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Background Stimulated-echo acquisition mode (STEAM) is one of the key pulse sequences in CMR imaging, as it alleviates rapid magnetization decay with T2 relaxation. Fat suppression is frequently implemented in cardiac imaging to improve visualization and tissue characterization, albeit at the cost of reduced temporal resolution and signal-to-noise ratio (SNR), as well as possible increase of specific absorption rate (SAR). The purpose of this work is to develop an efficient fat suppression method (Spectrally-Presaturated Modulation (SPM)) for STEAM sequences to enable imaging at high temporal-resolution, with high SNR, and no increase in scan time. Methods The developed method is based on saturating the fat magnetization prior to applying the STEAM modulation; therefore, only the water-content of the tissues is modulated by the sequence, resulting in fat-suppressed images without the need to run the fat suppression module during image acquisition (Figure 1). The potential significance of the proposed method has been tested in two STEAM-based cardiac MRI applications: complementary spatial-modulation of magnetization (CSPAMM) tagging, and black-blood cine imaging. In vivo experiments were conducted to evaluate the developed technique and compare it to the commonly implemented chemical-shift selective (CHESS)

Background The coronary arteries are embedded in epicardial fat. To improve visualization in coronary MR angiography (CMRA) fat suppression techniques such as Spectral Presaturation with Inversion Recovery (SPIR) are often employed. Recently, water-fat separation using the multiecho 2 point Dixon method has gained increasing interest as it allows decomposing the MR signal into a water and fat image during image reconstruction [Eggers, MRM 2011]. While the water image provides a coronary angiogram the fat image may also contain clinically useful information and could be used for epicardial/pericardial fat quantification [Koken, ISMRM, 2011]. The purpose of this study was to compare SPIR and 2 point Dixon for coronary vessel delineation for the first time on a 3T clinical scanner.

Background In myocardial T2-imaging, T2-preparation (T2P) is a common mechanism of creating T2-contrast to reveal pathophysiology. Because T2-contrast is often subtle, bright fat signal can hamper image analysis. Combining T2P with fat suppression (FS) is thus advantageous, but fat saturation is frequently inefficient, and fat inversion by Spectral Attenuated Inversion Recovery (SPAIR) requires high power and constrains sequence timing. We created a T2P module with integrated fat inversion by applying the novel concept of continuous composite RF pulses to create tip-down and flip-back components. We compared this module to two existing modules. Our aim was to develop a shorter T2P compatible FS requiring less power and allowing more flexible timing than SPAIR, but with equivalent suppression efficiency.

Background Fat-saturation and T1-weighting are fundamental for tissue differentiation, but combining these techniques is challenging. For instance, standard chemically selective saturation (CHESS) pulses provide insufficient fatsuppression with routine delayed enhancement imaging [1]. Fat-water separation using multi-echo Dixon techniques can robustly separate fat and water into individual images, but in the fat-suppressed (water only) image, fat may retain a significant amount of signal making identification of the fat-water border difficult. We previously described a new technique (Virtual Chemical Inversion, VCI, [1]) which has the advantage of providing T1-weighted images with and without fat suppression in a single acquisition without the need for additional data acquisition, RF pulses, or increased scan time. In this study, we compare the ability of the CHESS, a multi-echo Dixon technique (VARPRO, [2]), and our new method (VCI) to completely delineate the myocardium-fat interface in patients, and the level of fat suppression in phantoms.

Introduction Myocardial delayed enhancement (MDE) imaging of infarction is commonly performed using an inversion-recovery (IR) two-dimensional (2D) breath-held fast gradient recalled echo (FGRE) pulse sequence. Three-dimensional (3D) imaging can improve scanning efficiency by acquiring the desired volume in a single breath-hold. Fat suppression could greatly improve visualization of epicardial enhancement (which occurs in transmural myocardial infarction and myocarditis) as well as pericardial enhancement.

