Reducing femoral flow artefacts in radial magnetic resonance fingerprinting of the prostate using region-optimised virtual coils

Kaia I Sørland; Christopher G Trimble; Chia-Yin Wu; Tone F Bathen; Mattijs Elschot; Martijn A Cloos

doi:10.1002/nbm.5136

Reducing femoral flow artefacts in radial magnetic resonance fingerprinting of the prostate using region-optimised virtual coils

NMR Biomed. 2024 Mar 21:e5136. doi: 10.1002/nbm.5136. Online ahead of print.

Authors

Kaia I Sørland¹, Christopher G Trimble^{1

2}, Chia-Yin Wu^{3

4

5}, Tone F Bathen^{1

2}, Mattijs Elschot^{1

2}, Martijn A Cloos^{3

4}

Affiliations

¹ Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
² Department of Radiology and Nuclear Medicine, St. Olavs hospital, Trondheim University Hostpital, Trondheim, Norway.
³ Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland, Australia.
⁴ ARC Training Centre for Innovation on Biomedical Imaging Technology (CIBIT), The University of Queensland, St Lucia, Queensland, Australia.
⁵ School of Electrical Engineering and Computer Science, The University of Queensland, St Lucia, Queensland, Australia.

PMID: 38514929
DOI: 10.1002/nbm.5136

Abstract

High acceleration factors in radial magnetic resonance fingerprinting (MRF) of the prostate lead to strong streak-like artefacts from flow in the femoral blood vessels, possibly concealing important anatomical information. Region-optimised virtual (ROVir) coils is a beamforming-based framework to create virtual coils that maximise signal in a region of interest while minimising signal in a region of interference. In this study, the potential of removing femoral flow streak artefacts in prostate MRF using ROVir coils is demonstrated in silico and in vivo. The ROVir framework was applied to radial MRF k-space data in an automated pipeline designed to maximise prostate signal while minimising signal from the femoral vessels. The method was tested in 15 asymptomatic volunteers at 3 T. The presence of streaks was visually assessed and measurements of whole prostate T₁, T₂ and signal-to-noise ratio (SNR) with and without streak correction were examined. In addition, a purpose-built simulation framework in which blood flow through the femoral vessels can be turned on and off was used to quantitatively evaluate ROVir's ability to suppress streaks in radial prostate MRF. In vivo it was shown that removing selected ROVir coils visibly reduces streak-like artefacts from the femoral blood flow, without increasing the reconstruction time. On average, 80% of the prostate SNR was retained. A similar reduction of streaks was also observed in silico, while the quantitative accuracy of T₁ and T₂ mapping was retained. In conclusion, ROVir coils efficiently suppress streaking artefacts from blood flow in radial MRF of the prostate, thereby improving the visual clarity of the images, without significant sacrifices to acquisition time, reconstruction time and accuracy of quantitative values. This is expected to help enable T₁ and T₂ mapping of prostate cancer in clinically viable times, aiding differentiation between prostate cancer from noncancer and healthy prostate tissue.

Keywords: MR fingerprinting; artefacts; prostate; radial MRI; signal suppression.

Abstract

Grants and funding