60-S Retrogated Compressed Sensing 2D Cine of the Heart: Sharper Borders and Accurate Quantification

Figures

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  Figure 1. Edge sharpness measurement. An orthogonal profile line is drawn across the border between the interventricular myocardium and the left ventricular blood pool (blue line) on a 4-chamber view at end-diastole provided by (a) the reference segmented SSFP sequence, (b) the real-time compressed sensing sequence and (c) the retrogated compressed sensing prototype, providing intensity profiles (blue curves) along the line for (d) reference, (e) real-time and (f) prototype sequences. The edge sharpness was calculated as the inverse of the distance d (in pixels) from the positions corresponding to 20% and 80% (red stars) of the difference between the maximum and minimum signal intensities (black crosses) along the profile line and was expressed in pixel−1. Abbreviations: SSFPref, reference steady-state free precession; CSrt, real-time compressed sensing; CSrg, retrogated compressed sensing; ε, edge sharpness; Ymax, maximum signal intensity; Ymin, minimum signal intensity; d, distance along the intensity (pixels).

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  Figure 2. Midventricular short-axis cine slice acquired with the three cine sequences in a 37-year-old patient referred for myocarditis suspicion. (a) Reference steady-state free precession cine: Likert scale = 4/4; EuroCMR score = 0/10; ε = 0.082 pixel−1; LVEF = 59%, LVEDV = 135 mL, LVM = 83 g, RVEF = 63%, RVEDV = 159 mL; (b) Real-time compressed sensing cine: Likert scale = 4/3; EuroCMR score = 0/10; ε = 0.056 pixel−1; LVEF = 60%, LVEDV = 133 mL, LVM = 81 g, RVEF = 61%, RVEDV = 153 mL; (c) Retrogated compressed sensing cine: Likert scale = 4/4; EuroCMR score = 0/10; ε = 0.081 pixel−1; LVEF = 58%, LVEDV = 133 mL, LVM = 86 g, RVEF = 62%, RVEDV = 164 mL. Abbreviations: ε, edge sharpness; LVEF, left ventricular ejection fraction; LVEDV, left ventricular end-diastolic volume; LVM, left ventricular myocardial mass; RVEF, right ventricular ejection fraction; RVEDV, right ventricular end-diastolic volume.

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  Figure 3. Edge sharpness comparison assessed at end-diastole. (a) There was no significant difference regarding ε between CSrg and SSFPref (p = 0.0516) (b) but CSrg significantly improved ε while compared with CSrt (p = 0.0004). Abbreviations: CSrg, retrogated compressed sensing; CSrt, real-time compressed sensing; SSFPref, reference steady-state free precession; ε, edge sharpness.

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  Figure 4. Bland–Altman plots and linear regression trendlines applied to left ventricular functional parameters quantifications. Left column: Bland–Altman plots for (a) LVEF, (c) LVEDV, (e) LVESV, (g) LVSV and (i) LVM. Solid blue lines are the mean differences between parameters measured with SSFPref and CSrg sequences and dashed red lines are the 95% limits of agreement. Right column: linear regression trend lines for (b) LVEF, (d) LVEDV, (f) LVESV, (h) LVSV and (j) LVM. Abbreviations: SSFPref, reference steady-state free precession; CSrg, retrogated compressed sensing; SD, standard deviation; LVEF, left ventricular ejection fraction; LVEDV, left ventricular end-diastolic volume; LVESV, left ventricular end-systolic volume; LVSV, left ventricular stroke volume; LVM, left ventricular mass.

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  Figure 5. Bland–Altman plots and linear regression trendlines applied to right ventricular functional parameters quantifications. Left column: Bland-Altman plots for (a) RVEF, (c) RVEDV, (e) RVESV, and (g) RVSV. Solid blue lines are the mean differences between parameters measured with SSFPref and CSrg sequences and dashed red lines are the 95% limits of agreement. Right column: linear regression trend lines for (b) RVEF, (d) RVEDV, (f) RVESV, and (h) RVSV. Abbreviations: SSFPref, reference steady-state free precession; CSrg, retrogated compressed sensing; SD, standard deviation; RVEF, right ventricular ejection fraction; RVEDV, right ventricular end-diastolic volume; RVESV, right ventricular end-systolic volume; RVSV, right ventricular stroke volume.