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result(s) for
"Cheng, Andrew L."
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Fully‑automated deep‑learning segmentation of pediatric cardiovascular magnetic resonance of patients with complex congenital heart diseases
by
Cheng, Andrew L.
,
Jafarkhani, Hamid
,
Arafati, Arghavan
in
Adolescent
,
Age Factors
,
Algorithms
2020
Background
For the growing patient population with congenital heart disease (CHD), improving clinical workflow, accuracy of diagnosis, and efficiency of analyses are considered unmet clinical needs. Cardiovascular magnetic resonance (CMR) imaging offers non-invasive and non-ionizing assessment of CHD patients. However, although CMR data facilitates reliable analysis of cardiac function and anatomy, clinical workflow mostly relies on manual analysis of CMR images, which is time consuming. Thus, an automated and accurate segmentation platform exclusively dedicated to pediatric CMR images can significantly improve the clinical workflow, as the present work aims to establish.
Methods
Training artificial intelligence (AI) algorithms for CMR analysis requires large annotated datasets, which are not readily available for pediatric subjects and particularly in CHD patients. To mitigate this issue, we devised a novel method that uses a generative adversarial network (GAN) to synthetically augment the training dataset via generating synthetic CMR images and their corresponding chamber segmentations. In addition, we trained and validated a deep fully convolutional network (FCN) on a dataset, consisting of
64
pediatric subjects with complex CHD, which we made publicly available. Dice metric, Jaccard index and Hausdorff distance as well as clinically-relevant volumetric indices are reported to assess and compare our platform with other algorithms including U-Net and cvi42, which is used in clinics.
Results
For congenital CMR dataset, our FCN model yields an average Dice metric of
91.0
%
and
86.8
%
for LV at end-diastole and end-systole, respectively, and
84.7
%
and
80.6
%
for RV at end-diastole and end-systole, respectively. Using the same dataset, the cvi42, resulted in
73.2
%
,
71.0
%
,
54.3
%
and
53.7
%
for LV and RV at end-diastole and end-systole, and the U-Net architecture resulted in
87.4
%
,
83.9
%
,
81.8
%
and
74.8
%
for LV and RV at end-diastole and end-systole, respectively.
Conclusions
The chambers’ segmentation results from our fully-automated method showed strong agreement with manual segmentation and no significant statistical difference was found by two independent statistical analyses. Whereas cvi42 and U-Net segmentation results failed to pass the t-test. Relying on these outcomes, it can be inferred that by taking advantage of GANs, our method is clinically relevant and can be used for pediatric and congenital CMR segmentation and analysis.
Journal Article
Proof-of-concept for a non-invasive, portable, and wireless device for cardiovascular monitoring in pediatric patients
2020
Measurement of cardiac function is vital for the health of pediatric patients with heart disease. Standard tools to measure function including echocardiogram and magnetic residence imaging are time intensive, costly, and have limited accessibility. The Vivio is a novel, non-invasive, handheld device that screens for cardiac dysfunction by analyzing intrinsic frequencies (IF) ω1 and ω2 of carotid artery waveforms. Prior studies demonstrated that left ventricular ejection fraction can be derived from IFs in adults. This study 1) studies whether the Vivio can capture carotid arterial pulse waveform data in children ages 0-19 years old; 2) tests the performance of two sensor head geometries, one larger and smaller than the standard size used in adults, designed for the pediatric population; 3) compares the IFs between pediatric age groups and adults with normal function. The Vivio successfully measured a carotid artery waveform in all children over 5 years old and 28% of children under the age of five. The small head did not accurately measure a waveform in any age group. One-way analysis of variance (ANOVA) demonstrated a difference in the IF ω1 between the adult and pediatric cohorts (F = 7.3, Prob>F = 0.0001). Post host analysis demonstrated a difference between the adult cohort (ω1 = 99 +/- 5 bpm) and the cohorts ages 0-4 (ω1 = 111 +/- 2 bpm; p = 0.0006) and 15-19 years old (ω1 = 105 +/-5 bpm; p = 0.02). One-way ANOVA demonstrated a difference in the IF ω2 between the adult and pediatric cohorts (F = 4.8, Prob>F = 0.003), specifically between the adult (ω2 = 81 +/- 13 bpm) and age 0-4 cohorts (ω2 = 48 +/- 8 bpm; p = 0.002). These results suggest that the Vivio can be used to capture carotid pulse waveform data in pediatric populations and that the data produced can be used to measure intrinsic frequencies.
Journal Article
Decreased erythrocyte aggregation in Glenn and Fontan: univentricular circulation as a rheologic disease model
2024
Background
In the Fontan palliation for single ventricle heart disease (SVHD), pulmonary blood flow is non-pulsatile/passive, low velocity, and low shear, making viscous power loss a critical determinant of cardiac output. The rheologic properties of blood in SVHD patients are essential for understanding and modulating their limited cardiac output and they have not been systematically studied. We hypothesize that viscosity is decreased in single ventricle circulation.
Methods
We evaluated whole blood viscosity, red blood cell (RBC) aggregation, and RBC deformability to evaluate changes in healthy children and SVHD patients. We altered suspending media to understand cellular and plasma differences contributing to rheologic differences.
