Options
Saline bolus for negative contrast perfusion imaging in magnetic particle imaging
Citation Link: https://doi.org/10.15480/882.8557
Publikationstyp
Journal Article
Date Issued
2023-09-07
Sprache
English
TORE-DOI
Journal
Volume
68
Issue
17
Start Page
1
End Page
11
Article Number
175026
Citation
Physics in Medicine and Biology 68 (17): 175026 (2023-09-07)
Publisher DOI
Scopus ID
Publisher
IOP
Objective. Magnetic particle imaging (MPI) is capable of high temporal resolution measurements of the spatial distribution of magnetic nanoparticles and therefore well suited for perfusion imaging, which is an important tool in medical diagnosis. Perfusion imaging in MPI usually requires a fresh bolus of tracer material to capture the key signal dynamics. Here, we propose a method to decouple the imaging sequence from the injection of additional tracer material, without further increasing the administered iron dose in the body with each image. Approach. A bolus of physiological saline solution without any particles (negative contrast) diminishes the steady-state concentration of a long-circulating tracer during passage. This depression in the measured concentration contributes to the required contrast dynamics. The presence of a long-circulating tracer is therefore a prerequisite to obtain the negative contrast. As a quantitative tracer based imaging method, the signal is linear in the tracer concentration for any location that contains nanoparticles and zero in the surrounding tissue which does not provide any intrinsic signal. After tracer injection, the concentration over time (positive contrast) can be utilized to calculate dynamic diagnostic parameters like perfusion parameters in vessels and organs. Every acquired perfusion image thus requires a new bolus of tracer with a sufficiently large iron dose to be visible above the background. Main results. Perfusion parameters are calculated based on the time response of the proposed negative bolus and compared to a positive bolus. Results from phantom experiments show that normalized signals from positive and negative boli are concurrent and deviations of calculated perfusion maps are low. Significance. Our method opens up the possibility to increase the total monitoring time of a future patient by utilizing a positive-negative contrast sequence, while minimizing the iron dose per acquired image.
Subjects
long term monitoring
magnetic particle imaging
magnetic tracer
negative contrast
perfusion imaging
DDC Class
570: Life Sciences, Biology
Publication version
publishedVersion
Loading...
Name
Mohn_2023_Phys._Med._Biol._68_175026.pdf
Size
2.51 MB
Format
Adobe PDF