0000000000213286
AUTHOR
G. García-martí
Reproducibility and accuracy in the morphometric and mechanical quantification of trabecular bone from 3Tesla magnetic resonance images
Abstract Objective We used an animal model to analyze the reproducibility and accuracy of certain biomarkers of bone image quality in comparison to a gold standard of computed microtomography (μCT). Materials and methods We used magnetic resonance (MR) imaging and μCT to study the metaphyses of 5 sheep tibiae. The MR images (3 T) were acquired with a T1-weighted gradient echo sequence and an isotropic spatial resolution of 180 μm. The μCT images were acquired using a scanner with a spatial resolution of 7.5 μm isotropic voxels. In the preparation of the images, we applied equalization, interpolation, and thresholding algorithms. In the quantitative analysis, we calculated the percentage of …
Multimodal morphometry and functional magnetic resonance imaging in schizophrenia and auditory hallucinations
To validate a multimodal [structural and functional magnetic resonance (MR)] approach as coincidence brain clusters are hypothesized to correlate with clinical severity of auditory hallucinations.Twenty-two patients meeting Diagnostic and Statistical Manual of Mental Disorders (fourth edition, DSM-IV) criteria for schizophrenia and experiencing persistent hallucinations together with 28 healthy controls were evaluated with structural and functional MR imaging with an auditory paradigm designed to replicate those emotions related to the patients' hallucinatory experiences. Coincidence maps were obtained by combining structural maps of gray matter reduction with emotional functional increased…
Quantitative structural analysis of trabecular alveolar bone in the mandible by multidetector computed tomography: Differences according to tooth presence and type
Background and objective: There is a lack of quantitative measures of the quality of alveolar trabecular bone, an important factor in implantology. This study aimed to develop a method of objectively assessing the quality of trabecular bone by means of image processing and structural analysis of multidetector computed tomography images and to establish differences between tooth types and tooth presence/absence. Materials and methods: We analyzed 20 patients who underwent multidetector computed tomography to evaluate mandibular bone and tooth positioning. Image analysis included automatic segmentation of the mandible, obtainment of sections perpendicular to the dental arch, and structural an…
Modification of longitudinal relaxation time (T1) as a biomarker of patellar cartilage degeneration
Abstract Objectives To study the viability of longitudinal relaxation time ( T1 ) of patellar cartilage as a biomarker of the degree of degeneration. Material and methods We included 15 subjects classified into three groups according to clinical criteria (pain, functional limitation, and duration of symptoms) and imaging criteria as follows: (a) normal (3 men, 2 women; age 30 ± 14 years), (b) with initial degeneration of the patellar cartilage (3 men, 2 women; age 30 ± 6 years), or (c) with advanced degeneration (3 men, 2 women; age 57 ± 10 years). All underwent MRI examination using special echo-gradient sequences to segment the cartilage and calculate the T1 maps. We selected the entire c…
Análisis estructural cuantitativo del hueso alveolar trabecular de la mandíbula en tomografía computarizada multidetector: diferencias por tipo y estado dentario
Resumen Antecedentes y objetivo Existe una carencia de metricas cuantitativas de la calidad del hueso trabecular alveolar, factor determinante en implantologia. El objetivo de este estudio es desarrollar una metodologia con tomografia computarizada multidetector para objetivar la calidad del hueso trabecular y establecer diferencias entre los distintos tipos y el estado de las piezas dentarias mediante procesado de imagenes y analisis estructural. Materiales y metodos Se analizan 20 pacientes con exploracion de tomografia computarizada multidetector dental para la valoracion del hueso mandibular y posiciones dentales. El analisis de las imagenes incluyo la segmentacion automatica de la mand…
Reproducibilidad y exactitud en la cuantificación morfométrica y mecánica del hueso trabecular a partir de imágenes de resonancia magnética de Tesla
Resumen Objetivo En este trabajo se analizan en un modelo animal la reproducibilidad y la exactitud de ciertos biomarcadores de imagen de calidad osea utilizando como patron de referencia la microtomografia computarizada (μTC). Material y metodos Se estudiaron con RM y μTC 5 metafisis tibiales de oveja. Las imagenes de RM (3 Tesla) se adquirieron con una secuencia eco de gradiente potenciada en T1 y una resolucion espacial isotropica de 180 μm. Las imagenes de μTC se adquirieron en un escaner con una resolucion espacial de 7,5 μm en voxeles isotropicos. En la preparacion de las imagenes se aplicaron algoritmos de ecualizacion, interpolacion y umbralizacion. En el analisis cuantitativo se ca…