Acoustic Window Research Articles

Association between global longitudinal strain and myocardial fibrosis biomarkers in patients with end-stage chronic kidney disease

Abstract Introduction Myocardial fibrosis represents a landmark characteristic of uremic cardiomyopathy, leading to a high burden of arrhythmias, diastolic dysfunction (DD) and ultimately heart failure in this population. Collagen-derived biomarkers (Procollagen type I carboxy-terminal propeptide (PICP), Procollagen type III N-terminal peptide (P3NP)) and Galectin-3 (Gal-3) are associated with the extent of myocardial fibrosis on myocardial biopsy. Global longitudinal strain (GLS) as assessed by two-dimensional speckle tracking echocardiography (2D-STE) has been shown to detect subclinical myocardial dysfunction in various populations. The correlation between GLS and the serum level of these biomarkers has not been studied so far. Purpose The aim of this study was to evaluate the association between the left ventricular GLS measured by 2D-STE and the serum level of three biomarkers (PICP, P3NP, Gal-3) known to be associated with the presence of myocardial fibrosis, in patients with end-stage renal disease (ESRD), not on dialysis. Methods We conducted a cross-sectional study that included 135 patients with an eGFR (CKD-EPI) <15 ml/min/1.73 m2, stable, asymptomatic, not on dialysis. We performed a complete transthoracic echocardiography with 2D-STE and determined serum levels of PICP, P3NP and Gal-3 by ELISA. Patients in atrial fibrillation, with a permanent pacemaker or with a poor acoustic window were excluded. Results The mean age was 59.2±15.5 (median 61 years), 44% of the patients were males, 33% were diabetic, 11% had a history of myocardial infarction and 14% were smokers. The average volumetric ejection fraction (EF) was 54.4±9.8% (median 55%), with only 6.3% of the patients having an EF <40%. The majority of the patients (86.6%) had at least grade I DD, with only 5.3% having a restrictive pattern (grade III DD). The mean GLS was −16.8% ± 0.1 (median −17%). The average serum levels of PICP, P3NP and Gal-3 were 440.2±139.6, 244.9±380.1 and 10.8±6.7, respectively. After regression analysis, GLS was correlated with PICP, P3NP and Gal-3 levels (p=0.005, r=0.88; p=0.001, r=0.75; and p=0.006, r=0.81 respectively). Additionally, GLS was inversely correlated with the severity of DD (p=0.0001, r=0.84). In multiple regression analysis of a model consisting of GLS, PICP, P3NP and Gal-3, the serum level of PICP counted for 34% of the variance of GLS (R2=0.559, p=0.002, F=32.39). Conclusions In conclusion, this study proves that although stable and asymptomatic, patients with ESRD have lower values of GLS, a high proportion of DD and higher values of PICP, P3NP and Gal-3, when compared with the general population, in spite of a normal EF. Our study is the first to demonstrate that these biomarkers correlated with GLS in patients with ESRD, suggesting that GLS could represent an important tool for estimating the amount of fibrosis and risk stratification in this population. Funding Acknowledgement Type of funding sources: None.

Echocardiographic assessment alone is inadequate for determining elevated left sided filling pressures in patients with cardiogenic shock

Abstract Background Left atrial (LA) filling pressure assessment is of paramount importance in tailoring treatments for patients with cardiogenic shock (CS). ESC guidelines advocate for the use of mitral inflow Doppler and mitral annulus tissue Doppler measurements to predict elevated left atrial pressure in clinical practice. Echocardiographic measurement of LA pressures could reduce the need for invasive monitoring in CS patients, but its utility remains unproven in this population. Purpose We assessed the validity of mitral inflow velocity and mitral annulus velocity indices to determine LA pressures, correlating them with invasive measurement of pulmonary capillary wedge pressure (PCWP) in CS patients admitted to the cardiac intensive care unit (CICU). Methods We prospectively evaluated consecutive patients who underwent pulmonary artery catheter insertion in the CICU, measuring their haemodynamic parameters, including PCWP. This was immediately followed by a transthoracic echocardiography (TTE) performed by a critical care cardiologist, blinded to the invasive measurements. The early (E) and late (A) mitral inflow velocities were measured using mitral inflow Doppler and septal and lateral mitral annulus velocities (e') were measured using tissue Doppler, all in the apical 4-chamber view. TTE images were later reported by a second cardiologist, blinded to the invasive measurements and the patient. Correlations between E; E/A ratio; E/e' ratio and PCWP were evaluated using Pearson's correlation. Results Sixty patients were recruited into the study, aged 58±14 years, 27% female, with 96 assessments undertaken. The majority (55%) of patients were SCAI stage C, with 14% having had a cardiac arrest prior to CICU admission and 27% required mechanical ventilation at the time of assessment. Mean PCWP was 16.0±6.5 mmHg. Full mitral valve Doppler and tissue Doppler profiles were measured in 67 (70%) assessments, limited due to E/A fusion, atrial fibrillation and limited acoustic windows. There was only weak correlation between PCWP and E/A ratio (R=0.33, p=0.01), with no correlation between PCWP and the other measured values (Table 1), including E/e'. The AUC for identifying patients with elevated PCWP (≥15 mmHg) using E/A ratio was 0.67 (p=0.02), although there was no suitable value to use as a cut off with adequate sensitivity and specificity (Figure 1). Conclusion Echocardiographic non-invasive assessment of left sided cardiac filling pressures is technically challenging in patients with CS. Even when possible, there is weak correlation between echocardiographic and invasive measurements, suggesting limited value in this technique. Alternative non-invasive modalities, such as lung ultrasound, should be investigated in this population to assist clinical assessment. Funding Acknowledgement Type of funding sources: None.

