Accelerated acquisition of carotid MR angiography using 3D gradient-echo imaging with two-point Dixon

Ryusuke Irie,Osamu Abe,Hidemasa Takao,Harushi Mori,Kouhei Kamiya,Shiori Amemiya,Yuichi Suzuki,Tsuyoshi Ueyama

doi:10.1007/s00234-020-02452-6

Ryusuke Irie, Osamu Abe + Show 6 more

Open Access

https://doi.org/10.1007/s00234-020-02452-6

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Abstract

This pilot study tests the feasibility of rapid carotid MR angiography using the liver acquisition with volume acceleration-flex technique (LAVA MRA). Seven healthy volunteers and 21 consecutive patients suspected of carotid stenosis underwent LAVA and conventional time-of-flight (cTOF) MRAs. Artery-to-fat and artery-to-muscle signal intensity ratios were manually measured. LAVA MRA exhibited a significantly larger artery-to-fat signal intensity ratio compared with cTOF MRA in all slices (P < 0.001) and exhibited a larger (P < 0.001) or equivalent (P = 1.0) artery-to-muscle signal intensity ratio in the extracranial carotid arteries. The image quality of the cervical carotid bifurcation and the signal change on each MRA were visually assessed and compared among the MRAs. There was no significant difference between the two MRAs in visual assessment. LAVA MRA can provide visualization similar to cTOF MRA in the evaluation of the cervical carotid bifurcation while reducing scan time by one-fifth.

Highlights

Three-dimensional (3D) time-of-flight MR angiography (TOF MRA) is a widely used non-contrast-enhanced (CE) procedure for assessing the carotid artery [1]
LAVA MRA was imaged with flip angle (FA) set at 4°, 7°, 10°, and 13° (Supplement 2)
FA 4°, flip angle 4° (LAVA); FA 7°, flip angle 7° (LAVA); FA 10°, flip angle 10° (LAVA); cTOF, conventional time-of-flight; MIP, maximum intensity projection poorly rendered in the MIP image

Summary

Introduction

Three-dimensional (3D) time-of-flight MR angiography (TOF MRA) is a widely used non-contrast-enhanced (CE) procedure for assessing the carotid artery [1]. TOF MRA generally takes a few minutes to acquire and is more susceptible to motion artifacts due to swallowing or gross body movement [2–4]. When imaging patients with acute symptoms or patients who have difficulty maintaining posture, image quality can be improved by reducing scan time. To reduce the scan time of carotid inflowdependent MRA, we applied the liver acquisition with volume acceleration-flex (LAVA-Flex) technique. LAVA-Flex is a 3D fast spoiled gradient-echo T1-weighted imaging technique that uses the two-point Dixon method [5]. In the LAVA-Flex technique, because the repetition time (TR) is set as short as one-sixth of the TR of the conventional TOF MRA (cTOF MRA), the scan time can be remarkably shortened

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Conclusion