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Updated: Oct 28, 2025
Human Fetal Blood Flow Quantification with Magnetic Resonance Imaging and Motion Compensation
Published on: January 7, 2021
Fick versus flow: a real-time invasive cardiovascular magnetic resonance (iCMR) reproducibility study
Yousef Arar1,2, Tarique Hussain3,4,5, Riad Abou Zahr3,5
1Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA. Yousef.Arar@UTSouthwestern.edu.
Insights
Invasive cardiovascular magnetic resonance (iCMR) provides more accurate and reliable hemodynamic assessments in congenital heart disease (CHD) patients compared to traditional catheterization. This advanced imaging technique improves flow quantification for better patient management.
Area of Science:
- Cardiology
- Medical Imaging
- Pediatric Medicine
Background:
- Congenital heart disease (CHD) necessitates accurate hemodynamic assessment.
- Cardiac catheterization and cardiovascular magnetic resonance (CMR) imaging have distinct roles.
- Invasive CMR (iCMR) offers simultaneous hemodynamic assessment under consistent conditions, potentially improving flow quantification.
Purpose of the Study:
- To evaluate the incremental diagnostic value of iCMR for hemodynamic assessment in CHD.
- To compare the accuracy and reliability of flow quantification between iCMR and traditional catheterization.
Main Methods:
- Thirty CHD subjects underwent real-time 1.5 T iCMR with passive catheter tracking for simultaneous right (RHC) and left heart catheterization (LHC).
- Repeat iCMR and catheterization measurements were performed to assess reliability using Pearson (PCC) and concordance correlation coefficients (CCC).
Main Results:
- iCMR successfully completed RHC and LHC in all subjects without complications.
- iCMR-derived systemic blood flow (Qs) showed considerably higher accuracy (PCC=0.94) and reliability (CCC=0.52) than catheter-derived Qs (PCC=0.62, CCC=0.22).
- Pulmonary blood flow (Qp) also demonstrated high accuracy with iCMR (PCC=0.96) compared to catheterization (PCC=0.89).
Conclusions:
- iCMR provides validated and more reproducible hemodynamic assessments in the CHD population.
- iCMR demonstrates superior test-retest reliability for systemic blood flow (Qs) measurements.
- iCMR enhances diagnostic capabilities for CHD patients, offering more accurate flow quantification.
Background:
Cardiac catheterization and cardiovascular magnetic resonance (CMR) imaging have distinct diagnostic roles in the congenital heart disease (CHD) population. Invasive CMR (iCMR) allows for a more thorough assessment of cardiac hemodynamics at the same time under the same conditions. It is assumed but not proven that iCMR gives an incremental value by providing more accurate flow quantification.
Methods:
Subjects with CHD underwent real-time 1.5 T iCMR using a passive catheter tracking technique with partial saturation pulse of 40° to visualize the gadolinium-filled balloon, CMR-conditional guidewire, and cardiac structures simultaneously to aid in completion of right (RHC) and left heart catheterization (LHC). Repeat iCMR and catheterization measurements were performed to compare reliability by the Pearson (PCC) and concordance correlation coefficients (CCC).
Results:
Thirty CHD (20 single ventricle and 10 bi-ventricular) subjects with a median age and weight of 8.3 years (2-33) and 27.7 kg (9.2-80), respectively, successfully underwent iCMR RHC and LHC. No catheter related complications were encountered. Time taken for first pass RHC and LHC/aortic pull back was 5.1, and 2.9 min, respectively. Total success rate to obtain required data points to complete Fick principle calculations for all patients was 321/328 (98%). One patient with multiple shunts was an outlier and excluded from further analysis. The PCC for catheter-derived pulmonary blood flow (Qp) (0.89, p < 0.001) is slightly lower than iCMR-derived Qp (0.96, p < 0.001), whereas catheter-derived systemic blood flow (Qs) (0.62, p = < 0.001) was considerably lower than iCMR-derived Qs (0.94, p < 0.001). CCC agreement for Qp at baseline (C1-CCC = 0.65, 95% CI 0.41-0.81) and retested conditions (C2-CCC = 0.78, 95% CI 0.58-0.89) were better than for Qs at baseline (C1-CCC = 0.22, 95% CI - 0.15-0.53) and retested conditions (C2-CCC = 0.52, 95% CI 0.17-0.76).
Conclusion:
This study further validates hemodynamic measurements obtained via iCMR. iCMR-derived flows have considerably higher test-retest reliability for Qs. iCMR evaluations allow for more reproducible hemodynamic assessments in the CHD population.
