In 2020, breast cancer emerged as the most frequently diagnosed cancer globally, with over two million recorded cases. It represented 24.5% of cancer diagnoses in women and 15.5% of cancer-related deaths. In many developed nations, mammography screening programs serve as a key early detection strategy, contributing to reduced mortality rates. However, the complexity of reading mammograms, even for experts, presents a challenge. The low contrast of breast tissue under X-ray and the often unclear representation of the breast's complex interior by two-dimensional imaging complicate the process. Additionally, the mandatory compression of the breast for X-ray examination can cause discomfort or even pain, deterring some women from undergoing screenings. Now, researchers have successfully enhanced mammography, an X-ray imaging technique used for early-stage tumor detection, leading to significantly improved reliability and a less distressing experience for patients.

A research team that included scientists from the Paul Scherrer Institute (PSI, Aargau, Switzerland) has extended conventional computed tomography (CT) to yield significantly higher image resolution while maintaining the same radiation dose. This improvement could facilitate the earlier detection of small calcium deposits or microcalcifications, potential indicators of breast tumors, thus improving the survival prospects for affected women. The experts anticipate the swift clinical implementation of this X-ray phase contrast-based technique. Phase-contrast X-ray imaging improves tumor diagnostics by incorporating additional physical data. This allows for the utilization of an effect image creation, generally overlooked in conventional X-rays, that captures the information contained in signals produced when X-rays refract and scatter upon contact with biological tissue. This is due to electromagnetic waves, including X-rays and visible light, undergoing not only attenuation but also refraction and diffraction when traversing structures of varying densities. This information can be leveraged to enhance image contrast and resolution, enabling easier identification of minuscule objects.

The researchers employed grating interferometry (GI), a technique used to measure physical systems, for developing their method. In this approach, X-rays pass through not only the object under examination but also through three gratings with a line spacing of a few micrometers, making the additional information visible. The team has presented several images illustrating the superior resolution and contrast of GI computed tomography compared to traditional X-rays. The X-rays can originate from a standard source, delivering a radiation dose similar to conventional CT breast scans. Moreover, the new screening approach should increase patient comfort during the procedure. Patients can lie face down on a table with chest-area gaps while the shielded tomograph underneath rotates around the breasts to construct a three-dimensional image. The team aims to initiate clinical trials in collaboration with their clinical partners by the end of 2024, by which time they expect to have a prototype device ready for initial patient examinations.

“The phase-contrast X-rays reveal fine details of the tissue,” said Rahel Kubik-Huch, Director of the Department of Medical Services at Baden Cantonal Hospital (KSB) and Chief Physician for Radiology, who was involved in the research work. “This translational project is meant to explore the potential of this technique for detecting breast cancer in its early stages. We hope that one day our patients will be able to benefit from these advances.” 

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