Jingyan Xu, associate professor in the radiological physics division, is reimagining computed tomography (CT) through the development of a novel, ring-shaped device called the stationary spatial spectral encoder (S3E). Compact, adaptable and efficient, the S3E can be installed onto virtually any CT scanner, whether energy-integrating, dual-source or photon-counting, offering a flexible and cost-effective way to bring advanced spectral imaging to more clinical settings.

At the core of S3E’s innovation is its stationary design, which delegates spectral data collection to the encoder while leaving the CT’s traditional rotating gantry to handle tomographic imaging. By separating these functions, the device improves image clarity, reduces noise and may even lower radiation exposure. Working at the front end of the image formation process, where raw data is first captured from the patient before being reconstructed into an image, the encoder enhances diagnostic detail before the scan ever reaches a radiologist’s screen.

“Our goal is to make spectral CT not only more precise but also more practical for a wider range of clinical applications,” Xu explains. “With the S3E encoder, you can achieve similar image quality with a less expensive, easy-to-install and universal unit that can be customized for patient size.”

Xu’s research combines physics, engineering and imaging science in a collaborative effort with Yong Du — whose physics expertise contributes to scatter simulation and characterization of the device — and with partners at the University of Utah, who support engineering refinement and experimental studies. Together, the team aims to make spectral CT accessible beyond large research hospitals, transforming it into a clinical tool for more precise tissue characterization and diagnosis across health care environments.

Beyond her engineering achievements, Xu’s work reflects Johns Hopkins Radiology’s broader mission to connect fundamental physics with patient care. By bridging technical innovation with clinical practicality, her research is helping ensure that the next generation of CT technology is not only smarter, but also more equitable and widely available.

A 3d view showing location of the S3E ring (yellow) in relation to the x-ray source and the detector. (b) Our simulation set up. Drawing is not to scale. Inserts 1-3 are filled with half Iodine and half Calcium; inserts 4-6 have Iodine only. (c) Material decomposition. (left) iodine line-integral in parallel beam, (mid) iodine map, [0-0.05, 4 + 0.05] mg/ml; (right) water map, [1000-100, 1000 + 100] mg/ml. Water line-integrals are not shown as they are essentially that of a uniform 20 cm cylinder.