2d echo

We present measurements of the coherence times of excited states of hydrogen-like arsenic impurities in germanium (Ge:As) using a table-top two-dimensional time-domain spectroscopy (2D-TDS) system. We show that this laboratory system is capable of resolving the coherence lifetimes of atomic-like excited levels of impurity centers in semiconductors, such as those used in solid-state quantum information technologies, on a subpicosecond time scale. By fitting the coherent nonlinear response of the system with the known intracenter transition frequencies, we are able to monitor coherent population transfer and decay of the transitions from the 2p0 and 2p± states for different low excitation pulse fields...

AIMS: Conventional echocardiographic parameters such as tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and free-wall longitudinal strain (FWLS) offer limited insights into the complexity of right ventricular (RV) systolic function, while 3D echocardiography-derived RV ejection fraction (RVEF) enables a comprehensive assessment. We investigated the discordance between TAPSE, FAC, FWLS, and RVEF in RV systolic function grading and associated outcomes. METHODS: We analyzed 2D and 3D echocardiography data from two centers including 750 patients followed up for all-cause mortality...

BACKGROUND: Precapillary pulmonary hypertension (PH) is characterized by a sustained increase in right ventricular (RV) afterload, impairing systolic function. Two-dimensional (2D) echocardiography is the most performed cardiac imaging tool to assess RV systolic function; however, an accurate evaluation requires expertise. We aimed to develop a fully automated deep learning (DL)-based tool to estimate the RV ejection fraction (RVEF) from 2D echocardiographic videos of apical four-chamber views in patients with precapillary PH...

Background: Liver fibrosis is an important clinical endpoint of progression of autoimmune liver disease (AILD); its monitoring would benefit from noninvasive imaging tools. Objective: To assess the relationship between MR elastography (MRE) liver stiffness measurements and histologic liver fibrosis, as well as to evaluate the performance of MRE and biochemical-based clinical markers for stratifying histologic liver fibrosis severity, in children and young adults with AILD. Methods: This retrospective study used an existing institutional registry of children and young adults diagnosed with AILD [primary sclerosing cholangitis (PSC), ASC (autoimmune sclerosing cholangitis), or AIH (autoimmune hepatitis)]...

PURPOSE: Demonstrate the potential of spatiotemporal encoding (SPEN) MRI to deliver largely undistorted 2D, 3D, and diffusion weighted images on a 110 mT portable system. METHODS: SPEN's quadratic phase modulation was used to subsample the low-bandwidth dimension of echo planar acquisitions, delivering alias-free images with an enhanced immunity to image distortions in a laboratory-built, low-field, portable MRI system lacking multiple receivers. RESULTS: Healthy brain images with different SPEN time-bandwidth products and subsampling factors were collected...

BACKGROUND: Anthracyclines can cause left ventricular (LV) dysfunction. There is little data about right ventricular (RV) damage during chemotherapy. AIM: This study aimed to investigate the toxic effects of chemotherapy, analyzing its impact on right ventricular function. MATERIAL AND METHODS: A prospective study was conducted, enrolling 83 female patients (55 ± 11 years old) affected by breast cancer treated with anthracyclines...

PURPOSE: Conventional amide proton transfer (APT)-weighted imaging requires a chemical exchange saturation transfer (CEST) sequence with multiple saturation frequency offsets and a B0 correction sequence, plus a long acquisition time that can be reduced by applying the conventional method using CEST images with seven radiation pulses (i.e., the seven-points method). For a further reduction of acquisition times, we propose fast two-dimensional (2D) APT-weighted imaging based on a self B0 correction using the turbo spin echo (TSE)-Dixon method...

PURPOSE: Accurate quantification of liver iron concentration (LIC) can be achieved via magnetic resonance imaging (MRI). Maps of liver T2*/R2* are provided by commercially available, vendor-provided, 3-dimensional (3D) multiecho Dixon sequences and allow automated, inline postprocessing, which removes the need for manual curve fitting associated with conventional 2-dimensional (2D) gradient echo (GRE)-based postprocessing. The main goal of our study was to investigate the relationship among LIC estimates generated by 3D multiecho Dixon sequence to values generated by 2D GRE-based R2* relaxometry as the reference standard...

PURPOSE: To investigate the feasibility of a deep learning algorithm combining variational autoencoder (VAE) and two-dimensional (2D) convolutional neural networks (CNN) for automatically quantifying hard tissue presence and morphology in multi-contrast magnetic resonance (MR) images of peripheral arterial disease (PAD) occlusive lesions. METHODS: Multi-contrast MR images (T2-weighted and ultrashort echo time) were acquired from lesions harvested from six amputated legs with high isotropic spatial resolution (0...

BACKGROUND: Tissue motion of mitral annular displacement (TMAD) assessment has proved to be an effective method for several cardiovascular diseases including hypertrophic cardiomyopathy, heart failure, non-ST-elevation myocardial infarction, etc. However, there are no studies exploring the feasibility of TMAD in heart transplantation (HT) recipients, and the predictive value of this parameter for adverse outcomes in these patients remains unknown. Consequently, this study aimed to evaluate the feasibility of TMAD in the evaluation of left ventricular (LV) systolic function in clinically well adult HT patients, and further investigate the prognostic value of TMAD...

