Non-mydriatic ultra-wide field imaging versus dilated fundus exam and intraoperative findings for assessment of rhegmatogenous retinal detachment

Background: to compare the extent of the detached retina and retinal tears location in rhegmatogenous retinal detachment (RRD) among non-mydriatic ultra-wide field (UWF) imaging, dilated fundus exam (DFE), and intraoperative evaluation. Methods: this retrospective chart review comprised 123 patients undergoing surgery for RRD. A masked retina specialist analyzed the UWF fundus images for RRD area, status of the macula, and presence and location of retinal breaks. The same variables were collected from a database including DFE and intraoperative recordings. Evaluation methods were compared. Results: mean age was 59.8 ± 14.9 years. Best-corrected visual acuity improved from 0.25 ± 0.3 (Snellen) to 0.67 ± 0.3 at 12 months (p = 0.009). The RRD description and assessment of macula status (34.5% macula-on) did not differ between UWF, DFE, and intraoperative examination. The inferior quadrant was involved most frequently (41.5%), followed by the superior (38.9%), temporal (27.8%) and nasal quadrant (14.8%). Intraoperative exam detected 96.7% of retinal tears compared with DFE (73.2%, p = 0.008) and UWF imaging (65%, p=0.003). UWF imaging and DFE did not differ significantly. Conclusion: RRD extent on DFE and UWF images was consistent with intraoperative findings. UWF and DFE detection of peripheral retinal tears was similar, but 25% of retinal breaks were missed until intraoperative evaluation

Cuantificación del infarto de miocardio en imágenes PET mediante mapas polares

Actas de: XXVIII Congreso Anual de la Sociedad Española de Ingeniería Biomédica (CASEIB 2010). Madrid, 24-26 de noviembre de 2010.El análisis de la imagen de miocardio en cardiología nuclear es una herramienta muy importante para la valoración de la enfermedad coronaria, dado que permite la cuantificación objetiva de la extensión y de la intensidad del infarto de miocardio. En este trabajo se presenta una herramienta que permite realizar dicha cuantificación mediante el uso de mapas polares tanto estáticos como dinámicos, resultantes del análisis de la imagen PET que se viene realizando en los pacientes. Esta aproximación es una alternativa que permite la visualización integral del infarto en vez de requerir una segmentación (manual o asistida) de todas las rodajas tomográficas que componen el estudio.Este trabajo ha sido financiado por los proyectos del Ministerio de Ciencia e Innovación, TEC2007-64731, TEC 2008-06715-C02-1, la RETIC-RECAVA del Ministerio de Sanidad y Consumo, y el programa ARTEMIS S2009/DPI-1802 de la Comunidad de Madrid.Publicad

Segmentación automática de estudios PET cardíacos con ¹³NH_3 basada en correlación iterativa

Actas de: XXVIII Congreso Anual de la Sociedad Española de Ingeniería Biomédica (CASEIB 2010). Madrid, 24-26 de noviembre de 2010.La obtención de la función de entrada en estudios dinámicos de corazón a partir de la imagen PET se realiza habitualmente mediante la selección previa de una región de interés (ROI) o utilizando procedimientos de análisis factorial para encontrar aquellas curvas actividad/tiempo que mejor se adaptan a la función de entrada. En este trabajo se presenta un método novedoso de segmentación automática y obtención de la función de entrada que utiliza mapas de correlación calculados sobre estudios dinámicos que emplean ¹³NH_3 como trazador. Partiendo de un modelo analítico inicial, se buscan las curvas temporales más parecidas en el estudio real empleando la correlación. Tomando como datos estas curvas se calculan nuevos modelos con los que realizar sucesivas iteraciones. El resultado final es tanto una segmentación automática como la curva de actividad/tiempo de cada región segmentada.Ministerio de Ciencia e Innovación, TEC2007-64731, TEC 2008-06715-C02-1, la RETIC-RECAVA del Ministerio de Sanidad y Consumo, y el programa ARTEMIS S2009/DPI-1802 de la Comunidad de Madrid.Publicad

jClustering, an open framework for the development of 4D clustering algorithms

We present jClustering, an open framework for the design of clustering algorithms in dynamic medical imaging. We developed this tool because of the difficulty involved in manually segmenting dynamic PET images and the lack of availability of source code for published segmentation algorithms. Providing an easily extensible open tool encourages publication of source code to facilitate the process of comparing algorithms and provide interested third parties with the opportunity to review code. The internal structure of the framework allows an external developer to implement new algorithms easily and quickly, focusing only on the particulars of the method being implemented and not on image data handling and preprocessing. This tool has been coded in Java and is presented as an ImageJ plugin in order to take advantage of all the functionalities offered by this imaging analysis platform. Both binary packages and source code have been published, the latter under a free software license (GNU General Public License) to allow modification if necessary.Funded by TEC2011-28972-C02-01, Ministerio de Ciencia e Innovación, CEN-20101014; Programa CENIT-CDTI, Ministerio de Ciencia e Innovación; S2009/DPI-1802 (ARTEMIS), Comunidad de Madrid. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Publicad

Iterative Automatic Segmentation in cardiac PET based on TAC correlation: preliminary results

