Journal Article

Free breathing three-dimensional cardiac quantitative susceptibility mapping for differential cardiac chamber blood oxygenation – initial validation in patients with cardiovascular disease inclusive of direct comparison to invasive catheterization

Liu, Zhe, Nguyen, Thanh D., Deh, Kofi, Prince, Martin R., Eskreis-Winkler, Sarah, Wang, Yi, Singh, Harsimran, Kim, Jiwon, Spincemaille, Pascal, Kochav, Jonathan, Horn, Evelyn M., Weinsaft, Jonathan W., Wen, Yan

2019

Overview

Background Differential blood oxygenation between left (LV) and right ventricles (RV; ΔSaO 2 ) is a key index of cardiac performance; LV dysfunction yields increased RV blood pool deoxygenation. Deoxyhemoglobin increases blood magnetic susceptibility, which can be measured using an emerging cardiovascular magnetic resonance (CMR) technique, Quantitative Susceptibility Mapping (QSM) – a concept previously demonstrated in healthy subjects using a breath-hold 2D imaging approach (2D BH QSM). This study tested utility of a novel 3D free-breathing QSM approach (3D NAV QSM) in normative controls, and validated 3D NAV QSM for non-invasive ΔSaO 2 quantification in patients undergoing invasive cardiac catheterization (cath). Methods Initial control ( n  = 10) testing compared 2D BH QSM (ECG-triggered 2D gradient echo acquired at end-expiration) and 3D NAV QSM (ECG-triggered navigator gated gradient echo acquired in free breathing using a phase-ordered automatic window selection algorithm to partition data based on diaphragm position). Clinical testing was subsequently performed in patients being considered for cath, including 3D NAV QSM comparison to cine-CMR quantified LV function ( n  = 39), and invasive-cath quantified ΔSaO 2 ( n  = 15). QSM was acquired using 3 T scanners; analysis was blinded to comparator tests (cine-CMR, cath). Results 3D NAV QSM generated interpretable QSM in all controls; 2D BH QSM was successful in 6/10. Among controls in whom both pulse sequences were successful, RV/LV susceptibility difference (and ΔSaO 2 ) were not significantly different between 3D NAV QSM and 2D BH QSM (252 ± 39 ppb [17.5 ± 3.1%] vs. 211 ± 29 ppb [14.7 ± 2.0%]; p  = 0.39). Acquisition times were 30% lower with 3D NAV QSM (4.7 ± 0.9 vs. 6.7 ± 0.5 min, p  = 0.002), paralleling a trend towards lower LV mis-registration on 3D NAV QSM ( p  = 0.14). Among cardiac patients (63 ± 10y, 56% CAD) 3D NAV QSM was successful in 87% (34/39) and yielded higher ΔSaO 2 (24.9 ± 6.1%) than in controls ( p  < 0.001). QSM-calculated ΔSaO 2 was higher among patients with LV dysfunction as measured on cine-CMR based on left ventricular ejection fraction (29.4 ± 5.9% vs. 20.9 ± 5.7%, p < 0.001) or stroke volume (27.9 ± 7.5% vs. 22.4 ± 5.5%, p  = 0.013). Cath measurements ( n  = 15) obtained within a mean interval of 4 ± 3 days from CMR demonstrated 3D NAV QSM to yield high correlation (r = 0.87, p < 0.001), small bias (− 0.1%), and good limits of agreement (±8.6%) with invasively measured ΔSaO 2 . Conclusion 3D NAV QSM provides a novel means of assessing cardiac performance. Differential susceptibility between the LV and RV is increased in patients with cine-CMR evidence of LV systolic dysfunction; QSM-quantified ΔSaO 2 yields high correlation and good agreement with the reference of invasively-quantified ΔSaO 2 .

• Publisher: BioMed Central,BioMed Central Ltd,Elsevier
• Subject: Aged / Algorithms / Angiology / Biomarkers - blood / Cardiac Catheterization / Cardiac magnetic resonance / Cardiac patients / Cardiology / Cardiovascular diseases / Case-Control Studies / Catheterization / Comparative analysis / Electrocardiography / Female / Gadoterate meglumine / Heart catheterization / Humans / Imaging / Imaging, Three-Dimensional / Liu, Timothy / Magnetic Resonance Imaging, Cine / Male / Medicine / Medicine & Public Health / Middle Aged / Novels / Oxygen - blood / Oxygenation / Oxyhemoglobin / Predictive Value of Tests / Quantitative susceptibility mapping / Radiology / Reproducibility of Results / Systole / Ventricular Dysfunction, Left - blood / Ventricular Dysfunction, Left - diagnostic imaging / Ventricular Dysfunction, Left - physiopathology / Ventricular Function, Left / Ventricular Function, Right