Diagnostic efficacy of 2-shot compressed sensing cine sequence cardiovascular magnetic resonance imaging for left ventricular function

Abstract

Background: Cardiac magnetic resonance cine images are conventionally acquired in breath-hold with a segmented balanced steady-state free precession (bSSFP) sequence, which requires a relatively long acquisition time and high patient cooperation. The single-shot compressed sensing (ss CS) cine sequence is a real-time sequence that has reasonable spatial and temporal resolution and can be applied during free breathing. However, the contrast between the myocardium and surrounding soft tissue is relatively reduced, and the epicardial delineation results are not as accurate with the ss CS cine sequence compared with the bSSFP sequence. In this study, we evaluated the use of a 2-shot CS cine technique in quickly acquiring high-quality images and accurately assessing cardiac function in clinical practice.

Methods: The patients enrolled in the study underwent cardiovascular magnetic resonance (CMR) on a 3T scanner from Jul. to Dec. 2018. Cine imaging was performed with 3 different methods: a standard segment cine sequence, a real-time ss CS cine sequence, and a 2-shot CS cine sequence prototype. Quantitative analysis of image quality was performed using a 0-4 scoring system, and also edge sharpness was measured, and cardiac function analysis was performed for all 3 types of cine images.

Results: Thirty-eight patients underwent imaging with the three types of cine sequences. The average scan time of the standard cine sequence was 101±20 s, the average scan time of the ss CS cine sequence was 20±4 s, and the average scan time of the 2-shot CS cine sequence was 30±6 s. The standard cine sequence image score was 3.68±0.64 and edge sharpness was (2.47±0.18) mm, the ss CS cine sequence image score was 3.13±0.35 and edge sharpness was (4.69±0.02) mm, and the 2-shot cine sequence image score was 3.54±0.51 and the edge sharpness was (2.51±0.13) mm. In terms of the quantitative study of cardiac function, the differences between the standard cine sequence and the ss CS cine sequence were not statistically significant, except for those of the imaging score and LV mass. There were no significant differences in the cardiac function parameters between the standard cine sequence and the 2-shot cine sequence. There was a strong correlation between the standard cine and ss CS cine sequences and between the standard cine and 2-shot CS cine sequences (P<0.01) of all the cardiac function parameters.

Conclusions: The 2-shot CS cine sequence can acquire images with a level of quality comparable to that of the standard cine sequence in a significantly shorter period of time. The functional parameters are similar between the 2-shot CS cine sequence and the standard cine sequence.

Keywords: Compressed sensing (CS); cardiovascular magnetic resonance (CMR) imaging; cine.

Figure 1

Images of each cardiac magnetic resonance cine sequence of a dilated cardiomyopathy patient with regular rhythm. A 27-year-old male with dilated cardiomyopathy, with the average heart rate 58 beats per minute. Compared with the single-shot CS cine images, the 2-shot CS cine images have a sharper delineation in the myocardial margin, have better contrast in the myocardium blood pool, have fewer artifacts, and are more similar to the standard cine images. A1–A6: standard cine; B1–B6: single-shot compressed sensing cine; C1–C6: 2-shot compressed sensing cine. A1, B1, C1: 4-chamber long-axis view; A2, B2, C2: 3-chamber long-axis view; A3, B3, C3: 2-chamber long-axis view; A4, B4, C4: basal segment of the short-axis view; A5, B5, C5: middle segment of the short-axis view; A6, B6, C6: apex segment of the short-axis view.

Figure 2

Images of each cardiac magnetic resonance cine sequence of an atrial fibrillation patient. A 67-year-old male with atrial fibrillation at systolic phase, with the average heart rate 67 beats per minute. All images have some of the artifacts especially of the standard cine images. The 2-shot CS cine images have a sharper myocardial margin and better contrast, especially of the short-axis view images. A1–A6: standard cine; B1–B6: single-shot compressed sensing cine; C1–C6: 2-shot compressed sensing cine. A1, B1, C1: 4-chamber long-axis view; A2, B2, C2: 3-chamber long-axis view; A3, B3, C3: 2-chamber long-axis view; A4, B4, C4: basal segment of the short-axis view; A5, B5, C5: middle segment of the short-axis view; A6, B6, C6: apex segment of the short-axis view.

Figure 3

Bland-Altman plot of the results for each cardiac magnetic resonance cine sequence. Bland-Altman plot for the comparison of the cardiac function measurements between the standard cine and single-shot CS cine sequences (A,C,E,G,I) and between the standard cine and 2-shot CS cine sequences (B,D,F,H,J). The solid line indicates the difference between the two sequences; the lines with long dashes indicate the 95% limit agreement interval.