The impact of COVID-19 on right ventricular function in chronic kidney disease patients

Abstract Introduction In chronic kidney disease (CKD) patients, the case fatality rate caused by the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is higher than in the general population [1]. In patients hospitalised with COVID 19, right heart dysfunction is present in 20% of the cases, associated with an increased risk of all-cause death [2]. Purpose CARDIO-SCARS in CKD is a currently ongoing multi-center observational match controlled trial that aims to assess the cardiovascular (CV) risk in a CKD (stages 3 to 5), dialysis and kidney transplant population, following SARS-CoV-2 infection, by using clinical evaluation, various techniques and novel biomarkers (ClinicalTrials.gov Identifier NCT05125913). We hereby report the main baseline echocardiographic parameters that assess the right ventricular (RV) function. Methods We conducted a cross-sectional study that included 263 patients with CKD (dialysis, transplantation or eGFR <60 ml/min/1.73 m2). For assessing RV function, 5 parameters were measured: fractional area change (FAC, %), tricuspid annular plane systolic excursion (TAPSE, mm), tricuspid S' wave (S tric, cm/s), Tei index and right ventricular free wall longitudinal strain (RVFWLS, %). Patients in atrial fibrillation, with a permanent pacemaker or with a poor acoustic window were excluded. Results Our study included 263 patients with CKD, divided in two groups: 168 patients post COVID-19 (94 in dialysis, 38 post kidney transplantation and 36 with CKD) and 95 patients in the control group (57 in dialysis, 30 post kidney transplantation and 8 with CKD).The mean age was 57.3±15.4 years (median 60 years old), 55.2% of the patients were males, 24% were diabetic and 9.5% were smokers. The mean duration of dialysis in the COVID-19 group was 63.8 months vs. 62.6 months in the control group. In the COVID group, the echocardiography was performed at a mean distance of 2.2±2.1 months after testing positive for SARS-CoV-2.All the parameters of RV function were better in the control group (FAC (%): 43.6±11 vs. 41.3±11; TAPSE (mm): 23.2±6.9 vs. 21.4±4.9; S tric (cm/s): 13.4±3.4 vs. 13±3.1; Tei index: 0.5±0.2 vs. 0.6±0.2; RVFWLS (%): −20.1±3.8 vs. −18.6±5.1. After performing a two-sample t-Test, statistical significance was reached only for TAPSE, Tei index and RVFWLS (0.008, 0.0001 and 0.006, respectively). Conclusions Our study is the first to describe echocardiographic alterations post-COVID in a CKD population. All CKD patients had lower values of RV parameters than those reported in the general population. Still, the CKD COVID group had lower values than CKD control group, with the same magnitude as the changes reported in the general population [3,4]. The evolution of these parameters and their prognostic significance is of interest, regarding long-term CV sequelae of COVID-19. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Ministry of Research and Innovation, CNCS-UEFISCDI

The automatic identification of left ventricular chambers and quantification of ejection fraction using a novel artificial intelligence-based system – a validation against cardiac magnetic resonance

