Non-Contrast-Enhanced Carotid MRA: Clinical Evaluation of a Novel Ungated Radial Quiescent-Interval Slice-Selective MRA at 1.5T

Abstract

Background and Purpose Non contrast-enhanced (CE) magnetic resonance angiography (MRA) techniques have experienced a renaissance due to the known correlation between the use of gadolinium-based contrast agents and the development of nephrogenic systemic fibrosis, and also the deposition of gadolinium in some brain regions. The purpose of this study was to assess the diagnostic performance of ungated non-CE radial quiescent-interval slice-selective (QISS)-MRA of extracranial supra-aortic arteries in comparison with the conventional CE-MRA in patients with clinical suspicion of carotid stenosis. Material and Methods In this prospective study, both MRA-pulse sequences were performed in thirty-one consecutive patients (median 68.8 years, 19 males). For the evaluation, the cervical arterial system was divided into 35 segments (right and left side). Three blinded reviewers separately evaluated these segments. An ordinal scoring system was used to assess the image quality of arterial segments and the stenosis grading of carotids. Results Overall venous contamination in QISS-MRA was rated as “none” by all readers in 84.9% and in CE-MRA in 8.1% of cases (p<0.0001). The visualization quality of arterial segments was considered good to excellent in 40.2% for the QISS-MRA and in 52.2% for the CE-MRA (p<0.0001). The diagnostic accuracy of ungated QISS-MRA concerning the stenosis grading showed a total sensitivity and specificity of 85.7% and 90.0%, respectively. Conclusion Ungated QISS-MRA can be used clinically as an alternative to CE-MRA without a significantly different image quality or diagnostic accuracy for detection of carotid stenosis at 1.5 Tesla.

Relaxation-Enhanced Angiography Without Contrast and Triggering (REACT) for Fast Imaging of Extracranial Arteries in Acute Ischemic Stroke at 3 T

“…However, CE-MRA shows limitations regarding the potential side effects of contrast agents, such as allergic reactions, nephrogenic systemic fibrosis in end-stage renal disease, and uncertain longterm effects of gadolinium deposition in the brain [4][5][6][7][8]. Occasionally, mistiming of image acquisition regarding first-pass contrast bolus resulting in insufficient contrast or venous contamination leads to impaired image quality in CE-MRA [9,10]. In AIS, contrast agents might be reserved for perfusion MRI using first-pass dynamic imaging techniques [11].…”

“…Hence, several non-CE-MRA techniques have been developed in the past, with 2D/3D time-of-flight (TOF)-MRA being a possible approach for extracranial arteries; however, compared to CE-MRA, 2D/3D TOF-MRA has the disadvantages of a long acquisition time, sensitivity to respiratory and flow artifacts, inferior image quality, decreased anatomic coverage and overestimation of ICA stenosis [12][13][14][15][16]. Beyond TOF-MRA, different non-CE-MRA techniques have been recently proposed, with quiescent interval slice-selective (QISS)-MRA and its flowcompensated fast low-angle shot readout being one of the latest innovations to show promising results for different vascular territories, including extracranial and intracranial arteries [10,[17][18][19][20]. However, 2D acquisition and dependency on the inflow of spins from outside the saturation volume have to be considered [10,[18][19][20].…”

“…Beyond TOF-MRA, different non-CE-MRA techniques have been recently proposed, with quiescent interval slice-selective (QISS)-MRA and its flowcompensated fast low-angle shot readout being one of the latest innovations to show promising results for different vascular territories, including extracranial and intracranial arteries [10,[17][18][19][20]. However, 2D acquisition and dependency on the inflow of spins from outside the saturation volume have to be considered [10,[18][19][20].…”

High spatial resolution whole‐neck MR angiography using thin‐slab stack‐of‐stars quiescent interval slice‐selective acquisition

“…Twenty arterial segments were scored: 1, aortic arch; 2, brachiocephalic artery; 3 and 4, bilateral common carotid arteries; 5 and 6, bilateral proximal internal carotid arteries; 7 and 8, cervical internal carotid arteries; 9 and 10, bilateral petrous internal carotid arteries; 11‐18, bilateral V1, V2, V3, and V4 segments of the vertebral arteries; 19, basilar artery; and 20, the intracranial arteries. MIP rather than cross‐sectional source images were used for image quality analysis as they are frequently reviewed in clinical practice for disease detection and have been used in recent research studies 12,13,19,29 …”

Feasibility of a sub‐3‐minute imaging strategy for ungated quiescent interval slice‐selective MRA of the extracranial carotid arteries using radial k‐space sampling and deep learning–based image processing

“…However, a cardiac‐gated implementation of QISS lengthens and complicates patient setup (as cardiac leads are not applied during routine neuro imaging) and renders the approach sensitive to heart rate, arrhythmias, and mistriggering from poor lead contact and magnetohydrodynamic effects. To address these problems, ungated QISS‐FLASH MRA of the neck has been developed and applied with good results in two studies involving over 90 patients, but so far has carried scan times of approximately 7 minutes.…”