Comparative Analysis of Image Processing Techniques for Enhanced MRI Image Quality: 3D Reconstruction and Segmentation Using 3D U-Net Architecture.

Osteosarcoma is a common type of bone tumor, particularly prevalent in children and adolescents between the ages of 5 and 25 who are experiencing growth spurts during puberty. Manual delineation of tumor regions in MRI images can be laborious and time-consuming, and results may be subjective and difficult to replicate. Therefore, a convolutional neural network (CNN) was developed to automatically segment osteosarcoma cancerous cells in three types of MRI images. The study consisted of five main stages. First, 3692 DICOM format MRI images were acquired from 46 patients, including T1-weighted, T2-weighted, and T1-weighted with injection of Gadolinium (T1W + Gd) images. Contrast stretching and median filter were applied to enhance image intensity and remove noise, and the pre-processed images were reconstructed into NIfTI format files for deep learning. The MRI images were then transformed to fit the CNN's requirements. A 3D U-Net architecture was proposed with optimized parameters to build an automatic segmentation model capable of segmenting osteosarcoma from the MRI images. The 3D U-Net segmentation model achieved excellent results, with mean dice similarity coefficients (DSC) of 83.75%, 85.45%, and 87.62% for T1W, T2W, and T1W + Gd images, respectively. However, the study found that the proposed method had some limitations, including poorly defined borders, missing lesion portions, and other confounding factors. In summary, an automatic segmentation method based on a CNN has been developed to address the challenge of manually segmenting osteosarcoma cancerous cells in MRI images. While the proposed method showed promise, the study revealed limitations that need to be addressed to improve its efficacy.

Anaplastic Pleomorphic Xanthoastrocytoma: A Rare Variant of Astrocytoma.

Pleomorphic xanthoastrocytoma (PXA) is a rare glioma that affects 1% of astrocytic tumors. It most commonly affects children and teenagers. PXA cases with an anaplastic histopathological subtype have been reported in recent years. It was recently classified as a separate subtype in the 2016 World Health Organization (WHO) classification of central nervous system (CNS) tumors. A 48-year-old healthy gentleman presented with progressive right upper limb weakness. CT and MRI of the brain were done, which showed an intra-axial supratentorial tumor. A diagnosis of high-grade glioma was initially made based on its imaging features. The histopathological study came back as anaplastic pleomorphic xanthoastrocytoma. After a discussion with the neurosurgical and oncology teams, a decision was made to treat the patient with radiotherapy. In this case report, we describe a rare case of PXA with anaplastic characteristics.

A Case Report of Acute Necrotizing Encephalitis.

Acute necrotizing encephalitis (ANEC) is a rare entity seen primarily in East Asian infants and previously healthy children. A 5-year-old boy complained of fever and seizures, which developed into status epilepticus. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) brains showed acute necrotizing encephalitis features. Empirical treatment for meningoencephalitis with supportive therapy was administered. MRI was then repeated 25 days post-therapy, which showed the previously seen abnormal signal intensities resolution. The patient was subsequently discharged home with moderate neurological impairment. Although ANEC is a rare disease, a typical clinical scenario and MRI findings should prompt recognition of the disease, essential for treatment.