Assessment of myocardial function with interactive non-breath-hold real-time MR imaging: comparison with echocardiography and breath-hold Cine MR imaging.

Abstract

To compare a spiral gradient-echo sequence with a radial steady-state free precession sequence and to compare these two interactive real-time cardiac magnetic resonance (MR) imaging examinations with harmonic two-dimensional echocardiography (ECHO) for the evaluation of regional myocardial function. Electrocardiographically triggered breath-hold steady-state free precession (BH-SSFP) MR imaging was the reference standard. Thirty-five nonselected patients scheduled for routine ECHO were included. Data from corresponding two-, three-, and four-chamber long-axis views and a midventricular short-axis view were acquired with each modality. Image quality and depiction of segmental wall motion were scored semiquantitatively by using the 16-segment model of the American Society of Echocardiography. Repeated-measures analysis of variance was performed to assess differences in image quality and wall motion depiction scores among the four imaging methods. Agreement was assessed by using Cohen kappa statistics. Compared with the image quality achieved with BH-SSFP MR imaging, the image quality achieved with radial MR imaging was similar (nonsignificant difference), but that achieved with spiral MR imaging and ECHO was significantly inferior (P <.0001). There were no significant differences in the image quality of the long- and short-axis views between the radial and BH-SSFP sequences, while the image quality of the long-axis spiral (P <.05) and the short- and long-axis ECHO (P <.0001) views was lower than that of the BH-SSFP views. Compared with the mean wall motion score for BH-SSFP MR imaging, the mean wall motion score for radial MR imaging was not significantly different, but those for ECHO (P <.05) and spiral MR imaging (P =.0003) were significantly lower. Cohen kappa coefficients for agreement with the BH-SSFP sequence regarding wall motion scoring were 0.47 for ECHO, 0.67 for the spiral sequence, and 0.89 for the radial sequence. The radial sequence enables similar accurate assessment of regional wall motion compared with the BH-SSFP sequence and yields image quality that is superior to that yielded by the spiral sequence and ECHO.