X-ray microtomography (micro-CT) is a technique to noninvasively characterize microstructures in 3D at a micron level spatial resolution. Micro computed tomography (μCT) is one of the most commonly used imaging technologies in preclinical research. It provides detailed information about the volume, textures, and abnormal alterations of internal structures in high-resolution.
In preclinical research, the ability to visualize and analyze anatomical structures and physiological changes in small animal models is crucial for understanding disease mechanisms, evaluating treatment efficacy, and advancing scientific discoveries. In recent years, micro-computed tomography (micro-CT) has emerged as a powerful imaging modality that enables high-resolution, non-invasive imaging of small animal specimens. It offers many advantages including homogenous resolution, fast acquisition. Thus, μCT provides accurate anatomical information especially of dense tissues such as bones or calcified structures. The use of micro-CT in preclinical studies includes a wide range, some of which are discussed below:
The first advances in µCT technique were mainly driven by imaging needs for the evaluation of bone anatomy and density. The high X-ray density of osseous structures allows the precise µCT-based evaluation of stereology, volume, and trabecular architecture of bones at micrometer resolution. For the volumetric estimation of bone density, micro-CT is described as the method of choice. Furthermore, the non-invasive quality of micro-CT allows for the observation of bone structure before and after exposure to mechanical stress under experimental conditions. , micro-CT is capable of detecting the impact of illnesses and therapeutic interventions on bone density and structure. To provide an example for imaging of osseous structures, Fig. 5 shows a murine proximal femur volume rendering of a dataset acquired via µCT. Next to the evaluation of changes in trabecular structures, the quantification of osteopathologic processes is also very important. For this purpose, µCT is used in fundamental research in oncology for the quantification of bone metastases. Besides osteolytic alterations or processes, an increase in bone density, such as osteopetrosis can also be assessed using µCT.
Volume rendering of a murine femur dataset, acquired ex vivo with a continuous scan mode lasting 40s
Micro-CT imaging is highly valuable in studying cardiovascular diseases and assessing cardiac function in small animal models. By imaging the heart and blood vessels, researchers can analyze cardiac morphology, measure ventricular volumes and ejection fraction, and investigate cardiovascular remodeling. Micro-CT can also be combined with contrast agents to visualize and quantify vascular parameters, such as vessel density, tortuosity, and plaque burden. These studies contribute to a better understanding of cardiovascular pathophysiology and the development of potential therapeutic interventions.High temporal and spatial resolution and relatively short scanning times allow for high-throughput studies. An increasing number of research groups have demonstrated the use of micro-CT for cardiac morphology and global ventricular systolic indices, such as stroke volume, ejection fraction, and cardiac output.
Pancreatic tumor vasculature in a mice
Micro-computed tomography (micro-CT) is considered as one of the emerging imaging techniques for drug discovery and providing a better understanding of in-vivo pathology. This imaging technique is particularly useful in preclinical studies for drug development, as it can provide valuable information on the effects of a drug candidate on the anatomy and physiology of small animals. Micro-CT also can assist in the formulation and characterization of drug compounds. By visualizing the internal structure and morphology of pharmaceutical formulations, such as tablets, capsules, or microspheres, researchers can assess factors like drug distribution, porosity, dissolution profiles, and drug release kinetics. Micro-CT aids in understanding the physical properties of drug formulations and optimizing their design for enhanced drug delivery and efficacy.
Example of a 3D image made with LOTUS-3D software of a capsule
Micro CT is used in dentistry for a variety of applications, including the evaluation of dental implants, the assessment of root canal morphology, and the analysis of dental caries. In implant dentistry, micro CT can be used to accurately measure the bone density and volume around the implant, which is critical for ensuring the long-term success of the implant.
In endodontics, micro CT can be used to detect and analyze the complex root canal system, which can be difficult to visualize with traditional X-ray techniques. This allows dentists to accurately diagnose and treat root canal-related issues, such as infections and fractures.
In addition to dental implants and root canals, micro CT can also be used to analyze dental caries. By providing detailed images of the internal structure of teeth, micro CT can help dentists identify and diagnose dental caries at an early stage, when they are more easily treatable.
Example of a 3D image made with LOTUS-3D software of a human tooth
Micro-CT is an imaging technique that brought revolutionary changes in biomedical research, taking advantage of its ability to create 3D morphological and anatomical data with great resolution. It can depict the internal structure of the sample, offering reliable measurements of a series of characters such as volume, density, and porosity. Its non-destructive nature enables the scanning of rare and valuable samples, as well as of samples that need to be further processed by other methods, providing also the possibility to repeat the analysis. In conclusion, Micro-CT has contributed to dramatic advances in tissue engineering, enabling studies in scaffold characterization, evaluation of the cell based tissue engineering bone constructs and cell Distribution.
Example of a 3D image made with LOTUS-3D software of a PCL scaffold
Micro-CT has become an essential tool in preclinical studies, allowing researchers to investigate anatomical structures, monitor disease progression, and evaluate treatment responses in small animals. Its high-resolution imaging capabilities, increased availability and user-friendliness provide valuable insights into various research areas. As technology advances, micro-CT continues to evolve, and contributing to further breakthroughs in preclinical research, ultimately improving clinical outcomes.
Below is a summary of some of the applications of micro-CT in preclinical studies:
