Evaluating a Phase‐Specific Approach to Aortic Flow: A 4D Flow MRI Study

Journal of Magnetic Resonance Imaging, vol. 59, pp. 1056–1067

Abstract

BACKGROUND: Aortic flow parameters can be quantified using 4D flow MRI. However, data are sparse on how different methods of analysis influence these parameters and how these parameters evolve during systole. PURPOSE: To assess multiphase segmentations and multiphase quantification of flow-related parameters in aortic 4D flow MRI. STUDY TYPE: Prospective. POPULATION: 40 healthy volunteers (50% male, 28.9 ± 5.0 years) and 10 patients with thoracic aortic aneurysm (80% male, 54 ± 8 years). FIELD STRENGTH/SEQUENCE: 4D flow MRI with a velocity encoded turbo field echo sequence at 3 T. ASSESSMENT: Phase-specific segmentations were obtained for the aortic root and the ascending aorta. The whole aorta was segmented in peak systole. In all aortic segments, time to peak (TTP; for flow velocity, vorticity, helicity, kinetic energy, and viscous energy loss) and peak and time-averaged values (for velocity and vorticity) were calculated. STATISTICAL TESTS: Static vs. phase-specific models were assessed using Bland-Altman plots. Other analyses were performed using phase-specific segmentations for aortic root and ascending aorta. TTP for all parameters was compared to TTP of flow rate using paired t-tests. Time-averaged and peak values were assessed using Pearson correlation coefficient. P < 0.05 was considered statistically significant. RESULTS: (P = 0.481) for the ascending aorta. Vorticity, helicity, and energy loss in the ascending aorta, aortic arch, and descending aorta peaked significantly later than flow rate. Time-averaged velocity and vorticity values correlated significantly in all segments. DATA CONCLUSION: Static 4D flow MRI segmentation yields comparable results as multiphase segmentation for flow-related parameters, eliminating the need for time-consuming multiple segmentations. However, multiphase quantification is necessary for assessing peak values of aortic flow-related parameters. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

Authors 10

1. Mitch J. F. G. Ramaekers corresponding Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center · Maastricht University Medical Centre · Maastricht University

   Affiliation as printed

   Cardiovascular Research Institute Maastricht (CARIM) Maastricht The Netherlands

   Department of Cardiology Maastricht University Medical Center+ Maastricht The Netherlands

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology and Nuclear Medicine Maastricht University Medical Center+ Maastricht The Netherlands

   Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands

   Department of Cardiology, Maastricht University Medical Center+, Maastricht, The Netherlands

   Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

2. Jos J.M. Westenberg Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

3. Max F.G.H.M. Venner

   Maastricht University Medical Centre · Maastricht University

   Affiliation as printed

   Department of Cardiology Maastricht University Medical Center+ Maastricht The Netherlands

   Department of Cardiology, Maastricht University Medical Center+, Maastricht, The Netherlands

4. Joe F. Juffermans Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

5. Hans C. van Assen Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

6. Bastiaan J. C. te Kiefte Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

7. Bouke P. Adriaans

   Maastricht University Medical Centre · Maastricht University

   Affiliation as printed

   Department of Cardiology Maastricht University Medical Center+ Maastricht The Netherlands

   Department of Radiology and Nuclear Medicine Maastricht University Medical Center+ Maastricht The Netherlands

   Department of Cardiology, Maastricht University Medical Center+, Maastricht, The Netherlands

   Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands

8. Hildo J. Lamb Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

9. Joachim Ernst Wildberger

   Maastricht University Medical Centre · Maastricht University

   Affiliation as printed

   Cardiovascular Research Institute Maastricht (CARIM) Maastricht The Netherlands

   Department of Radiology and Nuclear Medicine Maastricht University Medical Center+ Maastricht The Netherlands

   Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands

   Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands

10. Simon M. Schalla

    Maastricht University Medical Centre · Maastricht University

    Affiliation as printed

    Cardiovascular Research Institute Maastricht (CARIM) Maastricht The Netherlands

    Department of Cardiology Maastricht University Medical Center+ Maastricht The Netherlands

    Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands

    Department of Cardiology, Maastricht University Medical Center+, Maastricht, The Netherlands