Image Quality Research Articles

Klasifikasi Tingkat Kemanisan Buah Kersen Berdasarkan Fitur Warna NTSC Menggunakan Jaringan Syaraf Tiruan Berbasis Pengolahan Citra Digital

<em><span lang="EN-US">The fruit of the calabura tree (Muntingia calabura) is a small red fruit originating from the Prunus genus, often found along roadsides. This fruit contains numerous nutrients beneficial for bodily health, serving as a highly potential source of nutrition. Presently, a challenge exists in determining the sweetness level of calabura fruit, relying heavily on manual human assessment. The development of classification utilizing technology is considered a crucial step. Previous research has concentrated on classifying various objects using RGB, HSV, YCbCr color feature extraction. However, it was observed that RGB, HSV, YCbCr color features are not universally suitable, particularly for calabura fruits. Hence, this study employs a method of classifying the sweetness level of calabura fruit based on NTSC color features using a Digital Image Processing-based Artificial Neural Network (ANN). This approach leverages color-based image processing features. The research involves several stages, starting from acquiring 300 calabura fruit images with 3 levels of classification to the classification process utilizing Backpropagation in the ANN. Multiple training and testing scenarios were conducted to select feature combinations with the highest accuracy and fastest computational time. Results revealed that the most effective feature used was the NTSC color feature as a skin characteristic parameter. Based on training outcomes using 210 training images, the accuracy reached 100% with a computational time of 1.66 seconds per image. Meanwhile, testing with 90 sample images showed an accuracy of 94% with a computational time of 4.23 seconds per image. Thus, it can be concluded that the employed method successfully classifies the quality of calabura fruit images based on color features and skin characteristics.</span></em>

Artificial intelligence-guided screening of under-recognized cardiomyopathies adapted for point-of-care echocardiography

Abstract Background Point-of-care ultrasonography (POCUS) enables access to cardiac imaging directly at the bedside but is limited by brief acquisition, variation in acquisition quality, and lack of advanced protocols. Purpose To develop and validate deep learning models for detecting underdiagnosed cardiomyopathies on cardiac POCUS, leveraging a novel acquisition quality-adapted modeling strategy. Methods To develop the models, we identified transthoracic echocardiograms (TTEs) of patients across five hospitals in a large U.S. health system with transthyretin amyloid cardiomyopathy (ATTR-CM, confirmed by Tc99m-pyrophosphate imaging), hypertrophic cardiomyopathy (HCM, confirmed by cardiac magnetic resonance), and random controls from the same period enriched for the presence of severe AS. In a sample of 290,245 TTE videos, we used novel augmentation approaches and a customized loss function to weigh image and view quality to train a multi-label, view agnostic video-based convolutional neural network (CNN) to discriminate the presence of ATTR-CM, HCM, and/or AS+ and AS- controls. Models were tested across 3,758 real-world POCUS videos from 1,879 studies in 1,330 independent emergency department (ED) patients from 2011 through 2023 (A). Results Our multi-label, view-agnostic classifier demonstrated state-of-the-art performance in discriminating ATTR-CM (AUROC 0.98 [95%CI: 0.96-0.99]) and HCM (AUROC 0.95 [95% CI: 0.94-0.96]) on standard TTE studies. Automated metrics of anatomical view correctness confirmed significantly lower quality in POCUS vs TTE videos (median view classifier confidence of 0.63 [IQR: 0.44-0.88] vs 0.93 [IQR: 0.69-1.00], p<0.001). When deployed to POCUS videos, our algorithm effectively discriminated ATTR-CM and HCM with AUROC of up to 0.94 (parasternal long-axis (PLAX)), and 0.85 (apical 4 chamber (A4C)) (B), corresponding to positive diagnostic odds ratios of 46.7, and 25.5, respectively. In total, 18/35 (51.4%) of ATTR-CM and 32/57 (41.1%) of HCM patients in the POCUS cohort had a positive AI screen in the year before their eventual confirmatory imaging (C). Conclusions We define and validate an AI framework that enables scalable, opportunistic screening of under-diagnosed cardiomyopathies using POCUS.

Automated non-invasive quantification of myocardial work using 3D echocardiography and validation with invasive catheter measurements

