163 research outputs found
An Anisotropic Diffusion Approach for Early Detection of Breast Cancer
International audienceThe prevalence of breast cancer in the modern world has motivated the development of new tools to assist radiologists in their quest to detect malignancy as early as possible. Following the successful introduction of the screening programmes, science must provide effective clinical methods to detect cancer and improve life expectancy. Considerable research has been undertaken to this end, but the results still lack the robustness necessary for routine clinical applications. Mammographic images are difficult to interpret even by radiologists and this makes their task error prone. This paper presents a new approach to filtering breast images, which highlights the structures of anatomical interest. A method to detect calcifications has been explored. The approach is based on an edge preserving filtering with anisotropic diffusion. The algorithm makes use of the advantages offered by the hint images, a normalised physical-based representation of the breast. The results are promising with excellent true positive rates in both detection of isolated coarse calcifications and microcalcifications with a very low number of false positives per image
Robust head CT image registration pipeline for craniosynostosis skull correction surgery
Craniosynostosis is a congenital malformation of the infant skull typically treated via corrective surgery. To accurately quantify the extent of deformation and identify the optimal correction strategy, the patient-specific skull model extracted from a pre-surgical computed tomography (CT) image needs to be registered to an atlas of head CT images representative of normal subjects. Here, the authors present a robust multi-stage, multi-resolution registration pipeline to map a patient-specific CT image to the atlas space of normal CT images. The proposed registration pipeline first performs an initial optimisation at very low resolution to yield a good initial alignment that is subsequently refined at high resolution. They demonstrate the robustness of the proposed method by evaluating its performance on 560 head CT images of 320 normal subjects and 240 craniosynostosis patients and show a success rate of 92.8 and 94.2%, respectively. Their method achieved a mean surface-to-surface distance between the patient and template skull of \u3c2.5 mm in the targeted skull region across both the normal subjects and patients. Keywords: image registration, bone, surgery, medical image processing, computerised tomography, deformation, biomechanics, image resolution, optimisation Keywords: robust head CT image registration pipeline, craniosynostosis skull correction surgery, congenital malformation, infant skull, corrective surgery, deformation, optimal correction strategy, patient-specific skull model extraction, presurgical computed tomography image, robust multistage multiresolution registration pipeline, patient-specihc CT image, normal CT images, initial optimisation, very low resolution, mean surface-to-surface distance, template skull, targeted skull regio
Computational Anatomy for Multi-Organ Analysis in Medical Imaging: A Review
The medical image analysis field has traditionally been focused on the
development of organ-, and disease-specific methods. Recently, the interest in
the development of more 20 comprehensive computational anatomical models has
grown, leading to the creation of multi-organ models. Multi-organ approaches,
unlike traditional organ-specific strategies, incorporate inter-organ relations
into the model, thus leading to a more accurate representation of the complex
human anatomy. Inter-organ relations are not only spatial, but also functional
and physiological. Over the years, the strategies 25 proposed to efficiently
model multi-organ structures have evolved from the simple global modeling, to
more sophisticated approaches such as sequential, hierarchical, or machine
learning-based models. In this paper, we present a review of the state of the
art on multi-organ analysis and associated computation anatomy methodology. The
manuscript follows a methodology-based classification of the different
techniques 30 available for the analysis of multi-organs and multi-anatomical
structures, from techniques using point distribution models to the most recent
deep learning-based approaches. With more than 300 papers included in this
review, we reflect on the trends and challenges of the field of computational
anatomy, the particularities of each anatomical region, and the potential of
multi-organ analysis to increase the impact of 35 medical imaging applications
on the future of healthcare.Comment: Paper under revie
Effectiveness of Automatic Planning of Fronto-orbital Advancement for the Surgical Correction of Metopic Craniosynostosis
The surgical correction of metopic craniosynostosis usually relies on the subjective judgment of surgeons to determine the configuration of the cranial bone fragments and the degree of overcorrection. This study evaluates the effectiveness of a new approach for automatic planning of fronto-orbital advancement based on statistical shape models and including overcorrection.The authors have no financial interest in relation
to the content of this article. This work was supported by grants
R42 HD081712 (Eunice Kennedy Shriver National Institute
of Child Health and Human Development), K99DE027993
(National Institute of Dental and Craniofacial Research), and
PI18/01625 (Ministerio de Ciencia e Innovación, Instituto
de Salud Carlos III and European Regional Development
Fund “Una manera de hacer Europa”)
Harmonization Across Imaging Locations(HAIL): One-Shot Learning for Brain MRI
For machine learning-based prognosis and diagnosis of rare diseases, such as
pediatric brain tumors, it is necessary to gather medical imaging data from
multiple clinical sites that may use different devices and protocols. Deep
learning-driven harmonization of radiologic images relies on generative
adversarial networks (GANs). However, GANs notoriously generate pseudo
structures that do not exist in the original training data, a phenomenon known
as "hallucination". To prevent hallucination in medical imaging, such as
magnetic resonance images (MRI) of the brain, we propose a one-shot learning
method where we utilize neural style transfer for harmonization. At test time,
the method uses one image from a clinical site to generate an image that
matches the intensity scale of the collaborating sites. Our approach combines
learning a feature extractor, neural style transfer, and adaptive instance
normalization. We further propose a novel strategy to evaluate the
effectiveness of image harmonization approaches with evaluation metrics that
both measure image style harmonization and assess the preservation of
anatomical structures. Experimental results demonstrate the effectiveness of
our method in preserving patient anatomy while adjusting the image intensities
to a new clinical site. Our general harmonization model can be used on unseen
data from new sites, making it a valuable tool for real-world medical
applications and clinical trials.Comment: Under revie
Automated Analysis of Basal Ganglia Intensity Distribution in Multisequence MRI of the Brain - Application to Creutzfeldt-Jakob Disease
We present a method for the analysis of basal ganglia (including the thalamus) for accurate detection of human spongiform encephalopathy in multisequence MRI of the brain. One common feature of most forms of prion protein infections is the appearance of hyperintensities in the deep grey matter area of the brain in T2-weighted MR images. We employ T1, T2 and Flair-T2 MR sequences for the detection of intensity deviations in the internal nuclei. First, the MR data is registered to a probabilistic atlas and normalised in intensity. Then smoothing is applied with edge enhancement. The segmentation of hyperintensities is performed using a model of the human visual system. For more accurate results, a priori anatomical data from a segmented atlas is employed to refine the registration and remove false positives. The results are robust over the patient data and in accordance to the clinical ground truth. Our method further allows the quantification of intensity distributions in basal ganglia. The caudate nuclei are highlighted as main areas of diagnosis of sporadic Creutzfeldt-Jakob Disease (CJD), in agreement with the histological data. The algorithm permitted to classify the intensities of abnormal signals in sporadic CJD patient FLAIR images with a more significant hypersignal in caudate nuclei (10/10) and putamen (6/10) than in thalami. Using normalised measures of the intensity relations between the internal grey nuclei of patients, we robustly differentiate sporadic CJD and new-variant CJD patients, as a first attempt towards an automatic classification tool of human spongiform encephalopathies
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