title: Intrinsic respiratory gating in small-animal CT.
abstract: Gating in small-animal CT imaging can compensate artefacts caused by physiological motion during scanning. However, all published gating approaches for small animals rely on additional hardware to derive the gating signals. In contrast, in this study a novel method of intrinsic respiratory gating of rodents was developed and tested for mice (n=5), rats (n=5) and rabbits (n=2) in a flat-panel cone-beam CT system. In a consensus read image quality was compared with that of non-gated and retrospective extrinsically gated scans performed using a pneumatic cushion. In comparison to non-gated images, image quality improved significantly using intrinsic and extrinsic gating. Delineation of diaphragm and lung structure improved in all animals. Image quality of intrinsically gated CT was judged to be equivalent to extrinsically gated ones. Additionally 4D datasets were calculated using both gating methods. Values for expiratory, inspiratory and tidal lung volumes determined with the two gating methods were comparable and correlated well with values known from the literature. We could show that intrinsic respiratory gating in rodents makes additional gating hardware and preparatory efforts superfluous. This method improves image quality and allows derivation of functional data. Therefore it bears the potential to find wide applications in small-animal CT imaging.
authors.affiliation: Junior Group Molecular Imaging, German Cancer Research Center (DKFZ), Heidelberg, Germany. soenkebartling@gmx.de
authors.forename: Soenke H
authors.initials: SH
authors.lastname: Bartling
authors.forename: Julien
authors.initials: J
authors.lastname: Dinkel
authors.forename: Wolfram
authors.initials: W
authors.lastname: Stiller
authors.forename: Michael
authors.initials: M
authors.lastname: Grasruck
authors.forename: Ijad
authors.initials: I
authors.lastname: Madisch
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Wolfhard
authors.initials: W
authors.lastname: Semmler
authors.forename: Rajiv
authors.initials: R
authors.lastname: Gupta
authors.forename: Fabian
authors.initials: F
authors.lastname: Kiessling
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D003287:Contrast Media; D051379:Mice; D011817:Rabbits; D011857:Radiographic Image Interpretation, Computer-Assisted; D015656:Respiratory Mechanics; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
chemical_list: D003287:Contrast Media