Intracranial black‐blood MR angiography with high‐resolution 3D fast spin echo

Abstract

Three-dimensional fast spin-echo (3DFSE) techniques are promising for black-blood imaging of cerebral vessels. In this study, flow-related signal dephasing was demonstrated as the primary mechanism for blood signal attenuation. Parameter optimization of TR (1500 to 3000 ms), receiver bandwidth (25 to 31.25 kHz), effective TE (25.7 to 30.1 ms), and ETL (7 to 8) was accomplished by making measurements of vessel-to-tissue contrast-to-noise ratios on vessels. A comparison of high-resolution 3DFSE and 3DTOF magnetic resonance angiography demonstrated that 3DFSE can generate images with equivalent or better small vessel detail than conventional techniques. 3DFSE black-blood techniques may provide improved sensitivity of small arteries and veins with slow or in-plane flow and immunity to flow-related distortions. Future studies with optimized parameters will determine the clinical efficacy of this technique.

Intracranial arterial wall imaging using three‐dimensional high isotropic resolution black blood MRI at 3.0 Tesla

“…It is known that 3D TSE has intrinsic black-blood effects from the dephasing of moving blood spins (16,22). With VISTA, the intrinsic black-blood effect is further enhanced by the long echo train.…”

“…Blood with a spectrum of velocities and accelerations flowing across a magnetic field gradient leads to widespread phase dispersion that results in signal loss. In particular, the complex state of motion such as turbulence or pulsation contributes to the spread of velocities and accelerations, and serendipitously induces additional signal attenuation (16). Furthermore, the flow suppression is more effective for vessels with small diameters, such as cerebral vessels (22).…”

“…For example, double inversion recovery techniques (14,15) typically used in 2D acquisitions generally provide inadequate flow suppression in 3D acquisitions because of the relatively thick re-inversion pulse required. Furthermore, the long echo train length (ETL) used to suppress flow by dephasing effects in 2D turbo spin echo (TSE) techniques (16) are not possible at 3D without impractically long scan times. A recently proposed 3D technique, Volumetric ISotropic TSE Acquisition (VISTA, Philips), uses variable-flip-angle refocusing pulses to achieve a longer ETL for more effective flow suppression without compromising signal and at relatively short scan times (17).…”

Noninvasive In Vivo Human Coronary Artery Lumen and Wall Imaging Using Black-Blood Magnetic Resonance Imaging

“…Thinner slice thickness, as used with 3D acquisition techniques, could further improve our coronary artery wall imaging. 18,37 Moreover, zero-filled interpolation of the 256ϫ256 images can be used to create 512ϫ512 images to reduce the partial-volume effects in imaging pixels. 38 This can be achieved by appending zeros on each side of the data before Fourier transformation.…”

“…In this context, the concept of black-blood MRI (BB-MR) is promising, because the signal from static tissue is maximized and the transverse magnetization of flowing blood is made intentionally incoherent, leading to blood signal void. 17,18 Therefore, by combining BB-MR with high-spatialresolution and fast-data-acquisition imaging, both lumen and wall imaging of the coronary arteries should be possible. A number of different methods are available for BB-MR. [17][18][19][20][21] However, none of these methods have been used for coronary lumen and wall imaging.…”