Proceeding of: 2010 IEEE Nuclear Science Symposium, Medical Imaging Conference and 17th Room Temperature Semiconductor Detector Workshop (IEEE), Knoxville, Tennessee, USA, October 30 - November 6, 2010Conventional kinetic parameter estimation based on compartmental models requires an accurate estimation of arterial blood input function. To avoid invasive blood sampling, an image-derived input function can be obtained by manually defining a Region of Interest. Here we propose a new and simple, iterative method for automatic segmentation and input function calculation of PET cardiac studies using correlation as a distance metric between a priori information regarding the approximate shape of the final time-activity curve (TAC) and the actual TAC extracted from the image temporal series.This work was supported in part by the CENIT-AMIT Ingenio 2010, Ministerio de Ciencia e Innovación, TEC2007-64731, TEC 2008-06715-C02-1, RETIC-RECAVA, Ministerio de Sanidad y Consumo, and the ARTEMIS de la Comunidad de Madrid (S2009/DPI-1802) programsPublicad

Automatic TAC extraction from dynamic cardiac PET imaging using iterative correlation from a population template

This work describes a new iterative method for extracting time-activity curves (TAC) from dynamic imaging studies using a priori information from generic models obtained from TAC templates. Analytical expressions of the TAC templates were derived from TACs obtained by manual segmentation of three 13NH3 pig studies (gold standard). An iterative method for extracting both ventricular and myocardial TACs using models of the curves obtained as an initial template was then implemented and tested. These TACs were extracted from masked and unmasked images; masking was applied to remove the lungs and surrounding non-relevant structures. The resulting TACs were then compared with TACs obtained manually; the results of kinetic analysis were also compared. Extraction of TACs for each region was sensitive to the presence of other organs (e.g., lungs) in the image. Masking the volume of interest noticeably reduces error. The proposed method yields good results in terms of TAC definition and kinetic parameter estimation, even when the initial TAC templates do not accurately match specific tracer kinetics.This work is supported by the following grants: RD07/0014/2009, Subprograma RETICS, Ministerio de Ciencia e Innovación. S2009/DPI-1802 (ARTEMIS), Comunidad de Madrid. CEN-20101014, Programa CENIT, CDTI, Ministerio de Ciencia e Innovación. European Commission, EFPIA, INNOVATIVE MEDICINE INITIATIVE (PredDICT-TB project, 115337-1)Publicad

Computed tomography assesment in the characterization of mouse model for Costello Syndrome

Proceeding of: 2008 World Molecular Imaging Congress (WMIC 2008), 10-13 september 2008. Nice, Franc

Prophylactic effect of brimonidine to minimize the incidence of subconjunctival hemorrhage in the early postoperative period after 23G pars plana vitrectomy

Background: Several studies have investigated and demonstrated the prophylactic effect of brimonidine drops in preventing subconjunctival hemorrhage in some microincisional ophthalmic surgeries, such as intravitreal injections or cataract surgery. However, there are no previous studies investigating this prophylactic effect after 23G microincisional vitreoretinal surgery. Aim: The aim of the current study was to determine whether subconjunctival hemorrhage after 23G pars plana vitrectomy (PPV) could be prevented with the use of prophylactic topical brimonidine. Methods: This was a phase III, prospective, interventional, randomized, controlled single-center clinical trial with a follow-up of 2 weeks. A total of 77 eyes (mean age: 68.4 ± 10.7 years) undergoing 23G PPV were included and randomized into two groups: group 1 including 41 patients receiving prophylactic preoperative treatment with brimonidine, and group 2 (control group) including 36 patients not receiving this prophylactic treatment. Differences in terms of number of conjunctival quadrants affected with subconjunctival hemorrhage were evaluated in each of the follow-up visits. Results: The presence of subconjunctival hemorrhage was similar in both groups the first days after surgery (p > 0.05). At the last visit (10–14 days after surgery), this condition was significantly more frequent in control group where there was a significant difference, being more frequent in the control group (7.3% vs 28.6%, p = 0.022). The number of conjunctival quadrants affected was also similar in both groups, except for the last visit in which most of the patients treated with brimonidine (92.7%) showed no bleeding compared to 71.4% in control group. No effect on the efficacy of brimonidine treatment of the presence of blood hypertension, diabetes, and antiplatelet or anticoagulant treatment was observed. Conclusion: Brimonidine seems to be a useful option to decrease subconjunctival hemorrhage after microincisional vitreoretinal surgery or improve its resolution during the first postoperative week. This finding should be mainly due to the vasoconstrictor effect of brimonidine. Trial registration: EudraCT, 2012-002895-15 (registered 19 December 2012); https://www.clinicaltrialsregister.eu/ctr-search/search?query=2012-002895-15D.P.P. has been supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016-20471

An innovative tool for intraoperative electron beam radiotherapy simulation and planning: description and initial evaluation by radiation oncologists

The lack of specific treatment planning tools limits the spread of Intraoperative Electron Radiation Therapy. An innovative simulation and planning tool is presented. Applicator positioning, isodose curves, and doseevolume histograms can be estimated for previously segmented regions to treat/protect. Evaluation by three radiation oncologists on 15 patients showed high parameter agreement in nine cases, demonstrating the possibilities in cases involving different anatomical locations, and identifying the importance of specialized surgical input in the preplanning process.Supported by grants PI08/90473, IPT 300000 2010 3, ARTEMIS S2009/DPI 1802(CAM), TEC2010 21619 C04 01, PI09/90568, ERD Funds.Publicad