A new 3D tissue imaging technique has been developed that allows the effects diseases to be studied at the cellular level in far greater detail. The imaging technique, called X-ray histotomography, allows researchers to create high resolution images of cells in 3D without having to cut the cells into slices, as is required for most cell imaging techniques.
Sectioning and staining tissue samples allows cellular features to be studied, but this method of analyzing cells is far from ideal. The physical process of sectioning tissue samples can cause damage to some cells. In addition to tissue loss, cells are distorted which can result in incomplete sampling and inaccurate visualization of what is happening inside cells. Traditional techniques also make it difficult to study features such as cell shape and volume. These problems are solved with X-ray histotomography. It allows cells to be visualized in 3D without having to cut tissue samples.
The new imaging technique was developed over 10 years by Dr. Keith Cheng, professor of pathology, pharmacology and biochemistry, and molecular biology at Penn State College of Medicine and a team of X-ray imaging physicists at the University of Chicago.
The imaging technique uses the same principles that are used in CT scans, which involve the use of a series of X-rays taken at slightly different angles that are then amalgamated by computer to form a 3D image.
The researchers used the principles of CT scanning and histology to create accurate high-resolution 3D images of small organisms and tissues. The team uses a micro-CT scanner that contains a powerful x-ray source called a synchrotron. The synchrotron has allowed the researchers to increase the resolution of images and process images more rapidly.
The new imaging technique has been used to create 3D reconstructions of young zebrafish from the whole-organism level down to the cellular level. Zebrafish were used to test the imaging technology as the size of the young larvae is similar to the size of the tissue samples that used to assess cancerous tumors.
Using the new technique, the researchers can study cell size, volume, 3D shapes, cell density, and count the number of cells in a sample, none of which is possible with traditional imaging techniques. Using this new imaging technique, researchers can simultaneously study the effects of disease on the organ, tissue, and at the cellular level in 3D.
The researchers hope their advanced imaging technique will aid the study of diseases at the cellular level and will help doctors develop personalized treatments for patients.
Details of the new imaging technique can be found in the paper – Computational 3D histological phenotyping of whole zebrafish by X-ray histotomography – which was recently published in the journal eLife: 10.7554/eLife.44898.