Abstract Background/Introduction Cardiac magnetic resonance imaging (CMR) is regarded as the reference method in assessing left ventricular (LV) ejection fraction (EF). However, 2-dimensional echocardiography (2D-Echo) is the most frequently used technique due to availability and practicability. The interpretation of 2D-Echo examinations depends on the user's expertise and may vary between different operators. A novel vendor-independent software based on artificial intelligence (AI) performs both, automated evaluation of 2D-Echo exams and calculations of LV EF in one workflow. Purpose We sought to assess the ability of the AI to automatically identify appropriate LV 4- and 2-chamber views (4CV) (2CV) from 2D-Echo exams and validate the resulting EF with CMR. Methods We consecutively enrolled 128 patients who underwent clinically indicated CMR examinations and performed a standard 2D-Echo at the same day. The server-based AI solution recognized the optimal LV 4CV and 2CV from 2D-Echo according to quality and depth criteria and automatically performed calculation of biplane EF by endocardial borderline detection. LV EF from CMR and AI were supervised by independent cardiologists blinded to the mutual results. Pearson's correlation (R) and Bland-Altman analysis with limits of agreement (LOA) were performed in order to assess bias between the two methods. Significance was defined as a 2-tailed P value <0.05. Results CMR was performed and LV EF was measured in all 128 patients. The median age was 60 years [20–86], 65% were males and CMR was performed due to coronary artery diseases (33%), suspected/florid myocarditis (20%) or further diagnosis of non-ischemic heart failure (47%). Eleven cases (9%) did not pass AI's criteria due to impaired acoustic window or poor 2D-Echo images. The AI system detected either 4CV or 2CV (ratio 1.2) in 13 patients (10%), and both 4CV and 2CV in 104 patients (81% overall feasibility) with a correct classification of 100%. For these 104 patients, excellent correlation was found for AI's biplane LV EF and LV EF from CMR with r=0.91 (p<0.001) (Figure 1, left). However, the absolute mean bias between AI and CMR was 3.5% (p<0.001) and LOAs were −10.6 and +17.5% (Figure 1, right). Conclusion The results provided by the AI-based software showed good capabilities and a perfect classification rate to identify 4CV and 2CV. In addition, the LV EF results were excellent compared to CMR, especially since our study did not include “echocardiographically” pre-selected patients. However, differences between AI and CMR measurements are not negligible and warrant further investigation. Funding Acknowledgement Type of funding sources: None.

Left ventricular ejection fraction – human vs artificial intelligence: quo vadis?

Abstract Background/Introduction Two-dimensional echocardiography (Echo) is a feasible method for assessing left ventricular (LV) ejection fraction (EF) in daily practice. However, the interpretation of Echo exams depends on the user's expertise and may vary between different operators. A novel, vendor-neutral artificial intelligence (AI) performs both, automated evaluation of Echo exams and calculations of biplane LV EF in one workflow. Purpose We sought to assess the ability of the AI to automatically identify appropriate LV 4- and 2-chamber views (4CV) (2CV) from routine Echo examinations and compare the resulting biplane EF with conventional hand-tracing biplane Simpson method (Human). Methods We prospectively enrolled 311 patients who underwent clinically indicated Echo exams. Biplane LV EF was manually traced online on 4CV and 2CV by cardiologists (Human). After completion of the exam, the AI-based solution recognized the optimal LV 4CV and 2CV according to quality and depth criteria and automatically performed the calculation of biplane EF by endocardial borderline detection without Human's interaction. Spearman's correlation (R) and Bland-Altman analysis with limits of agreement (LOA) were assessed for bias between the two methods. In a subgroup of 20 patients, Echo exams were automatically reanalyzed by the AI, and conventional biplane Simpson of LV EF was performed by two cardiologists blinded to the previous results to determine intraclass correlation (ICC). Significance was defined as a 2-tailed p value <0.05. Results 311 patients (median age 72 years [19–97]; 40% female) received an Echo for valvular heart disease, ischemic and non-ischemic heart failure or other indications (39, 31, 19 and 11%). 16 cases (5%) did not pass AI's criteria due to poor Echo imaging or impaired acoustic window of patients. In 53 patients (17%) either 4CV or 2CV were recognized, but the AI system successfully identified both 4CV and 2CV in 242 patients (overall feasibility 78%). For these 242 patients, correlation between AI and Human biplane LV EF was r=0.83 (p<0.001) (Figure 1 left). The absolute mean bias between methods was 5.2% (p<0.001) and absolute LOA ranged from −9.0 to +19.4% (Figure 1 right). ICC of LV EF by Human was 0.77 (p<0.001). The AI's ability to correctly re-/classify 4CV and 2CV was 100% with an ICC of 1 for fully automated LV EF measurements. Conclusion The results provided by the AI-based software showed very good capability to identify 4CV and 2CV and good LV EF result compared to Human manual tracings, especially since patients were not pre-selected. However, differences between AI and Human measurements are not negligible and warrant further investigations. Funding Acknowledgement Type of funding sources: None.

