A. Computed tomography (CT) Computed tomography (CT) is a biomedical imaging technique that produces images of cross-sections also called "slices" of the anatomy of the human body. Radiographic rays are made incident on the human body. The reflected radio rays create a detailed computer image taken with a specialized X-ray machine. CT is more precise than a standard x-ray and provides a clearer image. Fig.1 shows a CT scan of the transverse view of the brain. Cross-sectional images are used for a variety of diagnostic and therapeutic purposes. The CT imaging system consists of a motorized table that moves the patient through a circular opening. While the patient is inside the opening, an X-ray source and detector assembly within the system rotates around the patient. A single rotation typically takes a second or less. As the X-ray source rotates, it produces a narrow, fan-shaped beam of X-rays that passes through a section of the patient's body. Detectors arranged in rows opposite the X-ray source record the X-rays passing through the patient's body as a snapshot in the process of creating an image [3, 8]. Many different "snapshots" (from many angles across the patient) are collected during a complete rotation. For each rotation of the X-ray source and detector assembly, the image data is sent to a computer to reconstruct all the individual "snapshots" into one or more cross-sectional images (slices) of the internal organs and tissues [19] . Fig.2 shows CT images for multiple sections of the brain. The minimum and maximum number of CT slices ranges from 1 to 64 and 320 [18, 19].Fig. 1 Transverse view - CT scan of the brain Fig.2 multiple sections of CT scan of the brain CT scan is one of the most commonly used images...... middle of paper ......gery. You can also use a dye (contrast agent) to look at certain tissues, which stand out on the scan. Functional MRI provides detailed images of brain activity [69, 75, 76 and 77]. It is used to precisely determine which part of the brain handles critical functions such as thinking, speech, vision, movement and sensation. It can also show the effects of stroke, trauma or Alzheimer's disease on brain function [70, 71 and 73]. Functional MRI and DTI have similar risk factors as MRI. Fig. 10 indicates the DTI images of the brain. Fig. 10 In diffusion tensor imaging (DTI), each color represents a different white matter pathway. Fig. 11 a 3D reconstruction from fMRI and DTI images shows the areas of vision and hand movement that are located near the brain tumor (green area)Fig. 11 shows a 3D reconstruction from fMRI and DTI images. The 3D view offers a good view of the brain.