Alternative to biopsy
A group of engineers from Columbia University in New York has developed a technology that can replace standard biopsy and histological studies with real-time visualization of living tissues inside the body. MediSCAPE is a high–speed three-dimensional microscope that gives an image of living tissues. With its help, surgeons will be able to determine the boundaries of healthy and pathologically altered tissues during surgery without having to take samples and wait for the results of histological examination.
Currently, the standard of histological diagnosis is a biopsy. It is especially important for screening and diagnosis of oncological diseases. During a biopsy, a small tissue sample is excised, then fixed, sections are made, treated with dyes and placed on a slide, which the pathologist examines with a microscope. The researchers suggested that it is possible to speed up the process if you create a tool for visual assessment of tissues on the spot.
The instant result will allow surgeons to make informed decisions about the method and scope of intervention, and will also help to make sure that the pathological tissue is completely removed.
Surgical microscopes are already used by clinicians, but they give an image of a small two-dimensional area, which makes it difficult to quickly examine large volumes of tissue and interpret the results. These microscopes also usually require the introduction of a fluorescent dye, which may limit their use for some patients.
Over the past decade, the head of the study, Elizabeth Hillman, has been developing new types of microscopes for research in the field of neurobiology, which can give three-dimensional images of living neurons and axons of worms, fish and flies. The group decided to test the technology of swept Confocally Aligned plane excitation microscopy (Sweep Confocally Aligned Planar Excitation, SCAPE) for visualization of living mammalian and human tissues.
Visualization of the taste buds of the human tongue. The MediSCAPE visualizing head was slowly guided over the surface of the subject's tongue and high-speed 3D images were obtained. The images were then stitched together to form a long 3D strip (below).
First, a fresh mouse kidney was visualized; the resulting images were of high quality and resolution. MediSCAPE microscopy did not require the use of dyes, there was enough natural tissue fluorescence, which is usually too weak to see it. The microscope was so effective that it picked up these weak signals even when visualizing with movement at a speed identical to the movements in real time when the surgeon scans various areas of tissue in the operating wound.
During the experiment, the researchers managed to combine the obtained images and turn them into large three-dimensional images that are as informative as a complete set of histological sections during a pathoanatomic examination.
MediSCAPE visualization of a fresh human kidney compared to a histological section of the same tissue stained with Schiff reagent.
The group demonstrated the extensive capabilities of MediSCAPE for various purposes, from the analysis of pancreatic cancer in mice to the rapid evaluation of organs for human transplantation. Experiments with fresh samples of human kidneys with various disorders have proved that MediSCAPE allows you to see clear signs of diseases that echo histological images.
The researchers note that visualization of living tissues carries more information than microscopy of excised biopsies. They reported that they could even visualize blood flow and see the effects of ischemia and reperfusion at the cellular level. To do this, the blood supply to the kidney was mechanically limited, and then restored. Understanding whether the tissues remain healthy and whether they receive a good blood supply during surgical procedures is very important.
The group also worked on reducing the dimensions of the SCAPE microscope to a size that would allow it to fit in the operating room and be used during surgery. They developed a smaller version of the system with a sterile imaging cap.
Currently, the process of preparation for clinical trials is underway.
Article by K.B.Patel et al. High-speed light-sheet microscopy for the in-situ acquisition of volumetric histological images of living tissue is published in the journal Nature Biomedical Engineering.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Columbia University in the City of New York: New Technology Could Make Biopsies a Thing of the Past.