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As there is no contrast enhancement, the liver tumor area in nonenhanced MRI exists with blurred edges and low contrast, which greatly affects the speed and accuracy of liver tumor diagnosis. As a result, precise segmentation of liver tumor from nonenhanced MRI has become an urgent and challenging task. In this paper, we propose an edge constraint and localization mapping segmentation model (ECLMS) to accurately segment liver tumor from nonenhanced MRI. It consists of two parts: localization network and dual-branch segmentation network. We build the localization network, which generates prior coarse masks to provide position mapping for the segmentation network. This part enhances the ability of the model to localize liver tumor in nonenhanced images. We design a dual-branch segmentation network, where the main decoding branch focuses on the feature representation in the core region of the tumor and the edge decoding branch concentrates on capturing the edge information of the tumor. To improve the ability of the model for capturing detailed features, sSE blocks and dense upward connections are introduced into it. We design the bottleneck multiscale module to construct multiscale feature representations using kernels of different sizes while integrating the location mapping of tumor. The ECLMS model is evaluated on a private nonenhanced MRI dataset that comprises 215 different subjects. The model achieves the best Dice coefficient, precision, and accuracy of 90.23%, 92.25%, and 92.39%, correspondingly. The effectiveness of our model is demonstrated by experiment results, and our model reaches superior results in the segmentation task of nonenhanced liver tumor compared to existing segmentation methods.

Hepatocellular Carcinoma (HCC) detection, size grading, and quantification (i.e. the center point coordinates, max-diameter, and area) by using multi-modality magnetic resonance imaging (MRI) are clinically significant tasks for HCC assessment and treatment. However, delivering the three tasks simultaneously is extremely challenging due to: (1) the lack of effective an mechanism to capture the relevance among multi-modality MRI information for multi-modality feature fusion and selection; (2) the lack of effective mechanism and constraint strategy to achieve mutual promotion of multi-task. In this paper, we proposed a task relevance driven adversarial learning framework (TrdAL) for simultaneous HCC detection, size grading, and multi-index quantification using multi-modality MRI (i.e. in-phase, out-phase, T2FS, and DWI). The TrdAL first obtains expressive feature of dimension reduction via using a CNN-based encoder. Secondly, the proposed modality-aware Transformer is utilized for multi-modality MRI features fusion and selection, which solves the challenge of multi-modality information diversity via capturing the relevance among multi-modality MRI. Then, the innovative task relevance driven and radiomics guided discriminator (Trd-Rg-D) is used for united adversarial learning. The Trd-Rg-D captures the internal high-order relationships to refine the performance of multi-task simultaneously. Moreover, adding the radiomics feature as the prior knowledge into Trd-Rg-D enhances the detailed feature extraction. Lastly, a novel task interaction loss function is used for constraining the TrdAL, which enforces the higher-order consistency among multi-task labels to enhance mutual promotion. The TrdAL is validated on a corresponding multi-modality MRI of 135 subjects. The experiments demonstrate that TrdAL achieves high accuracy of (1) HCC detection: specificity of 93.71%, sensitivity of 93.15%, accuracy of 93.33%, and IoU of 82.93%; (2) size grading: accuracy of large size, medium size, small size, tiny size, and healthy subject are 90.38%, 87.74%, 80.68%, 77.78%, and 96.87%; (3) multi-index quantification: the mean absolute error of center point, max-diameter, and area are 2.74mm, 3.17mm, and 144.51mm

Statistically solitary pulmonary nodules are about 6% to 17% of juxtapleural nodules. The accurate segmentation of lung parenchyma sequences of juxtapleural nodules is the basis of subsequent pulmonary nodule segmentation and detection. In order to solve the problem of incomplete segmentation of the juxtapleural nodules and segmentation inefficiency, this paper proposes an automated framework to combine the threshold iteration method to segment the lung parenchyma images and the fractal geometry method to detect the depression boundary. The framework includes an improved convex hull repair to complete the accurate segmentation of the lung parenchyma. The evaluation results confirm that the proposed method can segment juxtapleural lung parenchymal images accurately and efficiently.