Computerized tomographic reconstruction method and system utilizing reflection

In the method for constructing a two-dimensional representation of an object slice lying in a quasi-plane by utilizing a source of penetrating radiation and radiation-detector means to effect measurements of plural sets of transmission data for multiple diverging transmission paths in a quasi-plane containing an object slice being examined;

• and reconstructing a two-dimensional representation of the object slice by convolving said data without reordering of same, and scaling and back projecting same;
• THE IMPROVEMENT COMPRISING:
• generating estimated transmission data for desired transmission paths through said object by reflecting said measured transmission data;
• and performing said reconstruction utilizing both said measured ad said estimated transmission data.

In a system for constructing a two-dimensional representation of an object slice lying in a quasi-plane;

• said system including a radiation source positioned for providing radiation in the form of a fan beam so that at least some of said radiation passes through said object;
• detector means including an array of side by side detector elements positioned opposite said source and aligned therewith and lying in said quasi-plane for detecting radiation in said quasi-plane not absorbed or scattered by said object;
• means for effecting relative rotation between said object and said source-detector combination about an axis of rotation such that said source and detector means remain in said quasi-plane;
• means for effecting measurements from said source at a plurality of angular positions during said rotation to obtain a multiplicity of measured data readings from said detector elements at each said projection;
• and means for reconstructing a two-dimensional representation of the object by convolving said data without reordering of same, and scaling and back projecting same;
• THE IMPROVEMENT COMPRISING:
• means for reflecting said measured detector data obtained during said projections to generate estimated detector data at desired projection angles;
• and
• means for providing both said measured and estimated data to said reconstructing means whereby said reconstruction is effected utilizing both said measured and said estimated detector data.