Abstract Background Myocardial work is an emerging technique for the assessment of left ventricular (LV) performance. Using blood pressure as an afterload determinate offers further insight into LV mechanics than can be detected with load-sensitive parameters of ejection fraction or global longitudinal strain (GLS). Observational studies have signalled benefit in identifying vulnerable ventricles in cardiomyopathy, valvular, and coronary disease. While the reference standard for calculating myocardial work is through catheterisation, this is impractical for routine assessment. Currently, a vendor specific non-invasive index of myocardial work is commercially available, but requires subjective manual analysis and identification of valvular events. With increasing availability of 3D echocardiography (3DE) and automated analysis techniques, there is potential to derive more reproducible estimates of myocardial work. Purpose We sought to test whether global myocardial work could be accurately, non-invasively, and automatically estimated using 3DE, in combination with standard non-invasive clinical measurements. Methods Patients undergoing left heart catheterisation as part of routine care were prospectively recruited, and 3DE was performed within one hour of invasive LV pressure measurement. A validated deep learning model was used to automatically analyse the 3DE image volumes to produce GLS curves, from which a smaller number of features (principal components) were extracted. The invasive pressure traces were separated into cycles, which were each paired with the strain trace that had the minimal difference in R-R interval (and excluded if the relative R-R interval difference exceeded 25%). For each patient, an invasively-derived estimate of myocardial work was calculated as the area enclosed by the median pressure-strain (PS) loop. A multivariate regression model was used to relate a set of routine clinical parameters to the invasively-derived myocardial work, and subsequently assessed using leave-one-out cross-validation. Results A total of 131 out of 153 patients were included for analysis (2 excluded due to R-R interval mismatch, 20 excluded due to poor image or pressure trace quality), with basic demographics presented in Table I. The final parameter set consisted of 6 variables: systolic and diastolic brachial cuff pressures, peak GLS, R-R interval, and two strain curve principal components. When fit into a leave-one-out model, this resulted in a Pearson r-value of 0.86, demonstrating a very high correlation between predicted and invasively-derived myocardial work estimates, with a bias of 0 mmHg% and 95% limits of agreement (LOA) of ± 423 mmHg% (Figure 1). Conclusion This study demonstrates that fully automated and reliable estimates of myocardial work can be derived using 3DE and deep learning combined with routine clinical parameters. Automated and non-invasive approaches may facilitate increased clinical uptake of myocardial work assessment.

Role of CT-derived global longitudinal strain in identifying left ventricular dysfunction in patients with severe aortic stenosis and preserved left ventricular ejection fraction

Abstract Introduction In patients with severe aortic stenosis, LVEF <50% is a current class 1 indication for aortic valve replacement. There are however studies showing increased mortality in patients with asymptomatic severe aortic stenosis and LVEF between 50-59% [1, 2]. Global longitudinal strain (GLS) has emerged as a more sensitive predictor of systolic dysfunction than ejection fraction in a wide number of cardiac diseases [3]. Purpose The aim of our study was to analyze left ventricular global longitudinal strain (GLS) by cardiac computed tomography (CT) in patients with severe aortic stenosis. We hypothesized that a larger portion of patients with LVEF 50-59% have signs of systolic dysfunction by GLS as compared to patients with LVEF ≥60%. Methods We identified 238 patients (median age 81, 51.3% females) with severe aortic stenosis, assessed by cardiac CT before undergoing transcatheter aortic valve replacement at Uppsala University hospital between 2016-2019. Patients in atrial fibrillation was excluded due to suboptimal image quality. Left ventricular mass index (LVMi), EF and peak GLS were calculated. The patients were divided into three groups based on LVEF (Reduced LVEF <50%, Low-Normal LVEF 50-59% and Normal LVEF ≥60%) and compared with each other regarding GLS, biomarkers and background variables. The cut off for significantly reduced GLS was set at <16%, in accordance with recently proposed criteria [4]. Results As expected GLS was significantly reduced in all patients with LVEF <50%. Among patients with Low-Normal LVEF, 62.3% had significantly reduced GLS as compared to only 3.8% patients with Normal LVEF >60% (p < 0.001). Median GLS in Low-Normal LVEF was 15.5% (IQR 14.1 - 17.4) as compared to 20.2% (IQR 18.4 - 21.9) in Normal LVEF (p < 0.001). Patients with Low-Normal LVEF had a significantly higher LV mass as compared to patients with Normal LVEF (median LVMi 85.8 g/m² vs. 75.8 g/m², p < 0.001). NT-pro-BNP was significantly higher in patients with Low-Normal LVEF compared to Normal LVEF (median 1130 vs. 664 ng/l, p = 0.003). Conclusions Almost two third of patients with severe aortic stenosis and lower range of normal LVEF (50-59%) had abnormally reduced GLS, reflecting systolic LV dysfunction, which was uncommon among those with LVEF >60%. Patients with LVEF 50-59% also presented with higher LV mass index and higher levels of NT-pro-BNP than patients with normal LVEF >60%, reflecting hypertrophic response of the myocardium to pressure overload which over time may lead to progressive myocardial decompensation. LVEF in the range of 50-59% might be an early sign of LV decompensation in severe aortic stenosis.

LA strain analysis in patients undergoing atrial fibrillation ablation using cryoballoon or pulsed-field-ablation

