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Kårsnäs, Andreas
Publikasjoner (8 av 8) Visa alla publikasjoner
Kårsnäs, A., Strand, R., Doré, J., Ebstrup, T., Lippert, M. & Bjerrum, K. (2015). A histopathological tool for quantification of biomarkers with sub-cellular resolution. Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 3(1), 25-46
Åpne denne publikasjonen i ny fane eller vindu >>A histopathological tool for quantification of biomarkers with sub-cellular resolution
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2015 (engelsk)Inngår i: Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, ISSN 2168-1163, Vol. 3, nr 1, s. 25-46Artikkel i tidsskrift (Fagfellevurdert) Published
HSV kategori
Forskningsprogram
Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-219287 (URN)10.1080/21681163.2014.885120 (DOI)
Tilgjengelig fra: 2014-02-27 Laget: 2014-02-26 Sist oppdatert: 2015-03-12bibliografisk kontrollert
Kårsnäs, A. & Strand, R. (2015). Multimodal histological image registration using locally rigid transforms. In: Proc. Interactive Medical Image Computing Workshop: . Paper presented at Interactive Medical Image Computing (IMIC) Workshop at MICCAI 2015, October 5–9, Munich, Germany.
Åpne denne publikasjonen i ny fane eller vindu >>Multimodal histological image registration using locally rigid transforms
2015 (engelsk)Inngår i: Proc. Interactive Medical Image Computing Workshop, 2015Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

Evaluating multimodal histological images is an important task within cancer diagnosis. Using aligned consecutive sections is still the most straight-forward approach for combining multimodal data.

To overcome the difficulties in aligning the sections, we present an interactive registration approach and show its usage for aligning TMA core images from consecutive sections stained for different biomarkers. In order to reduce distortion of local structures, a global deformable transform is approximated with locally more or less rigid transformations. This gives a trade-off between registration quality and distortion of local structures. The method divides the registration in an offline (global registration) and online step, where the local approximation is done in real-time within current field of view. This approach gives the viewer the ability to quickly adjust the rigidity from a deformable, well-aligned transformation to a rigid where structures "look right''.

HSV kategori
Forskningsprogram
Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-267414 (URN)
Konferanse
Interactive Medical Image Computing (IMIC) Workshop at MICCAI 2015, October 5–9, Munich, Germany
Tilgjengelig fra: 2015-11-23 Laget: 2015-11-23 Sist oppdatert: 2016-01-21
Kårsnäs, A. (2014). Image Analysis Methods and Tools for Digital Histopathology Applications Relevant to Breast Cancer Diagnosis. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Åpne denne publikasjonen i ny fane eller vindu >>Image Analysis Methods and Tools for Digital Histopathology Applications Relevant to Breast Cancer Diagnosis
2014 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

In 2012, more than 1.6 million new cases of breast cancer were diagnosed and about half a million women died of breast cancer. The incidence has increased in the developing world. The mortality, however, has decreased. This is thought to partly be the result of advances in diagnosis and treatment. Studying tissue samples from biopsies through a microscope is an important part of diagnosing breast cancer. Recent techniques include camera-equipped microscopes and whole slide scanning systems that allow for digital high-throughput scanning of tissue samples. The introduction of digital pathology has simplified parts of the analysis, but manual interpretation of tissue slides is still labor intensive and costly, and involves the risk for human errors and inconsistency. Digital image analysis has been proposed as an alternative approach that can assist the pathologist in making an accurate diagnosis by providing additional automatic, fast and reproducible analyses. This thesis addresses the automation of conventional analyses of tissue, stained for biomarkers specific for the diagnosis of breast cancer, with the purpose of complementing the role of the pathologist. In order to quantify biomarker expression, extraction and classification of sub-cellular structures are needed. This thesis presents a method that allows for robust and fast segmentation of cell nuclei meeting the need for methods that are accurate despite large biological variations and variations in staining. The method is inspired by sparse coding and is based on dictionaries of local image patches. It is implemented in a tool for quantifying biomarker expression of various sub-cellular structures in whole slide images. Also presented are two methods for classifying the sub-cellular localization of staining patterns, in an attempt to automate the validation of antibody specificity, an important task within the process of antibody generation.  In addition, this thesis explores methods for evaluation of multimodal data. Algorithms for registering consecutive tissue sections stained for different biomarkers are evaluated, both in terms of registration accuracy and deformation of local structures. A novel region-growing segmentation method for multimodal data is also presented. In conclusion, this thesis presents computerized image analysis methods and tools of potential value for digital pathology applications.

