3D coronary vessel wall imaging utilizing a local inversion technique with spiral image acquisition

Abstract

Current 2D black blood coronary vessel wall imaging suffers from a relatively limited coverage of the coronary artery tree. Hence, a 3D approach facilitating more extensive coverage would be desirable. The straightforward combination of a 3D-acquisition technique together with a dual inversion prepulse can decrease the effectiveness of the black blood preparation. To minimize artifacts from insufficiently suppressed blood signal of the nearby blood pools, and to reduce residual respiratory motion artifacts from the chest wall, a novel local inversion technique was implemented. The combination of a nonselective inversion prepulse with a 2D selective local inversion prepulse allowed for suppression of unwanted signal outside a user-defined region of interest. Among 10 subjects evaluated using a 3D-spiral readout, the local inversion pulse effectively suppressed signal from ventricular blood, myocardium, and chest wall tissue in all cases. The coronary vessel wall could be visualized within the entire imaging volume.

Basis function cross‐correlations for Robust k‐space sample density compensation, with application to the design of radiofrequency excitations

“…This is often of paramount importance, since multidimensional RF excitations are often employed precisely in order to reduce the imaging FOV (14,15,19). Conversely, a significant portion of the increased error observed in the experiments stemmed from a broadening of the transition region of the profile, likely due to the finite resonance linewidth and differences between the designed and actual k-space trajectory traced.…”

“…Application of this particular disk as a window function to smooth the desired profile results in reduced Gibbs ringing when used in conjunction with spiral trajectories (12). The desired FT coefficients were thus [14] as shown, for example, in Fig. 2d.…”

“…4), and b is the desired effective FT coefficient energy, e.g., Eq. [14]. This error can also be computed for the Same-Image method by executing a single iteration of that algorithm (8), but rather than using a unitary input, using the desired FT as an input.…”

“…Multidimensional RF excitation (1,10,11) has many applications, such as inner volume imaging, navigator acquisition, and accounting for field inhomogeneities (10,(12)(13)(14)(15)(16)(17)(18)(19). Conversely, non-Cartesian sampling (20) has applications in fast imaging (21).…”

Comparison of 2D and multislab 3D magnetic resonance techniques for measuring carotid wall volumes

“…Spatial encoding is performed in 3D by using additional phase encoding in the direction perpendicular to the selected slab, along with an additional dimension of Fourier transformation for image reconstruction (14). The 3D images have an inherently higher signal-to-noise ratio (SNR), so fewer cardiac cycles are needed than with 2D to produce similar image quality at the same voxel size (8,15).…”