Echocardiographic phenotype and prognostic value of relative apical sparing of longitudinal strain pattern in severe aortic stenosis with and without cardiac amyloidosis. The AMYTAVI study

Abstract Introduction It is estimated that 15% of patients with AS have concomitant cardiac amyloidosis (CA). Left ventricular (LV) longitudinal strain (LS) pattern with relative apical sparing (RELAPS>1), shown as bright red in the apical segments on the polar map, has been strongly associated with CA. Its presence and its significance in AS is yet to be determined. Purpose To determine the prevalence of the RELAPS>1 pattern in patients with severe AS with and without concomitant CA, and to analyze the echocardiographic phenotype associated with this strain pattern and its prognostic value. Methods Patients with severe symptomatic AS undergoing TAVI were prospectively and consecutively included between Jan-19 and Dec-20. Pre-procedure, a complete echocardiogram was performed that included deformation parameters using Speckle-Tracking. Strain derived Indices accepted for CA screening were calculated: RELAPS: relative apical LS (average apical LS/average basal+mid LS); SAB: (apical-septal/basal-septal LS); EFSR: (LVEF/GLS). After TAVI, a 99Tc-PYP scintigraphy and a proteinogram were performed to screen for CA. Results 324 patients were included. The mean age was 81 yo, 52% women. Strain analysis could be performed in 243 patients due to acoustic window and covid19 pandemic restrictions. Among those, 111 (46%) presented relative apical sparing (RELAPS>1). There were no differences in clinical characteristics between patients with RELAPS <1 and >1: similar age, sex, cardiovascular risk factors and funcional class, renal function or NT-proBNP. Among patients with RELAPS>1 there was more frecuently CA with uptake grade 2 and 3 on scintigraphy (15% vs. 4.5%, P=0.006) (Figure 1). RELAPS>1 group showed greater LV hypertrophic remodeling: thicker myocardial wall with smaller ventricular cavity, especially concentric hypertrophy; LVEF and GLS was similar, however, MAPSE and myocardial contraction fraction (MCF) were worse in RELAPS >1 group, and EFSR was significantly higher (4.2 vs 3.9, p=0.002). RELAPS >1 group had smaller aortic valve area (AVA: 0.6 vs 0.7 cm2, p=0.045), but similar transvalvular gradients due to lower stroke volume. It had larger atria and less left atrial (LA) fractional emptying, as well as higher prevalence of atrial fibrillation (AF: 41% vs 27%, p=0.03). Right ventricle (RV) size were similar, however, RV function was worse in RELAPS >1 group (TAPSE: 19 vs 21 mm, p=0.003; free Wall LS: −24 vs −27%, p=0.008). There was no difference in all-cause mortality at 1 year of follow-up between groups (6.4% vs. 6.3%, p=1). Figure 2 represents the morphological characteristics according to the LS phenotype. Conclusions In severe AS, RELAPS >1 is present in almost half of the patients. It is associated with worse cardiac remodeling, as well as higher prevalence of AF. However, it wasn't associated with higher mortality at 1 year. 1 in 7 patients with AS and RELAPS >1 have concomitant ATTR CA grade 2/3. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Pfizer

HFA-PEFF score as a prognostic factor in patients with liver cirrhosis

Abstract Introduction Cardiovascular complications of liver cirrhosis which are frequently referred to as cirrhotic cardiomyopathy (CCM), include high cardiac output, reduced afterload and diastolic dysfunction. However, there are only scarce or even conflicting data about the prognostic significance of CCM. HFA-PEFF score is a diagnostic score for heart failure with preserved ejection fraction (HFpEF), which has prognostic value in HFpEF patients. It has functional, morphological and biomarker domains and the score may vary from 0 to 6. Score of 5 or 6 is diagnostic of HFpEF in symptomatic patients. No study has calculated HFA-PEFF score in cirrhotic patients to date. Purpose The purpose of this prospective study was to calculate HFA-PEFF score in cirrhotic patients, correlate it with disease severity and determine its prognostic significance. Methods A total number of 92 consecutive cirrhotic outpatients were prospectively examined and 72 fulfilled the inclusion criteria. Patients older than 75 years old or patients with ejection fraction (LVEF) <50%, coronary artery disease, moderate or severe valvular heart disease, atrial fibrillation, ongoing alcohol consumption, hepatocellular carcinoma and poor acoustic window were excluded. In all patients a thorough echocardiographic examination was performed, BNP or NT-pro-BNP levels were measured and subsequently HFA-PEFF score was calculated. MELD score was used to define the severity of cirrhosis. The median follow-up was 20 months and the study end-point was defined as the composite of all-cause death. Results Mean age was 58.5±8.3 years, 52 (72.2%) were males, median Meld score was 12.9 (8.5–16.3) and mean LVEF was 61.1±5.4%. HFA-PEFF score was 5 or 6 in 38 (52.8%), 2–4 in 27 (37.5%) and 0 or 1 in 9 (9.7%) patients. According to Spearman's coefficient analysis, HFA-PEFF score was correlated with MELD score (rho=0.566, p<0.001), but not with age, systolic blood pressure (SBP) and heart rate. The survival analysis stratified by the HFA-PEFF score [low, score 0–4 (N=34) vs. high, score 5–6 (N=38)] indicated that the HFA-PEFF score successfully predicted all cause two-year survival (log-rank test p<0.001). According to the Cox-regression proportion hazard models HFA-PEFF score as a continuous variable correlated with six-month, one year and two year survival. When HFA-PEFF was treated as a categorical variable, hazard models were significant for the one and two-year survival. The multivatiate COX regression survival analysis showed that the increased HFA-PEFF score (low: score 0–4, N=34 vs high: score 5–6, N=38) was significantly associated with decreased two-year survival when patient age, gender and MELD score are taken into account [HR=3.659 (1.068–12.536), p=0.039]. Conclusions HFA-PEFF score is high among patients with liver cirrhosis, especially those with increased disease severity. HFA-PEFF score is associated with survival even when adjusting for the severity of the cirrhosis. Funding Acknowledgement Type of funding sources: None.

