A technology to ’see inside’ a human body without inserting a tool or conducting operation really began when the first X-ray was discovered by Wilhelm Rontgen at 1895. The X-ray could not only penetrate the human body, but penetrates into different tissues in different degrees, making the body transparant enabling the visualization of bones and other structures within the body. Today, the technique has been used as a standard diagnostic tool in medical floor till today.

The classical X-ray imaging is a direct manifestation of the interaction of X-ray radiation with tissue. In modern or contemporary medical imaging, technique called tomography is used to produce true reconstructed images from the ’shadow’ image taken by X-ray. Examples of tomography imaging modalities are widely known CT-Scan, magnetic resonance imaging (MRI) and positron emission tomography (PET).

'Slicing' without cutting: Tomography imaging technique is to generate a cross-section slice image of an object based on computed reconstruction from projections taken from different angles.