Black-blood imaging of the human heart using rapid stimulated echo acquisition mode (STEAM) MRI

Abstract

Purpose: To develop a rapid stimulated echo acquisition mode (STEAM) MRI technique for "black-blood" imaging of the human heart that overcomes the single-slice limitation and partially compromised blood suppression associated with double inversion-recovery techniques.

Materials and methods: Black-blood multislice images of the heart along anatomic orientations and triggered to end diastole were obtained from healthy human subjects at 3T using rapid STEAM MRI sequences with five-eighths partial Fourier encoding and variable flip angles. Single-shot STEAM images at 2.5 x 2.5 mm2 in-plane resolution and 6-mm section thickness were recorded in 230 msec from individual heartbeats. Improved signal-to-noise ratio (SNR) and higher spatial resolution of 2.0 x 2.0 mm2 and 1.5 x 1.5 mm2 were achieved by segmented multishot STEAM MRI with interleaved k-space acquisitions (160 msec each) from several heartbeats. In a single breathhold covering 18 heartbeats selected applications employed either three segments with six sections or six segments with three sections.

Results: Because stimulated echoes (STEs) dephase signals from moving spins, rapid STEAM images are free from blood signal contamination. The method offers a flexible tradeoff between spatial resolution, imaging speed (i.e., number of segments), and volume coverage (i.e., number of sections).

Conclusion: Rapid STEAM MRI of the heart emerges as a simple technique for multislice imaging of the myocardial wall with efficient flow suppression.