cardiovascular System (MT-MACS) technique with larger spatial coverage and water-fat separation for comprehensive aortocardiac assessment. MT-MACS adopts a low-rank tensor image model for 7D imaging, with three spatial dimensions for volumetric imaging, one cardiac motion dimension for cine imaging, one respiratory motion dimension for free-breathing imaging, one T2-prepared inversion recovery time dimension for multi-contrast assessment, and one T2*-decay time dimension for water-fat separation. Nine healthy subjects were recruited for the 3T study. Overall image quality was scored on bright-blood (BB), dark-blood (DB), and gray-blood (GB) contrasts using a 4-point scale (0-poor to 3-excellent) by two independent readers, and their interreader agreement was evaluated. Myocardial wall thickness and left ventricular ejection fraction (LVEF) were quantified on DB and BB contrasts, respectively. The agreement in these metrics between MT-MACS and conventional breath-held, electrocardiography-triggered 2D sequences were evaluated. MT-MACS provides both water-only and fat-only images with excellent image quality (average score=3.725/3.780/3.835/3.890 for BB/DB/GB/fat-only images) and moderate to high interreader agreement (weighted Cohen's kappa value=0.727/0.668/1.000/1.000 for BB/DB/GB/fat-only images). There were good to excellent agreements in myocardial wall thickness measurements (intraclass correlation coefficients [ICC]=0.781/0.929/0.680/0.878 for left atria/left ventricle/right atria/right ventricle) and LVEF quantification (ICC=0.716) between MT-MACS and 2D references. All measurements were within the literature range of healthy subjects. The refined MT-MACS technique provides multi-contrast, phase-resolved, and water-fat imaging of the aortocardiac systems and allows evaluation of anatomy and function. Clinical validation is warranted.

Validation of the Sonographic Measurement of Lateral Parapharyngeal Wall Thickness in Childhood Obstructive Sleep Apnea.

Lateral parapharyngeal wall (LPW) thickness is a potentially useful anatomical marker of childhood obstructive sleep apnea (OSA). Measuring LPW thickness by ultrasonography (USG) is technically feasible but its use in children has not been validated. Therefore, this study aimed to assess the intra- and inter-operator reliability of the sonographic measurements of LPW thickness in children and to assess its validity against magnetic resonance imaging (MRI) measurements. Prepubertal children aged 6-11 years suspected to suffer from OSA were recruited. Repeated measurements of LPW thickness by USG were conducted to evaluate the intra- and inter-operator reliability, examined by intraclass correlation coefficient (ICC). LPW thickness was measured as the distance between the internal carotid artery and the echogenic surface of the pharynx in an oblique coronal plane by USG. LPW thickness was measured by MRI at the retropalatal level. The agreement between the LPW thickness measured by USG and MRI was assessed by ICC and Bland-Altman plot. Thirty-four children (mean age: 8.66 ± 1.61, 26 male) were recruited. The intra- and inter-operator reliability of the LPW thickness by USG was good (ICC = 0.84 and 0.82, respectively). The agreement between the USG-measured and MRI-measured LPW thickness was moderate (ICC = 0.72). he Bland-Altman plot demonstrated a mean difference of 0.061 cm and a 95% limit of agreement from 0.91 to 1.12 cm. In this study, we demonstrated that ultrasonography is a valid and reliable method to assess LPW thickness in children. This study was supported by the Direct Grant for Research from the Research Committee of the Chinese University of Hong Kong (Project no. 2020.073).

Mechanics of lung cancer: A finite element model shows strain amplification during early tumorigenesis.

Early lung cancer lesions develop within a unique microenvironment that undergoes constant cyclic stretch from respiration. While tumor stiffening is an established driver of tumor progression, the contribution of stress and strain to lung cancer is unknown. We developed tissue scale finite element models of lung tissue to test how early lesions alter respiration-induced strain. We found that an early tumor, represented as alveolar filling, amplified the strain experienced in the adjacent alveolar walls. Tumor stiffening further increased the amplitude of the strain in the adjacent alveolar walls and extended the strain amplification deeper into the normal lung. In contrast, the strain experienced in the tumor proper was less than the applied strain, although regions of amplification appeared at the tumor edge. Measurements of the alveolar wall thickness in clinical and mouse model samples of lung adenocarcinoma (LUAD) showed wall thickening adjacent to the tumors, consistent with cellular response to strain. Modeling alveolar wall thickening by encircling the tumor with thickened walls moved the strain amplification radially outward, to the next adjacent alveolus. Simulating iterative thickening in response to amplified strain produced tracks of thickened walls. We observed such tracks in early-stage clinical samples. The tracks were populated with invading tumor cells, suggesting that strain amplification in very early lung lesions could guide pro-invasive remodeling of the tumor microenvironment. The simulation results and tumor measurements suggest that cells at the edge of a lung tumor and in surrounding alveolar walls experience increased strain during respiration that could promote tumor progression.

