1,238 research outputs found
Hacia el modelado 3d de tumores cerebrales mediante endoneurosonografía y redes neuronales
Las cirugías mínimamente invasivas se han vuelto populares debido a que implican menos riesgos con respecto a las intervenciones tradicionales. En neurocirugía, las tendencias recientes sugieren el uso conjunto de la endoscopia y el ultrasonido, técnica llamada endoneurosonografía (ENS), para la virtualización 3D de las estructuras del cerebro en tiempo real. La información ENS se puede utilizar para generar modelos 3D de los tumores del cerebro durante la cirugía. En este trabajo, presentamos una metodología para el modelado 3D de tumores cerebrales con ENS y redes neuronales. Específicamente, se estudió el uso de mapas auto-organizados (SOM) y de redes neuronales tipo gas (NGN). En comparación con otras técnicas, el modelado 3D usando redes neuronales ofrece ventajas debido a que la morfología del tumor se codifica directamente sobre los pesos sinápticos de la red, no requiere ningún conocimiento a priori y la representación puede ser desarrollada en dos etapas: entrenamiento fuera de línea y adaptación en línea. Se realizan pruebas experimentales con maniquíes médicos de tumores cerebrales. Al final del documento, se presentan los resultados del modelado 3D a partir de una base de datos ENS.Minimally invasive surgeries have become popular because they reduce the typical risks of traditional interventions. In neurosurgery, recent trends suggest the combined use of endoscopy and ultrasound (endoneurosonography or ENS) for 3D virtualization of brain structures in real time. The ENS information can be used to generate 3D models of brain tumors during a surgery. This paper introduces a methodology for 3D modeling of brain tumors using ENS and unsupervised neural networks. The use of self-organizing maps (SOM) and neural gas networks (NGN) is particularly studied. Compared to other techniques, 3D modeling using neural networks offers advantages, since tumor morphology is directly encoded in synaptic weights of the network, no a priori knowledge is required, and the representation can be developed in two stages: off-line training and on-line adaptation. Experimental tests were performed using virtualized phantom brain tumors. At the end of the paper, the results of 3D modeling from an ENS database are presented
A Survey on Deep Learning in Medical Image Analysis
Deep learning algorithms, in particular convolutional networks, have rapidly
become a methodology of choice for analyzing medical images. This paper reviews
the major deep learning concepts pertinent to medical image analysis and
summarizes over 300 contributions to the field, most of which appeared in the
last year. We survey the use of deep learning for image classification, object
detection, segmentation, registration, and other tasks and provide concise
overviews of studies per application area. Open challenges and directions for
future research are discussed.Comment: Revised survey includes expanded discussion section and reworked
introductory section on common deep architectures. Added missed papers from
before Feb 1st 201
Unsupervised Anomaly Localization with Structural Feature-Autoencoders
Unsupervised Anomaly Detection has become a popular method to detect
pathologies in medical images as it does not require supervision or labels for
training. Most commonly, the anomaly detection model generates a "normal"
version of an input image, and the pixel-wise -difference of the two is
used to localize anomalies. However, large residuals often occur due to
imperfect reconstruction of the complex anatomical structures present in most
medical images. This method also fails to detect anomalies that are not
characterized by large intensity differences to the surrounding tissue. We
propose to tackle this problem using a feature-mapping function that transforms
the input intensity images into a space with multiple channels where anomalies
can be detected along different discriminative feature maps extracted from the
original image. We then train an Autoencoder model in this space using
structural similarity loss that does not only consider differences in intensity
but also in contrast and structure. Our method significantly increases
performance on two medical data sets for brain MRI. Code and experiments are
available at https://github.com/FeliMe/feature-autoencoderComment: 10 pages, 5 figures, one table, accepted to the MICCAI 2021 BrainLes
Worksho
Self-supervised iRegNet for the Registration of Longitudinal Brain MRI of Diffuse Glioma Patients
Reliable and accurate registration of patient-specific brain magnetic
resonance imaging (MRI) scans containing pathologies is challenging due to
tissue appearance changes. This paper describes our contribution to the
Registration of the longitudinal brain MRI task of the Brain Tumor Sequence
Registration Challenge 2022 (BraTS-Reg 2022). We developed an enhanced
unsupervised learning-based method that extends the iRegNet. In particular,
incorporating an unsupervised learning-based paradigm as well as several minor
modifications to the network pipeline, allows the enhanced iRegNet method to
achieve respectable results. Experimental findings show that the enhanced
self-supervised model is able to improve the initial mean median registration
absolute error (MAE) from 8.20 (7.62) mm to the lowest value of 3.51 (3.50) for
the training set while achieving an MAE of 2.93 (1.63) mm for the validation
set. Additional qualitative validation of this study was conducted through
overlaying pre-post MRI pairs before and after the de-formable registration.
The proposed method scored 5th place during the testing phase of the MICCAI
BraTS-Reg 2022 challenge. The docker image to reproduce our BraTS-Reg
submission results will be publicly available.Comment: Accepted in the MICCAI BraTS-Reg 2022 Challenge (as part of the
BrainLes workshop proceedings distributed by Springer LNCS
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