Work

Characterization and suppression of stripe artifact in velocity‐selective magnetization‐prepared unenhanced MR angiography

Year: 2018

Type: article

Abstract: Purpose To characterize and suppress stripe artifact associated with velocity‐selective (VS) magnetization for unenhanced MRA. Methods Extended phase graph formalism was used to show that the stripe artifact contains multiples of the fundamental frequency that is determined by the area of unipolar VS gradient. Four VS preparation pulses whose excitation profiles are spatially shifted by quarter the fundamental period of the stripes, were applied alternately. For further suppression of the artifact, k‐space data at kz = 0 were averaged over the 4 VS preparations. The proposed schemes were tested in a chicken breast phantom and healthy human subjects. Results When the standard VS preparation scheme was used, stripe artifact was shown in all the reconstructed images and appeared as artifactual peaks in k‐space that corresponded to the first and second order harmonics of the fundamental frequency. Alternate application of the 4 phase‐shifted VS preparation pulses suppressed the stripes, but not completely, as evidenced by residual erroneous peaks in k‐space. After the k‐space averaging, the stripe artifact was nearly eliminated. Conclusion Stripe artifact in VS‐MRA consists of multiples of the fundamental frequency and can be effectively suppressed through alternate application of phase‐shifted VS preparations along with k‐space averaging.

Source: Magnetic Resonance in Medicine

DOI: 10.1002/mrm.27160

Authors: Taehoon Shin, Qin Qin

Institutions: Ewha Womans University, Case Western Reserve University, Kennedy Krieger Institute, Johns Hopkins University

Language: English

Topic: Advanced MRI Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, National Heart, Lung, and Blood Institute, National Institute of Biomedical Imaging and Bioengineering