Ultrasonic properties of human scalp

The goal of this study was to characterize the ultrasonic properties of human scalp. Thirty-two specimens were prepared from formalin-fixed scalp tissue from four human donors (age 35–65, 2 male, 2 female). Tissue specimens were mounted in acrylic frames with a 30 × 30-mm acoustic window. The specimens were scanned in a water tank with a broadband ultrasound transducer with center frequency 7.5 MHz using a motion-controlled system. The ultrasonic region of interest (ROI) was a 20 × 20-mm region with a step size of 410 μm. The signals acquired were analyzed to determine the speed of sound (SOS) and frequency slope of attenuation (FSA) at all scan locations (2500 locations per specimen). The mean ± standard deviation (SD) of the SOS and FSA over all the specimens respectively was 1536 ± 9 m/s and 1.88 ± 0.51 dBcm-1MHz-1. The SD within an ROI was 3–15 m/s for SOS and 0.15–0.85 dBcm-1MHz-1 for FSA, depending on specimen, indicating some heterogeneity in the ultrasonic properties of the tissue.

Transcranial Doppler ultrasound: Clinical applications from neurological to cardiological setting.

Transcranial Doppler (TCD) ultrasonography is a rapid, noninvasive, real-time, and low-cost imaging technique. It is performed with a low-frequency (2 MHz) probe in order to evaluate the cerebral blood flow (CBF) and its pathological alterations, through specific acoustic windows. In the recent years, TCD use has been expanded across many clinical settings. Actually, the most widespread indication for TCD exam is represented by the diagnosis of paradoxical embolism, due to patent foramen ovale, in young patients with cryptogenic stroke. In addition, TCD has also found useful applications in neurological care setting, including the following: cerebral vasospasm following acute subarachnoid hemorrhage, brain trauma, cerebrovascular atherosclerosis, and evaluation of CBF and cerebral autoregulation after an ischemic stroke event. The present review aimed to describe the most recent evidences of TCD utilization from neurological to cardiological setting.

Investigation and development of an empirical model for transmission loss of acoustic windows in alleviating road traffic noise impact

An Acoustic Window is comprised of a horizontal sliding window at the inner layer, and a side-hung window, which can be pushed to open, on one side of the outer layer, and a fixed glazing on the other side. The glazing of the sliding inner window serves as a “baffle” for screening off the noise passing through the opened outer window when it is slid behind the opened outer window. This baffle-type acoustic window is proved to reduce up to 8 dB(A) road traffic noise and is gaining popularity in residential developments of Hong Kong, particularly for those located in difficult sites in close proximity to heavily trafficked roads. This paper presents the experimental results from a study looking into the acoustical transmission loss of Acoustic Windows with respect to changes in window configuration and setting of line sources. Based on the experimental results, empirical models for noise reduction of Acoustic Windows are developed and investigated to assist quick design of Acoustic Windows for planning residential developments.