A new technique for ex situ solid-state nuclear magnetic resonance imaging of polymeric films has been developed. This method uses the static magnetic field gradient generated by a water-cooled copper electromagnet. The imaging process involves scanning the sample in the plane of the film under a static magnetic field gradient. Two-dimensional (2D) 19F MRI measurements are attempted, where the fast Fourier transform (FFT) spectra of the second half of a Hahn echo peak is used for the depth (X-axis) direction, and the sample film is mechanically moved for the Y-axis, which is in-plane with respect to the film surface and normal to the inter-magnetic-pole line (Z-axis)...

A new algorithm has been developed to simulate two-dimensional (2D) spectra with correlated anisotropic frequencies faster and more accurately than previous methods. The technique uses finite-element numerical integration on the sphere and an interpolation scheme based on the Alderman-Solum-Grant algorithm. This method is particularly useful for numerical calculations of joint probability distribution functions involving quantities with a parametric orientation dependence. The technique's efficiency also allows for practical least-squares fitting of experimental 2D solid-state nuclear magnetic resonance (NMR) datasets...

PURPOSE: Prolonged scanning of time-resolved 3D phase-contrast MRI (4D flow MRI) limits its routine use in clinical practice. An echo-planar imaging (EPI)-based sequence and compressed sensing can reduce the scan duration. We aimed to determine the impact of EPI for 4D flow MRI on the scan duration, image quality, and quantitative flow metrics. METHODS: This was a prospective study of 15 healthy volunteers (all male, mean age 33 ± 5 years)...

Ultrasonic nondestructive testing (NDT) usually utilizes conventional bulk piezoelectric transducers as transceivers. However, the complicated preparation and assembly process of bulk piezoelectric ceramics limits the development of NDT probes toward miniaturization and high frequency. In this paper, a 4.4 mm × 4.4 mm aluminum nitride (AlN) piezoelectric micromachined ultrasonic transducer (PMUT) array is designed, fabricated, characterized, and packaged for ultrasonic pulse-echo NDT of solids for the first time...

The right sinus of the Valsalva aneurysm (SVA) rupturing into the right atrium (RA) and dissecting into the interventricular septum (IVS) is rare. The disease can be definitively diagnosed using two-dimensional (2D) echocardiography and color Doppler ultrasonography. Real-time biplane imaging and three-dimensional (3D) echocardiography offer new perspectives for viewing and diagnosing this disease.

OBJECTIVE: Benign Brenner tumor (BBT) is a rare ovarian tumor, and there are few discrete reports about its manifestation in an ultrasound. This study sought to investigate the two-dimensional (2D) and contrast-enhanced ultrasound (CEUS) features of this entity. METHODS: This is a retrospective single-center study. The clinical manifestations, laboratory examination, and ultrasound data of 25 female patients with BBT were confirmed by pathology when they underwent 2D and/or CEUS examination at Ningbo First Hospital from January 2012 to June 2023...

BACKGROUND: Echocardiographic grading of mitral regurgitation (MR) in mitral valve prolapse (MVP) is challenging. 3D vena contracta area (3D VCA) has been proposed as valuable method. However, data defining the cut-off values of severity and validation in the subset of patients with MVP are scarce. The aim of this study was to validate the 3D VCA by 3D transesophageal color-Doppler echocardiography (3D-TEE) in patients with MVP and to define the cut-off values of severity grading. The secondary aim was to compare 3D VCA to the EROA-PISA method...

BACKGROUND: We aimed to investigate the impact of laparoscopic sleeve gastrectomy (LSG) on carotid intima-media thickness (CIMT) & left ventricular dysfunction (LVD) which are the independent predictors of subclinical atherosclerosis. METHODS: To assess the change in CIMT & echocardiographic parameters of left ventricular function & correlate with %EWL 6 months and 12 months after LSG, the mean CIMT of bilateral common carotid arteries were measured at 3 different places & 7 parameters were assessed for left ventricular dysfunction after 6 and 12 months of LSG & correlated with the %EWL...

Editing of 3D raw images acquired during transesophageal echocardiography could be similar to the post processing of raw images with digital software used in photography. 3D image editing in echocardiography is often underestimated in clinical practice, and people are satisfied with the first 3D image they are able to obtain during transesophageal examination. In fact, it is often believed to represent solely an aesthetic addition that does not change the information already obtained with 2D and baseline 3D...

Atherosclerosis is the most common cause of heart disease and stroke. Plaque thickness ≥4 mm in the ascending aorta or aortic arch is strongly correlated with cerebral embolic events and ischemic stroke. However, despite imaging workup, the cause of embolic stroke remains unidentified in many patients. Transesophageal echocardiography (TEE) is the preferred echocardiographic method for the evaluation of cardiac source of emboli. 2D TEE imaging evaluates aortic root and aortic arch in a single plane or two planes with biplane imaging...