Usefulness of hard X-ray microscope using synchrotron radiation for the structure analysis of insects

Muscle structure assessment using synchrotron radiation X-ray micro-computed tomography in murine with cerebral ischemia

Muscles are crucial for balance and walking, activities which depend specifically on the lower extremity muscles. Therefore, the evaluation of stroke induced atrophy and paralysis is essential; however, determining the extent of damage in the days after its occurrence remains challenging. In this study, we evaluated ischemic stroke-induced soleus muscle damage in gerbils using synchrotron radiation X-ray micro-computed tomography (SR-µCT), comparing a control group (n = 3), animals 7 days after stroke (7 d, n = 3), and animals 14 days after stroke (14 d, n = 3). The left muscle was paralyzed, whereas the right muscle was not. Subsequently, we quantified the assessment by segmenting the soleus muscle based on the extracellular space/matrix and fiber region to determine the degree of damage. The muscle fiber-to-extracellular space/matrix ratio were significantly damaged due to paralysis on the left side (control vs. 14 d, P = 0.040). Muscle area was significantly different at 14 d between the left and right sides (P = 0.010). Additionally, the left local fascicle surface area, thickness, global pennation angle, and local fascicle angle were significantly different between the control and 14 d groups (P = 0.002, P = 0.007, P = 0.005, and P = 0.014 respectively). These findings underscore the potential of post-stroke animal studies in improving rehabilitation treatment for the central nervous system by assessing the degree of muscle recovery.

Microstructure investigation of plant architecture with X-ray microscopy

In recent years, the plant morphology has been well studied by multiple approaches at cellular and subcellular levels. Two-dimensional (2D) microscopy techniques offer imaging of plant structures on a wide range of magnifications for researchers. However, subcellular imaging is still challenging in plant tissues like roots and seeds. Here we use a three-dimensional (3D) imaging technology based on the X-ray microscope (XRM) and analyze several plant tissues from different plant species. The XRM provides new insights into plant structures using non-destructive imaging at high-resolution and high contrast. We also utilized a workflow aiming to acquire accurate and high-quality images in the context of the whole specimen. Multiple plant samples including rice, tobacco, Arabidopsis and maize were used to display the differences of phenotypes. Our work indicates that the XRM is a powerful tool to investigate plant microstructure in high-resolution scale. Our work also provides evidence that evaluate and quantify tissue specific differences for a range of plant species. We also characterize novel plant tissue phenotypes by the XRM, such as seeds in Arabidopsis, and utilize them for novel observation measurement. Our work represents an evaluated spatial and temporal resolution solution on seed observation and screening.

Analysis of type I osteoporosis animal models using synchrotron radiation

Preclinical experiments to analyze the trabecular space of spongy bones using small animals are required for the evaluation and treatment of patients with osteoporosis (OP). We performed ovariectomy to create OP models. A total of four mice were used. Ovariectomized group (OVX, n = 2) in which both ovaries were resected at random, and the sham operated group (SHAM, n = 2) performed surgery without resecting the ovaries. We propose a study that enables OP analysis by analyzing tibia microstructures of OVX and SHAM using synchrotron radiation (SR). SR imaging is a technology capable of irradiating an extremely small object in the order of several tens of nanometers using a nondestructive method at the microscopic level. Unlike previous imaging diagnoses (staining, micro-CT [Computed Tomography]) it was possible to preserve the real shape and analyze bone microstructures in real-time and analyze and evaluate spongy bones to secure data and increase the reliability of OP analysis. We were able to confirm the possibility of OP diagnosis through experimental animals for spongy bone damage related to bone mineral density. Therefore, we aimed to provide a rehabilitation and medicine therapy intervention method through basic research on the evaluation of OP diagnosis through human-based segmentation of challenging spongy bones while supplementing the limitations of existing imaging methods. RESEARCH HIGHLIGHTS: We present an analysis of osteoporosis through spongy bone using phase-contrast X-ray source. Unlike existing methods, it is possible to analyze the internal microstructure of the tibia with this method. This is an objective mechanism for OP and a basis for rehabilitation.

