72 research outputs found
Why do employees stay with an organization? A qualitative study of key employee retention drivers in modern workplace settings
The purpose of this research is to find out why employees stay with an organization and
what factors influence employee retention in changing work environments shaped by digital
transformation and flexible work environments. Qualitative research has been carried out
through eleven in-depth semi-structured interviews and two focus groups with HR
professionals. The findings indicate that employees increasingly look for personalized
treatment by employers in various dimensions including rewards, relationships, corporate
culture, development possibilities and job content, leading to specific implication for
organizations and managers to consider in order to keep talent engaged and retain high
performers long-term
MixUp-MIL: Novel Data Augmentation for Multiple Instance Learning and a Study on Thyroid Cancer Diagnosis
Multiple instance learning exhibits a powerful approach for whole slide
image-based diagnosis in the absence of pixel- or patch-level annotations. In
spite of the huge size of hole slide images, the number of individual slides is
often rather small, leading to a small number of labeled samples. To improve
training, we propose and investigate different data augmentation strategies for
multiple instance learning based on the idea of linear interpolations of
feature vectors (known as MixUp). Based on state-of-the-art multiple instance
learning architectures and two thyroid cancer data sets, an exhaustive study is
conducted considering a range of common data augmentation strategies. Whereas a
strategy based on to the original MixUp approach showed decreases in accuracy,
the use of a novel intra-slide interpolation method led to consistent increases
in accuracy.Comment: MICCAI'23, https://gitlab.com/mgadermayr/mixupmi
MixUp-MIL: A Study on Linear & Multilinear Interpolation-Based Data Augmentation for Whole Slide Image Classification
For classifying digital whole slide images in the absence of pixel level
annotation, typically multiple instance learning methods are applied. Due to
the generic applicability, such methods are currently of very high interest in
the research community, however, the issue of data augmentation in this context
is rarely explored. Here we investigate linear and multilinear interpolation
between feature vectors, a data augmentation technique, which proved to be
capable of improving the generalization performance classification networks and
also for multiple instance learning. Experiments, however, have been performed
on only two rather small data sets and one specific feature extraction approach
so far and a strong dependence on the data set has been identified. Here we
conduct a large study incorporating 10 different data set configurations, two
different feature extraction approaches (supervised and self-supervised), stain
normalization and two multiple instance learning architectures. The results
showed an extraordinarily high variability in the effect of the method. We
identified several interesting aspects to bring light into the darkness and
identified novel promising fields of research.Comment: for code and data, see gitlab repo:
https://gitlab.com/mgadermayr/mixupmil. arXiv admin note: substantial text
overlap with arXiv:2211.0586
World Journal of Gastroenterology / Computer-aided texture analysis combined with experts' knowledge : improving endoscopic celiac disease diagnosis
AIM: To further improve the endoscopic detection of intestinal mucosa alterations due to celiac disease (CD). METHODS: We assessed a hybrid approach based on the integration of expert knowledge into the computer-based classification pipeline. A total of 2835 endoscopic images from the duodenum were recorded in 290 children using the modified immersion technique (MIT). These children underwent routine upper endoscopy for suspected CD or non-celiac upper abdominal symptoms between August 2008 and December 2014. Blinded to the clinical data and biopsy results, three medical experts> visually classified each image as normal mucosa (Marsh-0) or villous atrophy (Marsh-3). The experts decisions were further integrated into state-of-the-art texture recognition systems. Using the biopsy results as the reference standard, the classification accuracies of this hybrid approach were compared to the experts diagnoses in 27 different settings. RESULTS: Compared to the experts diagnoses, in 24 of 27 classification settings (consisting of three imaging modalities, three endoscopists and three classification approaches), the best overall classification accuracies were obtained with the new hybrid approach. In 17 of 24 classification settings, the improvements achieved with the hybrid approach were statistically significant (P < 0.05). Using the hybrid approach classification accuracies between 94% and 100% were obtained. Whereas the improvements are only moderate in the case of the most experienced expert, the results of the less experienced expert could be improved significantly in 17 out of 18 classification settings. Furthermore, the lowest classification accuracy, based on the combination of one database and one specific expert, could be improved from 80% to 95% (P < 0.001). CONCLUSION: The overall classification performance of medical experts, especially less experienced experts, can be boosted significantly by integrating expert knowledge into computer-aided diagnosis systems.KLI 429-B13(VLID)215382
Semi-Automatic Classification Of Histopathological Images: Dealing With Inter-Slide Variations
Introduction/ Background
The large size and high resolution of histopathological whole slide images renders their manual annotation time-consuming and costly. State-of-the-art computer-based segmentation approaches are generally able to classify tissue reliably, but strong inter-slide variations between training and evaluation data can cause significant decreases in classification accuracy.
