Propagation‐based x‐ray phase‐contrast tomography of mastectomy samples using synchrotron radiation

Abstract

Purpose Propagation‐based phase‐contrast computed tomography (PB‐CT) is a method for three‐dimensional x‐ray imaging that utilizes refraction, as well as absorption, of x rays in the tissues to increase the signal‐to‐noise ratio (SNR) in the resultant images, in comparison with equivalent conventional absorption‐only x‐ray tomography (CT). Importantly, the higher SNR is achieved without sacrificing spatial resolution or increasing the radiation dose delivered to the imaged tissues. The present work has been carried out in the context of the current development of a breast CT imaging facility at the Australian Synchrotron. Methods Seven unfixed complete mastectomy samples with and without breast cancer lesions have been imaged using absorption‐only CT and PB‐CT techniques under controlled experimental conditions. The radiation doses delivered to the mastectomy samples during the scans were comparable to those approved for mammographic screening. Physical characteristics of the reconstructed images, such as spatial resolution and SNR, have been measured and compared with the results of the radiological quality assessment of the complete absorption CT and PB‐CT image stacks. Results Despite the presence of some image artefacts, the PB‐CT images have outperformed comparable absorption CT images collected at the same radiation dose, in terms of both the measured objective image characteristics and the radiological image scores. The outcomes of these experiments are shown to be consistent with predictions of the theory of PB‐CT imaging and previous reported experimental studies of this imaging modality. Conclusions The results presented in this paper demonstrate that PB‐CT holds a high potential for improving on the quality and diagnostic value of images obtained using existing medical x‐ray technologies, such as mammography and digital breast tomosynthesis (DBT). If implemented at suitable synchrotron imaging facilities, PB‐CT can be used to complement existing imaging modalities, leading to more accurate breast cancer diagnosis.

Multiscale three-dimensional imaging of intact human organs down to the cellular scale using hierarchical phase-contrast tomography

“…There are no established sCT techniques that achieve cellular resolution in large soft tissues such as human organs. Phase-contrast based sCT 12,14,15 , specifically propagation-based imaging 16 , can theoretically be applied to image large, soft tissues. However, the X-ray beam coherence and X-ray source brilliance necessary to resolve cellular detail whilst penetrating into samples larger than a few millimetres, was not available at any synchrotron facility worldwide.…”

Recent advances in X-ray imaging of breast tissue: From two- to three-dimensional imaging

“…Research at the imaging and medical beamline (IMBL) of Australian Synchrotron also focusses on the propagation-based phase-contrast approach for BCT with synchrotron radiation on mastectomy specimens [80][81][82][83][84]. In 2018, the first freshlynot formalin fixateddissected mastectomy sample was scanned at the Australian Synchrotron with an energy of 32 keV and a MGD of 4 mGy which is comparable to conventional mammography [84].…”

“…Their outstanding studies, including the comparison of physical image quality and visual, radiological assessment, proved a better performance compared to conventional absorption based BCT. Although Gureyev et al finally concluded that this approach can be used in a complementary way in addition to the existing image modalities [82], it is rather unlikely to scan women in vivo at large-scale synchrotron facilities and thus, this approach is still far away from daily clinical application. Nevertheless, these results remain very promising and might be applied to conventional X-ray sources with other phase-contrast approaches.…”

Seeing the fetus from a DOHaD perspective: discussion paper from the advanced imaging techniques of DOHaD applications workshop held at the 2019 DOHaD World Congress

“…Synchrotron imaging has a growing interest in clinical radiography diagnostics/treatments, and recent advances have increased the sensitivity of detection and resulted in significant reductions in radiation dose. [100][101][102] In the future, this will have significant implications in both clinical and veterinary medicine, using either nonsynchrotron sources or compact X-ray sources.…”