Abstract Background Catheter ablation for atrial fibrillation (AF) is increasing as rhythm control therapy. Besides thermal ablation approaches, such as cryoballoon ablation (CBA), a novel non-thermal and tissue-specific ablation modality – pulsed field ablation (PFA) – has been introduced. Left atrial reservoir strain (LArS) has been suggested to predict arrhythmia recurrences after AF ablation. Up to now, data describing LArS in patients undergoing their first AF ablation using PFA or CBA are sparse. Purpose To compare LArS in patients undergoing first catheter ablation for AF using either PFA or CBA. Methods Patients with transthoracic echocardiography prior to their first catheter ablation for AF were included. Patients in AF during transthoracic echocardiography, with poor 2D image quality and those that did not have a transthoracic echocardiography after AF ablation were excluded. Clinical characteristics and echocardiography parameters were analyzed. LArS was measured before and after AF ablation and was correlated with the recurrence of atrial arrhythmias in the follow-up period. Results Of 267 patients undergoing their first AF ablation, 67 patients (69% male, 65 ± 11 years) fulfilled the inclusion criteria and were further analyzed. AF ablation was performed using PFA in 55% and CBA in 45% of patients. Baseline characteristics were similar in both groups. Before ablation LArS was similar for PFA (17.69 ± 6.92%) and CBA patients (19.38 ± 9.42%, P=0.45). After AF ablation, LArS did not change significantly compared to the values before (before ablation: 20.96 ± 15.9 vs. after ablation: 19.87 ± 9.38, P=0.18), irrespective of the ablation mode (PFA before: 17.69 ± 6.92%vs. PFA after: 18.06 ± 8.9%, P=0.53; CBA before: 19.38 ± 9.42% vs. CBA after: 21.08 ± 9.48%, P=0.36). After a median of 190 days [95% confidence interval: 89 - 454 days], 25 patients (37%) experienced an arrhythmia recurrence (PFA: 38%, CBA: 37%). Comparing patients with and without arrhythmia recurrences, LArS before catheter ablation was lower in those experiencing an arrhythmia recurrence (16.02 ± 6.8%) compared to those without arrhythmia recurrence (25.58 ± 20.32%, P=0.02). However, this was independent from the ablation mode (PFA: AF-recurrence: 16.51 ± 4.27 vs. no recurrence: 21.31 ± 15.9, P=0.19; CBA: AF-recurrence: 15.48 ± 9.03 vs. no recurrence: 27.34 ± 22.14, P=0.07). Univariable regression analysis - including sex, age and comorbidities - revealed a trend for baseline LArS being associated with arrhythmia recurrence (HR 0.92, 95% CI: 0.86 – 1.01; P=0.065). Conclusions This hypothesis generating study indicates that LArS is not affected by AF ablation irrespective of the ablation mode. Patients with lower LArS before ablation had more arrhythmia recurrences independent of the ablation mode. A larger patient population is needed to assess the association of LArS and arrhythmia recurrences after AF ablation using different ablation modalities.

Functional status is associated with mean right atrial pressure derived from cardiac MRI

Abstract Background Right atrial pressure (RAP) is a key metric in haemodynamic assessment. Elevated RAP is associated with poor prognosis in heart failure and pulmonary hypertension and physiologically with fluid overload. RAP can be measured invasively or non-invasively, but Cardiac MRI (CMR) currently cannot estimate RAP. Purpose To develop a model to estimate RAP from CMR from paired right heart catheter (RHC) and CMR assessments. Assess correlation to WHO functional status prior to prospective clinical validation studies. Methods Patients were recruited to a registry of those referred for assessment of dyspnoea between 2012 and 2020. Inclusion criteria were age >18 years, signs and symptoms of heart failure and adequate CMR image quality. Patients diagnosed with pulmonary arterial hypertension were excluded. RHC and CMR were performed on the same day. CMR 2- and 4- chamber cines were used to measure chamber dimensions, strain, ejection fraction and stroke volume with operator reviewed AI contours in MASS research software. Pearson’s product-moment correlation coefficient (r ) was used to assess relationships between CMR metrics and invasive mRAP. Variables were then included in stepwise multiple linear regression models to predict mRAP. These were compared with receiver-operator curve analysis and DeLong’s test. Kruskal-Wallis test compared median mRAP between WHO functional class groups. Results The cohort of 672 patients was divided based upon invasive mRAP ≤ 8mmHg (44%) and mRAP > 8mmHg (56%). Higher mRAP was associated with increased age, male sex and a higher diastolic blood pressure but there was no difference in rates of heart failure types although the majority had preserved ejection fraction (51% vs 52%) with few having reduced ejection fraction (4.1% vs 8%). Right atrial (RA) dimensions, strain and ejection fraction had the strongest correlation with mRAP with moderate correlation to right ventricular (RV) measurements. Multivariable models contained simple RA dimensions (model 1), RA dimensions and strain (model 2), RA and RV dimensions (model 3) and RA end systolic volume corrected for body mass index and sex (model 4). All models had similar predictive capability (Figure 1 Panel A). RA end systolic volume was isolated in model 1 as the only variable required for mRAP prediction (coefficient = 0.06, p < 0.001). Using a threshold of mRAP >8mmHg ROC analysis demonstrated an area under the curve of 0.78 (95% Confidence interval 0.75 to 0.81) (Figure 1 Panel B). Worse WHO functional Class at time of assessment was significantly associated with increased CMR derived mRAP (P<0.001) (Figure 2). Conclusions mRAP can be estimated with moderate confidence from CMR RA end systolic volume. Limited available clinical data suggest functional status may be predicted by CMR derived mRAP. Further studies on wider populations are required to validate this model externally, refine it and determine its prognostic clinical significance.

