Search results for "VOLUME"

Studio preliminare di parcellizzazione talamica per l’identificazione del target di trattamento applicato alle talamotomie trans-craniche mediante ul…

2018

Introduzione La tcMRgFUS consente di effettuare una vera e propria esplorazione neurofunzionale per confermare ed ottimizzare il target lesionale prima di indurre una lesione cerebrale permanete. La scelta del target di trattamento si basa tuttavia su coordinate stereotassiche che non tengono conto delle diversità anatomiche di ciascun individuo. L'ottimizzazione del target di trattamento viene effettuata sulla base del feedback del paziente durante la procedura stessa. Materiali e metodi È’ stato utilizzato uno scanner RM da 1.5T per acquisire sequenze morfologiche 3D e ultrastrutturali (DTI) in pazienti successivamente sottoposti a tcMRgFUS. È stata effettuata una segmentazione delle aree…

Platelet count and MPV as predictive markers of atherosclerosis in familial Mediterranean fever

2017

Familial Mediterranean Fever (FMF) is an auto inflammatory syndrome, characterized by recurrent febrile episodes, arthritis, oral aphthous stomatitis, rash, serositis, abdominal and thoracic pain. Longterm outcome is conventionally linked to the severity of the recurrent attacks and to the risk of systemic amyloidosis. However recent studies highlighted the role of chronic inflammatory diseases in the insurance of atherosclerosis. Risk factors for atherosclerosis are also recently identified in a higher medium platelet volume (MPV).

I Giovani e il futuro della Sanità Pubblica

2011

Capillary experiments of flow induced crystallization of HDPE

1990

Flow-induced crystallization experiments are made in a capillary apparatus modified with a downstream reservoir under pressure. Capillary length, diameter, and entrance angle are changed, as well as flow rate. The results show that the crystallization temperature is influenced both by the elongational flow at the capillary entrance and by the shear flow along the capillary. The independent effect of the pressure equals that obtained under static conditions. The effect of shear is correlated in terms of shearing work.

Intrapulmonary 3He Gas Distribution Depending on Bolus Size and Temporal Bolus Placement

2008

OBJECTIVE: Dynamic ventilation (3)He-MRI is a new method to assess pulmonary gas inflow. As differing airway diameters throughout the ventilatory cycle can influence gas inflow this study intends to investigate the influence of volume and timing of a He gas bolus with respect to the beginning of the tidal volume on inspiratory gas distribution. MATERIALS AND METHODS: An ultrafast 2-dimensional spoiled gradient echo sequence (temporal resolution 100 milliseconds) was used for dynamic ventilation (3)He-MRI of 11 anesthetized and mechanically ventilated pigs. The applied (3)He gas bolus was varied in volume between 100 and 200 mL. A 150-mL bolus was varied in its application time after the beg…

Flip angle considerations in (3)helium-MRI.

2000

3Helium-MRI ((3)He-MRI) can be used for analysis of lung function, e. g. dynamic imaging of ventilation and gas diffusion within the lung, assessment of intrapulmonary oxygen concentrations and their time course. During imaging, the irreversible signal loss due to depolarizing radio frequency excitations can be described using the flip angle (FA) alpha. This parameter has to be quantified in order to account for it during quantitative assessment of the (3)helium signal intensity and its temporal development. This technical report reviews two different methods to determine alpha. Limitations and possible error sources of each method are discussed.

An enhanced random walk algorithm for delineation of head and neck cancers in PET studies

2017

An algorithm for delineating complex head and neck cancers in positron emission tomography (PET) images is presented in this article. An enhanced random walk (RW) algorithm with automatic seed detection is proposed and used to make the segmentation process feasible in the event of inhomogeneous lesions with bifurcations. In addition, an adaptive probability threshold and a k-means based clustering technique have been integrated in the proposed enhanced RW algorithm. The new threshold is capable of following the intensity changes between adjacent slices along the whole cancer volume, leading to an operator-independent algorithm. Validation experiments were first conducted on phantom studies:…

Simplified analytical models for compressed concrete columns confined by FRP and FRCM system

2017

In order to consider the response of concrete columns confined by FRP and FRCM system, proper models have to be formulated. In this context the present paper shows a generalized criterion for the determination of the increase in strength, in ductility and in dissipated energy for varying corner radius ratio of the cross section and fiber volumetric ratio. The procedure is based on the best fitting of several experimental data and unlike the usual empirical approaches available in the literature, the proposed technique relates the confinement effectiveness to a single parameter representative of the relative stiffness between the original concrete core and the reinforcement system. Furthermo…

Adjuvant volumetric-modulated arc therapy with simultaneous integrated boost in endometrial cancer. Planning and toxicity comparison

2014

Objective. To report dosimetric and acute toxicity data in prospectively enrolled high-intermediate risk endometrial cancer (HIR-EC) patients postoperatively irradiated by simultaneous integrated boost volumetric modulated arc therapy (SIB-VMAT). Methods. Thirty prospectively enrolled HIR-EC patients were postoperatively treated by SIB-VMAT. Target coverage, dose homogeneity, and sparing of organs at risk (OARs) were compared with corresponding data retrieved from an historical control (30 consecutive selected matched patients) treated by concomitant boost three-dimensional conformal radiotherapy (3D CRT CB) from a previously published study (ADA-I trial). All patients received 45 Gy on pel…

Weekly Cisplatin and Volumetric-Modulated Arc Therapy With Simultaneous Integrated Boost for Radical Treatment of Advanced Cervical Cancer in Elderly…

2016

Background: To evaluate the feasibility and clinical preliminary results of weekly cisplatin and volumetric-modulated arc therapy to the pelvis with simultaneous integrated boost to macroscopic disease in a cohort of elderly patients. Materials and Methods: Inclusion criteria of this prospective study were age ≥70 years, Karnofsky performance status 70 to 100, locally advanced histologically proven squamous cervical carcinoma, and patients unable to undergo brachytherapy. Radiation doses prescribed were 66 Gy to the macroscopic disease and 54 Gy to the pelvic nodes in 30 fractions. Weekly cisplatin dose was 40 mg/mq. Results: A total of 30 patients were recruited. Median follow-up was 32 mo…