Divergence of the normalized wall shear stress as an effective computational template of low-density lipoprotein polarization at the arterial blood-vessel wall interface

Background and ObjectiveNear-wall transport of low-density lipoproteins (LDL) in arteries plays a relevant role in the initiation of atherosclerosis. Although it can be modelled in silico by coupling the Navier–Stokes equations with the 3D advection-diffusion (AD) equation, the associated computational cost is high. As wall shear stress (WSS) represents a first-order approximation of the near-wall velocity in arteries, we aimed at identifying computationally convenient WSS-based quantities to infer LDL near-wall transport based on the underlying near-wall hemodynamics in five models of three human arterial districts (aorta, carotid bifurcations, coronary arteries). The simulated LDL transport and its WSS-based surrogates were qualitatively compared with in vivo longitudinal measurements of wall thickness growth on the coronary artery models. MethodsNumerical simulations of blood flow coupled with AD equations for LDL transport and blood-wall transfer were performed. The co-localization of the simulated LDL concentration polarization patterns with luminal surface areas characterized by low cycle-average WSS, near-wall flow stagnation and WSS attracting patterns was quantitatively assessed by the similarity index (SI). In detail, the latter two represent features of the WSS topological skeleton, obtained respectively through the Lagrangian tracking of surface-born particles, and the Eulerian analysis of the divergence of the normalized cycle-average WSS vector field. ResultsConvergence of the solution of the AD problem required the simulation of 3 (coronary artery) to 10 (aorta) additional cardiac cycles with respect to the Navier-Stokes problem. Co-localization results underlined that WSS topological skeleton features indicating near-wall flow stagnation and WSS attracting patterns identified LDL concentration polarization profiles more effectively than low WSS, as indicated by higher SI values (SI range: 0.17–0.50 for low WSS; 0.24–0.57 for WSS topological skeleton features). Moreover, the correspondence between the simulated LDL uptake and WSS-based quantities profiles with the in vivo measured wall thickness growth in coronary arteries appears promising. ConclusionsThe recently introduced Eulerian approach for identifying WSS attracting patterns from the divergence of normalized WSS provides a computationally affordable template of the LDL polarization at the arterial blood-wall interface without simulating the AD problem. It thus candidates as an effective biomechanical tool for elucidating the mechanistic link amongst LDL transfer at the arterial blood-wall interface, WSS and atherogenesis.

Initial experience with dielectric-based local tissue assessment for catheter ablation

Abstract Background Dielectric imaging systems can be used to guide catheter ablation for cardiac arrhythmia. Currently, the KODEX-EPD system can be used to acquire high-resolution anatomical data for electroanatomical mapping. Future software versions of this system enable tissue assessment utilizing local dielectric sensing. These dielectric-based tissue assessments (KODEX Vision) enable new features, including wall thickness measurement, catheter-tissue contact assessment, and ablation lesion assessment. Purpose To gain insight in the dielectric-based tissue assessment features. Methods The KODEX-EPD system was used to perform repeat ablations in patients with recurrent atrial fibrillation after pulmonary vein isolation. A primary system with the current software version (1.4.8) was used by the operator. Ablation was performed with a non-contact force-sensing irrigated radiofrequency catheter, with power set at 30–35W and aiming for ablation times of 30–60s. A secondary system was blinded for the operator and loaded with beta software (1.5.0) to enable the KODEX Vision features. Only successful local tissue assessments are presented in this abstract. All patients were enrolled in a prospective registry study which was approved by the local ethics committee. Results Electroanatomic mapping in 25 patients (age 65±8yr, male 84%, LAVI 31±9ml/m2) revealed electrical reconnection in 66 of 100 pulmonary veins. A total of 308 radiofrequency applications were used to re-isolate the veins and create additional lesions (superior vena cava isolation in 6, box lesion in 1). Wall thickness at the sites of ablation ranged from 1.3–3.9 mm. Tissue contact assessment at the start of RF applications indicated “touch” in 77%, while 17.5% and 5.5% of results indicated `no touch' or “high touch”. Tissue Response Viewer indicated low dielectric response in 18.5% and high dielectric response in 81.5% of results. High dielectric response was associated with lower wall thickness (OR: 0.86, 95% CI [0.76–0.97], p=0.014). Conclusion This preliminary evaluation underlines the potential of dielectric-based tissue assessment features. Wall thickness measurement, catheter-tissue contact, and ablation lesion assessment seem feasible with the beta software. Further evaluation of the feasibility, accuracy and clinical impact of the finalized software is warranted. Funding Acknowledgement Type of funding sources: None.