Comparing the utility of 3D vs 2D left atrial volumes by echocardiography to predict stroke in the general population

Abstract Background Left atrial (LA) volume dilatation is associated with stroke in the general population. Two-dimensional echocardiography (2DE) is commonly used to measure LA size but is known to underestimate LA volumes compared to three-dimensional echocardiography (3DE). It is unknown whether this difference has clinical significance. Purpose We hypothesized that LA volumes by 3DE are more closely associated with stroke risk than 2DE in the general population. Methods We included 2,085 participants from a longitudinal cohort study from the general population who underwent 3DE and 2DE assessment of maximal and minimal LA volume index (LAVimax and LAVimin, respectively). After excluding participants with poor image quality, low volume rate, atrial fibrillation at baseline and non-sinus-rhythm during examination, a total of 1,956 participants were included for this analysis. The endpoint was stroke. Multivariable Cox regression models were adjusted for the CHA2DS2-VASc stroke risk score (age, sex, heart failure, hypertension, stroke, vascular disease, and diabetes). Results Mean age was 54±17 years, 43% were male, mean CHA2DS2-VASc score was 1.6±1.3. During a median follow-up of 4.8 years (interquartile range 4.3-5.5 years), 36 participants (1.8%) developed stroke. After multivariable adjustment, 2D LA volumes were not associated with stroke, whereas both 3D-LAVimax (HR 1.03 (95% CI 1.00-1.06), p=0.046, per 1 mL/m2 increase) and 3D-LAVimin (HR 1.05 (95% CI 1.02-1.08), p=0.002, per 1 mL/m2 increase) remained significantly associated with stroke (Figure 1). In addition, 3D-LAVimin showed the highest discrimination for predicting stroke with a C-statistic of 0.70 (95% CI: 0.59-0.80), which was significantly higher than 2D-LAVimax (C-statistic: 0.58 (95% CI 0.48-0.69); p=0.02), 2D-LAVimin (C-statistic: 0.54 (95% CI 0.42-0.65); p<0.001) and 3D-LAVimax (C-statistic: 0.62 (95% CI 0.52-0.73); p=0.004). 3D-LAVimin also showed incremental prognostic information when added to the CHA2DS2-VASc risk score (continuous net reclassification index 0.28±0.17; p=0.047). Conclusion Increasing 3D-LA volumes are significantly associated with higher risk of stroke in the general population which was not the case for 2D-derived LA volumes.

Radiation exposure of patients undergoing multiple-slice CT scans in Romania

Abstract Ionizing radiation is largely used in medicine due to its role in the diagnosis and treatment of patients. In the past 50 years computed tomography (CT) has become indispensable for medical practice because it offers sub-millimeter cross-sectional imaging of any region of the body. New CT scanners use thinner slices, providing more accurate results, but also an increased radiation exposure with possible long-term harmful effects for the patients. The parameter used as an indicator of radiation dose in CT is the dose-length product (DLP). The study included 4507 patients who were CT scanned using a 16, 32, 64 or 128-slice CT machine. DLP was measured for head, sinuses, thorax, abdomen, pelvis, abdomen+pelvis, and trunk scans - regions for which the health authorities have established national diagnostic reference levels (DRL - the expected radiation dose received by a patient in CT). One-way ANOVA was used to analyse data considering the use of contrast agents, the gender, age, and weight of patients. Average DLP values were higher (up to 80%) than national DRL for all regions in 64 and 128-slice scans. The highest DLP values were registered in contrast CT for all scanners (p < 0.01); the maximum average (a threefold increase compared to DRL) was measured in the 32-slice sinuses contrast CT. Average DLP correlated with patients’ gender and weight (p < 0.01), but the influence was lower compared to the use of contrast agents. In conclusion, CT scans acquired using thinner slices lead to more accurate results and high-quality images, but the study suggests an increased radiation exposure. CT has an uncontestable contribution to a precise and rapid diagnosis, but more attention must be given to the stochastic effects risks associated with the radiation dose received during a CT scan. Are all scans necessary? Do all patients really need to receive high doses? The role of the practitioner is decisive, and the justifiable process is “a must” in all radiodiagnosis practices. Key messages • CT doses must be kept “as low as reasonably achievable” while maintaining diagnostic image quality. • Justification, dose limitation, and optimisation are fundamental principles of radioprotection.

Strategi Komunikasi Pemasaran PT. Lakone Serasa Juara melalui Sosial Media Instagram dalam Menciptakan Brand Awareness

This research aims to determine the marketing communication strategy of PT. Lakone Serasa Champion on Instagram to increase brand awareness. This research is included in qualitative research, which is an important effort related to asking questions, through procedures, collecting specific data from informants. The circular model of some theory related to share, optimize, manage, and engage is used as an analytical theory. This research found that (1) PT. Lakone Serasa Juara uses a communication strategy through the use of advertising features on its social media. Using advertising features and paying a fee on each social media platform will have an effect on product recognition and sales; (2) PT. Lakone holds an annual event and also discounts for the winners; and (3) communication strategy through uploading photos and videos on online media by uploading photos and images in real pictures and of course having good image quality will attract consumers' interest in buying.

