T1 weighted three-dimensional structural magnetic resonance imaging is an imaging technique that enables high resolution imaging of tissue defects and volumetric losses in the brain due to diseases. With this imaging technique, images can be taken without any external intervention to the patient . Radio frequency technology is at the basis of physical image acquisition. Firstly, a radio frequency wave is sent in which the protons in the hydrogen atoms in the brain will interact. When the radio frequency wave is stopped, protons tend to return to their former state. While returning to their former state, the energy their emitted is collected and induced as a current, then the image is obtained by Fourier transforms. Images can be taken in different sequences upon request. Each sequence has different distinctive features in the clinic with respect to the disease. Magnetic resonance images consist of successive slices. The disease can be observed in any slice, or it can be seen by analyzing several slices in succession. Among the magnetic resonance image sequences, the most used images are in 3D T1-weighted images. Since soft brain tissue can be displayed in high resolution in this sequence, many rigid changes such as volumetric disorders, degeneration, symmetry disruption, tissue disruption, brain shrinkage and enlargement can be clearly observed. The images obtained are analyzed and interpreted by radiologists in hospitals. However, some numerical tools are needed especially in artificial intelligence and classification studies. In order to use these numerical tools, some preprocessing must be done on the images. In this study, axis conversion, image reorientation, normalization, modulation, segmentation, co-registration, noise and bias removal, smoothing, removal of non-brain structures are examined, which are the preprocessing methods of T1-weighted three-dimensional structural magnetic resonance images. How and in which order to use the numerical tools used for pre-processing has been defined and their applications are made on a three-dimensional magnetic resonance image.
Publication Date : August 31, 2020
|APA||Özi̇ç, M , Özşen, S . (2020). Üç Boyutlu T1 Ağırlıklı Manyetik Rezonans Görüntülerinde Ön İşleme Yöntemleri . Avrupa Bilim ve Teknoloji Dergisi , (19) , 227-240 . DOI: 10.31590/ejosat.719062|