Search results for "Sound"

Calibro dei sifoni carotidei e asimmetria del poligono di Willis: Studio Angio-RM

1997

A differenza dell'Angiografia, l'esame Angio-RM consente la simultanea visualizzazione dei vasi del poligono. Si è valutata la correlazione esistente tra calibro dei sifoni e asimmetrie di sviluppo del poligono nella popolazione normale. Sono stati esaminati 3 casi di occlusione totale di una carotide. 120 pazienti privi di patologie vascolari o neoplastiche sono stati sottoposti ad esame Angio-RM 3DTOF con Magnetization Tranfer e TONE. Sono state valutate le immagini di sorgente e 3DMIP, prima e dopo sottrazione dei pixel non vascolari. I pazienti sono stati suddivisi in 5 gruppi: I = aplasia di A1, II = ipoplasia di A1, III = lieve asimmetria di A1, IV ? arteria comunicante posteriore fe…

Su di un caso di Schwannoma primitivo intraorbitario

1994

Gli Schwannomi costituiscono il 6,8% dei tumori intracranici ed originano solitamente dai nervi sensitivi, con particolare predilezione per il V e VIII nervo cranico. Uno schwannoma a partenza da un nervo oculomotore costituisce invece una evenienza piuttosto rara, e solo 17 casi di s. del III n.c. sono stati documentati in letteratura. Sono da considerare ancora più rari gli schwannomi ad esclusiva localizzazione intraorbitaria (1–5, 7% dei tumori orbitari). Solitamente tipico dell'uomo adulto, con l'eccezione dei soggetti affetti da Neurofibromatosi di tipo 2, lo schwannoma orbitario esordisce solitamente come un processo espansivo a lento accrescimento, determinante diplopia, esoftalmo …

Accumulo di ferro a livello ipofisario in pazienti affetti da beta-talassemia major: Aspetti RM

1997

Gli autori si propongono di valutare le modificazioni del segnale RM a livello ipofisario nella emosiderosi secondaria in pazienti affetti da beta-talassemia major. Lo studio è stato condotto prospetticamente su un gruppo di 20 pazienti in regime alto-trasfusionale e trattamento ferro-chelante e su 10 volontari sani come gruppo di controllo. Gli esami RM sono stati condotti con apparecchiatura a magnete superconduttivo a 0,5T con sequenze SE TI-dipendenti e GRE TE*-dipendenti. Il sovraccarico di ferro è stato valutato mediante il dosaggio della ferritina sierica. è stata effettuata una valutazione quantitativa delle immagini RM SE T1- e GRE T2*-dipendenti attraverso la misurazione, mediant…

Differential associations of age with volume and microstructure of hippocampal subfields in healthy older adults

2015

Hippocampal atrophy in advanced healthy aging has frequently been reported. However, the vulnerability of different hippocampal subfields to age-related atrophy is still a source of debate. Moreover, the association of age with the microstructural integrity of subfields is largely unknown. In this study, we investigated the associations between age and volume as well as microstructural integrity of hippocampal subfields using a three-dimensional (3D) surface mapping approach. Forty-three healthy older adults spanning the age range from 60 to 85 years underwent T1-weighted and diffusion-tensor imaging. Analyses demonstrated an association of age with hippocampal volume predominantly in the m…

Republication de : Recommandations de bonne pratique pour la prise en charge de la maladie veineuse thromboembolique chez l’adulte. Version courte

2019

Estimation of Personalized Minimal Purkinje Systems From Human Electro-Anatomical Maps

2021

The Purkinje system is a heart structure responsible for transmitting electrical impulses through the ventricles in a fast and coordinated way to trigger mechanical contraction. Estimating a patient-specific compatible Purkinje Network from an electro-anatomical map is a challenging task, that could help to improve models for electrophysiology simulations or provide aid in therapy planning, such as radiofrequency ablation. In this study, we present a methodology to inversely estimate a Purkinje network from a patient's electro-anatomical map. First, we carry out a simulation study to assess the accuracy of the method for different synthetic Purkinje network morphologies and myocardial junct…

OP09.10: Hemodynamic effects of sildenafil administration in an animal model of preeclampsia

2011

Comparison of Single-Echo T2-weighted Fast Spin-Echo and Conventional Spin-Echo MR Sequences

1998

We compared single-echo T2-weighted fast spin-echo (FSE) magnetic resonance imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 16 patients with clinically definite MS underwent brain imaging at 0.5 T with T2-weighted single-echo fast spin-echo (FSE) and conventional spin-echo (CSE) sequences. Image analysis was performed by three of the investigators who worked together to reduce interobserver variability. Statistical analysis was performed using Student's t test to assess the difference in the contrast-to-noise (C/N) ratio of MS lesions between CSE and FSE sequences. The Wilcoxon signed rank test was used to evaluate …

Valutazione comparativa delle sequenze fast Spin-echo e Spin-echo T2-dipendenti nella dimostrazione delle lesioni demielinizzanti encefaliche in cors…

1997

We compared T2-weighted fast spin-echo (FSE) magnetic resonance (MR) imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 20 patients with clinically definite MS underwent brain imaging with both FSE and CSE T2-weighted imaging. There was no significant difference in total number of lesions detected on FSE vs CSE (1354 vs 1378). Slightly more periventricular and subcortical lesions were detected using CSE than FSE, whereas more posterior cranial fossa lesions were detected by FSE. There was no statistically significant difference in the signal intensity (SI) ratio of MS lesions to that of surrounding normal white matter …

Wavelet analysis and neural network classifiers to detect mid-sagittal sections for nuchal translucency measurement

2016

We propose a methodology to support the physician in the automatic identification of mid-sagittal sections of the fetus in ultrasound videos acquired during the first trimester of pregnancy. A good mid-sagittal section is a key requirement to make the correct measurement of nuchal translucency which is one of the main marker for screening of chromosomal defects such as trisomy 13, 18 and 21. NT measurement is beyond the scope of this article. The proposed methodology is mainly based on wavelet analysis and neural network classifiers to detect the jawbone and on radial symmetry analysis to detect the choroid plexus. Those steps allow to identify the frames which represent correct mid-sagitta…