High temporal resolution SSFP cine MRI for estimation of left ventricular diastolic parameters

Abstract

Purpose: To obtain high temporal resolution (HTR) magnetic resonance (MR) steady-state free-precession (SSFP) cine cardiac images by using multichannel radiofrequency (RF) hardware and parallel imaging techniques; to study the effect of temporal resolution; and to compare the derived left ventricular (LV) diastolic filling parameters with echocardiographic results. Materials and Methods: HTR images were acquired in 13 healthy volunteers using a 1.5 T scanner with 32 RF channels and sensitivity encoding (SENSE) and k-t broaduse linear-acquisition speedup technique (k-t BLAST) imaging techniques. LV diastolic parameters were calculated and compared to conventional echocardiographic indices such as the isovolumic relaxation time (IVRT) and E/A ratio. The need for HTR was assessed and the MR results were compared with echocardiographic results. Results: The HTR (≈6-ms) images yielded higher peak filling rates, peak ejection rates, and peak atrial filling rates. A progressive decline in filling and ejection rates was observed with worsening temporal resolution. The IVRTs and E/A ratios measured with MR versus echocardiography were in broad agreement. Also, SENSE and k-t BLAST yielded similar diastolic functional parameters. Conclusion: With SENSE or k-t BLAST and modern hardware, HTR cine images can be obtained. The lower temporal resolutions (30-50 ms) used in clinical practice reduce LV filling rates by ≤30% and may hinder characterization of transient phenomena such as the IVRT. © 2010 Wiley-Liss, Inc.