Results
Whole blood viscosity was similar between SVHD and healthy at their native hematocrits, while viscosity was lower at equivalent hematocrits for SVHD patients. RBC deformability is increased, and RBC aggregation is decreased in SVHD patients. Suspending SVHD RBCs in healthy plasma resulted in increased RBC aggregation and suspending healthy RBCs in SVHD plasma resulted in lower RBC aggregation.
Conclusions
Hematocrit corrected blood viscosity is lower in SVHD vs. healthy due to decreased RBC aggregation and higher RBC deformability, a viscous adaptation of blood in patients whose cardiac output is dependent on minimizing viscous power loss.
Impact
Patients with single ventricle circulation have decreased red blood cell aggregation and increased red blood cell deformability, both of which result in a decrease in blood viscosity across a large shear rate range.
Since the unique Fontan circulation has very low-shear and low velocity flow in the pulmonary arteries, blood viscosity plays an increased role in vascular resistance, therefore this work is the first to describe a novel mechanism to target pulmonary vascular resistance as a modifiable risk factor.
This is a novel, modifiable risk factor in this patient population.
Journal Article
Prenatal diagnosis of tetralogy of Fallot with a double aortic arch
by
Kung, Grace C.
,
Cheng, Andrew L.
,
Pruetz, Jay D.
in
Adult
,
Aorta, Thoracic - abnormalities
,
Aorta, Thoracic - surgery
2016
In this study, we present a case of prenatally diagnosed tetralogy of Fallot with a double aortic arch, correlating images from fetal echocardiography, transthoracic echocardiography, and cardiac MRI.
Journal Article
Left bronchial compression and pulmonary hypertension related to anomalous right pulmonary artery
by
Su, Jennifer A.
,
Cheng, Andrew L.
,
Szmuszkovicz, Jacqueline R.
in
Aorta - abnormalities
,
Brief Reports
,
Bronchial Diseases - diagnostic imaging
2016
Anomalous origin of a pulmonary artery from the ascending aorta is a congenital defect that can be complicated by pulmonary arterial hypertension, typically due to vascular disease if the anomaly is left uncorrected past 6 months of age. We describe a unique case of severe pulmonary arterial hypertension with this defect in a 1-month-old infant unexpectedly caused instead by bronchial compression from her dilated left pulmonary artery.
Journal Article
The NHLBI Study on Long-ter M O U tcomes after the Multisystem I nflammatory S yndrome I n C hildren (MUSIC): Design and Objectives
2022
BackgroundThe Long-terM OUtcomes after the Multisystem Inflammatory Syndrome In Children (MUSIC) study aims to characterize the frequency and time course of acute and long-term cardiac and non-cardiac sequelae in multisystem inflammatory syndrome in children associated with COVID-19 (MIS-C), which are currently poorly understood.MethodsThis multicenter observational cohort study will enroll at least 600 patients <21 years old who meet the Centers for Disease Control and Prevention case definition of MIS-C across multiple North American centers over 2 years. The study will collect detailed hospital and follow-up data for up to 5 years, and optional genetic testing. Cardiac imaging at specific time points includes standardized echocardiographic assessment (all participants) and cardiac magnetic resonance imaging (CMR) in those with left ventricular ejection fraction (LVEF) <45% during the acute illness. The primary outcomes are the worst LVEF and the highest coronary artery z-score of the left anterior descending or right coronary artery. Other outcomes include occurrence and course of non-cardiac organ dysfunction, inflammation, and major medical events. Independent adjudication of cases will classify participants as definite, possible, or not MIS-C. Analysis of the outcomes will include descriptive statistics and regression analysis with stratification by definite or possible MIS-C. The MUSIC study will provide phenotypic data to support basic and translational research studies.ConclusionThe MUSIC study, with the largest cohort of MIS-C patients and the longest follow-up period to date, will make an important contribution to our understanding of the acute cardiac and non-cardiac manifestations of MIS-C and the long-term effects of this public health emergency.
Journal Article
A fault tolerant single sided matrix converter for flight control actuation systems
by
Zhang, Jian-cheng
,
Lu, Qin-fen
,
Huang, Xiao-yan
in
Actuation
,
Circuit design
,
Control systems
2012
We describe a single sided matrix converter (SSMC) designed for safety critical applications like flight control actuation systems. Dynamic simulations of multi-phase SSMC using Matlab Simulink are carried out to evaluate the fault tolerance capabilities. Investigation into different numbers of phases and power converter topologies under single phase open circuit, single switch open circuit, and single switch short circuit has been executed. The simulation results confirm 5-phase SSMC design as a compromise between fault tolerance and converter size/volume. A 5-phase SSMC prototype was built. Experimental results verify the effectiveness of our design.
Journal Article
Orbital period change of Dimorphos due to the DART kinetic impact
by
Polakis, Tom
,
Osip, David J.
