Evaluation of 4D Flow MRI-Derived Aortic Hemodynamics and Their Relationships With Left Ventricular Remodeling in Patients With Moderate Aortic Stenosis: A Preliminary Study.

Purpose: Identifying factors associated with left ventricular (LV) remodeling is important for risk stratification of patients with moderate aortic stenosis (AS). The aim of this preliminary study was to explore aortic hemodynamics in these patients and assess their relationships with LV remodeling using four-dimensional (4D) flow magnetic resonance imaging (MRI).

Method: Data from 17 patients with moderate AS involving the tricuspid aortic valves and normal LV ejection fraction (EF > 55%) were analyzed.

Evaluation of blood-tumor barrier permeability and doxorubicin delivery in rat brain tumor models using additional focused ultrasound stimulation.

Focused ultrasound (FUS) has emerged as a promising technique for temporarily disrupting the blood-brain barrier (BBB) and blood-tumor barrier (BTB) to enhance the delivery of therapeutic agents. Despite its potential, optimizing FUS to maximize drug delivery while minimizing adverse effects remains a significant challenge. In this study, we evaluated a novel FUS protocol that incorporates additional FUS stimulation without microbubbles (MBs) ("FUS protocol") prior to conventional BBB disruption with MBs ("BBBD protocol") in a rat brain tumor model (n = 35).

The role of four-dimensional flow MRI as an adjunct to endoscopy for predicting variceal bleeding in patients with cirrhosis.

BackgroundNon-invasive approach other than conventional endoscopy could be effectively used for screening and monitoring esophageal variceal bleeding (EVB).PurposeTo retrospectively investigate the role of four-dimensional (4D) flow magnetic resonance imaging (MRI) as an add-on tool to endoscopy for predicting EVB in cirrhotic patients with esophageal varices (EVs).Material and MethodsA cohort of 109 cirrhotic patients with EVs was divided into four groups: A = negative red color [RC] sign, no EVB, n = 60; B = negative RC sign, EVB, n = 13; C = positive RC sign, no EVB, n = 10; and D = positive RC sign, EVB, n = 26.

Multi-Scale 3D Cephalometric Landmark Detection Based on Direct Regression with 3D CNN Architectures.

Background: Cephalometric analysis is important in diagnosing and planning treatments for patients, traditionally relying on 2D cephalometric radiographs. With advancements in 3D imaging, automated landmark detection using deep learning has gained prominence. However, 3D imaging introduces challenges due to increased network complexity and computational demands.

In Vivo 3-Dimensional Dynamic Evaluation of Shoulder Kinematics After the Latarjet Procedure: Comparison With the Contralateral Healthy Shoulder.

Background: Researchers have attempted to understand the underlying mechanism of the Latarjet procedure; however, its effects on shoulder kinematics have not been well studied.

Purpose/hypothesis: The purpose was to analyze shoulder kinematics after the Latarjet procedure. It was hypothesized that the nonanatomic transfer of the coracoid process during the procedure would affect normal shoulder kinematics.

A Customizable Proteinic Bioadhesive Patch with Water-Switchable Underwater Adhesiveness, Adjustable Biodegradability, and Modifiable Stretchability for Healing Diverse Internal Wounds.

Customizable bioadhesives for individual organ requirements, including tissue type and motion, are essential, especially given the rise in implantable medical device applications demanding adequate underwater adhesion. While synthetic bioadhesives are widely used, their toxicity upon degradation shifts focus to biocompatible natural biomaterials. However, enhancing the adhesive strengths of these biomaterials presents ongoing challenges while accommodating the unique properties of specific organs.

Effect of flow reduction surgery in a patient with high flow arteriovenous fistula with aortic dissection using 4D flow magnetic resonance imaging: A case report.

This study aimed to investigate cardiovascular function in a patient with high-flow arteriovenous fistula (AVF) who underwent aortic dissection (AD) using four-dimensional (4D) flow magnetic resonance imaging (MRI) as well as analyze the effect of flow reduction surgery on AD. On March 12, 2017, a 60-year-old woman underwent emergency surgery for AD. After that, she experienced acute kidney injury, and hemodialysis was initiated.

Valvular and ascending aortic hemodynamics of the On-X aortic valved conduit by same-day echocardiography and 4D flow MRI.

This study aims to assess whether the On-X aortic valved conduit better restores normal valvular and ascending aortic hemodynamics than other commonly used bileaflet mechanical valved conduit prostheses from St. Jude Medical and Carbomedics by using same-day transthoracic echocardiography (TTE) and 4D flow magnetic resonance imaging (MRI) examinations. TTE and 4D flow MRI were performed back-to-back in 10 patients with On-X, six patients with St.

Interpolation time-optimized aortic pulse wave velocity estimation by 4D flow MRI.

Four-dimensional flow magnetic resonance imaging-based pulse wave velocity (4D flow PWV) estimation is a promising tool for measuring regional aortic stiffness for non-invasive cardiovascular disease screening. However, the effect of variations in the shape of flow waveforms on 4D flow PWV measurements remains unclear. In this study, 4D flow PWV values were compared using cross-correlation algorithm with different interpolation times (iTs) based on flow rate and beat frequency.

Fluid-structure interaction simulation of visceral perfusion and impact of different cannulation methods on aortic dissection.

Hemodynamics in aortic dissection (AD) is closely associated with the risk of aortic aneurysm, rupture, and malperfusion. Altered blood flow in patients with AD can lead to severe complications such as visceral malperfusion. In this study, we aimed to investigate the effect of cannulation flow on hemodynamics in AD using a fluid-structure interaction simulation.

