CT dose reduction factors in the thousands using X-ray phase contrast

TL;DR

Phase-contrast X-ray CT imaging significantly enhances image quality at drastically reduced radiation doses, potentially enabling dose reductions in the thousands without compromising image quality.

Contribution

This study demonstrates that phase-contrast CT can achieve dose reductions in the thousands while maintaining high image quality, surpassing conventional methods.

Findings

300-fold dose reduction still yields nearly 10 times higher SNR than absorption contrast

SNR improvement increases as radiation dose decreases

Potential for dose reduction factors in the tens of thousands

Abstract

Phase-contrast X-ray imaging can improve the visibility of weakly absorbing objects (e.g. soft tissues) by an order of magnitude or more compared to conventional radiographs. Previously, it has been shown that combining phase retrieval with computed tomography (CT) can increase the signal-to-noise ratio (SNR) by up to two orders of magnitude over conventional CT at the same radiation dose, without loss of image quality. Our experiments reveal that as radiation dose decreases, the relative improvement in SNR increases. We discovered this enhancement can be traded for a reduction in dose greater than the square of the gain in SNR. Upon reducing the dose 300 fold, the phase-retrieved SNR was still almost 10 times larger than the absorption contrast data. This reveals the potential for dose reduction factors in the tens of thousands without loss in image quality, which would have a profound impact on medical and industrial imaging applications.