[Feasibility of Single-Breath-Hold Compressed Sensing Real-Time Cine Imaging for Assessment of Ventricular Function and Left Ventricular Strain in Cardiac Magnetic Resonance].

Objective: To explore the feasibility of single-breath-hold compressed sensing real-time cine imaging (CS-cine) in the assessment of ventricular function and left ventricular (LV) strain. Methods: A total of 70 subjects were enrolled prospectively, and all subjects underwent cardiac magnetic resonance imaging (cardiac MRI) using both the standard steady-state free procession cine (sta-cine) acquisition and a prototype CS-cine sequence. For both CS-cine and sta-cine imaging, continuous short-axis cine images were acquired from the base to the apex to cover the entire left ventricle, and long-axis cine images including two-, three-, and four-chamber views were also acquired. The scanning range, number of slices, slice thickness and intervals were kept identical for the two cine images of the same participant. Subjective evaluation of the image quality was performed on all cine images. For both sequences, the conventional function parameters of the left and the right ventricles and LV strain values were assessed with post-processing software analysis. The cine image quality, conventional ventricular function parameters, and LV strain values were compared between the two cine groups and the differences were examined. Inter- and intraobserver agreements for CS-cine images were measured using intraclass correlation coefficient ( ICC). Bland-Altman analysis was performed to assess reproducibility between the two cine methods. Results: The median scanning time of CS-cine was 21 s versus 272 s for sta-cine ( P<0.001). The median image quality scores of two groups were significantly different, 4 points for sta-cine and 2 points for CS-cine ( P<0.001). Bi-ventricular end-diastolic volumes (EDV), stroke volume (SV) and ejection fraction (EF) were significantly smaller in CS-cine ( P<0.001). Nevertheless, no significant differences between the two groups in bi-ventricular ESV or LV mass were observed ( P>0.05). LV strain parameters, including the peak radial strain, peak circumferential strain and peak longitudinal strain derived from LV mid-ventricular slice, were significantly different in the two sequences ( P<0.001). Moreover, CS-cine-derived functional parameters and strain measurements have a good correlation with those of sta-cine (for RV function parameters, and left ventricular PLS, PCS values, more than 95% points fell within the limits of agreement [ LoA]; meanwhile, more than 91% points fell within the LoA for other parameters) and inter- and intraobserver agreements were strong ( ICC=0.88 to 0.99) for CS-cine. Conclusion: CS-cine can well realize the rapid acquisition of cine images for quantitative analysis of cardiac function, and the conventional ventricular function parameters and LV globalized strain values obtained from CS-cine imaging have good reproducibility.

Can multiphase dynamic CT angiography provide a better assessment of aortic dissection compared with the standard triphasic protocol?

Background Acute aortic dissection (AD) is a life-threatening medical emergency. It has been debated whether the multiphase dynamic computed tomography angiography (CTA) protocol is superior to the standard triphasic protocol for revealing the characteristics of AD. Purpose To examine two multiphase dynamic protocols, Dynamic four-dimensional (4D) CTA using the shuttle mode and Flash 4D CTA using the high-pitch mode for the assessment of AD and to compare them with the standard triphasic protocol. Material and Methods A total of 54 consecutive patients were randomly and equally assigned to three groups and scanned with a second-generation DSCT scanner. Groups A, B, and C were assessed with the Dynamic 4D CTA in the shuttle mode, the Flash 4D CTA in the high-pitch mode, and the standard triphasic acquisition protocol, respectively. Image quality of all patients was evaluated. The effective radiation dose (ED) was recorded. Results In 54 patients, CTA images could display the true and false lumens, the intimal flap, the entry tear, and branch vessel involvement in the AD. Compared with group C, additional diagnostic information was obtained in groups A and B, including the dynamic enhancement delay between the true and false lumens (A = 18, B = 18); the presence of membrane oscillation (A = 8, B = 14); dynamic ejection of the contrast material from the true lumen into the false lumen (A = 6, B = 7); and the dynamic obstruction of the left renal artery (B = 2). The ED in these three groups was significantly different ( P < 0.05). Conclusion Compared to the standard triphasic protocol, the multiphase dynamic CTA protocol is feasible and is able to reveal additional diagnostic information. Therefore, we recommend using the high-pitch, dual-source multiphase dynamic CTA to assess ADs.