Cardiac late gadolinium-enhancement (LGE) MR is an important clinical tool for evaluating myocardial infarction and infiltrative cardiomyopathies. Traditionally, LGE-MR is performed 10-20 minutes after administration of gadolinium contrast using a 2D inversion recovery (IR) turbo gradient echo sequence with appropriate inversion time to null normal myocardium and highlight scar. Unfortunately, blood pool also appears bright on LGE, particularly when using phase sensitive IR (PSIR) techniques where TR is doubled. This can decrease scar conspicuity, particularly for subendocardial lesions bordering the blood pool. A novel black-blood pre-pulse was developed to provide black-blood LGE myocardial imaging that preserves myocardial image quality while improving depiction of subendocardial scar.First-moment-nulled motion-sensitized driven equilibrium (m2MSDE, Figure 1) was implemented as a black-blood prepulse (~20 ms duration) to the standard IR 3D or 2D gradient-echo LGE (non-PSIR) imaging sequence on a 3T whole body scanner (Ingenia, Philips, Best, the Netherlands). The pre-pulse utilized a motion-sensitized gradient scheme to null the first gradient moment, thus reducing sensitivity to bulk motion and improving myocardial image quality compared to standard MSDE. In addition, the direction of the m2MSDE gradients were specified in order to minimize the impact on myocardial image quality. For example, when imaging a short axis slice, the majority of myocardial motion is in-plane, so the m2MSDE gradients were applied through-plane. This leaves bulk motion unaffected, while intraventricular blood is nulled by intravoxel dephasing during the m2MSDE prepulse.¹ To maximize pre-pulse effectiveness, the readout was performed with a low-high acquisition order and minimal (usually 2) startup echoes. The amplitude and duration of the m2MSDE gradients and the cardiac trigger delay were varied to balance the effects of blood suppression and myocardial image quality degradation. With IRB approval, m2MSDE LGE has been applied to 2 volunteers (without Gd) and 8 patients undergoing conventional LGE.Using an IR-TFE sequence without contrast agent, good blood suppression can be obtained with m2MSDE (Figure 2). The optimal combination of quiescent myocardial motion and high blood flow occurs at the beginning of diastole, so best results were obtained when trigger delay was set (user defined) to early diastole as determined from cine images. m2MSDE blood suppression is more difficult post-contrast, as the short T1_blood leads to rapid recovery of dephased moving spins in the blood pool (Figure 3). For post-Gd suppression, a low-high k-space acquisition was used with shot length limited to approximately 100 ms. Blood is better suppressed in the high-flow base of the ventricle than in the apex where flow is limited – particularly in patients with reduced cardiac function. Figure 4 shows m2MSDE blood suppression in a patient with myocardial scar. In this case, blood was adequately suppressed in the basal portion of the left ventricle, but not suppressed near the apex. Fortuitously, the scar was well depicted as it was located in the basal portion of the LV.Other studies demonstrate MSDE can suppress enhanced flowing blood in the arteries.¹ However, myocardial motion and highly variable blood flow patterns increase the challenge of applying the technique to cardiac imaging. Particularly in ill patients, myocardial motion is not completely eliminated by cardiac triggering to diastole, and degradation of myocardial image quality cannot be tolerated in LGE imaging. m2MSDE was developed to be less sensitive to bulk motion, and early evaluation demonstrates m2MSDE can suppress both non-enhanced and enhanced blood in the heart without compromising myocardial image quality. Achieving significant suppression of Gd-enhanced blood is challenging, and requires low-high k-space acquisition with minimal startup echoes and relatively short shot duration. Suppression is particularly difficult in the apex where blood flow is slower. Efforts to optimize blood suppression in the apex are ongoing.