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Donostia / San Sebastián, Spain

Millan-Ortuondo E.,Subdireccion de Asistencia Sanitaria | Cabrera-Zubizarreta A.,Osatek | Muniz-Saitua J.,Subdireccion de Asistencia Sanitaria | Sola-Sarabia C.,Subdireccion de Asistencia Sanitaria
Revista de Neurologia

Introduction. The number of requests for magnetic resonance imaging (MRI) scans in healthcare systems is continually on the rise. An MRI scan of the head is one of the most frequent locations, which if used inappropriately entails a loss of resources. Consequently, guidelines are needed to help the physician make decisions and allow better management of resources. Aim. To establish the key indications of MRI scans in cases of adults with headache. Materials and methods. The RAND/UCLA appropriateness method was used, that is, following a systematic review, a list of possible indications of MRI in cases of headache was drawn up. This list was then assessed by a panel of experts and given a score between 1 ('totally inappropriate') and 9 ('totally appropriate'). An initial round of scoring was carried out online, the results were then discussed at a face-to-face meeting of the experts and finally another online round was undertaken. MRI was considered appropriate in each indication if the mean score was 6.5 or higher and there was agreement among the experts (using the IPRAS index). Results. MRI scanning was considered appropriate in cases of: new headache, new headache in immunodeficient patients, sudden intense headache, headache with focal neurological symptoms, postural headache, headache due to physical effort or Valsalva manoeuvres, suspected thrombosis in the venous sinuses, systemic involvement, progressive headache, headache in pregnancy, autonomic trigeminal headache or severe cranial traumatic injury with focus. Conclusions. It seems that indication can be summed up in headaches with a suspected secondary pathology. The methodology employed makes it possible to establish MRI indications that can be useful both in clinical practice and for healthcare management practitioners. © 2013 Revista de Neurología. Source

Savio A.,Grupo de Inteligencia Computacional | Grana M.,Grupo de Inteligencia Computacional | Villanua J.,Osatek
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Detection of Alzheimer's disease over brain Magnetic Resonance Imaging (MRI) data is a priority goal in the Neurosciences. In previous works we have studied the accuracy of feature vectors obtained from VBM studies of the MRI data. In this paper we report results working on deformation based features, obtained from the deformation vectors computed by non-linear registration processes. Feature selection is based on the correlation between the scalar values computed from the deformation maps and the control variable. Results with linear kernel SVM reach accuracies comparable to previous best results. © 2011 Springer-Verlag. Source

Fernandez E.,University of the Basque Country | Grana M.,University of the Basque Country | Villanua J.,Osatek
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Dynamic velocity-encoded Phase-contrast MRI (PC-MRI) techniques are being used increasingly to quantify pulsatile flows for a variety of flow clinical application. A method for igh resolution segmentation of cerebrospinal fluid (CSF) velocity is described. The method works on PC-MRI with high temporal and spatial resolution. It has been applied in this paper to the CSF flow at the Aqueduct of Sylvius (AS). The approach first selects the regions with high flow applying a threshold on the coefficient of variation of the image pixels velocity profiles. The AS corresponds to the most central detected region. We perform a lattice independent component analysis (LICA) on this small region, so that the image abundances provide the high resolution segmentation of the CSF flow at the AS. Long term goal of our work is to use this detection and segmentation to take some measurements and evaluate the changes in patients with suspected Idiopathic Normal Pressure Hydrocephalus (iNPH). © 2011 Springer-Verlag Berlin Heidelberg. Source

Rodriguez-Vigil Junco B.,Osatek | Gomez Leon N.,Hospital Universitario La Paz | Pinilla Fernandez I.,Hospital Universitario La Paz | Del Campo L.,Hospital Universitario La Paz | And 2 more authors.
Medicina Clinica

Background and objective: To prospectively analyze the diagnostic accuracy of PET/CT in non-Hodgkin's lymphoma (NHL) and to evaluate the most appropriate study protocol of this technique. Patients and method: Seventy-six biopsy proven NHL patients were enrolled in this prospective study for 3 years. Patients initially underwent a low-dose CT without intravenous contrast, then a PET emission scan and finally a full-dose CT with intravenous contrast. For every patient, two modalities of PET/CT images were reconstructed: a low-dose unenhanced PET/CT and a full-dose enhanced PET/CT. Each modality was evaluated by either of two pairs of readers, different for each modality. Enhanced CT and PET images were evaluated by an independent radiologist and nuclear medicine physician respectively. Results: Agreement between reference standard and techniques was as follows: 52.2% of patients with enhanced CT (κ = 0.458), 46% with PET (κ = 0.335), 75% with low-dose unenhanced PET/CT (κ = 0.664) and 76.8% with full-dose enhanced PET/CT (κ = 0.679), with p < 0.001. Although all techniques underestimated the stage in comparison to gold standard, the lowest percentage was for full-dose enhanced PET/CT (20.3%). Conclusions: PET/CT improved staging accuracy of NHL, being full-dose enhanced PET/CT the most accurate technique in our study. © 2010 Elsevier España, S.L. All rights reserved. Source

Garcia-Zapirain B.,University of Deusto | Garcia-Chimeno Y.,University of Deusto | Saralegui I.,Osatek | Fernandez-Ruanova B.,Osatek | Martinez R.,University Hospital of Cruces
Biomedical Signal Processing and Control

Non-invasive quantitative MRI methods, such as Diffusion Tensor Imaging (DTI) can offer insights into diverse developmental brain disorders such as dyslexia, the most prevalent reading disorder in childhood. In this article, we quantified the microstructural attributes of the main fascicles of both hemispheres related to the reading network in three groups of Spanish children: typically developing readers (TDR or controls), dyslexic readers (DXR) and readers with monocular vision due to ocular motility disorders (MVR), to assess whether the dyslexic children neuronal network for reading shares similarities with the neuronal network for reading in children with impaired binocular vision due to ocular motility disorders or not. Diffusion anisotropy, and mean, radial and axial diffusivity of cross-sectional subregions of the main fascicles studied were computed using a validated DTI methodology. Our results reveal differences in fractional anisotropy (FA) values between the DXR and the non-dyslexic readers, with a decreased FA for the DXR and no significant differences between TDR and MVR groups in the left Arcuate fasciculus, and a tendency to higher FA values in the DXR group compared to the other two groups in the genu of the Corpus Callosum (CC). In the splenium of the CC a trend towards higher FA values was observed in the DXR and MVR groups versus the TDR. This study reveals a different brain connectivity pattern for reading in Spanish children with dyslexia from those with impaired binocular vision due to ocular motility disorders, which would support the hypothesis that ocular motility disorders are not a causal factor of dyslexia. © 2015 Elsevier Ltd. Source

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