Improved black‐blood imaging using DANTE‐SPACE for simultaneous carotid and intracranial vessel wall evaluation

Abstract

Purpose The purpose of this work is to develop a 3D black-blood imaging method for simultaneously evaluating carotid and intracranial arterial vessel wall with high spatial resolution and excellent blood suppression with and without contrast enhancement. Methods DANTE preparation module was incorporated into SPACE sequence to improve blood signal suppression. Simulations and phantom studies were performed to quantify image contrast variations induced by DANTE. DANTE-SPACE, SPACE and 2D TSE were compared for apparent SNR, CNR and morphometric measurements in fourteen healthy subjects. Preliminary clinical validation was performed in six symptomatic patients. Results Apparent residual luminal blood was observed in 5 (pre-CE) and 9 (post-CE) subjects with SPACE, and only 2 (post-CE) subjects with DANTE-SPACE. DANTE-SPACE showed 31% (pre-CE) and 100% (post-CE) improvement in wall-to-blood CNR over SPACE. Vessel wall area measured from SPACE was significantly larger than that from DANTE-SPACE due to possible residual blood signal contamination. In patients DANTE-SPACE showed the potential to detect vessel wall dissection and identify plaque components. Conclusion DANTE-SPACE significantly improved arterial and venous blood suppression compared with SPACE. Simultaneous high-resolution carotid and intracranial vessel wall imaging to potentially identify plaque components was feasible with scan time under 6 minutes.

The Use and Pitfalls of Intracranial Vessel Wall Imaging: How We Do It

“…Most intracranial VW imaging sequences rely on the intrinsic "black blood" properties of three-dimensional (3D) turbo spin-echo (TSE) pulse sequences, with variable flip-angle refocusing pulses (17,(19)(20)(21)(22)(23). In these sequences, black blood is achieved by intravoxel dephasing of flowing blood, which is most effective when low-flip-angle refocusing pulses are used (17,24).…”

“…For intracranial VW imaging, both a high contrast-to-noise ratio (CNR) and a high spatial resolution are needed to visualize the thin arterial VW and to characterize VW lesions (1,(15)(16)(17)(18)(19). CNR in VW imaging comprises signal contrast of the VW relative to its direct surroundings, that is, blood and cerebrospinal fluid (CSF).…”

“…At 3 T, the CNR between VW and lumen is superior to the CNR between VW and CSF on most pulse sequences. Because an inversion-recovery pulse as a CSF-suppressing technique is both time consuming and detrimental to the VW signal-to-noise ratio (SNR), these VW imaging sequences rely implicitly (without use of CSF suppression preparation pulses) or explicitly (with use of DANTE) on CSF flow for CSF suppression (19)(20)(21)31,32). Consequently, suppression of CSF will be lower in compartments where there is a slower flow of CSF, for example, around the VW and at locations where there is little CSF surrounding the vessels.…”

Atherosclerosis in stroke‐related vascular beds and stroke risk: A 3‐D MR vessel wall imaging study

“…It is well established that MR vessel wall imaging is capable of characterizing carotid artery atherosclerosis validated by histology 7. Recently, investigators proposed three‐dimensional (3‐D) MR vessel wall imaging sequences which enable high isotropic resolution plaque imaging with large longitudinal coverage for craniocervical arteries8, 9 and aortic arch 10, 11. These emerging 3‐D MR vessel wall imaging techniques might be appropriate imaging modalities for the identification of coexisting atherosclerotic diseases in stroke‐related vascular beds.…”

Intracranial vessel wall MRI: a review of current indications and future applications

“…Both 2D and 3D IVWM techniques can be employed depending on the scanning environment and institutional experience [2][3][4][5][6][7][8][9][10][11][12][13] (Table 1). An important consideration for intracranial vessel wall imaging is blood and cerebrospinal fluid (CSF) suppression for better outer wall boundary evaluation.…”