A registration based approach for 4D cardiac micro‐CT using combined prospective and retrospective gating

Abstract

Recent advances in murine cardiac studies with three-dimensional cone beam micro-computed tomography (CT) have used either prospective or retrospective gating technique. While prospective gating ensures the best image quality and the highest resolution, it involves longer sampling times and higher radiation dose. Sampling is faster and the radiation dose can be reduced with retrospective gating but the image quality is affected by the limited number of projections with an irregular angular distribution which complicate the reconstruction process, causing significant streaking artifacts. This work involves both prospective and retrospective gating in sampling. Deformable registration is used between a high quality image set acquired with prospective gating with the multiple data sets during the cardiac cycle obtained using retrospective gating. Tests were conducted on a four-dimensional (4D) cardiac mouse phantom and after optimization, the method was applied to in vivo cardiac micro-CT data. Results indicate that, by using our method, the sampling time can be reduced by a factor of 2.5 and the radiation dose can be reduced 35% compared to the prospective sampling while the image quality can be maintained. In conclusion, we proposed a novel solution to 4D cine cardiac micro-CT based on a combined prospective with retrospective gating in sampling and deformable registration post reconstruction that mixed the advantages of both strategies.

Synchrotron Radiation Imaging for Advancing Our Understanding of Cardiovascular Function

“…In conventional high-speed micro-CT scanners, contrast resolution is traded for increased spatial resolution to limit radiation dose. 85 Dynamic SR micro-CT with less motion artefacts 86 now can be acquired in relatively rapid times 84 at much higher spatial resolution than conventional CT scanners at speeds that are dependent on the size of the imaging area. 84,87 In the immediate future, it should be possible to perform fast SR micro-CT angiography in rodents selective for arterial vessels faster than is possible with conventional devices.…”

3D identification of trabecular bone fracture zone using an automatic image registration scheme: A validation study

“…Many image registration methods have been applied to micro-CT datasets. (Waarsing et al, 2004;Boyd et al, 2006;Badea et al, 2008;Hulme et al, 2008;Hardisty and Whyne, 2009;Baiker et al, 2010;Lee et al, 2010;Nishiyama et al, 2010;Xiao et al, 2010;Nagaraja et al, 2011), but to the authors knowledge no methods for the identification of a discontinuity of the trabecular structure are presented in the literature. In Hulme et al (2008), a registration method was used for recording vertebral endplate deformations of functional spine units, under axial compression.…”

SPECT/CT image‐based dosimetry for Yttrium‐90 radionuclide therapy: Application to treatment response

“…The deformable registration algorithm applies multiresolution free‐form deformations based on cubic spline interpolation between sparse, uniformly distributed control points as its transformation model 18, 19. The registration provided a one‐to‐one correlation between voxels on different images and time points, allowing for mapping of anatomical data and structure sets from diagnostic to follow‐up imaging.…”