Search results for "ULTRASOUND"

ST elevāciju miokarda infarkta noteicošās artērijas intravaskulārās ultraskaņas audu raksturojuma saistība ar aterosklerozes asins biomarķieriem un s…

2013

Anotācija ST elevāciju miokarda infarkta gadījumā (STEMI) patofizioloģiskais substrāts ir rupturējusi vai erodējusi panga un tromboze. Šajā darbā veicām iMap IVUS audu analīzi STEMI mērķa bojājumiem 75 pacientiem, noteicām asinīs aterosklerozes biomarķierus un veicām 10 mēnešu apsekojumu. Mūsu rezultāti parādīja augstu nekrotisko audu daudzumu mērķa bojājumā un augstu, bet salīdzinoši zemāku, proksimālajā segmentā. Proksimālajā segmentā 10 mēnešu laikā samazinājās lipīdu audu daudzums par 10,2%. Neointimai 10 mēnešus pēc stenta implantācijas bija raksturīgs stabilāks audu sastāvs pēc iMap IVUS nekā natīvai aterosklerotiskai pangai šajā artērijā. Asins aterosklerozes biomarķieru saistību ar …

SURVEILLANCE PROGRAM FOR DIAGNOSIS OF HCC IN LIVER CIRRHOSIS: ROLE OF ULTRASOUND ECHOPATTERNS

2013

Extraction of Airways from CT (EXACT'09)

2012

Contains fulltext : 107854.pdf (Publisher’s version ) (Open Access) This paper describes a framework for establishing a reference airway tree segmentation, which was used to quantitatively evaluate fifteen different airway tree extraction algorithms in a standardized manner. Because of the sheer difficulty involved in manually constructing a complete reference standard from scratch, we propose to construct the reference using results from all algorithms that are to be evaluated. We start by subdividing each segmented airway tree into its individual branch segments. Each branch segment is then visually scored by trained observers to determine whether or not it is a correctly segmented part o…

Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound with a 1.5 Tesla Scanner: A Prospective Intraindividual Comparison Study of Intraop…

2021

Background: High-quality intraoperative imaging is needed for optimal monitoring of patients undergoing transcranial MR-guided Focused Ultrasound (tcMRgFUS) thalamotomy. In this paper, we compare the intraoperative imaging obtained with dedicated FUS-Head coil and standard body radiofrequency coil in tcMRgFUS thalamotomy using 1.5-T MR scanner. Methods: This prospective study included adult patients undergoing tcMRgFUS for treatment of essential tremor. Intraoperative T2-weighted FRFSE sequences were acquired after the last high-energy sonication using a dedicated two-channel FUS-Head (2ch-FUS) coil and body radiofrequency (body-RF) coil. Postoperative follow-ups were performed at 48 h usin…

Neural Mechanisms Underlying Human Auditory Evoked Responses Revealed By Human Neocortical Neurosolver

2022

Funding Information: This study was supported by National Institutes of Health (Grant Nos. NIBIB RO1 EB022889, NIMH RO1 MH106174). Publisher Copyright: © 2021, The Author(s). Auditory evoked fields (AEFs) are commonly studied, yet their underlying neural mechanisms remain poorly understood. Here, we used the biophysical modelling software Human Neocortical Neurosolver (HNN) whose foundation is a canonical neocortical circuit model to interpret the cell and network mechanisms contributing to macroscale AEFs elicited by a simple tone, measured with magnetoencephalography. We found that AEFs can be reproduced by activating the neocortical circuit through a layer specific sequence of feedforwar…

A study of synergetic effect of ionic liquids and ultrasounds on the aryl azides formation

PROPAGAZIONE DI ONDE DI RAYLEIGH LUNGO SUPERFICI CURVE: UNO STUDIO NUMERICO E SPERIMENTALE

2014

Il fenomeno della propagazione delle onde di superficie lungo confini rettilinei (superfici piane) è stato studiato adeguatamente. Tuttavia le indagini riguardanti la loro propagazione in superfici cilindriche sono limitate e risultano insufficienti ai fini di un loro utilizzo nelle tecniche d’ispezione non distruttive (NDE), nonostante possano essere di grande interesse per svariate applicazioni. E’ stato dimostrato sperimentalmente che l’onda superficiale subisce un cambiamento di fase durante la sua propagazione lungo una superficie cilindrica. Un approccio numerico è stato sviluppato per studiare questi effetti per diversi materiali, curvature e frequenze. I risultati numerici e sperime…

Referenceless thermometry using radial basis function interpolation

2014

The Proton Resonance Frequency (PRF) shift provide a method for temperature change measurements during thermotherapy. Conventional PRF thermometry works subtracting one or multiple baseline images. The method leads to artifacts caused by tissue motion and frequency drift. Various works estimating the background phase from each acquired image phase are present in literature. These algorithms are called “referenceless” because they don’t require any subtraction of baseline images for calculating temperature increment. Conventional referenceless methods estimate baseline image by fitting the background phase outside the heated region through a polynomial approach. In this work a background pha…

Radial Basis Function Interpolation for Referenceless Thermometry Enhancement

2015

MRgFUS (Magnetic Resonance guided Focused UltraSound) is a new and non-invasive technique to treat different diseases in the oncology field, that uses Focused Ultrasound (FUS) to induce necrosis in the lesion. Temperature change measurements during ultrasound thermo-therapies can be performed through magnetic resonance monitoring by using Proton Resonance Frequency (PRF) thermometry. It measures the phase variation resulting from the temperature-dependent changes in resonance frequency by subtracting one phase baseline image from actual phase. Referenceless thermometry aims to re-duce artefacts caused by tissue motion and frequency drift, fitting the back-ground phase outside the heated reg…

EFFETTI DELLA TERAPIA CON DIRECT ACTING ANTIVIRALS (DAAS) SUI PARAMETRI ECOGRAFICI DI IPERTENSIONE PORTALE

2017

Obiettivi dello studio: Tra gli end point della terapia antivirale con DAAs nella cirrosi HCV (LCHCV) oltre all' eradicazione del virus vi sono: la regressione della fibrosi e dell’ipertensione portale. Abbiamo valutato in pazienti LCHCV e risposta sostenuta (SVR) alla terapia con DAAs il comportamento dell’AST to Platelet Ratio Index (APRI) (marker indiretto di fibrosi) e di due segni ecografici di ipertensione portale: calibro della vena porta (cVP) e diametro longitudinale della milza (DLM). Materiali: 98 pazienti con LCHCV,al Baseline (BL) a fine terapia (FT) e tre mesi (PostT3) e 9 mesi dopo la fine della terapia (PostT9) eseguivano i test di funzionalità epatica e la conta piastrinica…