Marian Willner, Presenter: Nothing to Disclose

Kai Scherer, Abstract Co-Author: Nothing to Disclose

Michael Chabior, Abstract Co-Author: Nothing to Disclose

Eva Braig, Abstract Co-Author: Nothing to Disclose

Konstantin Willer, Abstract Co-Author: Nothing to Disclose

Julia Herzen, Abstract Co-Author: Nothing to Disclose

Alexander Andre Fingerle MD, Abstract Co-Author: Nothing to Disclose

Matthias Johannes Eiber MD, Abstract Co-Author: Speaker, Siemens AG Speaker, Astellas Group Speaker, Johnson & Johnson

Peter B. Noel PhD, Abstract Co-Author: Nothing to Disclose

Ernst J. Rummeny MD, Abstract Co-Author: Nothing to Disclose

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

Knowledge of the composition of urinary calculi is a fundamental part of the preoperative patient evaluation and this information influences treatment plans and recurrence prevention. The most common techniques for stone analysis are in-vitro and require removal of exemplary stones. Recently, the characterization of renal stones has been demonstrated to be feasible using dual-energy computed tomography. The objective of this study is to evaluate the potential of the lately developed X-ray dark-field (scattering) contrast to differentiate most common types of urinary calculi in radiographic imaging.

A total of 113 extracted urinary calculi from 18 patients were imaged at a compact laboratory setup using a three-grating Talbot-Lau interferometer and a conventional X-ray tube operated at 40 kV. Corresponding attenuation and dark-field (scattering) signals were evaluated and matched to the respective stone compositions determined by Fourier-transform infrared spectroscopy. The analysis included 63 calciumoxolate stones from nine patients, 10 uric acid stones from four patients and further 40 stones of diverse composition from five patients.

Calciumoxolate and uric acid stones could be clearly differentiated by their distinct attenuation and scattering behaviour. While the calcified calculi present as high absorbing masses with rather low dark-field contrast, the uric acid stones yield a strong scattering signal due to their crystalline inner structure. The discrimination of the two types of calculi could be repeated with stones embedded in renal tissue of 4 cm thickness and an applied dose exposure below 5 mSv. The mixed stones showed intermediate attenuation-scattering ratios.

Our work demonstrates the potential of the dark-field (scattering) signal as additional imaging contrast to perform renal stone assessment in X-ray radiography.

X-ray dark-field (scattering) contrast might complement conventional radiographic imaging to allow for characterization of urinary calculi.

Willner, M, Scherer, K, Chabior, M, Braig, E, Willer, K, Herzen, J, Fingerle, A, Eiber, M, Noel, P, Rummeny, E, Pfeiffer, F, Renal Stone Assessment with X-ray Dark-field Radiography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017484.html