Search results for "Radiological and Ultrasound Technology"
showing 10 items of 423 documents
Umbilical cord cysts: evaluation with different 3-dimensional sonographic modes.
2010
Objective. The purpose of this series was to determine whether the use of different 3-dimensional (3D) sonographic modes allows better definition of umbilical cord cysts and pseudocysts in utero. Methods. Two cases of umbilical cord cysts and 1 of a pseudocyst were analyzed and compared with 2-dimensional (2D), 3D, angiopower Doppler, tomographic ultrasound imaging (TUI), virtual organ computer-aided analysis (VOCAL), and automatic volume calculation (AVC) sonographic modes. All cases were followed during pregnancy. A karyotype analysis was also obtained. Results. Three-dimensional sonography, TUI, and VOCAL allowed clear visualization and evaluation of the sizes, locations, and numbers of …
Diagnostic value of MR-based texture analysis for the assessment of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD)
2019
PurposeTo investigate the performance of MR-based texture analysis (TA) for the assessment of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).MethodsFifty-four adult patients (33 females, 21 males, mean age 49.813.5years) with biopsy-proven NAFLD were enrolled and underwent MR imaging on a 1.5T system. TA parameters were extracted on axial noncontrast 3D-GRE T1W images (slice thickness=4.6mm) using a commercially available research software (TexRAD). Receiver operating curves (ROC), areas under the ROC (AUROC) and 95% confidence intervals (CI) were calculated to assess the accuracy of each TA parameter for the diagnosis of significant (F2) and advanced fibrosis (F…
Analysis of different contrast enhancement patterns after microbubble-based contrast agent injection in liver hemangiomas with atypical appearance on…
2006
BACKGROUND: We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection. METHODS: From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). …
Probabilistic liver atlas construction
2017
Background Anatomical atlases are 3D volumes or shapes representing an organ or structure of the human body. They contain either the prototypical shape of the object of interest together with other shapes representing its statistical variations (statistical atlas) or a probability map of belonging to the object (probabilistic atlas). Probabilistic atlases are mostly built with simple estimations only involving the data at each spatial location. Results A new method for probabilistic atlas construction that uses a generalized linear model is proposed. This method aims to improve the estimation of the probability to be covered by the liver. Furthermore, all methods to build an atlas involve p…
Towards a unified analysis of cerebellum maturation and aging across the entire lifespan: A MRI analysis
2021
[EN] Previous literature about the structural characterization of the human cerebellum is related to the context of a specific pathology or focused in a restricted age range. In fact, studies about the cerebellum maturation across the lifespan are scarce and most of them considered the cerebellum as a whole without investigating each lobule. This lack of study can be explained by the lack of both accurate segmentation methods and data availability. Fortunately, during the last years, several cerebellum segmenta- tion methods have been developed and many databases comprising subjects of dif- ferent ages have been made publically available. This fact opens an opportunity window to obtain a mo…
Evaluation of the apparent diffusion coefficient in patients with recurrent glioblastoma under treatment with bevacizumab with radiographic pseudores…
2017
Abstract Background Response Assessment in Neuro-Oncology Criteria (RANO), are used to asses response to first-line treatment of glioblastoma (GBM). Differentiation between response and pseudoresponse under treatment with Bevacizumab (BVZ) remains challenging. This study evaluates ADC changes in patients with radiographic pseudoresponse under treatment with (BVZ). Methods Patients (n = 40) with recurrent GBM under-treatment with BVZ underwent MRI before, two and four months after treatment with BVZ. In patients with radiological pseudoresponse (n = 11), ADC analyses were performed. Areas with decreasing T1 contrast enhancement (CE) and FLAIR signal decrease were manually selected and compar…
Differential impact of continuous theta-burst stimulation over left and right DLPFC on planning
2011
Most neuroimaging studies on planning report bilateral activations of the dorsolateral prefron- tal cortex (dlPFC). Recently, these concurrent activations of left and right dlPFC have been shown to dou- ble dissociate with different cognitive demands imposed by the planning task: Higher demands on the extraction of task-relevant information led to stronger activation in left dlPFC, whereas higher demands on the integration of interdependent information into a coherent action sequence entailed stronger activa- tion of right dlPFC. Here, we used continuous theta-burst stimulation (cTBS) to investigate the supposed causal structure-function mapping underlying this double dissociation. Two grou…
Changes in cerebellar activation pattern during two successive sequences of saccades
2002
The changes in the cerebellar activation pattern of two successive fMRI scanning runs were determined for visually guided to‐and‐fro saccades in 12 healthy volunteers familiar with the study paradigm. Group and single subject‐analyses revealed a constant activation of the paramedian cerebellar vermis (uvula, tonsils, tuber, folium/declive), which reflects constant ocular motor activity in both runs. A significant decrease in activation of the cerebellar hemispheres found in the second run is best explained by either a decrease in attention or the effects of motor optimization and learning. The significant, systematic changes of the cerebellar activation pattern in two successive runs were n…
The role of the right temporo-parietal junction in social decision-making
2018
Identifying someone else's noncooperative intentions can prevent exploitation in social interactions. Hence, the inference of another person's mental state might be most pronounced in order to improve social decision‐making. Here, we tested the hypothesis that brain regions associated with Theory of Mind (ToM), particularly the right temporo–parietal junction (rTPJ), show higher neural responses when interacting with a selfish person and that the rTPJ‐activity as well as cooperative tendencies will change over time. We used functional magnetic resonance imaging (fMRI) and a modified prisoner's dilemma game in which 20 participants interacted with three fictive playing partners who behaved a…
Evaluation of texture analysis for the differential diagnosis of focal nodular hyperplasia from hepatocellular adenoma on contrast-enhanced CT images
2018
PurposeTo explore the value of CT texture analysis (CTTA) for differentiation of focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) on contrast-enhanced CT (CECT).MethodsThis is a retrospective, IRB-approved study conducted in a single institution. A search of the medical records between 2008 and 2017 revealed 48 patients with 70 HCA and 50 patients with 62 FNH. All lesions were histologically proven and with available pre-operative CECT imaging. Hepatic arterial phase (HAP) and portal venous phase (PVP) were used for CTTA. Textural features were extracted using a commercially available research software (TexRAD). The differences between textural parameters of FNH and HCA wer…