Aims and objectives
Dark field (DF) x-ray imaging is a recent innovation that produces diagnostic images based on the refraction of x-rays.
Different from conventional attenuation based x-ray imaging,
it visualizes the lung tissue itself and is said to differentiate between collapsed and aerated lung.
This makes dark field a promising tool for lung imaging.
This is in particular interesting for paediatrics patients,
where lung injuries are a major problem.
The high sensitivity of DF imaging for pneumothoraces,
a common condition in premature children,
has already been demonstrated...
Methods and materials
Dark field scanner – Dark field x-ray images were acquired with a Talbot-Lau interferometer at the first Talbot distance.
The pixel spacing was 100x100 μm² and the G2 period 2 μm [2].
The system visibility was on average 22% in a central region of interest and using 40 kVp. Every acquisition simultaneously produces an attenuation image allowing,
in a first approximation,
to benchmark DF imaging to conventional approaches.
The incident air kerma at the level of the animal was 0.51 mGy for every acquisition.
Imaging...
Results
Fig. 2-Fig. 4display the images of respectively Control,
1h and 4h CPAP.
In (a) the DF images are shown and in (b) the corresponding attenuation images.
Each image shows from left to right the different animals (1 to 4) and from top to bottom the time points (A,B,…) as described in the measurement scheme of Fig. 1 .
Alveolar recruitment visualization in DF – DF imaging clearly distinguishes between the efficacy of the different treatments with obvious alveolar recruitment for all (4/4) 4h CPAP treated...
Conclusion
Compared to conventional attenuation x-ray imaging,
DF imaging shows the aerated lung tissue itself,
and is therefore a promising modality for optimizing CPAP treatment in neonates.
Extra studies should investigate further the sensitivity of DF imaging to different CPAP treatment schemes.
Personal information
Ph.D Janne Vignero,
department of Imaging and Pathology,
KULeuven,
Oude Markt 13,
Leuven Belgium.
email:
[email protected]
References
[1] Hellbach K et al.,
(2018) Depiction of pneumothoraces in a large animal model using x-ray dark field radiography,
Sci.
Rep.
8,2602
[2] Vignero J et al.,
(2018) A hybrid simulation framework for computer simulation and modelling studies of grating-based x-ray phase-contrast images,
Phys.
Med.
Biol.
10 (8)