Improved diagnostic accuracy for apical hypertrophic cardiomyopathy

Abstract Introduction The diagnosis of apical hypertrophic cardiomyopathy (ApHCM) is contingent on demonstrating apical maximum wall thickness (MWT) of ≥15mm; the same threshold as other HCM subtypes. However, the myocardium naturally tapers towards the apex in healthy individuals, so ≥15mm MWT is proportionately higher in the apex than in naturally thicker basal segments. Using cardiac magnetic resonance (CMR), relative ApHCM has been described (typical ECG features, loss of apical tapering, cavity obliteration but hypertrophy &amp;lt;15mm). Wall thickness measurement using machine learning now exceeds human performance. Purpose We aimed to redefine the optimal diagnostic threshold for ApHCM using segment-specific criteria based on a large cohort of healthy control subjects. Methods Segmental wall thickness was measured using healthy subjects from the UK Biobank using a clinically validated machine learning algorithm1,2. A normative reference range was established for all 16 segments, conditioned to body surface area (BSA), sex and age. Derived segment-specific wall thickness thresholds were used to define optimal disease thresholds for patients clinically managed with overt (MWT ≥15mm) and relative ApHCM (MWT &amp;lt;15mm, but typical ECG and imaging findings). Results 4118 UK biobank subjects were used to define normal segmental thicknesses and reference ranges. These were applied to ApHCM (73 overt, 31 relative). There were no apical wall thickness age related differences. The upper limit of the 95% confidence interval corresponded to a combined maximum apical MWT for both males and females of 10.4mm using non-indexed measurement, or 5.6mm/m2 when indexed to BSA. Non-indexed segmental threshold identified 100% of ApHCM patients (true positives), 81% (25 of 31) relative ApHCM and 3% (115 of 4118) of healthy UK biobank subjects (false positives). Indexed segmental thresholds improved the diagnostic potential in relative ApHCM without an increase in false positives (100% of ApHCM patients, 84% (26 of 31) of relative ApHCM patients, and 3% healthy UK biobank (127 of 4118). Conclusion We propose new diagnostic criteria for ApHCM using segmental indexed apical wall thickness of &amp;gt;5.6 mm/m2 to better identify inappropriate apical hypertrophy in those whose wall thickness does not meet current criteria for diagnosis. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Effect of Motexafin lutetium-mediated ultrasound-guided red laser photodynamic therapy on endothelial dysfunction using a new automatic ultrasound image processing software

