Researchers target tenfold increase in X-ray resolution

But increasing emphasis is placed on imaging the functions of the body, preferably at the molecular level. Magnetic resonance imaging (MRI) and ultrasound show physiological functions, while tomographic cameras such as SPECT and PET can provide insight on the molecular function level.

“A picture is worth a thousand words, especially in the biomedical field,” says Hans Hertz, Professor of Biomedical and X-ray Physics at KTH. “With higher resolution in the macroscopic methods, and the ability observe the smallest detail, we can expect increased biomedical understanding and better diagnostic tools in the future.”

Hertz is the main applicant for the research, Molecular X-ray Micro Imaging, which has received more than SEK 33 million, spread over five years, from the Knut and Alice Wallenberg Foundation.

Classical X-ray provides the best resolution and clean detail, down to .5 mm in human subjects, and .1 in mice. “Then however we get almost only structural information. MRI and ultrasound are somewhere around 1 mm, while molecular methods PET and SPECT can show 2-3 mm.

In this research project, we intend to develop molecular medical imaging with a goal of reaching 0.1 mm while retaining acceptable exposure times and doses.” That means ten times better detail for medical imaging.

The immediate objective is to improve pre-clinical medical X-ray imaging in small animals, but long-term methods should be developed to clinically benefit humans. The new imaging method uses X-ray fluorescence of metallic nanoparticles that, for example, could search for tumors with the help of specific surface molecules.

The system is based on a unique combination of matched nanoparticles and new technologies and methods. “The nanoparticles provide a so-called molecular selection,” Hertz says. “Targeted nanoparticles are a strong and growing research field of nanomedicine with broad applications in the future.”

Besides the field of medical imaging, targeted nanoparticles could be used in drug targeting, he says. “We will benefit greatly from the knowledge from this development to produce nanoparticles with appropriate biomedical parameters for our project.”

Already the first applications to be tested are relevant in areas such as tumor biology research. “When the method works, we will continue to develop it with other applications and long-term clinical applications.”