Computed Tomography (CT) is a radiological imaging technique for producing cross-sectional tomographic images. At present it is one of the most useful imaging modality in diagnostic medicine. The main goal of this study to identify the basic physics & principles of imaging by computed tomography .This study was a descriptive study. Data were collected from different books, journal articles and internet sources.CT provides tomographic section where different body structure is not superimposed like conventional radiography. Image quality contrast and resolution of CT image are very high. Size, location and extension of pathological lesion can be determined with extreme accuracy. Density difference as low as 0.5% can be easily distinguish by CT. CT is one of the most useful modality in diagnostic medicine. Although there are some limitations, CT becomes more and more acceptable day to day in our country due to better diagnostic value.

Keywords: CT, Cross-sectional tomographic images, Pathological lesion.

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Dr Shah Md. Ejajul Islam

MBBS. DNM (DU), Assistant Professor, Nuclear Medicine, Dhaka Medical College, Bangladesh