sted, utgiver, år, opplag, sider
Uppsala: Acta Universitatis Upsaliensis, 2014. s. 129
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1128
Emneord
image analysis, breast cancer diagnosis, digital histopathology, immunohistochemistry, biomarker quantification
HSV kategori
Forskningsprogram
Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-219306 (URN)978-91-554-8889-5 (ISBN)
Disputas
2014-04-11, Room 2446, Polacksbacken, Lägerhyddsvägen 2, Uppsala, 10:15 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2014-03-20 Laget: 2014-02-26 Sist oppdatert: 2014-07-21
Kårsnäs, A. & Strand, R. (2014). Multimodal histological image registration using locally rigid transforms. IEEE Transactions on Biomedical Engineering
Åpne denne publikasjonen i ny fane eller vindu >>Multimodal histological image registration using locally rigid transforms
2014 (engelsk)Inngår i: IEEE Transactions on Biomedical Engineering, ISSN 0018-9294, E-ISSN 1558-2531Artikkel i tidsskrift (Annet vitenskapelig) Submitted
Abstract [en]

Evaluating multimodal histological images is animportant task within cancer diagnosis and research. Newmethods are currently under development, such as multiplexingand destaining/restaining protocols, but comparing data fromconsecutive monomodal sections is still the most common methodfor acquiring multimodal data. To allow for comparison of con-secutive sections, registration of the sections is needed. Becauseof the spatial distance between the sections as well as non-uniform deformations, due to mechanical and chemical stressduring handling and staining, this is not a trivial task. Inthis paper, we confirm that deformable transforms outperformlinear transforms when it comes to registration quality. However,large deformations can result in a poor viewing experience forthe pathologist when evaluating the slides, as local structuresare distorted and may look unnatural. The deformations alsoaffect measurements made on the deformed image. We presenta method for locally approximating the global deformabletransform with a rigid transform, and we introduce a gradeof rigidity term that enables a trade-off between registrationquality and measurement distortion. We use a strategy of dividingthe registration in an offline and online step, which gives usthe possibility to perform the approximation in real-time. Thisability offers the viewer with the possibility to quickly switchbetween a view that has optimal registration and a view wheremeasurements are not distorted and where structures ”lookright”. To facilitate further research within the subject, wepresent a registration tool that provides an intuitive interfacefor making comparisons between global deformable transformsand locally rigid approximations with varying degree of rigidity.

Emneord
Multimodal registration, digital histopathology, locally rigid transforms
HSV kategori
Forskningsprogram
Datoriserad bildanalys; Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-219290 (URN)
Tilgjengelig fra: 2014-02-26 Laget: 2014-02-26 Sist oppdatert: 2018-01-11bibliografisk kontrollert
Issac Niwas, S., Kårsnäs, A., Uhlmann, V., Ponnusamy, P., Kampf, C., Simonsson, M., . . . Strand, R. (2013). Automated classification of immunostaining patterns in breast tissue from the Human Protein Atlas. Journal of Pathology Informatics, 4(14)
Åpne denne publikasjonen i ny fane eller vindu >>Automated classification of immunostaining patterns in breast tissue from the Human Protein Atlas
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2013 (engelsk)Inngår i: Journal of Pathology Informatics, ISSN 2229-5089, E-ISSN 2153-3539, Vol. 4, nr 14Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background:

The Human Protein Atlas (HPA) is an effort to map the location of all human proteins (http://www.proteinatlas.org/). It contains a large number of histological images of sections from human tissue. Tissue micro arrays (TMA) are imaged by a slide scanning microscope, and each image represents a thin slice of a tissue core with a dark brown antibody specific stain and a blue counter stain. When generating antibodies for protein profiling of the human proteome, an important step in the quality control is to compare staining patterns of different antibodies directed towards the same protein. This comparison is an ultimate control that the antibody recognizes the right protein. In this paper, we propose and evaluate different approaches for classifying sub-cellular antibody staining patterns in breast tissue samples.