Three-Dimensional Structure Analysis of Mouse Nails using Synchrotron Radiation

Until now, studies on nail disease have been performed through microscopic diagnosis and microscopic computed tomography (micro-CT). However, these kinds of conventional methods have some limitations. Firstly, the microscopic method is considered the gold standard for medical diagnosis. However, due to the use of fluorescent materials, the sample is damaged and it takes a long time to get results. Secondly, while micro-CT is a non-invasive method to get inner structure images of the sample with high resolution, the penetration and spatial resolution are insufficient for studying the microstructures of the sample, such as the sponge bone and the muscle fibers. In contrast, synchrotron radiation (SR) X-ray imaging technology has the advantage of very vividly demonstrating the anatomic structure of the sample with high penetration, sensitivity, and resolution. In this study, we compared the optical microscopic method using hematoxylin and eosin (H&E) staining and SR imaging to analyze the nail tissue in a mouse model. The results showed that SR could depict the inner structures of a mouse nail without physical damage. Additionally, we could divide the important anatomical structures nail unit into three parts with three-dimensional images: the nail bed, nail matrix, and hyponychium. The images showed that SR could be used for analyzing nails by visualizing the relatively clear and medically semantic structures in a three-dimensional section. We expect that the results of this study will be applied to study nail diseases and pharmaceutical research on their treatment.

Three-dimensional analysis of injury conditions of single muscle fibers in small animals using phase-contrast X-ray imaging

Muscle damage can reduces the biological functions and lead to ultimately a disease state. For the reason, it is important to accurately check the state of an injury such as atrophy, and it is required to identify the state of fibers constituting the muscle. This study describes a novel method of analyzing single muscle fibers with injury conditions in three-dimensions. The muscle fibers of the mice were visualized using phase-contrast X-ray projection the microstructure. In additions, it was possible to confirm the status by quantitatively analyzing the injury severity of muscle fibers. Significantly, the muscle conditions of multiple individuals were individually determined. This study could contributes to areas where it is very important to identify microdetailed and quantitative changes of state, such as new drug development.

Synchrotron radiation imaging analysis of neural damage in mouse soleus muscle

Damage to lower limb muscles requires accurate analysis of the muscular condition via objective microscopic diagnosis. However, microscopic tissue analysis may cause deformation of the tissue structure due to injury induced by external factors during tissue sectioning. To substantiate these muscle injuries, we used synchrotron X-ray imaging technology to project extremely small objects, provide three-dimensional microstructural analysis as extracted samples. In this study, we used mice as experimental animals to create soleus muscle models with various nerve injuries. We morphologically analyzed and quantified the damaged Section and Crush muscles, respectively, via three-dimensional visualization using synchrotron radiation X-ray imaging to diagnose muscle injury. Results of this study can also be used as basic data in the medical imaging field.

Evaluation of X-ray tomography contrast agents: A review of production, protocols, and biological applications

X-ray computed tomography is a strong tool that finds many applications both in medical applications and in the investigation of biological and nonbiological samples. In the clinics, X-ray tomography is widely used for diagnostic purposes whose three-dimensional imaging in high resolution helps physicians to obtain detailed image of investigated regions. Researchers in biological sciences and engineering use X-ray tomography because it is a nondestructive method to assess the structure of their samples. In both medical and biological applications, visualization of soft tissues and structures requires special treatment, in which special contrast agents are used. In this detailed report, molecule-based and nanoparticle-based contrast agents used in biological applications to enhance the image quality were compiled and reported. Special contrast agent applications and protocols to enhance the contrast for the biological applications and works to develop nanoparticle contrast agents to enhance the contrast for targeted drug delivery and general imaging applications were also assessed and listed.

3D printing from microfocus computed tomography (micro-CT) in human specimens: education and future implications

Microfocus CT (micro-CT) is an imaging method that provides three-dimensional digital data sets with comparable resolution to light microscopy. Although it has traditionally been used for non-destructive testing in engineering, aerospace industries and in preclinical animal studies, new applications are rapidly becoming available in the clinical setting including post-mortem fetal imaging and pathological specimen analysis. Printing three-dimensional models from imaging data sets for educational purposes is well established in the medical literature, but typically using low resolution (0.7 mm voxel size) data acquired from CT or MR examinations. With higher resolution imaging (voxel sizes below 1 micron, <0.001 mm) at micro-CT, smaller structures can be better characterised, and data sets post-processed to create accurate anatomical models for review and handling. In this review, we provide examples of how three-dimensional printing of micro-CT imaged specimens can provide insight into craniofacial surgical applications, developmental cardiac anatomy, placental imaging, archaeological remains and high-resolution bone imaging. We conclude with other potential future usages of this emerging technique.