Background Intracranial aneurysm (IA) is a nodular protrusion of the arterial wall caused by the localized abnormal enlargement of the lumen of a brain artery, which is the primary cause of subarachnoid hemorrhage. Accurate rupture risk prediction can effectively aid treatment planning, but conventional rupture risk estimation based on clinical information is subjective and time-consuming. Methods We propose a novel classification method based on the CTA images for differentiating aneurysms that are prone to rupture. The main contribution of this study is that the learning-based method proposed in this study leverages deep learning and radiomics features and integrates clinical information for a more accurate prediction of the risk of rupture. Specifically, we first extracted the provided aneurysm regions from the CTA images as 3D patches with the lesions located at their centers. Then, we employed an encoder using a 3D convolutional neural network (CNN) to extract complex latent features automatically. These features were then combined with radiomics features and clinical information. We further applied the LASSO regression method to find optimal features that are highly relevant to the rupture risk information, which is fed into a support vector machine (SVM) for final rupture risk prediction. Results The experimental results demonstrate that our classification method can achieve accuracy and AUC scores of 89.78% and 89.09%, respectively, outperforming all the alternative methods. Discussion Our study indicates that the incorporation of CNN and radiomics analysis can improve the prediction performance, and the selected optimal feature set can provide essential biomarkers for the determination of rupture risk, which is also of great clinical importance for individualized treatment planning and patient care of IA.

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Automatic risk prediction of intracranial aneurysm on CTA image with convolutional neural networks and radiomics analysis

Received Sep 30, 2021 Revised Dec 7, 2021 Accepted Dec 15, 2021 Nowadays, in the medical world, analyzing and diagnosing acute brain stroke and its location is a difficult process. In many hospitals, however, striking symptoms with the use of computed tomography (CT) imaging for patients is an important step in screening and diagnosis. Furthermore, computer-assisted accurate detection of diseased brain regions Because of the several sorts of strokes, their uneven form, and their great intensity and size, aided design is extremely challenging. Using the bit plan slice technique and the canny detector, we created and suggested a novel approach. Our algorithm produces excellent outcomes. The results demonstrate that our proposed algorithm is an accurate and reliable technique. This study also indicates that this system can detect two different types of strokes: hemorrhagic and ischemic strokes. The results of a comparison study of our suggested technique and other methods such as negative and logarithmic transformation methods are also included in this article.

Indonesian Journal of Electrical Engineering and Computer Science

Introduction Computed tomography perfusion (CTP) imaging is widely used in cases of suspected acute ischemic stroke to positively identify ischemia and assess suitability for treatment through identification of reversible and irreversible tissue injury. Traditionally, this has been done via setting single perfusion thresholds on two or four CTP parameter maps. We present an alternative model for the estimation of tissue fate using multiple perfusion measures simultaneously. Methods We used machine learning (ML) models based on four different algorithms, combining four CTP measures (cerebral blood flow, cerebral blood volume, mean transit time and delay time) plus 3D-neighborhood (patch) analysis to predict the acute ischemic core and perfusion lesion volumes. The model was developed using 86 patient images, and then tested further on 22 images. Results XGBoost was the highest-performing algorithm. With standard threshold-based core and penumbra measures as the reference, the model demonstrated moderate agreement in segmenting core and penumbra on test images. Dice similarity coefficients for core and penumbra were 0.38 ± 0.26 and 0.50 ± 0.21, respectively, demonstrating moderate agreement. Skull-related image artefacts contributed to lower accuracy. Discussion Further development may enable us to move beyond the current overly simplistic core and penumbra definitions using single thresholds where a single error or artefact may lead to substantial error.

https://www.frontiersin.org/articles/10.3389/fneur.2023.1098562/pdf

Machine learning segmentation of core and penumbra from acute stroke CT perfusion data

Computed Tomography Perfusion (CTP) images have drawn extensive attention in acute ischemic stroke assessment due to its imaging speed and ability to provide dynamic perfusion quantification. However, the cerebral ischemic infarcted core has high individual variability and low contrast, and multiple CTP parametric maps need to be referred for precise delineation of the core region. It has thus become a challenging task to develop automatic segmentation algorithms. The widely applied segmentation algorithms such as U-Net lack specific modeling for image subtype in the dataset, and thus the performance remains unsatisfactory. In this paper, we propose a novel cluster-representation learning approach to address these difficulties. Specifically, we first cluster the training samples based on their similarities of the segmentation difficulty. Each cluster represents a different subtype of training images and is then used to train its own cluster-representative model. The models will be capable of extracting cluster-representative features from training samples as clustering priors, which are further fused into an overall segmentation model (for all training samples). The fusion mechanism is able to adaptively select optimal subset(s) of clustering priors which can further guide the segmentation of each unseen testing image and reduce influences from high variability of CTP images. We have applied our method on 94 subjects of ISLES 2018 dataset. By comparing with the baseline U-Net, the experiments have shown an absolute increase of 8% in Dice score and a reduction of 10mm in Hausdorff Distance for ischemic infarcted core segmentation. This method can also be generalized to other U-Net-like architectures to further improve their representative capacity.

Jianyuan Zhang

Papers

Ischemic Stroke Segmentation from CT Perfusion Scans Using Cluster-Representation Learning