Assessment of the precision and reproducibility of ventricular volume, function, and mass measurements with ferumoxytol‐enhanced 4D flow MRI

Abstract

Purpose To compare the precision and inter-observer agreement of ventricular volume, function and mass quantification by three-dimensional time-resolved (4D) flow MRI relative to cine steady state free precession (SSFP). Materials and Methods With research board approval, informed consent, and HIPAA compliance, 22 consecutive patients with congenital heart disease (CHD) (10 males, 6.4±4.8 years) referred for 3T ferumoxytol-enhanced cardiac MRI were prospectively recruited. Complete ventricular coverage with standard 2D short-axis cine SSFP and whole chest coverage with axial 4D flow were obtained. Two blinded radiologists independently segmented images for left ventricular (LV) and right ventricular (RV) myocardium at end systole (ES) and end diastole (ED). Statistical analysis included linear regression, ANOVA, Bland-Altman (BA) analysis, and intra-class correlation (ICC). Results Significant positive correlations were found between 4D flow and SSFP for ventricular volumes (r = 0.808–0.972, p<0.001), ejection fraction (EF) (r = 0.900–928, p<0.001), and mass (r = 0.884–0.934, p<0.001). BA relative limits of agreement for both ventricles were between −52% to 34% for volumes, −29% to 27% for EF, and −41% to 48% for mass, with wider limits of agreement for the RV compared to the LV. There was no significant difference between techniques with respect to mean square difference of ED-ES mass for either LV (F=2.05, p=0.159) or RV (F=0.625, p=0.434). Inter-observer agreement was moderate to good with both 4D flow (ICC 0.523–0.993) and SSFP (ICC 0.619–0.982), with overlapping confidence intervals. Conclusion Quantification of ventricular volume, function and mass can be accomplished with 4D flow MRI with precision and inter-observer agreement comparable to that of cine SSFP.

Free‐breathing pediatric chest MRI: Performance of self‐navigated golden‐angle ordered conical ultrashort echo time acquisition

“…This ultrasmall superparamagnetic iron oxide medication was developed to treat anemia but has shown promise as a contrast agent, although is not approved by the US Food and Drug Administration for such use. Ferumoxytol had been administered per established, albeit off‐label, institutional protocol in patients undergoing 4D flow for cardiovascular indications and is not required for our conical UTE acquisition . However, we suspect it may further enhance the signal‐to‐noise ratio (SNR) and overall image quality.…”

“…All scans were enhanced with ferumoxytol (Feraheme, AMAG Pharmaceuticals, Waltham, MA), injected intravenously before imaging as a slow infusion over 5–15 minutes using a diluted volume in normal saline (3 mg/kg with 1:5 dilution or 0.1 mL/kg) . Vital signs were monitored for 30 minutes after ferumoxytol administration in the radiology department or an inpatient unit under the supervision of an advanced cardiac life support (ACLS) or pediatric advanced life support (PALS)‐certified physician.…”

Current and potential imaging applications of ferumoxytol for magnetic resonance imaging

“…On the other hand, ferumoxytol supports the acquisition of 4-dimensional images of the beating heart with Four-Dimensional, Multiphase, Steady-State Imaging with Contrast Enhancement (MUSIC) (Figure 16) (99). Similarly, comprehensive motion-compensated highly accelerated 4D flow MRI with ferumoxytol enhances the quality of 4-dimensional flow information with reduced respiratory motion artifacts in children with congenital heart disease (100, 101). …”

“…Further, a free-breathing volumetric comprehensive MRI yielding flow, function, and anatomic assessment in less than 10 min has been achieved (100). Additionally, ventricular mass may be quantified with this same technique (101). As a result, no special operator knowledge of cardiac anatomy is required, and the duration of anesthesia and complexity of the procedure for congenital heart MRI can be greatly reduced.…”

Right heart imaging in patients with heart failure

“…4D flow MRI allows the evaluation of blood flow including valvular regurgitation (Figure 4, left panel), quantification of biventricular volumes, function and mass, and visualization of intracardiac and extracardiac structures (70,71). A recent study demonstrated that RV volume, function, and mass can be quantified with 4D flow MRI with precision and inter-observer agreement comparable to that of cine Steady-State Free Precession (SSFP) (72). Whole heart 4D flow MRI also enables detection and visualization of both normal and abnormal right heart flow patterns (73).…”