Initial Experience with the 4D Mini-TEE Probe in the Adult Population

Background: Transesophageal echocardiography (TEE) is a vital diagnostic tool in clinical practice, particularly in transcatheter interventions where it aids in both pre-operative planning and intra-operative guidance. Traditional TEE probes often require general anesthesia due to patient discomfort. However, the development of miniaturized TEE probes presents a promising alternative, enabling routine examinations and interventions with minimal sedation. This study evaluates the feasibility of performing a complete 2D/4D TEE protocol with the new 4D mini-TEE probe in the echocardiography department and its application in transcatheter interventions. Methods: This is a retrospective study that included 30 consecutive patients from two high-volume European hospitals (Interbalkan Medical Center, Thessaloniki, Greece, and Rennes University, France) that underwent TEE or transcatheter interventions. The new 4D mini-TEE 9VT-D probe (GE Healthcare) was utilized. The quality of the images and the tolerance of the probe were assessed in the cath lab during interventions and in the echocardiography department during routine TEE examinations. Results: Direct comparison of the 4D mini-TEE probe with the standard 6VT-D probe confirmed the excellent image quality of this new pediatric probe. Most of the patients required minimal sedation or local oropharyngeal anesthesia, with satisfactory tolerance reported. Most of the transcatheter procedures did not require general anesthesia and intubation, resulting in shorter procedural time. Both 2D and 4D imaging modalities offered adequate intra-operative guidance for transcatheter procedures. Conclusions: The 4D mini-TEE probe delivers exceptional imaging capabilities for routine examinations and transcatheter interventions without needing sedation. Its use reduces esophageal trauma and the need for general anesthesia, enhancing patient comfort and safety.

Atrial and ventricular mitral regurgitation in the general population

Abstract Background Functional mitral valve regurgitation (FMR) is the result of two concurrent pathomechanisms: (1) the dilatation of mitral valve annulus (atrial) or (2) remodelling of the left ventricle (ventricular) in the absence of relevant leaflet degeneration¹. Even though FMR has been reported to be the most common cause of relevant MR², there is no general accepted definition of the two subtypes, nor are there population-based data regarding their prevalence, distribution and risk profiles¹. Purpose We aimed to evaluate the prevalence of FMR and to provide an in-depth characterisation of the subtypes aFMR and vFMR in the general population. Methods The study included the first 10,000 participants of the population-based Hamburg City Health Study enrolled between 2016 and 2019. Of these, 8.543 echocardiographic samples were available for analysis. Mitral valve was assessed by two independent investigators. Isolated degenerative MRs as determined by valve mobility (prolapse or restrictive) were excluded. FMR was classified as ventricular when fulfilling one of the following criteria: history of myocardial infarction or coronary artery disease, left ventricular ejection fraction (LVEF) ≤ 40%, restrictive leaflet, tenting area ≥ 150 mm² or coaptation depth ≥ 10 mm. All FMR with LVEF > 55% were classified as atrial. Results After excluding the samples with an insufficient image quality or missing data and re-assessment by the second investigator, 216 of 282 participants with a relevant MR (i.e. moderate or severe) remained (2,6% of the total cohort, see figure 1). In the next step, 153 participants were classified as pure FMR (68.9%), the remaining were mainly functional with minor degenerative features. A total of 31 (14.4%) MRs were classified as vFMR, the remaining 185 participants had an aFMR. Female gender was significantly more common in the aFMR cohort. The remaining demographic variables (age, body mass index) as well as established cardiovascular risk factors (i.e., diabetes, smoking, hypertension) were comparable between the vFMR and aFMR cohort. However, vFMR patients had significantly higher levels of NT-proBNP or NHYA state and presented more frequently with an atrial fibrillation (see figure 2). LVEF and LV stroke volume, TAPSE, left atrial ejection fraction and E/A ratio as a parameter of diastolic dysfunction were lower in the vFMR cohort whereas tenting area and left atrial endsystolic volume was significantly increased. Conclusion In our population-based study, aFMR was found to be the predominant subtype of FMR. The established cardiovascular risk factors were comparable in the vFMR and aFMR cohort. Echocardiographic variables differed significantly and indicate more advanced heart failure and LV remodelling in the vFMR cohort. Further categorization of FMR, in particular regarding the prognostic impact and long-term outcomes, is strongly warranted to allow a clinically relevant definition of aFMR and vFMR.Figure 1:Overview of sample sizeFigure 2:Baseline characteristics

Normal reference values of left atrioventricular coupling index on two-dimensional echocardiography

Abstract Background From a physiological background, there is close relationship between left atrial (LA) and left ventricular (LV) expressed as coupling. The assessment of LA/LV coupling may reflect LV dysfunction and differentiate between normal and abnormal LV function. Aim of study The study is designed to sample normal subjects to provide the normal reference values of LA/LV coupling index (LACI) according to age and sex using 2-dimensional echocardiography (2DE). Methods 550 healthy subjects (51.9±17.8 years, 56% males) were included with good 2DE image quality enabled measurement of end-diastolic volumes of both LA and LV. LACI was defined as the ratio between LA to LV end-diastolic volumes. Results An off-line analysis of apical 4-chamber and 2-chamber views to obtain the 2DE measurements was performed within short time (1.5± 0.3 min). Measurement of LACI was obtained in all individuals. Subjects were divided into 3 age groups (G I: 18-40 years, G II: 41-65 years, and GIII: >65 years). As shown in table 1, the normal LACI values in the whole population was 0.17±0.08 with significantly higher in females (0.178±0.09) than males (0.15±0.06); P<0.02. The LACI values tends to be higher in females than males in the subdivided 3 age groups but not statistically significant. In both sexes, increasing age was associated with significant reduction of the mean LVEDV (P<0.0001), significant increase of the mean LAEDV (P= 0.004), and significant increase of LACI (P< 0.0001); especially considering the differences between the youngest and oldest age groups. Conclusions Measurement of LACI is feasible and easily obtainable using 2DE. Age and sex should be considered when defining normal reference values for LACI. The standardization of normal LACI values will help the future studies to assess the changes of these normal values in various cardiac abnormalities for prognostic risk stratification.