“ROLE OF FETAL MRI IN EVALUATION OF CONGENITAL ANOMALIES”

When US evaluation of the second and third-trimester foetus is limited, MR imaging might be used as a supplemental test. Due to a lack of an acceptable acoustic window, US is often limited in cases of oligohydramnios or breech presentation. In both cases, however, MR imaging can clearly show the foetal anatomy in detail. Ossification of the calvaria[1], which inhibits view of the posterior fossa at US, can also impede third trimester foetal assessment. US frequently suggests intracranial pathologic abnormalities such as posterior fossa anomalies (Chiari II syndrome, cerebellar aplasia or hypoplasia). MR imaging can corroborate the US findings, and it can also provide a diagnosis in some circumstances, such as neuronal migrational anomalies. MR imaging certainly has the advantage of being able to analyse the foetus in many planes within a greater field of view. T1-weighted MR imaging can show acute and chronic germinal matrix bleeding, as well as ischemia alterations. Although ultrasound is helpful in detecting corpus callosum abnormalities, it can miss many of the central nervous system problems associated with corpus callosum agenesis. Because the prognosis of agenesis of the corpus callosum is so unpredictable, detecting concomitant central system defects on MR imaging can help with prenatal and postnatal medical care. Although the majority of prenatal MR imaging applications are related to the cranial nervous system, new developments in foetal surgical intervention have expanded the utility of foetal MR imaging in thoracoabdominal illness detection. Fetal MR imaging can help diagnose abnormalities such congenital cystic adenomatoid malformation, congenital diaphragmatic hernia, cystic hygroma, and bronchopulmonary sequestration. Accurate assessment of foetal lung and liver sizes is critical in foetal surgical planning and postnatal prognosis in the case of congenital diaphragmatic hernia. Some high-risk pregnancies may also benefit from obstetric MR imaging, according to preliminary research. With a combination of foetal weight estimates and liver volume measurements, birth weight may be correctly predicted and the diagnosis of intrauterine growth retardation or macrosomia can be made with confidence.

A 3D volume capture for ultrasound assessment of various organs and vessels by novice operators

IntroductionThe quality of ultrasound images is dependent on operator skill level. Therefore, an automated system is required for situations, such as spaceflight, where a trained sonographer is not present. The current study compared an automated 3D volume capture method of ultrasound assessment (triggered by novices) with respect to teleoperation by sonographer expert (T-echo). MethodsUltrasound images were collected from 14 participants (8 male) using a commercial portable echograph with motorized probes for volume capture (3D) and later teleoperated assessment (T-echo). A novice operator positioned the ultrasound probe over the acoustic window (AW) of interest using an AW body mapping with only confirmation of the placement by the distant sonographer, and held the probe stationary for both the 3D assessment and the teleoperated investigation. ResultsThere were no differences between the quality of T-echo and 3D images for the majority of structures assessed. Strong relationships were found between the measurements made with both methods (r values between 0.79 and 0.961) with an average difference less than 5% for all parameters measured. ConclusionThe automated 3D capture method acquired images with minimal effect on measurement values. While this 3D method may not be appropriate for structures that are moving during the volume capture (heart), it does present a functional method of acquiring ultrasound diagnostic images with a distant sonographer only verifying the positioning of the ultrasound probe on the AW. With software (under development) driving automatically the novice hand directly to the AW the 3D echography, will be fully automated.

Satellite remote sensing of environmental variables can predict acoustic activity of an orthopteran assemblage.

Passive acoustic monitoring (PAM) is a promising method for biodiversity assessment, which allows for longer and less intrusive sampling when compared to traditional methods (e.g., collecting specimens), by using sound recordings as the primary data source. Insects have great potential as models for the study and monitoring of acoustic assemblages due to their sensitivity to environmental changes. Nevertheless, ecoacoustic studies focused on insects are still scarce when compared to more charismatic groups. Insects’ acoustic activity patterns respond to environmental factors, like temperature, moonlight, and precipitation, but community acoustic perspectives have been barely explored. Here, we provide an example of the usefulness of PAM to track temporal patterns of acoustic activity for a nocturnal assemblage of insects (Orthoptera). We integrate satellite remote sensing and astronomically measured environmental factors at a local scale in an Andean Forest of Colombia and evaluate the acoustic response of orthopterans through automated model detections of their songs for nine weeks (March and April of 2020). We describe the acoustic frequency range and diel period for the calling song of each representative species. Three species overlapped in frequency and diel acoustics but inhabit different strata: canopy, understory, and ground surface level. Based on the acoustic frequency and activity, we identified three trends: (i) both sampled cricket species call at lower frequency for shorter periods of time (dusk); (ii) all sampled katydid species call at higher frequency for longer time periods, including later hours at night; and (iii) the diel acoustic activity span window seems to increase proportionally with dominant acoustic frequency, but further research is required. We also identified a dusk chorus in which all the species sing at the same time. To quantify the acoustic response to environmental factors, we calculated a beta regression with the singing activity as a response variable and moon phase, surface temperature and daily precipitation as explanatory variables. The response to the moon phase was significant for the katydids but not for the crickets, possibly due to differences in diel activity periods. Crickets are active during dusk, thus the effects of moonlight on acoustic activity are negligible. The response to precipitation was significant for the two crickets and not for the katydids, possibly because of higher likelihood of rain interrupting crickets’ shorter diel activity period. Our study shows how the local survey of orthopteran acoustic assemblages, with a species taxonomic resolution coupled with remote-sensing environmental measurements can reveal responses to environmental factors. In addition, we demonstrate how satellite data might prove to be a useful alternative source of environmental data for community studies with geographical, financial, or other constraints.

