Compressed sensing real-time cine cardiovascular magnetic resonance: accurate assessment of left ventricular function in a single-breath-hold

Abstract

BackgroundCardiovascular cine magnetic resonance (CMR) accelerated by compressed sensing (CS) is used to assess left ventricular (LV) function. However, it is difficult for prospective CS cine CMR to capture the complete end-diastolic phase, which can lead to underestimation of the end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), compared to retrospective standard cine CMR. This prospective study aimed to evaluate the diagnostic quality and accuracy of single-breath-hold full cardiac cycle CS cine CMR, acquired over two heart beats, to quantify LV volume in comparison to multi-breath-hold standard cine CMR.MethodsEighty-one participants underwent standard segmented breath-hold cine and CS real-time cine CMR examinations to obtain a stack of eight contiguous short-axis images with same high spatial (1.7 × 1.7 mm2) and temporal resolution (41 ms). Two radiologists independently performed qualitative analysis of image quality (score, 1 [i.e., “nondiagnostic”] to 5 [i.e., “excellent”]) and quantitative analysis of the LV volume measurements.ResultsThe total examination time was 113 ± 7 s for standard cine CMR and 24 ± 4 s for CS cine CMR (p < 0.0001). The CS cine image quality was slightly lower than standard cine (4.8 ± 0.5 for standard vs. 4.4 ± 0.5 for CS; p < 0.0001). However, all image quality scores for CS cine were above 4 (i.e., good). No significant differences existed between standard and CS cine MR for all quantitative LV measurements. The mean differences with 95 % confidence interval (CI), based on Bland–Altman analysis, were 1.3 mL (95 % CI, −14.6 – 17.2) for LV end-diastolic volume, 0.2 mL (95 % CI, −9.8 to10.3) for LV end-systolic volume, 1.1 mL (95 % CI, −10.5 to 12.7) for LV stroke volume, 1.0 g (95 % CI, −11.2 to 13.3) for LV mass, and 0.4 % (95 % CI, −4.8 – 5.6) for LV ejection fraction. The interobserver and intraobserver variability for CS cine MR ranged from −4.8 – 1.6 % and from −7.3 – 9.3 %, respectively, with slopes of the regressions ranging 0.88–1.0 and 0.86–1.03, respectively.ConclusionsSingle-breath-hold full cardiac cycle CS real-time cine CMR could evaluate LV volume with excellent accuracy. It may replace multi-breath-hold standard cine CMR.

Assessment of Left Ventricular Function and Mass on Free-Breathing Compressed Sensing Real-Time Cine Imaging

“…10 Given, however, that many patients who undergo CMR have dyspnea or shortness of breath, image acquisition over 2 heart beats increases the required BH time as well as patient burden. FB MRI could be an alternative approach in patients who cannot hold their breath adequately.…”

“…7-10 Prospective ECG-triggered CS cine MRI, however, might be unable to capture the first and last phases of the cardiac cycle, because the acquisition window is set to a fixed length at the beginning of the scan. [8][9][10] This often leads to underestimation of end-dia-a prototype sequence with sparse incoherent sampling of k-space and non-linear iterative SENSE-type image reconstruction. Details regarding data acquisition and reconstruction of CS real-time cine MRI have been given in a previous report.…”

“…Details regarding data acquisition and reconstruction of CS real-time cine MRI have been given in a previous report. 10 In the present study, temporal and spatial resolution as well as slice orientation were kept identical between the 2 cine MRI protocols. Imaging parameters are summarized in Table 2.…”

“…Epicardial and endocardial contours rendered by automated analysis were reviewed and manually corrected, if necessary. 10 Papillary muscles and trabeculations of the LV were included in the LV chamber volume. 13,14…”

“…10 To overcome this limitation, imaging data have been acquired over 2 heart beats, thus capturing the complete end-diastole between the first and second heart beats. 10 Given that CS cine MRI has the advantage of being inherently insensitive to respiratory motion because of single-shot acquisition, 11,12 it is suitable for free-breathing (FB) imaging. The purpose of this study was therefore to compare the accuracy of FB full cardiac cycle CS and BH standard cine MRI at 3.0 T for LV volume assessment in patients with cardiac conditions.…”