In patients with ischemic heart disease, accurate assessment of the extent of myocardial perfusion deficit may be important in predicting prognosis of clinical cardiac outcomes. The aim of this study was to compare the ability of three dimensional (3D) and of two dimensional (2D) multi-slice myocardial perfusion imaging (MPI) using cardiovascular magnetic resonance (CMR) in determining the size of defects, and to demonstrate the feasibility of 3D MPI in healthy volunteers at 3 Tesla.

Three‐dimensional cardiac magnetic resonance perfusion imaging is promising for the precise sizing of defects and for providing high perfusion contrast, but remains an experimental approach primarily due to the need for large‐dimensional encoding, which, for traditional 3DFT imaging, requires either impractical acceleration factors or sacrifices in spatial resolution. We demonstrated the feasibility of rapid three‐dimensional cardiac magnetic resonance perfusion imaging using a stack‐of‐spirals acquisition accelerated by non‐Cartesian k‐t SENSE, which enables entire myocardial coverage with an in‐plane resolution of 2.4 mm. The optimal undersampling pattern was used to achieve the largest separation between true and aliased signals, which is a prerequisite for k‐t SENSE reconstruction. Flip angle and saturation recovery time were chosen to ensure negligible magnetization variation during the transient data acquisition. We compared the proposed three‐dimensional perfusion method with the standard 2DFT approach by consecutively acquiring both data during each R–R interval in cardiac patients. The mean and standard deviation of the correlation coefficients between time intensity curves of three‐dimensional versus 2DFT were 0.94 and 0.06 across seven subjects. The linear correlation between the two sets of upslope values was significant (r = 0.78, P < 0.05). Magn Reson Med, 2013.

Non‐contrast‐enhanced MR angiography is a promising alternative to the established contrast‐enhanced approach as it reduces patient discomfort and examination costs and avoids the risk of nephrogenic systemic fibrosis. Inflow‐sensitive slab‐selective inversion recovery imaging has been used with great promise, particularly for abdominal applications, but has limited craniocaudal coverage due to inflow time constraints. In this work, a new non‐contrast‐enhanced MR angiography method using velocity‐selective inversion preparation is developed and applied to renal and abdominal angiography. Based on the excitation k‐space formalism and Shinnar‐Le‐Roux transform, a velocity‐selective excitation pulse is designed that inverts stationary tissues and venous blood while preserving inferiorly flowing arterial blood. As the magnetization of the arterial blood in the abdominal aorta and iliac arteries is well preserved during the magnetization preparation, artery visualization over a large abdominal field of view is achievable with an inversion delay time that is chosen for optimal background suppression. Healthy volunteer tests demonstrate that the proposed method significantly increases the extent of visible arteries compared with the slab‐selective approach, covering renal arteries through iliac arteries over a craniocaudal field of view of 340 mm. Magn Reson Med, 2013.

Purpose: To develop a new velocity‐selective (VS) excitation pulse sequence which is robust to field inhomogeneity, and demonstrate its application to non‐contrast‐enhanced peripheral MR angiography (MRA).Methods: The off‐resonance‐robust VS saturation pulse is designed by incorporating 180° refocusing pulses into the k‐space‐based reference design and tailoring sequence parameters in a velocity region of interest. The VS saturation pulse is used as magnetization preparation for non‐contrast‐enhanced peripheral MRA to suppress background tissues but not arterial blood based on their velocities. Non‐contrast‐enhanced peripheral MRA using the proposed VS preparation was tested in healthy volunteers and a patient with arterial stenosis.Results: Calf angiograms obtained using the new VS preparation show more uniform background suppression than the reference VS preparation, as demonstrated by larger mean values and smaller standard deviations of artery‐to‐vein and artery‐to‐muscle contrast‐to‐noise ratios (71.0 ± 11.4 and 75.3 ± 12.1 versus 61.7 ± 22.7 and 58.5 ± 27.8). Two‐station peripheral MRA using the new VS preparation identifies stenosis of the femoral and popliteal arteries in the patient, as validated by digital subtraction angiography.Conclusion: Non‐contrast‐enhanced MRA using the new VS magnetization preparation can reliably provide high angiographic contrast in the lower extremities with significantly improved immunity to field inhomogeneity. Magn Reson Med 70:1229–1240, 2013.