Free-breathing variable flip angle balanced SSFP cardiac cine imaging with reduced SAR at 3T

Comparison between pre- and post-contrast cardiac MRI cine images: the impact on ventricular volume and strain measurement

To explore whether contrast agent administration will affect ventricular volume and strain parameters measured on cardiac magnetic resonance cine images. This prospective study enrolled 88 patients, including 32 patients with cardiac amyloidosis (CA), 32 patients with hypertrophic cardiomyopathy (HCM), and 24 control participants, to perform steady-state free precession (SSFP)-cine imaging twice, respectively before and after contrast agent injection. Indexed left and right ventricular (LV and RV) volume and LV strain parameters (peak radial strain [PRS], peak circumferential strain [PCS], peak longitudinal strain [PLS]) were analyzed and compared between the pre- and post-contrast cine groups. Compared to the group of pre-contrast cine, the end-diastolic volume index (EDVi) and end-systolic volume index (ESVi) significantly increased in the group using post-contrast cine images (all p < 0.05), especially in the right ventricle. After contrast injection, the right ventricular ejection fraction (RVEF) decreased significantly (p < 0.05), while the left ventricular ejection fraction (LVEF) only reduced for patients with HCM (p < 0.05). The PRS (37.1 ± 15.2 vs. 32.0 ± 15.4, p < 0.001) and PCS (- 14.9 ± 4.3 vs. - 14.0 ± 4.1, p < 0.001) derived from post-contrast cine images reduced significantly in all patients and this tendency remained in subgroup analysis except for PCS in the control group. The administration of a contrast agent may influence the measurements of ventricular volume and strain. Acquiring pre-contrast cine images were suggested for patients who required more accurate right ventricle evaluation or precise strain assessment.

Highly Accelerated Breath-Hold Noncontrast Electrocardiographically- and Pulse-Gated Balanced Steady-State Free Precession Magnetic Resonance Angiography of the Thoracic Aorta: Comparison With Electrocardiographically-Gated Computed Tomographic Angiography

OBJECTIVE

The aim of this study was to evaluate agreement of measured thoracic aortic caliber in patients with aortic disease, using electrocardiographically-(ECG) and pulse-gated breath-hold noncontrast balanced steady-state free precession MRA (ECG-MRA, P-MRA) at 1.5 T, compared with ECG-gated computed tomographic angiography (CTA).

METHODS

Thirty-one patients underwent ECG-MRA, P-MRA, and CTA. Two readers independently measured aortic caliber in 7 segments, with agreement between techniques and readers evaluated. Image quality was qualitatively assessed.

RESULTS

There was overall excellent agreement among ECG-MRA, P-MRA, and CTA for measured aortic caliber (Lin's concordance correlation coefficient ≥0.94, all comparisons); however, lower concordance was noted at the annulus (Lin's concordance correlation coefficient <0.6) at segmental assessment. There was excellent interreader agreement for aortic caliber for all 3 techniques (intraclass correlation coefficient >0.94). Image quality was poorer for both MRA techniques compared with CTA, particularly at the aortic root.

CONCLUSIONS

Electrocardiographically-gated MRA and P-MRA at 1.5 T achieve comparable thoracic aortic measurements to gated CTA in clinical patients, despite inferior image quality.