Search results for "ABLATION"

Chirurgia trans-cranica mediante ultrasuoni focalizzati ad alta intensità su guida RM: esperienza preliminare a 1,5T

2015

Da qualche anno la chirurgia mediante ultrasuoni focalizzati ad alta intensità guidati da Risonanza Magnetica (Magnetic Resonance guided Focused Ultrasound Surgery, MRgFUS) si sta diffondendo anche in Italia per la palliazione del dolore da metastasi ossee, per il trattamento di tumori ossei primitivi (benigni e non), dei fibromi e dell’adenomiosi uterina; sono già stati inoltre pubblicati i risultati preliminari del trattamento di alcuni tumori epatici, pancreatici, prostatici e della mammella mediante MRgFUS. Questa innovativa tecnica prevede l’utilizzo di un’apparecchiatura di Risonanza Magnetica per il monitoraggio della procedura e sfrutta le caratteristiche fisico- meccaniche degli …

Self-limiting and complete oxidation of silicon nanostructures produced by laser ablation in water

2016

Oxidized Silicon nanomaterials produced by 1064 nm pulsed laser ablation in deionized water are investigated. High-resolution transmission electron microscopy coupled with energy dispersive X-ray spectroscopy allows to characterize the structural and chemical properties at a sub-nanometric scale. This analysis clarifies that laser ablation induces both self-limiting and complete oxidation processes which produce polycrystalline Si surrounded by a layer of SiO2 and amorphous fully oxidized SiO2, respectively. These nanostructures exhibit a composite luminescence spectrum which is investigated by time-resolved spectroscopy with a tunable laser excitation. The origin of the observed luminescen…

Laser-Ablation-Induced Synthesis of SiO2-Capped Noble Metal Nanoparticles in a Single Step

2010

Here we describe a simple, powerful technique based on the laser ablation of a target immersed in a water solution of a metal salt. With this method, nanoparticles of different metals and alloys can be processed very quickly. Both the target and the salt solution can be chosen to produce metal nanoparticles of different sizes, surface-oxidized nanoparticles (silica-silver, for example), or even more complex structures to be defined by the researcher on one or more steps because the technique combines the advantages of both physical and chemical methods. We have applied this technique to the fabrication of inert silica-metal (silver, gold, and silver-gold) nanoparticles with a strong surface…

The usefulness of Sonovue-enhanced pulse-inversion US to assess hepatocellular carcinoma response after percutaneous radiofrequency thermal ablation …

2006

Multimodal approaches to the treatment of hepatocellular carcinoma.

2008

The prevalence of hepatocellular carcinoma in Europe and the US is increasing and is currently the leading cause of death in patients with cirrhosis. Surveillance programs for patients with cirrhosis aim to detect tumors at an early stage, when the greatest therapeutic benefits can be achieved. Curative treatments for early-stage tumors include liver transplantation, resection and percutaneous ablation. Transarterial chemoembolization (TACE) and sorafenib can improve survival for patients with intermediate and advanced tumors, respectively. In clinical practice, combination therapies are often used, despite limited evidence to support this approach from randomized controlled trials. Combina…

Future perspectives in hepatocellular carcinoma.

2010

Hepatocellular carcinoma (HCC) is one of the most common and lethal malignancies worldwide. Due to late diagnosis and advanced underlying liver cirrhosis, only limited treatment options with marginal clinical benefits have been available in up to 70% of patients. However, major progress has been achieved with regard to surveillance, early diagnosis, and multimodal treatment approaches during the last years leading to an improvement in prognosis. Particularly, the increasing knowledge of molecular hepatocarcinogenesis today provides the opportunity for targeted therapy. The multikinase inhibitor sorafenib has broadened the therapeutic horizon for patients with advanced disease and is current…

Combining split-and-merge and multi-seed region growing algorithms for uterine fibroid segmentation in MRgFUS treatments

2016

Uterine fibroids are benign tumors that can affect female patients during reproductive years. Magnetic resonance-guided focused ultrasound (MRgFUS) represents a noninvasive approach that uses thermal ablation principles to treat symptomatic fibroids. During traditional treatment planning, uterus, fibroids, and surrounding organs at risk must be manually marked on MR images by an operator. After treatment, an operator must segment, again manually, treated areas to evaluate the non-perfused volume (NPV) inside the fibroids. Both pre- and post-treatment procedures are time-consuming and operator-dependent. This paper presents a novel method, based on an advanced direct region detection model, …

Analysis of paper by laser-induced plasma spectroscopy

2001

Abstract Material distributions in paper and paper coatings are important factors which determine the characteristics and quality of paper. We have used laser-induced plasma spectroscopy (LIPS) to determine various properties of coated and uncoated papers. Depth profiles of double coated papers were determined. Microscopic variations of pigments in a double-coated paper were analyzed. It was observed, that the two coating layers can be distinguished, if they differ enough in composition. Filler distributions of uncoated copier papers were determined. The surface of the paper was studied for five samples containing different amounts of binder in the coating. Lateral contamination in paper an…

MRgFUS results Italy

2017

PURPOSE: To present our preliminary results achieved with the first Italian installation of a trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS) certified system for functional neurosurgery. Moreover, to our knowledge, this is the world-first tcMRgFUS system ever installed on a 1.5T MRI unit. Technical issues faced to achieve a safe and effective treatment will be discussed focusing on MR high-resolution live imaging and thermometry sequences optimization. METHOD AND MATERIALS: Patient enrollment was based on indication for functional neurosurgery and evidence of medication-refractory disease; a detailed medical history has been collected together with a complete clinical examin…

Fast offline data reduction of laser ablation MC-ICP-MS Sr isotope measurements: Via an interactive Excel-based spreadsheet 'SrDR'

2020

Strontium isotopes are applied to a wide range of scientific fields and to different types of sample materials, providing valuable information foremost about provenance and age, but also on diagenetic processes and mixing relationships between different Sr reservoirs. The development of in-situ analytical techniques, such as laser ablation ICP-MS, has improved our understanding of Sr isotope variability in several field of application, because of the possibility to discriminate small-scale changes and their spatial distribution. However, large outputs of Sr isotope data are produced by laser ablation MC-ICP-MS systems, which necessitate of multiple offline steps to correct and assess the da…