Search results for "tomografia"

Porosity analysis of MTA and Biodentine cements for use in endodontics by using micro?computed tomography

2018

Background The purpose of this study is to compare the porosity of two repair cements, White ProRoot® MTA and Biodentine®. These samples were analyzed by using micro-computed microtomography. Material and methods Sixteen samples were used in the study that were divided according to the composition of the materials used. White ProRoot® MTA (n = 8) and Biodentine® (n = 8) were the samples prepared according to the manufacturer's instructions. They were placed in silicone molds of 5 ± 0.1mm in height and an internal diameter of 5 ± 0.1mm, 24 hours after its preparation, the samples were scanned through a micro-CT, the porosity results were analyzed statistically by independent "t" tests. Resul…

Leukocyte and Skeletal Muscle Telomere Length and Body Composition in Monozygotic Twin Pairs Discordant for Long-term Hormone Replacement Therapy

2017

Estrogen-based hormone replacement therapy (HRT) may be associated with deceleration of cellular aging. We investigated whether long-term HRT has effects on leukocyte (LTL) or mean and minimum skeletal muscle telomere length (SMTL) in a design that controls for genotype and childhood environment. Associations between telomeres, body composition, and physical performance were also examined. Eleven monozygotic twin pairs (age 57.6 ± 1.8 years) discordant for HRT were studied. Mean duration of HRT use was 7.3 ± 3.7 years in the user sister, while their co-twins had never used HRT. LTL was measured by qPCR and SMTLs by southern blot. Body and muscle composition were estimated by bioimpedance an…

Three-dimensional analysis of tumour vascular corrosion casts using stereoimaging and micro-computed tomography

2009

Objective: In order to perform effective translational research for cancer therapy, we need to employ preclinical models which reflect the clinical situation. The purpose of this study was to quantitatively compare the vascular architecture of human colorectal cancer and experimental tumour models to determine the suitability of animal models for vascular studies and antivascular therapy.Methods: In this study we investigated the three-dimensional properties of colonic tumour vasculature in both human clinical tissues (normal mucosa control [n = 20], carcinoma [n = 20] and adenoma In = 61) and murine colorectal xenografts (LS147T [n = 6] and SW1222 [n = 6]). Scanning Electron Microscope Ste…

Diagnosis of pre-sarcopenia from a single selectional crosscut at C3 region, using CT scans before radiotherapy

2019

espanolProposito: el proposito de este estudio fue diagnosticar la presarcopenia en pacientes con cancer que no disponen de imagenes por tomografia computarizada (TC) a nivel abdominal mediante un metodo novedoso basado en cortes a nivel cervical. Material y metodos: se analizaron y se compararon mediante unidades la masa muscular y la masa muscular esqueletica en 37 pacientes con cancer de pulmon y neoplasias del aparato digestivo superior que incluian cortes en la TC de planificacion a nivel de C3 y L3. La presarcopenia se identifico de acuerdo con los puntos de corte establecidos actualmente: ≤ 41 cm2/m2 para mujeres, ≤ 43 cm2/m2 en hombres con un IMC ≤ 25 kg/m2 y ≤ 53 cm2/m2 en hombres …

Multisectorial changes in the ciliary muscle during accommodation measured with high-resolution optical coherence tomography

2019

ABSTRACT Purpose: To measure changes in the anterior ciliary muscle during accommodation at the nasal, superior, temporal, and inferior sectors by means of an anterior chamber optical coherence tomographer, and correlate them with vergence changes. Methods: Twenty-four subjects with healthy, phakic eyes, whose mean age was 27.1 ± 8.9 years, underwent measurement with an anterior chamber optical coherence tomographer. The anterior ciliary muscle was measured at the nasal, temporal, superior, and inferior sectors for 0, -1, -2, and -3 D of vergence. A linear model was used to assess the correlation of each eye parameter with the accommodative demand. Results: The anterior ciliary muscle area …

Avaliação por OCT in vivo do comprimentos axiais centrais do segmento anterior

2017

ABSTRACT Purpose: To assess changes in anatomic structures in the anterior eye segment in terms of axial lengths with accommodation via optical coherence tomography. Methods: In this observational study, 25 eyes of 25 healthy adults were examined using the Visante® omni optical coherence tomography system. Central corneal thickness, anterior chamber depth, central lens thickness, and anterior segment length were assessed. The evaluated parameters were obtained with accommodation using different stimulus vergences, namely 0.0, -1.0, -2.0, and -3.0 D. Variation of these parameters was compared among different levels of accommodation. Results: Central corneal thickness was not altered at any s…

Reliability of upper-limb diaphyseal mineral and soft-tissue measurements using peripheral quantitative computed tomography (pQCT)

2018

Objectives: To quantify between-day reliability of upper-body diaphyseal measurements (radius, ulna, humerus) using peripheral Quantitative Computed Tomography (pQCT). - Methods: Fourteen males (age: 25.8±2.3 years,) underwent repeat pQCT scans (one to two days apart) at mid-shaft ulna (60%), mid-shaft radius (60%) and mid-shaft humerus (50%) cross-sections of the non-dominant limb. Intraclass correlation coefficients (ICC) and coefficients of variation (CV) were determined for musculoskeletal morphology variables. - Results: Reliability was excellent (ICC: 0.76–0.99; CV: 1.3– 7.3) at all sites for bone mass, stress-strain index, endocortical and pericortical radius, endocortical volumetric…

Cardioradiologia

2009

Visualizzazione non invasiva dell’aterosclerosi coronarica con TC e RM

2007

Putting molecules in their place.

2014

Each class of microscope is limited to imaging specific aspects of cell structure and/or molecular organization. However, imaging the specimen by complementary microscopes and correlating the data can overcome this limitation. Whilst not a new approach, the field of correlative imaging is currently benefitting from the emergence of new microscope techniques. Here we describe the correlation of cryogenic fluorescence tomography (CFT) with soft X‐ray tomography (SXT). This amalgamation of techniques integrates 3D molecular localization data (CFT) with a high‐resolution, 3D cell reconstruction of the cell (SXT). Cells are imaged in both modalities in a near‐native, cryopreserved state. Here we…