Validation of left ventricular volume and ejection fraction measurements by high‐definition blood flow imaging: Comparisons with cardiac magnetic resonance imaging and contrast echocardiography

BACKGROUND: We recently reported the efficacy of High-definition blood flow imaging (HDI) in the assessment of left ventricular (LV) function and demonstrated that the results are comparable to those obtained by contrast echocardiography (CE). The present study validates HDI in measurements of LV volumes and ejection fraction (EF) by simultaneous comparisons with CE and cardiac magnetic resonance imaging (CMR). METHODS: Eighteen patients (age range 25-79 years) with limited echocardiographic images had measurements of LV end-diastolic volume (EDV, mL), end-systolic volume (ESV, mL), and EF (%) by HDI, CE, and CMR. RESULTS: Using the three techniques, measurements of EDV, ESV, and EF correlated well with correlation coefficients (r) ranging from .91 to .98 in comparisons between HDI and CMR, and .89 to .97 in comparisons between CE and CMR. The limits of agreement for the inter-methods comparisons by Bland-Altman analysis (mean ± 1.96 SD) between HDI and CMR were 4.92 ± 16.87% for EF, 21.53 ± 32.18 mL for EDV, and 10.69 ± 36.12 mL for ESV, between CE and CMR, the agreement limits were 2.48 ± 18.52% (LVEF), 24.58 ± 47.41 mL (EDV), and 14.09 ± 43.55 mL (ESV). CONCLUSIONS: Measurements of LV volumes and EF by HDI and CE correlated well with CMR. Using CMR as the gold standard, the agreements in measurements of LV volumes were superior for HDI compared to CE. In measurements of EF, CE showed less mean difference when compared to HDI. HDI measurements compared well with those obtained by CMR.