Carlos Velásquez

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PURPOSE Tumor heterogeneity in medical imaging is a current research trend due to its potential relationship with tumor malignancy. The aim of this study is to analyze the effect of dynamic range and matrix size changes on the results of different heterogeneity measures. MATERIALS AND METHODS Four patients harboring three glioblastomas and one metastasis(More)
OBJECTIVE The main objective of this retrospective work was the study of three-dimensional (3D) heterogeneity measures of post-contrast pre-operative MR images acquired with T1 weighted sequences of patients with glioblastoma (GBM) as predictors of clinical outcome. METHODS 79 patients from 3 hospitals were included in the study. 16 3D textural(More)
The potential of a tumour’s volumetric measures obtained from pretreatment MRI sequences of glioblastoma (GBM) patients as predictors of clinical outcome has been controversial. Mathematical models of GBM growth have suggested a relation between a tumour’s geometry and its aggressiveness. A multicenter retrospective clinical study was designed to study(More)
Determinant aspects of the development cycle of Panstrongylus rufotuberculatus (Champion, 1899) were evaluated under laboratory conditions. Fertility, duration of life cycle, mortality rate, feeding time, defecation time, thermal reaction time to food source, and volume of blood ingested were studied. From an initial cohort of fifth instars, nine adult(More)
BACKGROUND An exophytic tumor is defined as a tumor that has its epicenter in the nervous tissue but grows outside the anatomical superficial boundaries of the brain within an adjacent space. Exophytic extension of hemispheric gliomas is extremely rare. The object of this study is to describe the exophytic growth pattern of insular gliomas. METHODS A(More)
BACKGROUND The accurate histologic diagnosis of germ cell tumors in the pineal region is a keystone for determining the best treatment strategy and prognosis. This situation poses a challenge for the neuropathologist, considering the lack of a standarized procedure to obtain biopsy samples, which results in few and small specimens, which are not suitable(More)
This report describes a reliable and simple technique for securing external ventricular drains (EVDs) to the scalp and avoiding pullout complications. The operative technique consists of fixing the drain between 2 hydrocolloid dressings and securing it with staples. A 10-year retrospective analysis of EVD pullout complications was performed in a series of(More)
Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones(More)
INTRODUCTION Gliomas are characterized by a infiltrative pattern of growth, with cellular migration along the white matter fiber tracts, exophytic growth in low-grade gliomas has not been described yet. A case of hemispheric glioma with slow growing and an exophytic component is presented. CASE REPORT 55 year-old male, with motor partial seizures. MRI(More)
Three experiments were conducted to study the possibility of improving the nutritive value of broad beans (Vicia faba, L.) in poultry diets. In the first experiment, raw and autoclaved (1.0 kg/cm2/15 min) beans, with and without antibiotic supplementation, were studied. The results after 21 days showed no significant differences among treatments in regard(More)