Quantification of vortex flow in pulmonary arteries of patients with chronic thromboembolic pulmonary hypertension

Hiroki Kamada; Hideki Ota; Masanori Nakamura; Wenyu Sun; Tatsuo Aoki; Haruka Sato; Koichiro Sugimura; Kei Takase

doi:10.1016/j.ejrad.2021.110142

Quantification of vortex flow in pulmonary arteries of patients with chronic thromboembolic pulmonary hypertension

Eur J Radiol. 2022 Mar:148:110142. doi: 10.1016/j.ejrad.2021.110142. Epub 2022 Jan 8.

Authors

Hiroki Kamada¹, Hideki Ota², Masanori Nakamura³, Wenyu Sun⁴, Tatsuo Aoki⁵, Haruka Sato⁶, Koichiro Sugimura⁷, Kei Takase⁸

Affiliations

¹ Department of Diagnostic Radiology, Tohoku University Hospital, Sendai, Japan. Electronic address: hkamada@rad.med.tohoku.ac.jp.
² Department of Diagnostic Radiology, Tohoku University Hospital, Sendai, Japan. Electronic address: h-ota@rad.med.tohoku.ac.jp.
³ Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya, Japan. Electronic address: nakamura.masanori@nitech.ac.jp.
⁴ Department of Diagnostic Radiology, Tohoku University Hospital, Sendai, Japan.
⁵ Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
⁶ Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. Electronic address: haruka.s@cardio.med.tohoku.ac.jp.
⁷ Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. Electronic address: ksugimura@cardio.med.tohoku.ac.jp.
⁸ Department of Diagnostic Radiology, Tohoku University Hospital, Sendai, Japan. Electronic address: ktakase@rad.med.tohoku.ac.jp.

PMID: 35066341
DOI: 10.1016/j.ejrad.2021.110142

Abstract

Purpose: This study proposes an objective method of quantifying the vortex flow in pulmonary arteries to compare the duration of its presence before and after balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Methods: Thoracic 4D-flow magnetic resonance imaging was performed in 28 CTEPH patients before and after BPA. Planes were set in pulmonary arteries to evaluate volume flow rate (VFR), the duration, and area of backward flow in the pulmonary trunk, which is a component of the vortex flow. The full width at half maximum (FWHM) of the peak of the time course of VFR of backward flow was assessed to quantify the duration of the vortical flow.

Results: Although overall flow patterns after BPA appeared to be the same as the one before BPA, significant decreases in the FWHM, area, and VFR of the backward flow after BPA were found (FWHM: before, 1.88 × 10^-1 ± 1.51 × 10^-2 [cardiac cycle] vs. after, 1.65 × 10^-1 ± 1.86 × 10^-2 [cardiac cycle]; area ratio: before, 2.67 × 10^-1 ± 1.30 × 10^-2 vs. after, 2.38 × 10^-1 ± 1.31 × 10^-2; VFR: before, 13.6 ± 2.21 [mL/s] vs. after, 11.3 ± 2.36 [mL/s]).

Conclusion: BPA promoted significant decreases in the FWHM, area, and VFR of backward flow in the pulmonary trunk, thereby facilitating efficient blood transport. The tendencies for these changes were to be larger for cases where BPA more greatly decreased the pressure. The results suggest that the FWHM, area, and VFR are useful indicators for the noninvasive evaluation of the therapeutic effects of BPA.

Keywords: 4D-flow MRI; BPA; Blood flow; CTEPH.

MeSH terms

Angioplasty, Balloon* / methods
Chronic Disease
Humans
Hypertension, Pulmonary*
Lung
Pulmonary Artery / diagnostic imaging
Pulmonary Embolism* / complications
Pulmonary Embolism* / diagnostic imaging