Impact of assuming a circular orifice on flow error through elliptical regurgitant orifices: computational fluid dynamics and in vitro analysis of proximal flow convergence.

Grounded in hydrodynamic theory, proximal isovelocity surface area (PISA) is a simplistic and practical technique widely used to quantify valvular regurgitation flow. PISA provides a relatively reasonable, though slightly underestimated flow rate for circular orifices. However, for elliptical orifices frequently seen in functional mitral regurgitation, PISA underestimates the flow rate.

Relationship between treatment types and blood-brain barrier disruption in patients with acute ischemic stroke: Two case reports.

Background: Blood-brain barrier (BBB) disruption plays an important role in the development of neurological dysfunction in ischemic stroke. However, diagnostic modalities that can clearly diagnose the degree of BBB disruption in ischemic stroke are limited. Here, we describe two cases in which the usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in detecting BBB disruption was evaluated after treatment of acute ischemic stroke using two different methods.

Numerical Evaluation of the Effects of Transducer Displacement on Transcranial Focused Ultrasound in the Rat Brain.

Focused ultrasound is a promising therapeutic technique, as it involves the focusing of an ultrasonic beam with sufficient acoustic energy into a target brain region with high precision. Low-intensity ultrasound transmission by a single-element transducer is mostly established for neuromodulation applications and blood-brain barrier disruption for drug delivery. However, transducer positioning errors can occur without fine control over the sonication, which can affect repeatability and lead to reliability problems.

Two wrongs sometimes do make a right: errors in aortic valve stenosis assessment by same-day Doppler echocardiography and 4D flow MRI.

This study aims to systematically verify if the simplified geometry and flow profile of the left ventricular outflow tract (LVOT) assumed in 2D echocardiography is appropriate while examining the utility of 4D flow MRI to assess valvular disease. This prospective study obtained same-day Doppler echocardiography and 4D flow MRI in 37 healthy volunteers (age: 51.9 ± 18.

Quantification of visceral perfusion and impact of femoral cannulation: in vitro model of aortic dissection.

Objectives: We aimed to simulate blood flow at an aortic dissection in an in vitro vascular model and assess the impact of the cannulation method on visceral perfusion.

Methods: An aortic-dissection model with an acrylic aortic wall and silicone intimal flap was developed to study visceral perfusion under various cannulation conditions. The primary tear was placed in the proximal descending aorta and the re-entry site in the left common iliac artery.

The blood-brain barrier disruption after syncope: a dynamic contrast-enhanced magnetic resonance imaging study: A case report.

Rationale: Using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), we demonstrated blood-brain barrier (BBB) disruption following syncope.

Patient Concerns: A 45-year-old man experienced syncope with a chief complaint of syncope (duration: 1 minutes), 1 day before visiting a university hospital for examination. He had no history of medical problems and was not taking any medications.

Effect of age and sex on fully automated deep learning assessment of left ventricular function, volumes, and contours in cardiac magnetic resonance imaging.

Deep learning algorithms for left ventricle (LV) segmentation are prone to bias towards the training dataset. This study assesses sex- and age-dependent performance differences when using deep learning for automatic LV segmentation. Retrospective analysis of 100 healthy subjects undergoing cardiac MRI from 2012 to 2018, with 10 men and women in the following age groups: 18-30, 31-40, 41-50, 51-60, and 61-80 years old.

A local difference in blood-brain barrier permeability in the caudate putamen and thalamus of a rat brain induced by focused ultrasound.

A blood-brain barrier (BBB) opening induced by focused ultrasound (FUS) has been widely studied as an effective way of treating brain diseases. We investigate the effect of ultrasound's incidence angle at caudate putamen (Cp) and thalamus (Th) of the rat brain by inducing the same power of focused ultrasound that corresponds to the acoustic pressure of 0.65 MPa in free field.

Impact of age, sex, and global function on normal aortic hemodynamics.

Purpose: To examine the effects of age, sex, and left ventricular global function on velocity, helicity, and 3D wall shear stress (3D-WSS) in the aorta of N = 100 healthy controls.

Methods: Fifty female and 50 male volunteers with no history of cardiovascular disease, with 10 volunteers per age group (18-30, 31-40, 41-50, 51-60, and 61-80 years) underwent aortic 4D-flow MRI. Quantification of systolic aortic peak velocity, helicity, and 3D-WSS distribution and the calculation of age group-averaged peak systolic velocity and 3D-WSS maps ("atlases") were computed.

An advanced focused ultrasound protocol improves the blood-brain barrier permeability and doxorubicin delivery into the rat brain.

Despite the recent development of a focused ultrasound (FUS) technique for disrupting the blood-brain barrier (BBB) and enabling the delivery of drugs into the targeted brain region, different sonication protocols have not been fully explored. In this study, we suggest a simple and cost-effective protocol that improves the BBB permeability and drug delivery without damaging the tissue. In this protocol, called "FUS+BBBD protocol", an additional FUS stimulation without microbubbles ("FUS protocol"; 0.

Aortic 4D flow MRI in 2 minutes using compressed sensing, respiratory controlled adaptive k-space reordering, and inline reconstruction.

Purpose: To evaluate the accuracy and feasibility of a free-breathing 4D flow technique using compressed sensing (CS), where 4D flow imaging of the thoracic aorta is performed in 2 min with inline image reconstruction on the MRI scanner in less than 5 min.

Methods: The 10 in vitro 4D flow MRI scans were performed with different acceleration rates on a pulsatile flow phantom (9 CS acceleration factors [R = 5.4-14.