Impact of left atrial appendage occlusion in atrial flow evaluated through 4D flow cardiac magnetic resonance

Abstract Introduction Device-related thrombus (DRT) and peri-device leak constitute significant complications following left atrial appendage occlusion (LAAO), primarily due to its association with strokes and thromboembolic events. Patient-specific fluid simulations have been employed to explore this hypothesis(1). However, these simulations require detailed anatomical and physiological data, rely on certain assumptions when defining boundary conditions, and involve long computational times. Recently, there has been growing interest in the use of 4D flow cardiac magnetic resonance (CMR) imaging for various cardiovascular diseases, owing to its capability to reproduce blood flow. While its role in the LAAO scenario has been evaluated in silico(2), there are no reported cases of its application in patients undergoing LAAO. Purpose Our objective was to evaluate the impact of LAAO in atrial flow through 4D flow CMR. Methods Five patients undergone LAAO were included in the pilot study. A pre- and 90-days post-procedure 4D flow CMR scans were performed. One of the patients was excluded due to suboptimal image quality. To assess the impact of LAAO on atrial flow dynamics, three parameters were evaluated: a) mean velocity, b) stasis velocity ratio, and c) endothelial cell activation potential (ECAP) index — all associated with an elevated risk of thrombus formation(3,4). Results Baseline and procedural characteristics, along with imaging results, are presented in Table 1. Preprocedural 4D flow CMR for all patients revealed low velocities (Figure 1A) and a high ECAP index (Figure 2A) in the left atrial appendage, indicating flow stasis and an elevated risk of thrombus formation. Successful device implantation was performed in all cases, and no periprocedural complications were detected. Postprocedural 4D flow CMR was feasible in all cases, and no artifacts were detected despite the presence of the LAAO device. An objective increase in velocities and a decrease in the ECAP index were observed in all cases following LAAO. No DRT or ischemic events were reported during follow-up. Conclusions Our preliminary study demonstrates that 4D flow CMR provides valuable information on left atrial flow dynamics following the LAAO procedure. Further studies are warranted to evaluate this promising technique.Table 1.Patient characteristicsFigure 1 and 2.Representative example

Subclinical left ventricular dysfunction detected by speckle tracking echocardiography predicts mortality in COVID-19 patients

Abstract In COVID-19 patients, both preexisting cardiovascular disease and cardiac injury resulting from SARS-CoV-2 infection are associated with increased mortality. In this patient population the value of speckle tracking echocardiography (STE) for detecting high-risk patients has not been evaluated thoroughly. Aim The aim of study was to determine the prevalence of subclinical myocardial dysfunction revealed by STE and its association with in-hospital and two-year mortality in patients with COVID-19 and preserved left ventricular ejection fraction (LVEF). Methods The study group comprised 163 consecutive patients with preserved LVEF(>/=50%) and maintained right ventricular function evaluated by assessment of tricuspid annular plane systolic excursion (TAPSE >14 mm) hospitalized in the cardiology department due to COVID-19 in 2020 and 2021. All patients underwent transthoracic echocardiographic examination with off-line analysis using STE. Left ventricular global longitudinal strain(GLS), right ventricular global longitudinal strain (RV-GLS), right ventricular free wall strain(RV-FWS) and myocardial work parameters: global work index(GWI), global wasted work(GWW), global constructive work(GCW) and global work efficiency(GWE) were measured. The primary outcome was in-hospital and two-year mortality. Results 96 patients (mean age 66 years, 59 [61%] male) had adequate image quality to evaluate deformation-derived parameters.19 patients (19.8%) died during hospitalization and 9 (9,4%) patients died within two years after discharge. In-hospital non-survivors were older, had lower baseline oxygen saturation(SpO2) and had higher NTproBNP. In non-survivors STE revealed significant impairment of LV and RV function compared to the group of survivors(Table 1). The independent predictors of in-hospital death were: age (OR 1.1 [95% CI 1.01 – 1.19]), SpO2 on admission (OR 0.83 [95% CI 0.75 – 0.93]), NTproBNP (OR 1.0003 [95% CI 1.0001 – 1.0006]) and LV-GLS (OR 1.45 (1.06 – 1.99)]. Based on the analysis of the ROC curves, the cut-off points optimal for predicting in-hospital death were identified: age >71 years (sensitivity [sens.] 74%, specificity [spec.] 68%) , baseline SpO2 value ≤ 89% (sens. 89%, spec. 74%,) NTproBNP >951 pg/ml (sens. 79%, spec. 58%) and GLS >-16% (sens. 63%, spec. 89%). The independent predictors of two-year mortality were: age (OR 1.10 [95% CI 1.02 – 1.19]), Sp02 on admission (OR 0.82 [95% CI 0.73 – 0.91]) and NTproBNP (OR 1.0006 [95% CI 1.0001 – 1.0011]).Based on the ROC curve analysis, the cut-off points optimal for predicting death within 24 months after COVID-19 were also identified: age>71 years (sens. 71%; spec. 72%), Sp02 <89% (sens. 69%, spec. 73%), NTproBNP >520 pg/ml (sens. 89%, spec. 48%). Conclusions STE allows for the detection of subclinical myocardial dysfunction in COVID-19 patients with preserved LVEF. However, LV GLS is the only independent STE-based predictor of in-hospital mortality in this patient population.

