Multimodal‐3D imaging based on μMRI and μCT techniques bridges the gap with histology in visualization of the bone regeneration process

Abstract

Bone repair/regeneration is usually investigated through X-ray computed microtomography (μCT) supported by histology of extracted samples, to analyse biomaterial structure and new bone formation processes. Magnetic resonance imaging (μMRI) shows a richer tissue contrast than μCT, despite at lower resolution, and could be combined with μCT in the perspective of conducting non-destructive 3D investigations of bone. A pipeline designed to combine μMRI and μCT images of bone samples is here described and applied on samples of extracted human jawbone core following bone graft. We optimized the coregistration procedure between μCT and μMRI images to avoid bias due to the different resolutions and contrasts. Furthermore, we used an Adaptive Multivariate Clustering, grouping homologous voxels in the coregistered images, to visualize different tissue types within a fused 3D metastructure. The tissue grouping matched the 2D histology applied only on 1 slice, thus extending the histology labelling in 3D. Specifically, in all samples, we could separate and map 2 types of regenerated bone, calcified tissue, soft tissues, and/or fat and marrow space. Remarkably, μMRI and μCT alone were not able to separate the 2 types of regenerated bone. Finally, we computed volumes of each tissue in the 3D metastructures, which might be exploited by quantitative simulation. The 3D metastructure obtained through our pipeline represents a first step to bridge the gap between the quality of information obtained from 2D optical microscopy and the 3D mapping of the bone tissue heterogeneity and could allow researchers and clinicians to non-destructively characterize and follow-up bone regeneration.

Micro-CT and Microscopy Study of Internal and Marginal Gap to Tooth Surface of Crenelated versus Conventional Dental Indirect Veneers

“…The latter must also be used for a porosity analysis, which is necessary to assess avoiding leakages, micro-infiltration, and fissures within the cement layer. Such micro-CT investigations come in the context of their use for a range of studies, including dental adhesives [ 28 ] or bone regeneration [ 29 , 30 ], coupled with other investigation methods, for example, microscopy [ 28 ] or optical coherence tomography (OCT) [ 31 ].…”

Three-Dimensional Reconstruction of Erythrocytes Using the Novel Method For Corrective Realignment of the Transmission Electron Microscopy Cross-Section Images

“…The present study is the continuation of the recent efforts conducted by Sinibaldi et al (2018) who managed to accommodate the need the bridge the gap between the quality of information obtained from 2D optical microscopy and the 3D mapping of the bone tissue heterogeneity. To that purpose, the histology was combined with MRI and microcomputed tomography ( μ CT).…”

Optimized 3D co-registration of ultra-low-field and high-field magnetic resonance images

“…Moreover, SWIM could be effectively adapted to images from different modalities to track changes in tissues or in material structures in order to detect the effect of therapeutic treatments or micro-morphology changes [ 30 , 43 ]. Since the implementation of reliable and robust methods of multimodal image co-registration and image fusion [ 44 – 46 ] is central in several medicine-related research and clinical fields [ 42 ], it would be worth exploiting our pipeline in other imaging modalities in the future.…”