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（相当于True-FISP、FIESTA或Balanced-FFE）的开发，以及3种Telsa临床扫描仪的开发和可用性。两者都提供了SNR和对比度的实质性改善，但3 T和SSFP在快速高分辨率心脏成像方面相对不兼容。传统SSFP受到带状伪影的严重限制，需要在3 T下在心脏中使用3 ms或更少的重复时间。这限制了可实现的空间分辨率，并且阻止使用时间有效的采集方案来减少扫描时间。该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，该技术使用交替重复时间来实现稳态，提供高达传统SSFP两倍的带宽，具有可比的SNR和对比度。这种带宽改进允许使用更长的成像TR，其将支持大约4 ms的读出，以实现高空间分辨率（增加的读出梯度区域）和高时间分辨率（使用时间有效的采集方案）。该提案的目标是充分表征和开发宽带SSFP，并将其应用于3特斯拉的快速高分辨率心脏MRI。利用3 T平台和SSFP序列的SNR改善来实现更高的空间和时间分辨率，直接解决了临床心脏MRI的当前局限性。

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.