A Lightweight underwater detector enhanced by Attention mechanism, GSConv and WIoU on YOLOv8

The underwater target detection is the most important part of monitoring for environment, ocean, and other fields. However, the detection accuracy is greatly decreased by the poor image quality resulted from the complex underwater environments. The storage and computing power of underwater equipments are not enough for complex underwater target detection technology. Therefore, many YOLO series algorithms have been applied to underwater target detection. On the basis of YOLOv8, a lightweight underwater detector enhanced by Attention mechanism, GSConv and WIoU, AGW-YOLOv8, is proposed in this paper. Firstly, by the combination of limited contrast adaptive histogram equalization and wavelet transform(LCAHE-WT), the fidelity and detail of images are improved; Secondly, by CBAM, the key channel features can be effectively extracted with retaining spatial information to improve the performance of the network when dealing with complex image tasks; Thirdly, by GSConv, composed of depth-wise separable convolution and regular convolution, the model parameters and computational complexity are reduced; Fourth, the SE attention mechanism is integrated into the C2f module of the neck, and the channel dimension is weighted to make the network more focus on important features, and to further enhance the feature extraction capability; Finally, by the dynamic nonmonotonic mechanism of WIoU, the gradient gain can be reasonably distributed, the harmful gradients of extreme samples can be reduced, and the generalization ability and overall performance of the model are improved. By the experiments on the URPC2020 data-set, it can been proved that the mAP of AGW-YOLOv8 can reaches 82.9%, is 2.5% higher than that of YOLOv8; and the parameters is 2.95M, is lower than 3.01M of YOLOv8.

Global longitudinal strain predicts clinical outcome in patients after acute ischemic stroke without left ventricular dysfunction

Abstract Background Global longitudinal strain (GLS) is a sensitive marker of myocardial dysfunction that could help predict adverse outcomes. Purpose We assessed whether GLS can help predict adverse clinical outcomes in patients after acute ischemic stroke (AIS). Methods Patients without LV dysfunction after AIS were divided into groups according to abnormal GLS (≤15.9%) or normal GLS (≥16%). Blood samples were obtained to determine levels of high-sensitive troponin I (hs-cTnI). Clinical data, functional outcome, and all-cause mortality at 1 year were compared between groups. National Institutes of Health Stroke Scale (NIHSS) at the time of admission and the modified Rankin Scale (mRS) 90 days following the patient’s discharge from the hospital were used to assess stroke severity and clinical outcome. All analyses were performed with SPSS 29.0 (SPSS Inc). Results In our study, between 8/2020-8/2022 155 enrolled patients after AIS had echocardiographic examination, due to image quality or LV dysfunction, GLS was assessed in 110 patients with normal LV function, 28 patients (25.6%) had abnormal GLS. After a year follow-up, the overall mortality was more common in patients with abnormal GLS compared to patients with normal GLS (hazard ratio [HR] 2.9610, 95% confidence interval [CI] 0.9015 to 9.7255, p =0.074) and was significant when comparing mean values (p<0.001) (Fig. 1A). The Kaplan-Meier survival curve accentuated a significantly elevated all-cause mortality among patients with abnormal GLS (Fig 2). Moreover, abnormal GLS was associated with positive hs-cTnI (Fig. 1B), and was connected with unfavorable functional outcome evaluated by mRS at 90 days (Fig. 1C). At last, severe stroke (NIHSS >15) was not significantly associated with abnormal GLS (HR 2.2121, 95% CI 0.7091 to 6.9009, p = 0.1714) Conclusion In patients after AIS, abnormal GLS could be helpful predictor for clinical events and subclinical myocardial injury.

