Methods and Apparatus for Keystone Effect

Apparatus comprising:

• an x-ray source;
• an x-ray detector positioned to receive x-rays emitted from said source;
• and
• a collimator positioned between said x-ray source and said x-ray detector, said collimator configured to have movable parts that provide for a keystone correction.

An imaging system comprising:

• an energy source;
• a detector positioned to receive energy emitted from said source;
• and
• a collimator positioned between said source and said detector, said collimator configured to provide a rectangular FOV that utilizes all of said detector for single and dual energy exposures when said detector is not perpendicular to energy emitted from said source, such that all the collimated energy can be used for diagnosis.

A computer configured to:

• receive image data from a first detector position acquisition;
• receive image data from a second detector position acquisition;
• wherein an x-ray source to detector angle is different between the acquisitions, and
• combine the received image data, without performing any keystone correction on the data, to generate a single image of an area greater than the size of the detector.