This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Seeing inside an object is one thing; seeing exactly what it is made of, in three dimensions, is far more difficult. Now, researchers at Bar-Ilan University and collaborating institutions have developed a new X-ray imaging technique that can map the three-dimensional chemical composition of an object 43 times faster than conventional approaches, while using more than 97% less measurement data.
The new method, reported in Optica, could eventually make it easier for researchers to examine materials, biological samples and other complex structures that are difficult or too time-consuming to study with existing techniques. Traditional X-ray fluorescence imaging can determine which chemical elements are present in a sample and where they are located. But creating a three-dimensional map usually requires scanning an object point by point, a process that can take considerable time and generate enormous amounts of data.
The researchers took a different approach. Instead of measuring every point individually, they placed a randomly patterned tungsten mask in front of the X-ray beam, creating a structured pattern that encodes information from multiple parts of the sample at once. They rotated a sample containing copper, zirconium and silver while measuring the fluorescent X-rays emitted by the different elements.
A mathematical algorithm then reconstructed the three-dimensional elemental structures directly from the compressed data. The result: the researchers were able to eliminate more than 97% of the measurements normally required while still accurately reconstructing the locations of microscopic metal wires and particles. "The surprising part was how much information we could recover from so little data," says Adi Ben-Yehuda, a Ph.D. student in professor Sharon Shwartz's laboratory at Bar-Ilan University's Department of Physics.
"Instead of measuring every point separately, we use a structured X-ray pattern and let the reconstruction algorithm piece together the information. It is a different way of thinking about how an X-ray image can be created." The technique builds on the team's previous work on two-dimensional X-ray fluorescence "ghost imaging," extending the concept into a full 3D imaging system. The advance could be particularly valuable at synchrotron facilities, where scientists use extremely bright X-ray beams to study materials at microscopic scales.
Access to these facilities is limited, making measurement time particularly valuable. Faster imaging could allow researchers to scan larger samples, follow chemical processes as they happen and study delicate materials while reducing their exposure to X-rays. Potential applications range from materials science and green energy to biology and geology.
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