,
Knight, Matthew M.
in
639/33/34/4117
,
639/33/445/847
,
639/33/445/848
2023
The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision
1
, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement (
β
) was possible
2
,
3
. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos
4
–
6
. Here we report the change in the orbital period of Dimorphos as a result of the DART kinetic impact to be −33.0 ± 1.0 (3
σ
) min. Using new Earth-based lightcurve and radar observations, two independent approaches determined identical values for the change in the orbital period. This large orbit period change suggests that ejecta contributed a substantial amount of momentum to the asteroid beyond what the DART spacecraft carried.
The 33 minute change in the orbital period of Dimorphos after the DART kinetic impact suggests that ejecta contributed a substantial amount of momentum to the asteroid compared with the DART spacecraft alone.
Journal Article
Cabozantinib plus atezolizumab versus sorafenib for advanced hepatocellular carcinoma (COSMIC-312): a multicentre, open-label, randomised, phase 3 trial
by
Ryoo, Baek-Yeol
,
Benzaghou, Fawzi
,
Kaseb, Ahmed
in
Adverse events
,
Alanine
,
Alanine transaminase
2022
Cabozantinib has shown clinical activity in combination with checkpoint inhibitors in solid tumours. The COSMIC-312 trial assessed cabozantinib plus atezolizumab versus sorafenib as first-line systemic treatment for advanced hepatocellular carcinoma.
COSMIC-312 is an open-label, randomised, phase 3 trial that enrolled patients aged 18 years or older with advanced hepatocellular carcinoma not amenable to curative or locoregional therapy and previously untreated with systemic anticancer therapy at 178 centres in 32 countries. Patients with fibrolamellar carcinoma, sarcomatoid hepatocellular carcinoma, or combined hepatocellular cholangiocarcinoma were not eligible. Tumours involving major blood vessels, including the main portal vein, were permitted. Patients were required to have measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), Barcelona Clinic Liver Cancer stage B or C disease, an Eastern Cooperative Oncology Group performance status of 0 or 1, adequate organ and marrow function, and Child-Pugh class A. Previous resection, tumour ablation, radiotherapy, or arterial chemotherapy was allowed if more than 28 days before randomisation. Patients were randomly assigned (2:1:1) via a web-based interactive response system to cabozantinib 40 mg orally once daily plus atezolizumab 1200 mg intravenously every 3 weeks, sorafenib 400 mg orally twice daily, or single-agent cabozantinib 60 mg orally once daily. Randomisation was stratified by disease aetiology, geographical region, and presence of extrahepatic disease or macrovascular invasion. Dual primary endpoints were progression-free survival per RECIST 1.1 as assessed by a blinded independent radiology committee in the first 372 patients randomly assigned to the combination treatment of cabozantinib plus atezolizumab or sorafenib (progression-free survival intention-to-treat [ITT] population), and overall survival in all patients randomly assigned to cabozantinib plus atezolizumab or sorafenib (ITT population). Final progression-free survival and concurrent interim overall survival analyses are presented. This trial is registered with ClinicalTrials.gov, NCT03755791.
Analyses at data cut-off (March 8, 2021) included the first 837 patients randomly assigned between Dec 7, 2018, and Aug 27, 2020, to combination treatment of cabozantinib plus atezolizumab (n=432), sorafenib (n=217), or single-agent cabozantinib (n=188). Median follow-up was 15·8 months (IQR 14·5–17·2) in the progression-free survival ITT population and 13·3 months (10·5–16·0) in the ITT population. Median progression-free survival was 6·8 months (99% CI 5·6–8·3) in the combination treatment group versus 4·2 months (2·8–7·0) in the sorafenib group (hazard ratio [HR] 0·63, 99% CI 0·44–0·91, p=0·0012). Median overall survival (interim analysis) was 15·4 months (96% CI 13·7–17·7) in the combination treatment group versus 15·5 months (12·1–not estimable) in the sorafenib group (HR 0·90, 96% CI 0·69–1·18; p=0·44). The most common grade 3 or 4 adverse events were alanine aminotransferase increase (38 [9%] of 429 patients in the combination treatment group vs six [3%] of 207 in the sorafenib group vs 12 [6%] of 188 in the single-agent cabozantinib group), hypertension (37 [9%] vs 17 [8%] vs 23 [12%]), aspartate aminotransferase increase (37 [9%] vs eight [4%] vs 18 [10%]), and palmar-plantar erythrodysaesthesia (35 [8%] vs 17 [8%] vs 16 [9%]); serious treatment-related adverse events occurred in 78 (18%) patients in the combination treatment group, 16 (8%) patients in the sorafenib group, and 24 (13%) in the single-agent cabozantinib group. Treatment-related grade 5 events occurred in six (1%) patients in the combination treatment group (encephalopathy, hepatic failure, drug-induced liver injury, oesophageal varices haemorrhage, multiple organ dysfunction syndrome, and tumour lysis syndrome), one (<1%) patient in the sorafenib group (general physical health deterioration), and one (<1%) patient in the single-agent cabozantinib group (gastrointestinal haemorrhage).
Cabozantinib plus atezolizumab might be a treatment option for select patients with advanced hepatocellular carcinoma, but additional studies are needed.
Exelixis and Ipsen.
Journal Article