Aims
In this study, we focus on alpha-SMA stainings of the mouse kidney, and in particular on the classification of glomerular vs. non-glomerular regions. Even though all slides had been recorded using a common staining protocol, inter-slide variations could be observed. We investigate the impact of these variations as well as methods of resolution.
Methods
We propose an interactive, semi-automatic tissue classification approach [1] which adapts a pre-trained classification model to the new image on which classification should be performed. Image patches for which the class (glomerular/non-glomerular) is uncertain are automatically selected and presented to the user to determine the class label. The user interaction step is repeated several times to iteratively adjust the model to the characteristics of the new image. For image representation and classification, well known methods from the literature are utilized. Specifically, we combine Local Binary Patters with the support vector classifier.
Results
In case of 50 available labelled sample patches of a certain whole slide image, the overall classification rate increased from 92 % to 98 % through including the interactive labelling step. Even with only 20 labelled patches, accuracy already increased to 97 %. Without a pre-trained model, if training is performed on target domain data only, 88 % (20 labelled samples) and 95 % (50 labelled samples) accuracy, respectively, were obtained. If enough target domain data was available (about 20 images), the amount of source domain data was of minor relevance. The difference in outcome between a source domain training data set containing 100 patches from one whole slide image and a set containing 700 patches from seven images was lower than 1 %. Contrarily, without target domain data, the difference in accuracy was 10 % (82 % compared to 92 %) between these two settings. Execution runtime between two interaction steps is significantly below one second (0.23 s), which is an important usability criterion.
It proved to be beneficial to select specific target domain data in an active learning sense based on the currently available trained model. While experimental evaluation provided strong empirical evidence for increased classification performance with the proposed method, the additional manual effort can be kept at a low level. The labelling of e.g. 20 images per slide is surely less time consuming than the validation of a complete whole slide image processed with a fully automatic, but less reliable, segmentation approach. Finally, it should be highlighted that the proposed interaction protocol could easily be adapted to other histopathological classification or segmentation tasks, also for implementation in a clinical system.
Evaluation of the Classification Accuracy of the Kidney Biopsy Direct Immunofluorescence through Convolutional Neural Networks
Background and objectives: Immunohistopathology is an essential technique in the diagnostic workflow of a kidney biopsy. Deep learning is an effective tool in the elaboration of medical imaging. We wanted to evaluate the role of a convolutional neural network as a support tool for kidney immunofluorescence reporting.
Design, setting, participants, & measurements: High-magnification (
7400) immunofluorescence images of kidney biopsies performed from the year 2001 to 2018 were collected. The report, adopted at the Division of Nephrology of the AOU Policlinico di Modena, describes the specimen in terms of \u201cappearance,\u201d \u201cdistribution,\u201d \u201clocation,\u201d and \u201cintensity\u201d of the glomerular deposits identified with fluorescent antibodies against IgG, IgA, IgM, C1q and C3 complement fractions, fibrinogen, and \u3ba- and \u3bb-light chains. The report was used as ground truth for the training of the convolutional neural networks.
Results: In total, 12,259 immunofluorescence images of 2542 subjects undergoing kidney biopsy were collected. The test set analysis showed accuracy values between 0.79 (\u201cirregular capillary wall\u201d feature) and 0.94 (\u201cfine granular\u201d feature). The agreement test of the results obtained by the convolutional neural networks with respect to the ground truth showed similar values to three pathologists of our center. Convolutional neural networks were 117 times faster than human evaluators in analyzing 180 test images. A web platform, where it is possible to upload digitized images of immunofluorescence specimens, is available to evaluate the potential of our approach.
Conclusions: The data showed that the accuracy of convolutional neural networks is comparable with that of pathologists experienced in the field
Structure Preserving Stain Normalization of Histopathology Images Using Self Supervised Semantic Guidance
© 2020, Springer Nature Switzerland AG. Although generative adversarial network (GAN) based style transfer is state of the art in histopathology color-stain normalization, they do not explicitly integrate structural information of tissues. We propose a self-supervised approach to incorporate semantic guidance into a GAN based stain normalization framework and preserve detailed structural information. Our method does not require manual segmentation maps which is a significant advantage over existing methods. We integrate semantic information at different layers between a pre-trained semantic network and the stain color normalization network. The proposed scheme outperforms other color normalization methods leading to better classification and segmentation performance
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