Physics-Informed Neural Networks for Brain Hemodynamic Predictions Using Medical Imaging.

Determining brain hemodynamics plays a critical role in the diagnosis and treatment of various cerebrovascular diseases. In this work, we put forth a physics-informed deep learning framework that augments sparse clinical measurements with one-dimensional (1D) reduced-order model (ROM) simulations to generate physically consistent brain hemodynamic parameters with high spatiotemporal resolution. Transcranial Doppler (TCD) ultrasound is one of the most common techniques in the current clinical workflow that enables noninvasive and instantaneous evaluation of blood flow velocity within the cerebral arteries. However, it is spatially limited to only a handful of locations across the cerebrovasculature due to the constrained accessibility through the skull's acoustic windows. Our deep learning framework uses in vivo real-time TCD velocity measurements at several locations in the brain combined with baseline vessel cross-sectional areas acquired from 3D angiography images and provides high-resolution maps of velocity, area, and pressure in the entire brain vasculature. We validate the predictions of our model against in vivo velocity measurements obtained via four-dimensional (4D) flow magnetic resonance imaging (MRI) scans. We then showcase the clinical significance of this technique in diagnosing cerebral vasospasm (CVS) by successfully predicting the changes in vasospastic local vessel diameters based on corresponding sparse velocity measurements. We show this capability by generating synthetic blood flow data after cerebral vasospasm at various levels of stenosis. Here, we demonstrate that the physics-based deep learning approach can estimate and quantify the subject-specific cerebral hemodynamic variables with high accuracy despite lacking knowledge of inlet and outlet boundary conditions, which is a significant limitation for the accuracy of the conventional purely physics-based computational models.

Corrected and Republished

Transesophageal echocardiography (TEE) has unique advantages over conventional transthoracic echocardiography (TTE). Compared with TTE, TEE generally provides excellent quality images, especially of the posteriorly situated cardiac structures, such as atria, pulmonary veins, mitral valve, and left atrial appendage. TEE also offers a useful alternative to TTE in patients in whom transthoracic acoustic windows are suboptimal. Furthermore, TEE is the most suited imaging modality for use in the operating rooms and cardiac catheterization labs for guiding cardiac surgical or interventional procedures. However, specific training and competence are required for performing TEE successfully, smoothly, safely and with minimum patient discomfort. This document describes the basic principles of TEE examination, including patient selection and preparation, periprocedural monitoring, and probe handling and maneuvers. Commonly recommended views and the techniques to obtain these views are described in detail, followed by evaluation of specific cardiac structures. Finally, the role of TEE in certain specific clinical settings, such as during advanced circulatory support, is also discussed.

The Relationship of Liver Stiffness with Liver Size, Age, Gender, and Body Mass Index in Child and Adult Age Groups by 2-D Shear Wave Elastography

Aim: The study aimed to evaluate the normal liver stiffness value (LSV) with shear wave elastography (SWE) in children and adults, and reveal the relationship between LSV and age, gender, body mass index (BMI), and liver size. Material and Methods: A total of 173 healthy volunteers, 92 female and 81 male, aged between 4 and 50 years were included in this study. LSV measurements were performed in the supine position during normal breathing and from the right intercostal space where the acoustic window is best. The mean of the five valid measurements was accepted as the mean LSV. The relationship between the mean LSV and age, gender, liver size, and BMI was evaluated. Results: There was a moderate positive correlation between LSV and age (p<0.001, r=0.609), LSV and BMI (p<0.001, r=0.512), and LSV and liver size (p<0.001, r=0.485). However, the multivariate linear regression analysis revealed that the effects of liver size and gender on LSV were not significant (p=0.091, and p=0.759, respectively), while the effects of age and BMI were significant (p<0.001, and p=0.019, respectively). Conclusion: 2-D SWE is an effective imaging method to evaluate LSV both in children and adults. LSV increases with increasing age and BMI, however, it is not affected by gender and liver size. The normal LSV obtained in the present study can be used as reference values in the evaluation of various liver diseases with 2-D SWE.