Left atrial strain demonstrates the ability to distinguish patients with pre and post-capillary pulmonary hypertension

Abstract Background The characterization of pulmonary hypertension (PH) patients into pre or postcapillary (pcPH)phenotypes poses a challenge during screening due to the ambiguity surrounding their comorbidities. This distinction is crucial as it influences treatment decisions and prognostication. Purpose Investigating Left Atrial Strain as a Discriminant Marker for Distinguishing Pre and Post-Capillary PH. Methods Out of 164 patients exhibiting both pre- and post-capillary phenotypes, 97 had optimal left atrial 2D strain. Left atrial 2D strain was performed with a GE Vivid9 ultrasound machine equipped with dedicated software, ensuring meticulous attention to image quality and region of interest thickness restricted to a maximum of 6 mm. Subsequently, the peak left atrial strain during reservoir function was quantified as part of the investigation. To determine the optimal cut-off value, ROC curve analysis was employed. Results 60 patients had pcPH while 37 had pre-capillary PH. Mean age was 65±12y. Mean pulmonary artery pressure, wedge pressure, cardiac output and pulmonary vascular resistance averaged 40,9±10,7 mm Hg, 15,7±8,7 mm Hg, 5,9±2,0 l/min and 4,7±3,1 WU, respectively. Left atrial 2D strain ranged from +2,5% to 60%, with a mean of +18,2±11,2%. From ROC cure analysis, patients with LA 2D strain > +19,1% had a precapillary phenotype with a sensitivity and a specifity of 93% and 88% respectively (Fig 1). Left atrial 2D strain demonstrates higher sensitivity compared to various parameters, such as scores from the European Society of Respiratory Disease, left ventricular end-diastolic pressure estimation from the American Society of Echocardiography, HFA-PEFF score, and H2FPEF from the AHA. Conclusion Left atrial 2D strain demonstrates superior sensitivity in distinguishing between patients with pre and post-capillary pulmonary hypertension compared to other assessment methods.FIG 1:Left atrial 2D strainFig 2:SENS of parameters and scores

Multiple description image coding using Schur transform

A novel obvious and robust image Multiple Description Coding (MDC) using Schur transform (ST)is presented in this work. To overcome the inherent drawbacks in the discrete wavelet transform (DWT)which are the hardware implementation and computational complexityIn the MDC approach, two or more correlated descriptions of the same data aregenerated, which can be independently decoded, and yield mutually refinable information. Therefore, the quality of the recovered signal is dependent only on the number of received descriptions, and not on the specific loss pattern. The new techniquewas analyzed and compared to the conventional approach in the case of four descriptions by using multiple grayscale test images having different spectral characteristics.Theexperimental results of Schur transform (ST) compared to discrete wavelet transform (DWT)show that our method achievesbetter performance in terms of delivered peaksignal to noise ratio (PSNR) and visual image quality reconstruction.The proposed MDC has a low redundancy and outperforms the conventionalscheme for image transmission over error-prone networks.Therefore, the proposed approach provides an easier practical implementation and a better redundancy performancethan the classical approach.

3D distortion-free, reduced FOV diffusion-prepared gradient echo at 3 T.

To develop a 3D distortion-free reduced-FOV diffusion-prepared gradient-echo sequence and demonstrate its application in vivo for diffusion imaging of the spinal cord in healthy volunteers. A 3D multi-shot reduced-FOV diffusion-prepared gradient-echo acquisition is achieved using a slice-selective tip-down pulse in the phase-encoding direction in the diffusion preparation, combined with magnitude stabilizers, centric k-space encoding, and 2D phase navigators to correct for intershot phase errors. The accuracy of the ADC values obtained using the proposed approach was evaluated in a diffusion phantom and compared to the tabulated reference ADC values and to the ADC values obtained using a standard spin echo diffusion-weighted single-shot EPI sequence (DW-SS-EPI). Five healthy volunteers were scanned at 3 T using the proposed sequence, DW-SS-EPI, and a clinical diffusion-weighted multi-shot readout-segmented EPI sequence (RESOLVE) for cervical spinal cord imaging. Image quality, perceived SNR, and image distortion were assessed by two expert radiologists. ADC maps were calculated, and ADC values obtained with the proposed sequence were compared to those obtained using DW-SS-EPI and RESOLVE. Consistent ADC estimates were measured in the diffusion phantom with the proposed sequence and the conventional DW-SS-EPI sequence, and the ADC values were in close agreement with the reference values provided by the manufacturer of the phantom. In vivo, the proposed sequence demonstrated improved image quality, improved perceived SNR, and reduced perceived distortion compared to DW-SS-EPI, whereas all measures were comparable against RESOLVE. There were no significant differences in ADC values estimated in vivo for each of the sequences. 3D distortion-free diffusion-prepared imaging can be achieved using the proposed sequence.

Polarization remote sensing of ships in sea haze

ABSTRACT Sea haze reduces the visibility of ships and makes the optical imaging system blind, which increases the difficulty of ship remote sensing. In this paper, we propose a new method for polarization remote sensing of ships in sea haze. The method takes advantage of image haze removal and exposure correction to improve the visibility of ships in sea haze. Different from the existing polarization-based image haze removal methods, the proposed method does not depend on any assumptions about the polarization properties of incident light. The exposure correction method is proposed based on the Retinex model and Bayes theorem, which can improve the visibility of ships in haze removal images. To evaluate the effectiveness of the proposed method, we implemented an outdoor experiment on polarization remote sensing of ships in sea haze weather. The experimental results indicate that the method can improve the visibility of ships significantly. In addition, the method outperforms the Stokes parameter-based ship remote sensing method in terms of the image quality metric fog aware density evaluator and can be easily generalized to RGB image haze removal.