Larin’s Imaging Device Captures First High-Resolution Video of Mammalian Heartbeat
Imaging the cardiovascular system in its earliest stages of development is a feat that could provide researchers unequivocal knowledge into the how the heart forms. Until now, the developmental dynamics of the heart have been well theorized and modeled, though very little experimental visual evidence exists to better explain how it forms and why.
One researcher at the University of Houston is collaborating with scientists at Baylor College of Medicine to document the formation of the mammalian heart through a high-resolution, non-invasive imaging device, providing perhaps the best live imagery taken of the vital organ.
“Everything we know about early development of the heart and formation of the vasculature system comes from in vitro studies of fixed tissue samples or studies of amphibian and fish embryos,” said Kirill Larin, assistant professor of biomedical engineering, who is using optical-coherence tomography to image mouse and rat embryos. “With this technology, we are able to image life as it happens, see the heart beat in a mammal for the very first time.”
Optical-coherence tomography (OCT) is a technique that relies on a depth-resolved analysis created by the reflection of an infrared laser beam off an object. Whereas ultrasound utilizes sound waves to create viewable yet grainy video images, OCT utilizes optical contrast and infrared broadband laser sources to help generate a real-time, high-resolution output.
Larin and colleagues at Baylor College of Medicine’s Dickinson Lab are using the technique to study what leads to cardiovascular abnormalities. Some one percent of babies are born with abnormalities and, according to Larin, a better understanding of how the heart and cardiovascular system form could shed light on how to prevent and treat heart-related problems before birth.
“We are able to capture video of the embryonic heart before it begins beating,” said Larin about the video taken just over seven days beyond conception, out of a 20-day typical mammalian pregnancy. “A day later, we can see the heart beginning to form in the shape of a tube and see whether or not the chambers are contracting. Then we begin to see blood distribution and the heart rate.”
Over the course of several years, Larin has been refining his laser-based spectroscopic imaging system to provide high-resolution images of protein biomarkers in blood samples and to study tissue samples to explore factors contributing to disease states. He has been working to adapt this technology to capture video of mammalian heart chambers, as they more closely relate to that of the human.
Currently, the researchers are able to capture these images at a six-micrometer resolution. Utilizing a $1.7 million grant from the National Institutes of Health, Larin plans to modify the device not only to improve the resolution but also speed the imaging process in order to further the study of developmental processes in animals with known heart abnormalities.
“At higher speeds and increased resolution, we’ll be able to witness the dynamics, exactly what factors into the formation of the heart and what causes developmental problems,” he said. “We’d like to discover how the different gene mutations affect cardiovascular development and ultimately reduce the number of babies born with abnormities.”