Magnetic Resonance Engineering Laboratory, Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California, USA.
Magn Reson Med. 2010 Jun;63(6):1716-22. doi: 10.1002/mrm.22384.
Cine balanced steady-state free precession (SSFP) is the most widely used sequence for assessing cardiac ventricular function at 1.5 T because it provides high signal-to-noise ratio efficiency and strong contrast between myocardium and blood. At 3 T, the use of SSFP is limited by susceptibility-induced off-resonance, resulting in either banding artifacts or the need to use a short-sequence pulse repetition time that limits the readout duration and hence the achievable spatial resolution. In this work, we apply wideband SSFP, a variant of SSFP that uses two alternating pulse repetition times to establish a steady state with wider band spacing in its frequency response and overcome the key limitations of SSFP. Prospectively gated cine two-dimensional imaging with wideband SSFP is evaluated in healthy volunteers and compared to conventional balanced SSFP, using quantitative metrics and qualitative interpretation by experienced clinicians. We demonstrate that by trading off temporal resolution and signal-to-noise ratio efficiency, wideband SSFP mitigates banding artifacts and enables imaging with approximately 30% higher spatial resolution compared to conventional SSFP with the same effective band spacing.
电影平衡稳态自由进动（SSFP）是在 1.5T 下评估心脏心室功能最常用的序列，因为它提供了高信噪比效率和心肌与血液之间的强对比度。在 3T 下，SSFP 的使用受到感抗引起的离频的限制，导致带纹伪影或需要使用短序列重复时间，从而限制了读取时间，进而限制了可实现的空间分辨率。在这项工作中，我们应用了宽带 SSFP，这是 SSFP 的一种变体，它使用两个交替的重复时间来建立一个具有更宽频带间隔的稳态，从而克服了 SSFP 的关键限制。我们前瞻性地对健康志愿者进行了宽带 SSFP 的电影二维成像评估，并与传统的平衡 SSFP 进行了比较，使用定量指标和经验丰富的临床医生的定性解释。我们证明，通过折衷时间分辨率和信噪比效率，宽带 SSFP 减轻了带纹伪影，并能够以与传统 SSFP 相同的有效带宽间隔相比，提高约 30%的空间分辨率进行成像。
