ABSTRACT The basic aim of this thesis work is to assess and investigate the profiles of 2D and 3D structure CT scanner images of a lodged bullet inside a human brain. To determine the location of lodged bullet, the scanning parameters of the CT imaging were used 120 KV and 10 mA with automatic mode to generate the 255 slices of the brain. To investigate this images the CT scanner (optima CT540) at Felege hiwot referral hospital in Bahir Dar Ethiopia) was used. To determine the physical parameters a MATLAB and 3D MPR method of a radiant viewer software were used. Qualitatively, the current was increased in the slices of brain with lodged bullet due to low resistance of a metallic bullet as compared with the current on the normal slices. To farther investigate, a bullet and the brain parts were mapped by the Hounsfield Unit (HU). Low radiation attenuated in soft tissues and fluids inside the brain. Thus, allowing most of the radiation to pass through and hit the detector, the resulting image displayed was dark and low HU values obtained. In contrast a lodged bullet with high attenuation absorbs most of the radiation only allowing a small amount of radiation to pass through it. The image at the center of the slices displayed pure white and 3071 HU obtained. 3D structures of brain images were generated and visualized in different viewing positions. Qualitatively and quantitatively the logged bullet location was determined. The lodged bullet has been observed that 11.28 cm far from its entry (frontal), 7.92 cm from the back, and 6.96 cm deep down from the upper part of brain. Closely it has been located in the left hemisphere of the brain on part of thalamus and parietal.