Convolutional Sparse Coding based framework for the diagnosis of Alzheimer’s Disease


The learning and selection of features are leveraged to the Convolutional Sparse Coding approach, which is applied to the 3-dimensional MRIs in the dataset. They can be fed to any classifier, a fully connected neural network is shown here. The output corresponds to the prediction of the model for a given brain scan.

Diagnosis in medicine can be further aided by the automated inspection of structural images from the various body parts. Thus, the automated algorithm should be able to learn features from the images such that they will further aid in the accurate distinction of the disease, if present, from the image. This process can be done end-to-end using state-of-the-art techniques such as Convolutional Neural Networks (CNNs). In this work, we propose an alternative algorithm in which the diagnosis is performed as a two-step process. First, we learn the features from the 3-dimensional data, structural Magnetic Resonance Imaging (MRI) scans via Convolutional Sparse Coding (CSC). The features learned are then fed into some classifier –even CNNs—to fit a model able to differentiate the classes of interest, which correspond to the different diagnosis the patient could have for a particular disease

Contact

Perla Mayo, Alin Achim

Line Artefacts Quantification for Lung Ultrasound Images via Non-convex Regularisation

In this project, we present a novel method for line artefacts quantification in lung ultrasound (LUS) images of COVID-19 patients. We formulate this as a non-convex regularisation problem involving the heavy-tailed Cauchy-based penalty function, and the inverse Radon transform.

We employ a simple local maxima detection technique in the Radon transform domain, associated with known clinical definitions of line artefacts.

Line Artefacts in LUS Images
Line artefacts in Radon Domain

Despite being non-convex, the proposed technique is guaranteed to convergence through our proposed Cauchy proximal splitting (CPS) method, and accurately identifies both horizontal and vertical line artefacts in LUS images. In order to reduce the number of false and missed detection, our method includes a two-stage validation mechanism, which is performed in both Radon and image domains.

We evaluate the performance of the proposed method in comparison to the current state-of-the-art B-line identification method and show a considerable performance gain with 87% correctly detected B-lines in LUS images of nine COVID-19 patients.

Detection results. (a)-(e) Original Images. (f)-(j) Ground truth. (k)-(o) The proposed method.

Further information

[1] Karakuş, O., Anantrasirichai, N., Aguersif, A., Silva, S., Basarab, A., & Achim, A. (2020). Detection of Line Artifacts in Lung Ultrasound Images of COVID-19 Patients Via Nonconvex Regularization. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 67(11), 2218-2229.

Talk

Talk by Dr Oktay Karakus in Acoustics Virtually Everywhere The 179th Meeting of the Acoustical Society of America 7-11 December 2020

https://player.vimeo.com/video/479873161

Contact

Oktay Karakuş, Pui Anantrasirichai, Alin Achim

Code

O Karakus, A Achim. (2020): QuantLUS – CPS v1.0 https://doi.org/10.5523/bris.z47pfkwqivfj2d0qhyq7v3u1i

Funding

This work was supported in part by
** the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/R009260/1,
** an EPSRC Impact Acceleration Award (IAA) from the University of Bristol, ** a Leverhulme Trust Research Fellowship to Achim (INFHER).