Automated intracranial vessel segmentation of 4D flow MRI data in patients with atherosclerotic stenosis using a convolutional neural network.

Introduction: Intracranial 4D flow MRI enables quantitative assessment of hemodynamics in patients with intracranial atherosclerotic disease (ICAD). However, quantitative assessments are still challenging due to the time-consuming vessel segmentation, especially in the presence of stenoses, which can often result in user variability. To improve the reproducibility and robustness as well as to accelerate data analysis, we developed an accurate, fully automated segmentation for stenosed intracranial vessels using deep learning.

Aortic annular dimensions by non-contrast MRI using k-t accelerated 3D cine b-SSFP in pre-procedural assessment for transcatheter aortic valve implantation: a technical feasibility study.

To evaluate k-t accelerated 3D cine b-SSFP (balanced steady state free precession) as magnetic resonance imaging (MRI) technique for aortic annular area measurement in transcatheter aortic valve replacement (TAVR) planning compared to computed tomography angiography (CTA) and other non-contrast MRI sequences with reduced imaging time and without contrast administration. 6 volunteers and 7 TAVR candidates were prospectively enrolled. The volunteers underwent an MRI while TAVR candidates underwent an MRI and CTA.

Detection and Hemodynamic Evaluation of Flap Fenestrations in Type B Aortic Dissection with 4D Flow MRI: Comparison with Conventional MRI and CTA.

Purpose: The purpose of this study was to compare dissection flap fenestration visualization between 4D flow MRI, clinical MRI/MRA, and clinical CTA studies and describe the presence of hemodynamically active fenestration flow using 4D flow.

Materials And Methods: Nineteen patients with type B dissection (age: 57±5 years) who had undergone standard of-care MRI/MRA of the chest including 4D flow MRI were retrospectively identified. Fourteen of the 19 patients also had CTA performed within 2 years of the MRI/MRA study with no interval surgery.

Thoracic aorta 3D hemodynamics in pediatric and young adult patients with bicuspid aortic valve.

Background: To evaluate the 3D hemodynamics in the thoracic aorta of pediatric and young adult bicuspid aortic valve (BAV) patients.

Methods: 4D flow MRI was performed in 30 pediatric and young adult BAV patients (age: 13.9 ± 4.

Neurofunctional effects of quetiapine in patients with bipolar mania.

Objectives: Several lines of evidence suggest that abnormalities within portions of the extended limbic network involved in affective regulation and expression contribute to the neuropathophysiology of bipolar disorder. In particular, portions of the prefrontal cortex have been implicated in the appearance of manic symptomatology. The effect of atypical antipsychotics on activation of these regions, however, remains poorly understood.

4D flow imaging with MRI.

Magnetic resonance imaging (MRI) has become an important tool for the clinical evaluation of patients with cardiovascular disease. Since its introduction in the late 1980s, 2-dimensional phase contrast MRI (2D PC-MRI) has become a routine part of standard-of-care cardiac MRI for the assessment of regional blood flow in the heart and great vessels. More recently, time-resolved PC-MRI with velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage (also termed '4D flow MRI') has been developed and applied for the evaluation of cardiovascular hemodynamics in multiple regions of the human body.

Magnetic resonance spectroscopy imaging of lactate in patients with bipolar disorder.

Although brain lactate levels are typically low and difficult to measure, a few previous investigators have reported that brain lactate levels are elevated in patients with bipolar disorder. The present study investigated the distribution of lactate in bipolar and healthy brains using 2D proton magnetic resonance spectroscopic imaging on a 4-Tesla magnetic resonance imaging system. Ratios of the concentration of lactate to N-acetylaspartate, and of lactate to total creatine, were significantly higher in bipolar than in healthy subjects.

Neurochemical effects of quetiapine in patients with bipolar mania: a proton magnetic resonance spectroscopy study.

Although the neurophysiology underlying pharmacotherapy for bipolar disorder remains poorly understood, recent studies suggest that therapeutic mechanisms may be reflected in changes in concentrations of N-acetylaspartate (NAA), a putative measure of neuronal integrity and metabolism. In this study, we used magnetic resonance spectroscopy (MRS) to examine prefrontal NAA in patients receiving quetiapine for bipolar mania. On the basis of previous findings, we hypothesized that remission would be associated with increased NAA concentrations in the prefrontal cortex.

Progressive neurostructural changes in adolescent and adult patients with bipolar disorder.

Objectives: Several lines of evidence suggest that bipolar disorder is associated with progressive changes in gray matter volume (GMV), particularly in brain structures involved in emotional regulation and expression. The majority of these studies however, have been cross-sectional in nature. In this study we compared baseline and follow-up scans in groups of bipolar disorder and healthy subjects.