Phase contrast and time-of-flight magnetic resonance angiography of the intracerebral arteries at 1.5, 3 and 7 T

Stamm, Anna C.; Wright, Chadwick; Knopp, Michael V.; Schmalbrock, Petra; Heverhagen, Johannes T.

doi:10.1016/j.mri.2012.10.023

Cited by 33 publications

(26 citation statements)

References 21 publications

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“…The lack of contrast administration in TOF-MRA may predispose to signal loss due to saturation effects, particularly in vessels with slow blood flow (like small arteries) [22]. Furthermore, more complex flow patterns might be present in patients with vascular lesions leading to changed signal properties [11]. Contrast administration shortens the T 1 relaxation time of blood and thereby might improve the contrast-to-noise ratio between the blood and the surrounding brain parenchyma, giving a clearer depiction of slow-moving blood in distal vessels [22, 23].…”

Section: Introductionmentioning

confidence: 99%

High-Resolution Postcontrast Time-of-Flight MR Angiography of Intracranial Perforators at 7.0 Tesla

et al. 2015

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Background and PurposeDifferent studies already demonstrated the benefits of 7T for precontrast TOF-MRA in the visualization of intracranial small vessels. The aim of this study was to assess the performance of high-resolution 7T TOF-MRA after the administration of a gadolinium-based contrast agent in visualizing intracranial perforating arteries.Materials and MethodsTen consecutive patients (7 male; mean age, 50.4 ± 9.9 years) who received TOF-MRA at 7T after contrast administration were retrospectively included in this study. Intracranial perforating arteries, branching from the parent arteries of the circle of Willis, were identified on all TOF-MRA images. Provided a TOF-MRA before contrast administration was present, a direct comparison between pre- and postcontrast TOF-MRA was made.ResultsIt was possible to visualize intracranial perforating arteries branching off from the entire circle of Willis, and their proximal branches. The posterior cerebral artery (P1 and proximal segment of P2) appeared to have the largest number of visible perforating branches (mean of 5.1 in each patient, with a range of 2–7). The basilar artery and middle cerebral artery (M1 and proximal segment M2) followed with a mean number of 5.0 and 3.5 visible perforating branches (range of 1–9 and 1–8, respectively). Venous contamination in the postcontrast scans sometimes made it difficult to discern the arterial or venous nature of a vessel.ConclusionHigh-resolution postcontrast TOF-MRA at 7T was able to visualize multiple intracranial perforators branching off from various parts of the circle of Willis and proximal intracranial arteries. Although confirmation in a larger study is needed, the administration of a contrast agent for high-resolution TOF-MRA at 7T seems to enable a better visualization of the distal segment of certain intracranial perforators.

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Section: Introductionmentioning

confidence: 99%

High-Resolution Postcontrast Time-of-Flight MR Angiography of Intracranial Perforators at 7.0 Tesla

et al. 2015

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“…They could show the diagnostic equivalence of all three field strengths for the assessment of the large primary vessels of the Circle of Willis and an improved depiction of the first-and second-order branch arteries at 7 Tesla. Analysis of the SNR in the primary vessels revealed only a minor increase at 7 Tesla, mainly due to the acquisition of smaller voxel sizes [37]. Apart from vessel imaging, the increase of the field strength has also been demonstrated to be beneficial for functional MRI, based on the increased SNR and supralinear increase of BOLD (bloodoxygen-level-dependent) signal changes [38].…”

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confidence: 99%

7 Tesla MR Imaging: Opportunities and Challenges

Umutlu

Ladd

Forsting³

et al. 2013

Fortschr Röntgenstr

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The urge to increase magnetic field strength is driven by a number of potentially beneficial physical changes, possibly resulting in improved MR diagnostics. With the successful introduction of in-vivo ultra-high-field MR imaging, by means of 7 Tesla MRI, the focus of scientific research has been set on compiling different applications of brain and body imaging. This review presents an overview on the current status of 7?T MR imaging, investigating the opportunities as well as challenges associated with ultra-high-field MRI. Citation Format: ??Umutlu L, Ladd ME, Forsting M et?al. 7 Tesla MR?Imaging: Opportunities and Challenges. Fortschr R?ntgenstr 2014; 186: 121???129

