Creating hemodynamic atlases of cardiac 4D flow MRI

J Magn Reson Imaging. 2017 Nov;46(5):1389-1399. doi: 10.1002/jmri.25691. Epub 2017 Mar 13.

Abstract

Purpose: Hemodynamic atlases can add to the pathophysiological understanding of cardiac diseases. This study proposes a method to create hemodynamic atlases using 4D Flow magnetic resonance imaging (MRI). The method is demonstrated for kinetic energy (KE) and helicity density (Hd ).

Materials and methods: Thirteen healthy subjects underwent 4D Flow MRI at 3T. Phase-contrast magnetic resonance cardioangiographies (PC-MRCAs) and an average heart were created and segmented. The PC-MRCAs, KE, and Hd were nonrigidly registered to the average heart to create atlases. The method was compared with 1) rigid, 2) affine registration of the PC-MRCAs, and 3) affine registration of segmentations. The peak and mean KE and Hd before and after registration were calculated to evaluate interpolation error due to nonrigid registration.

Results: The segmentations deformed using nonrigid registration overlapped (median: 92.3%) more than rigid (23.1%, P < 0.001), and affine registration of PC-MRCAs (38.5%, P < 0.001) and affine registration of segmentations (61.5%, P < 0.001). The peak KE was 4.9 mJ using the proposed method and affine registration of segmentations (P = 0.91), 3.5 mJ using rigid registration (P < 0.001), and 4.2 mJ using affine registration of the PC-MRCAs (P < 0.001). The mean KE was 1.1 mJ using the proposed method, 0.8 mJ using rigid registration (P < 0.001), 0.9 mJ using affine registration of the PC-MRCAs (P < 0.001), and 1.0 mJ using affine registration of segmentations (P = 0.028). The interpolation error was 5.2 ± 2.6% at mid-systole, 2.8 ± 3.8% at early diastole for peak KE; 9.6 ± 9.3% at mid-systole, 4.0 ± 4.6% at early diastole, and 4.9 ± 4.6% at late diastole for peak Hd . The mean KE and Hd were not affected by interpolation.

Conclusion: Hemodynamic atlases can be obtained with minimal user interaction using nonrigid registration of 4D Flow MRI.

Level of evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1389-1399.

Keywords: 4D Flow MRI; cardiac flow; helicity density; hemodynamic atlas; kinetic energy; nonrigid registration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Angiography
  • Diastole
  • Female
  • Heart / anatomy & histology*
  • Heart / diagnostic imaging*
  • Heart Ventricles / physiopathology
  • Hemodynamics
  • Humans
  • Hydrodynamics
  • Kinetics
  • Magnetic Resonance Imaging*
  • Male
  • Microscopy, Phase-Contrast
  • Reference Values
  • Stroke Volume
  • Systole
  • Ventricular Function, Left
  • Young Adult