Post-stenotic plug-like jet with a vortex ring demonstrated by 4D flow MRI

Guk Bae Kim; Hojin Ha; Jihoon Kweon; Sang Joon Lee; Young-Hak Kim; Dong Hyun Yang; Namkug Kim

doi:10.1016/j.mri.2015.11.010

Post-stenotic plug-like jet with a vortex ring demonstrated by 4D flow MRI

Magn Reson Imaging. 2016 May;34(4):371-5. doi: 10.1016/j.mri.2015.11.010. Epub 2015 Dec 2.

Authors

Guk Bae Kim¹, Hojin Ha², Jihoon Kweon¹, Sang Joon Lee³, Young-Hak Kim⁴, Dong Hyun Yang⁵, Namkug Kim⁶

Affiliations

¹ Biomedical Engineering Research Center, Asan Institute of Life Science, Asan Medical Center, Seoul, Republic of Korea.
² POSTECH Biotech Center, Pohang University of Science and Technology, Pohang, Republic of Korea.
³ Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea.
⁴ Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
⁵ Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea. Electronic address: donghyun.yang@gmail.com.
⁶ Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea; Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea. Electronic address: namkugkim@gmail.com.

PMID: 26657978
DOI: 10.1016/j.mri.2015.11.010

Abstract

Purpose: To investigate the details of the flow structure of a plug-like jet that had a vortex ring in pulsatile stenotic phantoms using 4D flow MRI.

Method: Pulsatile Newtonian flows in two stenotic phantoms with 50% and 75% reductions in area were scanned by 4D flow MRI. Blood analog working fluid was circulated via the stenotic phantom using a pulsatile pump at a constant pulsating frequency of 1Hz. The velocity and vorticity fields of the plug-like jet with a vortex ring were quantitatively analyzed in the spatial and temporal domains.

Results: Pulsatile stenotic flow showed a plug-like jet at the specific stenotic degree of 50% in our pulsatile waveform design. This plug-like jet was found at the decelerating period in the post-stenotic region of 26.4mm (1.2 D). It revealed a vortex ring structure with vorticity strength in the range of ±100s(-1).

Conclusion: We observed a plug-like jet with a vortex ring in pulsatile stenotic flow by in vitro visualization using 4D flow MRI. In this plug-like jet, the local fastest flow region occurred at the post-systole phase in the post-stenotic region, which was distinguishable from a typical stenotic jet flow at systole phase.

Keywords: 4D flow MRI; Plug-like jet; Pulsatile stenotic flow; Vortex ring.

MeSH terms

Constriction, Pathologic*
Humans
Magnetic Resonance Imaging / methods*
Phantoms, Imaging*
Pulsatile Flow
Pulse Wave Analysis*
Systole