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“…With TOF-MRA at 7T, a more detailed demonstration of the BPAs has been reported with contrast enhancement [23] , but visualization of both the BPAs and the background anatomical structures has only rarely been reported in a single acquisition. A modified T1-weighted magnetization prepared imaging sequence, referred to as 'magnetization prepared anatomical reference MRA (MPARE-MRA)', has been used as an alternative angiography method to visualize both BPAs and related anatomy at 7T.…”

Section: Discussionmentioning

confidence: 99%

The Posterior Limb of the Internal Capsule as the Subcortical Transitional Zone of the Anterior and Posterior Circulations: Insights from Human 7T MRI

Kurabe

Okamoto²,

Suzuki³

et al. 2016

Cerebrovasc Dis

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Background: In patients with cerebral infarction, identifying the distribution of infarction and the relevant artery is essential for ascertaining the underlying vascular pathophysiological mechanisms and preventing subsequent stroke. However, visualization of the basal perforating arteries (BPAs) has had limited success, and simultaneous viewing of background anatomical structures has only rarely been attempted in living human brains. Our study aimed at identifying the BPAs with 7T MRI and evaluating their distribution in the subcortical structures, thereby showing the clinical significance of the technique. Methods: Twenty healthy subjects and 1 patient with cerebral infarction involving the posterior limb of the internal capsule (ICpost) and thalamus underwent 3-dimensional fast spoiled gradient-echo sequence as time-of-flight magnetic resonance angiography (MRA) at 7T with a submillimeter resolution. The MRA was modified to detect inflow signals from BPAs, while preserving the background anatomical signals. BPA stems and branches in the subcortical structures and their origins were identified on images, using partial maximum intensity projection in 3 dimensions. Results: A branch of the left posterior cerebral artery (PCA) in the patient ran through both the infarcted thalamus and ICpost and was clearly the relevant artery. In 40 intact hemispheres in healthy subjects, 571 stems and 1,421 branches of BPAs were detected in the subcortical structures. No significant differences in the numbers of stems and branches were observed between the intact hemispheres. The numbers deviated even less across subjects. The distribution analysis showed that the subcortical structures of the telencephalon, such as the caudate nucleus, anterior limb of the internal capsule, and lenticular nucleus, were predominantly supplied by BPAs from the anterior circulation. In contrast, the thalamus, belonging to the diencephalon, was mostly fed by BPAs from the posterior circulation. However, compared with other subcortical structures, the ICpost, which marks the anatomical boundary between the telencephalon and the diencephalon, was supplied by BPAs with significantly more diverse origins. These BPAs originated from the internal carotid artery (23.1%), middle cerebral artery (38.5%), PCA (17.3%), and the posterior communicating artery (21.1%). Conclusions: The modified MRI method allowed the detection of the relevant BPA within the infarcted area in the stroke survivor as well as the BPAs in the subcortical structures of living human brains. Based on in vivo BPA distribution analyses, the ICpost is the transitional zone of the anterior and posterior cerebral circulations.

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Phase contrast and time-of-flight magnetic resonance angiography of the intracerebral arteries at 1.5, 3 and 7 T

Cited by 33 publications

References 21 publications

High-Resolution Postcontrast Time-of-Flight MR Angiography of Intracranial Perforators at 7.0 Tesla

High-Resolution Postcontrast Time-of-Flight MR Angiography of Intracranial Perforators at 7.0 Tesla

7 Tesla MR Imaging: Opportunities and Challenges

The Posterior Limb of the Internal Capsule as the Subcortical Transitional Zone of the Anterior and Posterior Circulations: Insights from Human 7T MRI

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