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About the Authors:
Dustin R. Osborne
* E-mail: [email protected]
Affiliations University of Tennessee Graduate School of Medicine, Knoxville, Tennessee, United States of America, Siemens Medical Solutions, Knoxville, Tennessee, United States of America
Shikui Yan
Affiliation: Siemens Medical Solutions, Knoxville, Tennessee, United States of America
Alan Stuckey
Affiliation: University of Tennessee Graduate School of Medicine, Knoxville, Tennessee, United States of America
Lindy Pryer
Affiliation: Siemens Medical Solutions, Knoxville, Tennessee, United States of America
Tina Richey
Affiliation: University of Tennessee Graduate School of Medicine, Knoxville, Tennessee, United States of America
Jonathan S. Wall
Affiliation: University of Tennessee Graduate School of Medicine, Knoxville, Tennessee, United States of America
Introduction
microCT is an important component of the imaging tools available for preclinical researchers because of its ability to generate high-resolution three-dimensional images of the body by using X-rays to create a slice-by-slice reconstruction of the subject being imaged [1]. This process involves using an X-ray source and detector attached to a rotating circular gantry. Typical CT systems use a single poly-energetic X-ray tube with an opposing detector that acquires raw acquisition data as it rotates around the subject [2]. This modality provides the information necessary to determine anatomical structures with the subject and for key data corrections for PET and SPECT data [3].
The Inveon system used in this study uses 3rd generation technology as shown in Figure 1 [4]. It acquires data via a step-and-shoot method meaning that the X-ray source and detector are used to acquire data by rotating to a specified angle and then collecting data at that angle for a specified interval of time called the exposure time. The gantry is then rotated to the next angle and data acquired for the subsequent projections. This set of projection data is then used to reconstruct the final 3D image volume [5]. This particular system also has a continuous rotation step-and-shoot mode to shorten acquisition times but it yields lower-resolution images and was not used in this study. The exposure time, X-ray beam settings (flux) and the number of projections acquired in the image are the primary settings that determine delivered dose during a CT acquisition.
[Figure omitted. See PDF.]
Figure 1. 3rd generation detector technology with the X-ray source and detector rotating about the subject.
https://doi.org/10.1371/journal.pone.0049936.g001