An imaging system configured to acquire a selected dose x-ray image projection of a subject, comprising: a source configured to emit x-rays as a whole beam with a first energy spectra; a filter assembly, including: a filter member configured to limit a transmission x-rays to a filtered beam with a second energy spectra that has a different HVL than the first energy spectra, a filter carrier configured to move the filter member relative to the whole beam; a detector configured to detect the whole beam and the filtered beam; a control system configured to control the position of the filter member with the filter carrier to selectively acquire projections of the subject; wherein the control system is configured to execute instructions to control movement of the filter carrier to position the filter member in filtering position and a non-filtering position; wherein the filter member limits the whole beam to the filtered beam in the filtering position; wherein the imaging system is configured to acquire a selected number of projection to reconstruct a model of the subject, wherein the imaging system further comprises: a reconstruction system configured to reconstruct the model of the subject with image data acquired with the whole beam and the filtered beam for a reduced x-ray dose image acquisition; wherein the filtered beam includes a lower dose of x-rays relative to the whole beam, characterized in that the filtered beam is operable with the detector to identify edges of selected portion of the subject. a source configured to emit x-rays as a whole beam with a first energy spectra; a filter assembly, including: a filter member configured to limit a transmission x-rays to a filtered beam with a second energy spectra that has a different HVL than the first energy spectra, a filter carrier configured to move the filter member relative to the whole beam; a filter member configured to limit a transmission x-rays to a filtered beam with a second energy spectra that has a different HVL than the first energy spectra, a filter carrier configured to move the filter member relative to the whole beam; a detector configured to detect the whole beam and the filtered beam; a control system configured to control the position of the filter member with the filter carrier to selectively acquire projections of the subject; wherein the control system is configured to execute instructions to control movement of the filter carrier to position the filter member in filtering position and a non-filtering position; wherein the filter member limits the whole beam to the filtered beam in the filtering position; wherein the imaging system is configured to acquire a selected number of projection to reconstruct a model of the subject, wherein the imaging system further comprises: a reconstruction system configured to reconstruct the model of the subject with image data acquired with the whole beam and the filtered beam for a reduced x-ray dose image acquisition; wherein the filtered beam includes a lower dose of x-rays relative to the whole beam, characterized in that the filtered beam is operable with the detector to identify edges of selected portion of the subject. a reconstruction system configured to reconstruct the model of the subject with image data acquired with the whole beam and the filtered beam for a reduced x-ray dose image acquisition; wherein the filtered beam includes a lower dose of x-rays relative to the whole beam, characterized in that the filtered beam is operable with the detector to identify edges of selected portion of the subject.