Abstract Background As is well recognized, the majority of atherosclerosis start with an inflammatory process, resulting in endothelial dysfunction. Purpose In this study, we developed an experimental photosensitizer Motexafin lutetium (Lu-Tex)-mediated photodynamic therapy system, and investigated its effectiveness on endothelial dysfunction improvement in an animal model of balloon dilation injury, using a new automatic ultrasound image processing software. Methods Briefly, Golden Syrian hamsters' femoral artery underwent balloon dilatation injury. After four weeks, femoral arteries of the treatment group at the lesion region, treated using Motexafin lutetium - mediated fiber optic catheter-based red low level laser (742 nm, 150 J/cm2) photodynamic therapy. In order to evaluate endothelial-dependent relaxation, acetylcholine-mediated dilation (AMD) was measured during the infusion of acetylcholine at a rate of 0.5 μg/kg/min and endothelial independent relaxation was evaluated by measuring nitroglycerin mediated dilation (NMD) during the infusion of nitroglycerin at a rate of 5μg/kg/min. For off-line analysis, a computerized analysis method for evaluating instantaneous changes in the wall of the hamster femoral artery was used. For automatic measurement of the mean wall thickness and the lumen diameter from longitudinal B-mode ultrasound images, two algorithms, i.e., maximum gradient and dynamic programming were composed and implemented. Reference points and cost function were based on dynamic programming and maximum gradient, respectively. Results Results from computerized B-mode ultrasound image processing software showed significant differences in AMD between the treated and the non-treated hamsters (p&amp;lt;0.05), whereas there were no significant differences in NMD between the treatment and normal groups (p&amp;gt;0.05). Conclusion Cytotoxic and anti-inflammatory effect of Motexafin lutetium, induced by red laser photodynamic therapy accompanied by photobiomodulation effect of red laser, can cause to reduce the immune cells in intimal layer and improve the endothelial dysfunction via increasing the endothelial nitric oxide synthase function. Furthermore, it is concluded that the new automatic method enables accurate and repeated evaluation of the endothelial dysfunction using photodynamic therapy in this model. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Mehrad Research Lab

Size matters - redefining sex differences among patients with transthyretin amyloid cardiomyopathy – have we been wrong all along?

Abstract Background Transthyretin amyloid cardiomyopathy (ATTR-CM) is most often diagnosed in men (1–5). The few available studies suggest affected women have a more favourable cardiac phenotype (5–8), but remain unclear regarding differences in outcomes. Objectives and methods To characterise sex differences among consecutive patients with non-hereditary and two prevalent forms of hereditary ATTR-CM diagnosed over a 20-year period at our specialist centre through analysis of deep phenotyping at presentation, changes on serial echocardiography and overall prognosis. Results In total, 1732 patients were studied, comprising: 1095 with wild-type (wt)ATTR-CM; 206 with T60A-hATTR-CM; and 431 with V122I-hATTR-CM. Female prevalence was greater in T60A-hATTR-CM (29.6%) and V122I-hATTR-CM (27.8%) compared to wtATTR-CM (6%). At presentation, females were 3.3 years older than males (81.9 vs 77.8 years for wtATTR-CM; 68.7 vs 65.1 years for T60A-hATTR-CM; 77.1 vs 74.9 years for V122I-hATTR-CM). At diagnosis, non-indexed measures of wall thickness were significantly greater in males (interventricular septum in diastole (IVSd) of 17.13mm in males &amp; 16.15mm in females; p&amp;lt;0.001). When indexed for body surface area (BSA), we observed that the mean indexed IVSd was fairly constant in males throughout the study period, but in females, had a tendency to decrease over the same study period. Furthermore, BSA significantly influenced measures of disease severity. When indexed for BSA, overall structural and functional phenotype was similar between sexes; the few observed significant differences including indexed IVSd (9.62mm/m2 in females &amp; 8.88mm/m2 in males; p&amp;lt;0.001), indexed left ventricular (LV) end-diastolic volume (35.07ml/m2 in females &amp; 41.05ml/m2 in males; p&amp;lt;0.001) and indexed LV end-systolic volume (17.95ml/m2 in females &amp; 21.74ml/m2 in males; p&amp;lt;0.001) suggested a mildly worse phenotype in females. No significant differences were observed in disease progression on serial echocardiography and mortality across the overall population (p=0.459) and when divided by genotype (p=0.730 for wtATTR-CM; p=0.161 for T60A-hATTR-CM; p=0.056 for V122I-hATTR-CM). Conclusion This study of a well-characterized large cohort of ATTR-CM patients, contrary to previous dogmas, did not demonstrate overall differences between sexes in either clinical phenotype, when indexed, or with respect to disease progression and prognosis. The analysis highlighted the deficiencies in using non-indexed values which can not only lead to the inaccurate perception of a milder clinical phenotype in women compared to men, but has been shown to result in female patients presenting at an older age and with a worse phenotype compared to men. These findings indicate the need for revision of existing clinical guidelines regarding awareness and diagnosis of ATTR-CM in women, and modification of clinical trials which currently use single non-indexed threshold for wall thickness as key inclusion criterion. Funding Acknowledgement Type of funding sources: Foundation.