Positioning, immobilization, and organ motion are some of the major concerns in all imaging modalities. With synchrotron X-ray imaging, alignment of the region of interest to the beam is usually done inside the experimental hutch. However, because specimen alignment can be time consuming; such a system is wasteful of valuable beam time. For the purposes of the Biomedical Imaging and Therapy (BMIT) beamlines at the Canadian Light Source, we propose an effective and versatile means of positioning a wide range of subjects (human and animal) with a wide range of sizes using a laser-based fiducial system to define the region of interest (ROI) before imaging; i.e., outside the experimental hutch. This system will allow the beam path through a specific region of interest to be modeled outside the imaging hutch in a way that it can be reproduced relative to the fixed X-ray beamline inside the hutch. The model will include an indication of the center of the beam and a rectangular area around the target delineating the limits of the area to be imaged (i.e., encompassing the region of interest). The rectangular field of view would be projected on the incoming (entrance) side of the subject as well as the outgoing (exit) side of the subject, and these projections must be coaxial with each other and parallel with the X-ray beam. This method is user friendly, allows mistake to be corrected before experiment and most importantly saves time.

Positioning, immobilization, and organ motion are some of the major concerns in all imaging modalities. With synchrotron X-ray imaging, alignment of the region of interest to the beam is usually done inside the experimental hutch. However, because specimen alignment can be time consuming; such a system is wasteful of valuable beam time. For the purposes of the Biomedical Imaging and Therapy (BMIT) beamlines at the Canadian Light Source, we propose an effective and versatile means of positioning a wide range of subjects (human and animal) with a wide range of sizes using a laser-based fiducial system to define the region of interest (ROI) before imaging; i.e., outside the experimental hutch. This system will allow the beam path through a specific region of interest to be modeled outside the imaging hutch in a way that it can be reproduced relative to the fixed X-ray beamline inside the hutch. The model will include an indication of the center of the beam and a rectangular area around the target delineating the limits of the area to be imaged (i.e., encompassing the region of interest). The rectangular field of view would be projected on the incoming (entrance) side of the subject as well as the outgoing (exit) side of the subject, and these projections must be coaxial with each other and parallel with the X-ray beam. This method is user friendly, allows mistake to be corrected before experiment and most importantly saves time.