Mikro-CT

Abstract

The strength and fracture resistance of bone is determined by the structure of the trabecular network and the cortical shell. While standard 2D techniques like histomorphometry are inadequate to assess the 3D nature of the trabecular network, isotropic 3D datasets of this network can be acquired with the new imaging modality of microCT. However, so far the quantitative analysis of the generated datasets, in particular the extraction of appropriate parameters describing the bone structure, has not been finally solved. In this article we describe the technology and applications of microCT systems relevant in the field of osteology. The most important technical features of current microCT systems in this context are: 1. A spatial resolution down to 5-10 microns can be achieved. 2. The maximum sample size is related to the desired resolution by a factor of approximately 1000, that is, a resolution of 10 microns limits the maximum sample size to approximately 1 cm. 3. Scan times for microCT systems vary between minutes and hours. Currently five areas for the application of microCT systems in osteology can be identified: 1. The search of parameters characterizing the 3D trabecular structure. 2. The application of finite element models to determine the biochemical competence of the structural parameters. 3. The use of microCT in preclinical trials to study drug effects in small animals. 4. The validation of analysis methods used in high-resolution in-vivo imaging systems. 5. The 3D quantification of modeling and remodeling processes.

Ultrafast High-Resolution In Vivo Volume-CTA of Mice Cerebral Vessels

“…27 However, such protocols are not suitable for in vivo studies because of restrictions resulting from the need to keep the animals anesthetized, to minimize movement artifacts, and to limit the radiation dose. We have, therefore, developed a completely new scanning protocol the hallmarks being (1) intravenous instead of intraarterial administration of the contrast medium, (2) rotation by 180°only, and (3) a high frame rate providing a sufficient number of images within a 40 seconds scanning time.…”

Repetitive recombinant human bone morphogenetic protein 2 injections improve the callus microarchitecture and mechanical stiffness in a sheep model of distraction osteogenesis

“…23 Therefore the strength and the fracture resistance of bone are determined by the architecture of its trabecular network and its cortical shell. 24,25 However, a potential modification of the trabecular microarchitecture by rhBMP-2 application during DO has been investigated by Ming and Zhu et al , but these studies examined rhBMP-2 in combination with other biological agents. Other studies investigated the effect of rhBMP-2 on bone microarchitecture in anterior lumbar interbody fusion.…”

Micro CT analysis of the subarticular bone structure in the area of the talar trochlea

“…The disadvantage of these procedures, in addition to the elaborate sample preparation required, is that for interpretation of the 2D sections, a model for extrapolation to the third dimension is required, and is not always successful [5]. …”

“…According to Engelke et al [5], with smaller trabecular volumes, the values of histomorphometric structural parameters can vary between 10 and 20 percent. With micro CT, the assessment of histomorphometric and other structures is dependent on imaging process resolution and the exponentially increasing amounts of data occurring at higher resolutions.…”