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Flow artifact removal in carotid wall imaging based on black and gray‐blood dual‐contrast images subtraction
Author(s) -
Li Hao,
Li Bo,
Huang Wenjian,
Dong Li,
Zhang Jue
Publication year - 2017
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.26218
Subject(s) - subtraction , contrast to noise ratio , blood flow , magnetic resonance imaging , lumen (anatomy) , medicine , image quality , nuclear medicine , biomedical engineering , mathematics , radiology , artificial intelligence , computer science , arithmetic , image (mathematics)
Purpose To develop and validate a dual‐contrast image subtraction (DCIS) strategy for eliminating the flow artifacts in black‐blood carotid MRI. Methods Twelve patients with carotid stenosis and eight healthy volunteers were imaged using the black and gray‐blood dual‐contrast imaging based on the relaxation‐enhanced compressed sensing three‐dimensional motion‐sensitizing driven equilibrium prepared rapid‐gradient‐echo (RECS‐3D MERGE) sequence. Subtraction of black‐blood images (BBIs) and gray‐blood images (GBIs), together with a preweighting procedure, was performed to eliminate the residual blood signal in BBIs. A wavelet denoising procedure was applied to offset the noise amplification. In addition to the lumen signal‐to‐noise ratio (SNR) and wall‐lumen contrast‐to‐noise ratio (CNR), the signal variance ratio (SVR) and contrast variance ratio (CVR) were also used to evaluate the blood suppression efficiency. Results By choosing the weighting factor of one, the lumen SNR of DCIS images was approximately 1% of that of the original BBIs, and the CNR showed a 91.4% improvement as compared with the BBIs. The median of the lumen SVR decreased to zero, and the CVR increased to 123% of that of the BBIs. Conclusions DCIS is demonstrated to be an effective strategy for sufficiently removing the residual flow signal from black‐blood carotid MRI. Magn Reson Med 77:1612–1618, 2017. © 2016 International Society for Magnetic Resonance in Medicine