Pericapsular hip desensitization in dogs: a cadaveric study and case series

ObjectiveTo develop and assess the efficacy of an ultrasound (US)-guided pericapsular hip desensitization (PHD) technique in dogs. Study designProspective, randomized, anatomical study and a case series. AnimalsA total of 30 healthy dogs, eight canine cadavers and seven dogs with hip osteoarthritis. MethodsAfter studying the US anatomy of the medial aspect of the coxofemoral joint and determining an acoustic window to perform an US-guided PHD in healthy dogs, the US-guided PHD was performed bilaterally in canine cadavers. A low [(LV) 0.1 mL kg–1] and high [(HV) 0.2 mL kg–1] volume of dye was injected per hip on each cadaver. The staining of the pericapsular nerves was assessed by anatomical dissection, and comparison between LV and HV was assessed using Fisher’s exact test. Then, the US-guided PHD was performed using a triamcinolone–bupivacaine solution in dogs with hip osteoarthritis. Dynamic pain response was assessed before and after injection. The canine brief pain inventory (CBPI) questionnaire was used to assess treatment efficacy and duration. ResultsThe US-guided PHD could be performed by inserting the needle between the iliopsoas muscle and the periosteum of the ilium. The articular branches of the femoral and obturator nerves were stained in all cadavers using both volumes. The main femoral nerve was never stained, but the main obturator nerve was stained in 37.5% and 100% of injections using LV and HV, respectively (p = 0.026). Treated animals showed decreased dynamic pain response after the injection. Compared with baseline, CBPI scores were reduced by ≥ 50% for ≥ 12 weeks in all but one dog. Conclusions and clinical significanceThe US-guided PHD with both 0.1 and 0.2 mL kg–1 volumes stained the articular branches of the femoral and obturator nerves in canine cadavers and was associated with clinical improvement in dogs with hip osteoarthritis.

Lung consolidation as an acoustic window to superior vena cava by transthoracic ultrasonography in the intensive care unit.

Lung consolidation as an acoustic window to superior vena cava by transthoracic ultrasonography in the intensive care unit.

Feasibility of leadless left ventricular septal pacing with the WiSE-CRT system to target the left bundle branch area: A porcine model and multicenter patient experience

The WiSE-CRT system delivers leadless endocardial left ventricular (LV) pacing to achieve cardiac resynchronization therapy. The electrode is conventionally placed on the lateral wall, but implanting on the LV septum may have advantages, including capture of the left bundle branch, and improved battery longevity owing to reduced distance from the transmitter. The purpose of this study was to assess the feasibility of leadless LV septal pacing via the WiSE-CRT system. Two pigs underwent electrode implantation on the LV septum with subsequent anatomical and histological examination. Eight patients underwent implantation of the WiSE-CRT system with deployment of the electrode on the LV septum via an interatrial transseptal approach. Deployment of the electrode on the LV septum was successful in both animals. Histological examination demonstrated electrode tines in close proximity to Purkinje tissue. WiSE-CRT implantation with an LV septal electrode was successful in all patients. Biventricular capture was confirmed, with a significant reduction in QRS duration (187.1 ± 33.8 ms vs 149.5 ± 15.7 ms; P = .009). Temporary LV pacing achieved further QRS reduction (139.8 ± 12.4 ms), and in 4 patients the peak LV activation time in lead V5/V6 was <90 ms, suggesting left bundle branch capture. At early follow-up, the median LV pacing percentage was 98.5% and 5 patients (62.5%) improved symptomatically. The transmitter-to-electrode distance was lower than the distance to the lateral wall during acoustic window screening (8.8 ± 1.6 cm vs 11.9 ± 1.5 cm; P = .002). Leadless LV septal pacing with the WiSE-CRT system to target the left bundle branch appears feasible. Further study is required to assess the efficacy and safety of this technique.

Sonographic Assessment of Placenta Previa with and without History of Cesarean Section or Abortion

Background: The incidence of placenta Previa has increased with increasing maternal age due to late marriages. Objective: To assess occurrence of placenta Previa in females with and without history of C- section, abortion and both. Methodology: Descriptive cross sectional study conducted in Sir Ganga Ram Hospital Lahore, radiology department. Duration of study was nine months after the approval of synopsis. Main aim was to assess occurrence of placenta Previa in females with and without history of C-section and abortion or both. The examination will start with the patient in the supine position (3.5 – 5 MHz) convex probe will be used .From the anteriorly using urinary bladder as acoustic window ultrasound will be performed in the longitudinal planes. In Transabdominal study (TAS) the bladder will be adequately distended to visualization of the cervix and lower uterine segment and to check the relationship of the placenta to the inner os. If indicated, positioning the patient in a right or left posterior oblique position may be helpful to check the posterior placenta. The diagnosis of placenta Previa will be considered if the lower placental edge covers the internal os.