Search results for " mr"

Reward networks changes in the brain of pathological gamblers: a resting state functional magnetic resonance imaging study

2017

Aims and objectives Methods and materials Results Conclusion Personal information References

INTRAPAROTID FACIAL NERVE SCHWANNOMA MRI FINDINGS

2009

USE-Net: Incorporating Squeeze-and-Excitation blocks into U-Net for prostate zonal segmentation of multi-institutional MRI datasets

2019

Prostate cancer is the most common malignant tumors in men but prostate Magnetic Resonance Imaging (MRI) analysis remains challenging. Besides whole prostate gland segmentation, the capability to differentiate between the blurry boundary of the Central Gland (CG) and Peripheral Zone (PZ) can lead to differential diagnosis, since tumor's frequency and severity differ in these regions. To tackle the prostate zonal segmentation task, we propose a novel Convolutional Neural Network (CNN), called USE-Net, which incorporates Squeeze-and-Excitation (SE) blocks into U-Net. Especially, the SE blocks are added after every Encoder (Enc USE-Net) or Encoder-Decoder block (Enc-Dec USE-Net). This study ev…

STUDIO DEL COMPORTAMENTO DINAMICO DI UN MODELLO HALF CAR E CONFRONTO FRA AMMORTIZZAZIONE PASSIVA E SEMIATTIVA A FLUIDO MAGNETO-REOLOGICO

2010

Questo lavoro inizia con la progettazione di massima del pistone di un ammortizzatore a fluido magnetoreologico, effettuata con l’ausilio di Solid Works e del software di simulazione magnetica FEMM. Le dimensioni preliminari sono state assegnate facendo uso delle relazioni teoriche, mentre il software FEMM ha confermato il risultato. Sono state poi ricavate le equazioni della dinamica di un modello half car, sia in forma di sistema di equazioni differenziali che in forma di spazio di stato. Tramite l’interfaccia SimuLink di MatLab, è eseguito un confronto fra i risultati ottenuti dal sistema in condizioni di funzionamento passivo con quelli in funzionamento semi-attivo. Scelta la geometria …

Nuovi gel di Fricke ad alta sensibilità e bassa diffusione per dosimetria 3D tramite MRI

2017

One of the most recent and promising developments in radiotherapy dosimetry was the introduction of 3D radiationsensitive gels. These gels present tissue equivalent composition and density, so they also serve as phantoms, and their response is largely independent of radiation quality and dose rate. Some gels are infused with ferrous sulfate and rely on the radiation-induced oxidation of ferrous ions to ferric ions (Fricke-gel). In this work Fricke gel dosimeters produced with a matrix of poly-vinyl alcohol (PVA) cross-linked with glutaraldehyde (GTA) were analyzed with magnetic resonance imaging (MRI). This work focused on the analysis of the temporal diffusion of ferric ions through PVA-GT…

PVA-GTA Fricke gel: studio della risposta NMR in funzione della concentrazione degli additivi e studi preliminari con scanner MRI 7 T

2016

Sono stati analizzati tramite rilassometria NMR ed acquisizioni MRI dosimetri gel di tipo Fricke realizzati utilizzando un'innovativa matrice gel sintetica e tessuto equivalente: Polyvinyl alcohol (PVA) attivando chimicamente il processo di gelificazione tramite l'aggiunta di Glutaraldehyde (GTA). Questi gel sono stati irradiati con fasci di fotoni (LINAC) nel range 0--20 Gy. Per valutare la sensibilità a fotoni è stata studiata la dipendenza dei tempi di rilassamento nucleari dalla dose e dalla concentrazione di ferro nei gel. Inoltre è stata monitorata la stabilità del segnale dopo l'irraggiamento. Acquisizioni preliminari MRI con uno scanner MRI da 7 T sono state affiancate alle misure N…

Testing and calibration of ESR response of Fricke gel dosimeters in mixed neutron-gamma fields

2013

Characterization of Fricke gel dosimeters exposed to gamma rays and neutrons

2013

Keypoint descriptor matching with context-based orientation estimation

2014

Abstract This paper presents a matching strategy to improve the discriminative power of histogram-based keypoint descriptors by constraining the range of allowable dominant orientations according to the context of the scene under observation. This can be done when the descriptor uses a circular grid and quantized orientation steps, by computing or providing a global reference orientation based on the feature matches. The proposed matching strategy is compared with the standard approaches used with the SIFT and GLOH descriptors and the recent rotation invariant MROGH and LIOP descriptors. A new evaluation protocol based on an approximated overlap error is presented to provide an effective an…

Comparison of 1.0 M gadobutrol and 0.5 M gadopentate dimeglumine-enhanced MRI in 471 patients with known or suspected renal lesions : results of a mu…

2008

The purpose of this phase III clinical trial was to compare two different extracellular contrast agents, 1.0 M gadobutrol and 0.5 M gadopentate dimeglumine, for magnetic resonance imaging (MRI) in patients with known or suspected focal renal lesions. Using a multicenter, single-blind, interindividual, randomized study design, both contrast agents were compared in a total of 471 patients regarding their diagnostic accuracy, sensitivity, and specificity to correctly classify focal lesions of the kidney. To test for noninferiority the diagnostic accuracy rates for both contrast agents were compared with CT results based on a blinded reading. The average diagnostic accuracy across the three bli…