Two Novel Techniques Allow a Closer Look Inside

"Up until now, imaging the way lungs function in real time has been limited by conventional methods which result in rather low resolution images," comments Warren Gefter, MD, Chief of Thoracic Imaging in the Radiology Department at the University of Pennsylvania. "We are developing a way to get a better look inside the lungs by polarizing atoms -- making them all spin in the same direction -- with magnetic resonance [MR], which allows the atoms to have a strong signal for sharper images."

Hyperpolarized 3He gas allows radiologists to observe the lung as gas flows in and out, giving them high resolution images of human ventilation. Combining several techniques enables researchers to measure the rate of diffusion of these helium gas molecules, which reflect the size of the air sacs in the lung. This, in turn, allows researchers to detect very early emphysema.

Gefter adds, "We have moved from imaging the structure to imaging the function of the lung to a scale well below a millimetre in size." To use this tool, patients must inhale the helium at the exact right time, after it is been exposed to a laser light to make all of the atoms spin in the same direction, creating the polarized helium, which then enters the lung.

Utilizing another new MR technique, Penn imaging researchers are pushing the scale of what we see in the lung down to an even smaller level - to the cellular and intracellular level. Investigators have figured out a way in which they hope to look for a "marker" of disease inside the body. In animal models, they are injecting polarized carbon-13-labeled molecules and watching its conversion in real time. They can take images of the carbon-13 as it shuffles through the metabolic steps inside the cell.

Rahim Rizi, PhD, Associate Professor of Radiology at Penn, explains, "We observe the polarized carbon-13 labelled molecule as it breaks down and releases energy. What this 'flagged molecule' converts into could tell us whether the cell is normal or abnormal. For the first time, we can now follow the C-13 molecule, in real time, as it moves throughout the body."

COMPAMED.de; Source: University of Pennsylvania School of Medicine