Materials and Methods:

The proposed methods include the computation of various features including gray level co-occurrence matrix (GLCM) features, complex wavelet co-occurrence matrix (CWCM) features, and weighted neighbor distance using compound hierarchy of algorithms representing morphology (WND-CHARM)-inspired features. The extracted features are used into two different multivariate classifiers (support vector machine (SVM) and linear discriminant analysis (LDA) classifier). Before extracting features, we use color deconvolution to separate different tissue components, such as the brownly stained positive regions and the blue cellular regions, in the immuno-stained TMA images of breast tissue.

Results:

We present classification results based on combinations of feature measurements. The proposed complex wavelet features and the WND-CHARM features have accuracy similar to that of a human expert.

Conclusions:

Both human experts and the proposed automated methods have difficulties discriminating between nuclear and cytoplasmic staining patterns. This is to a large extent due to mixed staining of nucleus and cytoplasm. Methods for quantification of staining patterns in histopathology have many applications, ranging from antibody quality control to tumor grading.

HSV kategori
Forskningsprogram
Medicinsk beteendevetenskap; Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-212564 (URN)10.4103/2153-3539.109881 (DOI)
Tilgjengelig fra: 2013-12-11 Laget: 2013-12-11 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Issac Niwas, S., Kårsnäs, A., Uhlmann, V., Palanisamy, P., Kampf, C., Simonsson, M., . . . Strand, R. (2012). Automated classification of immunostaining patterns in breast tissue from the Human Protein Atlas. In: Histopathology Image Analysis (HIMA): a MICCAI 2012 workshop. Paper presented at Histopathology Image Analysis (HIMA), a MICCAI 2012 workshop, 5 October, 2012, Nice, France.
Åpne denne publikasjonen i ny fane eller vindu >>Automated classification of immunostaining patterns in breast tissue from the Human Protein Atlas
Vise andre…
2012 (engelsk)Inngår i: Histopathology Image Analysis (HIMA): a MICCAI 2012 workshop, 2012Konferansepaper, Poster (with or without abstract) (Fagfellevurdert)
Abstract [en]

Background:

The Human Protein Atlas (HPA) is an effort to map the location of all human proteins (http://www.proteinatlas.org/ ). It contains a large number of histological images of sections from human tissue. Tissue micro arrays are imaged by a slide scanning microscope, and each image represents a thin slice of a tissue core with a dark brown antibody specific stain and a blue counter stain. When generating antibodies for protein profiling of the human proteome, an important step in the quality control is to compare staining patterns of different antibodies directed towards the same protein. This comparison is an ultimate control that the antibody recognizes the right protein. In this paper, we propose and evaluate different approaches for classifying sub-cellular antibody staining patterns in breast tissue samples.

Methods and Material:

The proposed methods include the computation of various features including gray level co-occurrence matrix (GLCM) features, complex wavelet co-occurrence matrix (CWCM) features and WND-CHARM-inspired features. The extracted features are used into two different multivariate classifiers (SVM and LDA classifier). Before extracting features, we use color deconvolution to separate different tissue components, such as the brownly stained positive regions and the blue cellular regions, in the immuno-stained TMA images of breast tissue.

Results:

Good results have been obtained by using the combinations of GLCM and wavelets and texture features, edge features, histograms, transforms, etc. (WND-CHARM). The proposed complex wavelet features and the WND-CHARM features have accuracy similar to that of a human expert.

Conclusions:

Both human experts and the proposed automated methods have difficulties discriminating between nuclear and cytoplasmic staining patterns. This is to a large extent due to mixed staining of nucleus and cytoplasm. Methods for quantification of staining patterns in histopathology have many applications, ranging from antibody quality control to tumour grading.

HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-188447 (URN)
Konferanse
Histopathology Image Analysis (HIMA), a MICCAI 2012 workshop, 5 October, 2012, Nice, France
Tilgjengelig fra: 2012-12-17 Laget: 2012-12-17 Sist oppdatert: 2013-07-05bibliografisk kontrollert
Kårsnäs, A., Dahl, A. L. & Larsen, R. (2012). Learning histopathological patterns. Journal of Pathology Informatics, 2, 12
Åpne denne publikasjonen i ny fane eller vindu >>Learning histopathological patterns
2012 (engelsk)Inngår i: Journal of Pathology Informatics, ISSN 2229-5089, E-ISSN 2153-3539, Vol. 2, s. 12-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Aims: The aim was to demonstrate a method for automated image analysis of immunohistochemically stained tissue samples for extracting features that correlate with patient disease. We address the problem of quantifying tumor tissue and segmenting and counting cell nuclei. Materials and Methods: Our method utilizes a flexible segmentation method based on sparse coding trained from representative image samples. Nuclei counting is based on a nucleus model that takes size, shape, and nucleus probability into account. Nuclei clustering and overlays are resolved using a gray-weighted distance transform. We obtain a probability measure for pixels belonging to a nucleus from our segmentation procedure. Experiments are carried out on two sets of immunohistochemically stained images - one set based on the estrogen receptor (ER) and the other on antigen KI-67. For the nuclei separation we have selected 207 ER image samples from 58 tissue micro array-cores corresponding to 58 patients and 136 KI-67 image samples also from 58 cores. The images are hand-annotated by marking the center position of each nucleus. For the ER data we have a total of 1006 nuclei and for the KI-67 we have 796 nuclei. Segmentation performance was evaluated in terms of missing nuclei, falsely detected nuclei, and multiple detections. The proposed method is compared to state-of-the-art Bayesian classification. Statistical analysis used: The performance of the proposed method and a state-of-the-art algorithm including variations thereof is compared using the Wilcoxon rank sum test. Results: For both the ER experiment and the KI-67 experiment the proposed method exhibits lower error rates than the state-of-the-art method. Total error rates were 4.8 % and 7.7 % in the two experiments, corresponding to an average of 0.23 and 0.45 errors per image, respectively. The Wilcoxon rank sum tests show statistically significant improvements over the state-of-the-art method. Conclusions: We have demonstrated a method and obtained good performance compared to state-of-the-art nuclei separation. The segmentation procedure is simple, highly flexible, and we demonstrate how it, in addition to the nuclei separation, can perform precise segmentation of cancerous tissue. The complexity of the segmentation procedure is linear in the image size and the nuclei separation is linear in the number of nuclei. Additionally the method can be parallelized to obtain high-speed computations.

Emneord
Computer-aided classification, digital histopathology, flexible learning-based segmentation, image segmentation
HSV kategori
Forskningsprogram
Datoriserad bildanalys; Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-167255 (URN)10.4103/2153-3539.92033 (DOI)
Tilgjengelig fra: 2012-01-19 Laget: 2012-01-24 Sist oppdatert: 2017-12-08bibliografisk kontrollert
Kårsnäs, A., Strand, R. & Saha, P. K. (2012). The Vectorial Minimum Barrier Distance. Paper presented at International Conference on Pattern Recognition, 2012. International Conference on Pattern Recognition, 792-795
Åpne denne publikasjonen i ny fane eller vindu >>The Vectorial Minimum Barrier Distance
2012 (engelsk)Inngår i: International Conference on Pattern Recognition, ISSN 1051-4651, s. 792-795Artikkel i tidsskrift, Meeting abstract (Fagfellevurdert) Published
Abstract [en]

We introduce the vectorial Minimum Barrier Distance (MBD), a method for computing a gray-weighted distance transform while also incorporating information from vectorial data. Compared to other similar tools that use vectorial data, the proposed method requires no training and does not assume having only one background class. We describe a region growing algorithm for computing the vectorial MBD efficiently.

The method is evaluated on two types of multi-channel images: color images and textural features. Different path-cost functions for calculating the multi-dimensional path-cost distance are also compared.

The results show that by combining multi-channel images into vectorial information the performance ofthe vectorial MBD segmentation is improved compared to when one channel is used. This implies that the method can be a good way of incorporating multi-channel information in interactive segmentation.

HSV kategori
Forskningsprogram
Datoriserad bildbehandling
Identifikatorer
urn:nbn:se:uu:diva-190013 (URN)978-1-4673-2216-4 (ISBN)
Konferanse
International Conference on Pattern Recognition, 2012
Tilgjengelig fra: 2013-01-07 Laget: 2013-01-07 Sist oppdatert: 2014-04-29bibliografisk kontrollert
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