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Efficient joint estimation of tracer distribution and background signals in magnetic particle imaging using a dictionary approach
Publikationstyp
Journal Article
Publikationsdatum
2021-06-21
Sprache
English
Author
Institut
Enthalten in
Volume
40
Issue
12
Start Page
3568
End Page
3568
Citation
IEEE Transactions on Medical Imaging 40 (12) : 3568-3579 (2021)
Publisher DOI
Scopus ID
PubMed ID
34152980
ArXiv ID
Publisher
IEEE
Background signals are a primary source of artifacts in magnetic particle imaging and limit the sensitivity of the method since background signals are often not precisely known and vary over time. The state-of-the art method for handling background signals uses one or several background calibration measurements with an empty scanner bore and subtracts a linear combination of these background measurements from the actual particle measurement. This approach yields satisfying results in case that the background measurements are taken in close proximity to the particle measurement and when the background signal drifts linearly. In this work, we propose a joint estimation of particle distribution and background signal based on a dictionary that is capable of representing typical background signals. Reconstruction is performed frame-by-frame with minimal assumptions on the temporal evolution of background signals. Thus, even non-linear temporal evolution of the latter can be captured. Using a singular-value decomposition, the dictionary is derived from a large number of background calibration scans that do not need to be recorded in close proximity to the particle measurement. The dictionary is sufficiently expressive and represented by its principle components. The proposed joint estimation of particle distribution and background signal is expressed as a linear Tikhonov-regularized least squares problem, which can be efficiently solved. In phantom experiments it is shown that the method strongly suppresses background artifacts and even allows to estimate and remove the direct feed-through of the excitation field.
Schlagworte
background signal
Biomedical measurement
Dictionaries
dictionary approach
Estimation
Image reconstruction
image reconstruction
Imaging
joint estimation
magnetic particle imaging
Particle measurements
Time measurement
DDC Class
004: Informatik
570: Biowissenschaften, Biologie
610: Medizin