ABSTRACT
Objective@#To investigate the feasibility of cine three-dimensional (3D) balanced steady-state free precession (b-SSFP) imaging combined with a non-local means (NLM) algorithm for image denoising in evaluating cardiac function in children with repaired tetralogy of Fallot (rTOF). @*Materials and Methods@#Thirty-five patients with rTOF (mean age, 12 years; range, 7–18 years) were enrolled to undergo cardiac cine image acquisition, including two-dimensional (2D) b-SSFP, 3D b-SSFP, and 3D b-SSFP combined with NLM. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) of the two ventricles were measured and indexed by body surface index. Acquisition time and image quality were recorded and compared among the three imaging sequences. @*Results@#3D b-SSFP with denoising vs. 2D b-SSFP had high correlation coefficients for EDV, ESV, SV, and EF of the left (0.959– 0.991; p < 0.001) as well as right (0.755–0.965; p < 0.001) ventricular metrics. The image acquisition time ± standard deviation (SD) was 25.1 ± 2.4 seconds for 3D b-SSFP compared with 277.6 ± 0.7 seconds for 2D b-SSFP, indicating a significantly shorter time with the 3D than the 2D sequence (p < 0.001). Image quality score was better with 3D b-SSFP combined with denoising than with 3D b-SSFP (mean ± SD, 3.8 ± 0.6 vs. 3.5 ± 0.6; p = 0.005). Signal-to-noise ratios for blood and myocardium as well as contrast between blood and myocardium were higher for 3D b-SSFP combined with denoising than for 3D b-SSFP (p < 0.05 for all but septal myocardium). @*Conclusion@#The 3D b-SSFP sequence can significantly reduce acquisition time compared to the 2D b-SSFP sequence for cine imaging in the evaluation of ventricular function in children with rTOF, and its quality can be further improved by combining it with an NLM denoising method.
ABSTRACT
Objective@#To investigate the feasibility of cine three-dimensional (3D) balanced steady-state free precession (b-SSFP) imaging combined with a non-local means (NLM) algorithm for image denoising in evaluating cardiac function in children with repaired tetralogy of Fallot (rTOF). @*Materials and Methods@#Thirty-five patients with rTOF (mean age, 12 years; range, 7–18 years) were enrolled to undergo cardiac cine image acquisition, including two-dimensional (2D) b-SSFP, 3D b-SSFP, and 3D b-SSFP combined with NLM. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) of the two ventricles were measured and indexed by body surface index. Acquisition time and image quality were recorded and compared among the three imaging sequences. @*Results@#3D b-SSFP with denoising vs. 2D b-SSFP had high correlation coefficients for EDV, ESV, SV, and EF of the left (0.959– 0.991; p < 0.001) as well as right (0.755–0.965; p < 0.001) ventricular metrics. The image acquisition time ± standard deviation (SD) was 25.1 ± 2.4 seconds for 3D b-SSFP compared with 277.6 ± 0.7 seconds for 2D b-SSFP, indicating a significantly shorter time with the 3D than the 2D sequence (p < 0.001). Image quality score was better with 3D b-SSFP combined with denoising than with 3D b-SSFP (mean ± SD, 3.8 ± 0.6 vs. 3.5 ± 0.6; p = 0.005). Signal-to-noise ratios for blood and myocardium as well as contrast between blood and myocardium were higher for 3D b-SSFP combined with denoising than for 3D b-SSFP (p < 0.05 for all but septal myocardium). @*Conclusion@#The 3D b-SSFP sequence can significantly reduce acquisition time compared to the 2D b-SSFP sequence for cine imaging in the evaluation of ventricular function in children with rTOF, and its quality can be further improved by combining it with an NLM denoising method.
ABSTRACT
Objective:To evaluate the feasibility of cardiac MRI three dimensional (3D) balanced steady state free precession (b-SSFP) cine imaging in evaluating cardiac function in children with repaired tetralogy of Fallot (TOF).Methods:Thirty children with repaired TOF underwent cardiac MRI examination at Shanghai Children′s Medical Cent er Affiliated to Shanghai Jiao Tong University School of Medicine, were retrospectively collected from April 2018 to October 2019. From June 2017 to August 2018, 10 healthy children were enrolled. Cardiac images of subjects were obtained using both two dimensional (2D) b-SSFP and 3D b-SSFP cardiac cine MRI and the total acquisition time was recorded. The image quality was scored using a 5-point scale, with a score≥3 as diagnostic image quality. The left and right ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), and cardiac index (CI) were measured. The left and right ventricle parameters were compared using paired ttest or Wilcoxon test. The Pearson correlation or Spearman correlation analysis were used to evluate the correlation between the parameters measured with the 2 methods. Results:The acquisition time of 2D b-SSFP images was (426.5±13.0) s, and the total time of 3D b-SSFP images was (24.7±2.5) s. The 2D b-SSFP image quality score was better than 3D b-SSFP, and the differences were statistically significant (TOF patients: Z=-3.879, P<0.001; volunteers: Z=-2.646, P=0.003). All 2D and 3D b-SSFP image quality scores were ≥ 3 points, which can be used for clinical diagnosis. There were no statistically significant differences in cardiac function parameters between two series measurements in both TOF patients and volunteers ( P>0.05). For TOF patients, the left ventricular EDV, ESV, SV, EF, CO and right ventricular EDV, ESV, and SV showed highly positive correlation ( r>0.8, P<0.05). For volunteers, the left ventricular EDV, ESV, SV and right ventricular EDV and SV showed highly positive correlation ( r>0.8, P<0.05). Conclusion:Compared with the 2D b-SSFP sequence, 3D b-SSFP sequence with fairy good image quality can meet the diagnostic requirement and can accurately measure the cardiac function with shorter acquisition time. The 3D b-SSFP has a good application prospect in pediatric cardiac MRI.