Superior Cardiac MRI using Wideband SSFP at 3 Tesla

描述（由申请人提供）：心脏磁共振成像（MRI）显示出巨大的潜力，但需要在对比度，空间分辨率和速度方面进行实质性改进。最近两项特别令人感兴趣的进展是平衡稳态自由进动（SSFP）成像序列的发展（相当于称为True-FISP， FIESTA或balanced - ffe），以及3台Telsa临床扫描仪的发展和可用性。两者都能显著改善信噪比和对比度，但3T和SSFP在快速高分辨率心脏成像中相对不兼容。传统的SSFP受到条带伪影的严重限制，这些伪影要求在3T时在心脏中使用3ms或更少的重复时间。这限制了可实现的空间分辨率，并阻止使用时间高效的采集方案来减少扫描时间。本提案的目的是开发和验证一种新的成像技术，我们称之为宽带SSFP，它使用交替重复次数来实现稳定状态，提供高达传统SSFP带宽的两倍，具有相当的信噪比和对比度。这种带宽的改进允许使用更长的成像TRs，它将支持4毫秒数量级的读出，以实现高空间分辨率（增加读出梯度面积）和高时间分辨率（使用时间高效的采集方案）。本提案的目标是充分表征和发展宽带SSFP，并将其应用于3特斯拉的快速高分辨率心脏MRI。利用3T平台和SSFP序列的信噪比改进来实现更高的空间和时间分辨率，直接解决了目前临床心脏MRI的局限性。

DESCRIPTION (provided by applicant): Cardiac magnetic resonance imaging (MRI) shows great potential but requires substantial improvements in contrast, spatial resolution, and speed. Two recent advances of particular interest are the development of balanced steady state free precession (SSFP) imaging sequences (equivalently known as True-FISP, FIESTA, or Balanced-FFE), and the development and availability of 3 Telsa clinical scanners. Both provide substantial improvements in SNR and contrast but together, 3T and SSFP are relatively incompatible for rapid high-resolution cardiac imaging. Conventional SSFP is critically limited by banding artifacts that require the use of repetition times of 3 ms or less in the heart at 3T. This limits the achievable spatial resolution, and prevents the use of time-efficient acquisition schemes to reduce scan time. The aim of this proposal is to develop and validate a new imaging technique, which we call Wideband SSFP, that uses alternating repetition times to achieve a steady-state that provides up to double the bandwidth of conventional SSFP, with comparable SNR and contrast. This bandwidth improvement allows the use of longer imaging TRs which will supporting readouts on the order of 4 ms, to enable high spatial resolution (increased readout gradient area) and high temporal resolution (using time-efficient acquisition schemes). The goal of this proposal is to fully characterize and develop Wideband SSFP and apply it to rapid high- resolution cardiac MRI at 3 Tesla. Utilizing SNR improvements from the 3T platform and from SSFP sequences to achieve higher spatial and temporal resolution directly addresses the current limitations of clinical cardiac MRI.