Methods Thirteen patients with suspected CAD were scanned at 1.5 T (MAGNETOM Sonata, Siemens, Germany) after written informed consent was obtained. WH-CMRA was acquired using a 3D ECG-triggered, navigator-gated, fat-suppressed, T2-prepared steady-state-free-precession sequence. Cross-sectional coronary wall imaging (thinkness = 5 mm) was performed using a 2D-black-blood, navigator and ECG-gated, Turbo-Spin-Echo sequence with asymmetric-adiabatic-spectral inversion-recovery fat suppression [3]. Continous slices without gap for wall imaging were positioned from pre to post of the suspected from 13th Annual SCMR Scientific Sessions Phoenix, AZ, USA. 21-24 January 2010

Objective To explore the suppression efficiency of spectrally selective fat suppression schemes when different black blood imaging pre-pulses are used. Background Sufficient peri-vascular fat suppression is critical for the outer wall boundary delineation in vessel wall imaging. The MSDE technique has been shown to significantly improve the blood suppression efficiency and measurement reproducibility. A limitation is that, due to the uncompensated eddy currents, undesired frequency shift can be observed after the MSDE prepulse, making the spectrally selective fat suppression ineffective. The aim of this study is to explore whether a previously proposed improved MSDE (iMSDE) technique is more robust against this system imperfection than the conventional MSDE approach, thus improving the fat suppression efficiency in vivo. Methods

Introduction There has been few report on myocardial fat in MI using traditional MR techniques discriminating fat (i.e, T1WI with and without fat suppression), which probably attributes to reduced ability to characterize myocardial fat due to poor contrast of microscopic fat and partial-volume effects. Therefore somewhat sophisticated means such as multiecho Dixon method and IR-SSFP sequence were recently introduced to increase sensitivity of fat detection. We hypothesized that myocardial fat can be readily identified on cine imaging among generally used CMR sequences in which cancellation artifact occurs in borders of fat and water.

Introduction Limited temporal resolution underestimates peak velocities assessed by phase contrast MRI (PC-MRI) [1]. Segmented EPI with partial Fourier as previously proposed [2] has relatively long TE, and is prone to chemical-shift artifact. We propose centric reordered water-excitation EPI for PC-MRI with short TE and fat suppression. It improves temporal resolution by twofold while halving scan time compared with turboFLASH.

This is the second of two reviews that is intended to cover the essential aspects of cardiovascular magnetic resonance (CMR) physics in a way that is understandable and relevant to clinicians using CMR in their daily practice. Starting with the basic pulse sequences and contrast mechanisms described in part I, it briefly discusses further approaches to accelerate image acquisition. It then continues by showing in detail how the contrast behaviour of black blood fast spin echo and bright blood cine gradient echo techniques can be modified by adding rf preparation pulses to derive a number of more specialised pulse sequences. The simplest examples described include T2-weighted oedema imaging, fat suppression and myocardial tagging cine pulse sequences. Two further important derivatives of the gradient echo pulse sequence, obtained by adding preparation pulses, are used in combination with the administration of a gadolinium-based contrast agent for myocardial perfusion imaging and the assessment of myocardial tissue viability using a late gadolinium enhancement (LGE) technique. These two imaging techniques are discussed in more detail, outlining the basic principles of each pulse sequence, the practical steps required to achieve the best results in a clinical setting and, in the case of perfusion, explaining some of the factors that influence current approaches to perfusion image analysis. The key principles of contrast-enhanced magnetic resonance angiography (CE-MRA) are also explained in detail, especially focusing on timing of the acquisition following contrast agent bolus administration, and current approaches to achieving time resolved MRA. Alternative MRA techniques that do not require the use of an endogenous contrast agent are summarised, and the specialised pulse sequence used to image the coronary arteries, using respiratory navigator gating, is described in detail. The article concludes by explaining the principle behind phase contrast imaging techniques which create images that represent the phase of the MR signal rather than the magnitude. It is shown how this principle can be used to generate velocity maps by designing gradient waveforms that give rise to a relative phase change that is proportional to velocity. Choice of velocity encoding range and key pitfalls in the use of this technique are discussed.

BackgroundLocalization of the heart is typically performed using amulti-step approach involving the acquisition of double-oblique localizer images. Based on the localizers thestandard heart views are planned. This approach isoperator-dependent and time consuming.ObjectiveTo demonstrate feasibility of a fully automatic and fastapproach to heart localization and slice prescriptionfrom a highly-accelerated, single breath-hold 3D acquisi-tion through a machine learning method.MethodsA 3D full-chest MR scan is obtained through parallelimaging within a single breath-hold. A single volume isacquired at mid-diastole using an ECG gated segmentedacquisition with T2-prepared SSFP readout with chemi-cal shift fat suppression. Typical protocol parametersare: 400x400x220 mm