Altered saturation pulse with a high flip angle for venous saturation on 7 T time-of-flight magnetic resonance angiography

AbstractThis study aimed to apply minimum-time variable-rate selective excitation (MinVER) to a presaturation pulse (PSP) with a high flip angle on 7 T time-of-flight magnetic resonance angiography (7T TOF-MRA), to attain a superior vessel-to-tissue contrast (VTCR), short acquisition time, and minor off-resonance effect. An altered PSP modified by using the 90° flip angle (FA)-MinVER was implemented in the 7 T TOF-MRA, and its performance was evaluated with a signal profile and vessel-tissue contrast ratios and compared to the conventional PSP and 45 FA-TOF. The 90 FA-MinVER showed a similar signal profile to that of the conventional PSP and improved the vessel-tissue contrast ratios (0.313 ± 0.80) compared to all conventional types (45 FA-TOF: 0.088 ± 0.84, 90 FA-TOF: 0.203 ± 0.72). Moreover, this noteworthy approach achieved substantially reduced total acquisition time (5 min and 55 s) with a short repeat-to-time (28 ms), indicating that at the 7 T TOF-MRA, the 90 FA-MinVER could be applied by default to suppress the venous signals regardless of individual human status and the specific absorption ratio constraint and with rapid imaging. Ultimately, its application could also help to observe subtle microvascular changes in the early stages and serve as key biomarkers in various vascular diseases.

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Intralateral and Perilateral Ventricular Arteries on Original Axial Magnetic Resonance Angiography in Adult Moyamoya Disease

European Neurology ◽

10.1159/000514429 ◽

2021 ◽

Vol 84 (2) ◽

pp. 119-123

Author(s):

Mami Ishikawa ◽

Satoshi Terao ◽

Hiroshi Kagami ◽

Makoto Inaba ◽

Heiji Naritaka

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Cerebral Infarction ◽

Moyamoya Disease ◽

Disease Onset ◽

Time Of Flight ◽

Unruptured Aneurysms ◽

Tof Mra ◽

Adult Moyamoya Disease

Background: Patients with moyamoya disease often develop cerebral infarction and hemorrhage, but the ischemic and hemorrhagic subtypes are difficult to diagnose prior to disease onset. We aimed to differentiate the ischemic and hemorrhagic subtypes of moyamoya disease by analyzing the intralateral and perilateral ventricular arteries on the original axial magnetic resonance angiography (MRA) images. Methods: We retrospectively analyzed the intralateral and perilateral ventricular arteries on the original axial time-of-flight (TOF)-MRA images of 18 patients with hemorrhagic moyamoya disease, 25 patients with ischemic moyamoya disease, and 22 control patients with unruptured aneurysms. Results: There were significantly more intralateral and perilateral ventricular arteries on the original axial MRA images in the patients with hemorrhagic moyamoya disease (6.3 ± 2.7) than in those with ischemic moyamoya disease (0.8 ± 0.9) and those with unruptured aneurysms (0.4 ± 0.8). Conclusion: The intralateral and perilateral ventricular arteries on the original axial TOF-MRA images might suggest the hemorrhagic type of moyamoya disease prior to onset.

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The Use of Pointwise Encoding Time Reduction With Radial Acquisition MRA to Assess Middle Cerebral Artery Stenosis Pre- and Post-stent Angioplasty: Comparison With 3D Time-of-Flight MRA and DSA

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.739332 ◽

2021 ◽

Vol 8 ◽

Author(s):

Feifei Zhang ◽

Yuncai Ran ◽

Ming Zhu ◽

Xiaowen Lei ◽

Junxia Niu ◽

...

Keyword(s):

Magnetic Resonance ◽

Image Quality ◽

Magnetic Resonance Angiography ◽

Flow Visualization ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Time Of Flight ◽

Intervention Evaluation ◽

Tof Mra ◽

Angioplasty And Stenting

Background and Purpose: 3D pointwise encoding time reduction magnetic resonance angiography (PETRA-MRA) is a promising non-contrast magnetic resonance angiography (MRA) technique for intracranial stenosis assessment but it has not been adequately validated against digital subtraction angiography (DSA) relative to 3D-time-of-flight (3D-TOF) MRA. The aim of this study was to compare PETRA-MRA and 3D-TOF-MRA using DSA as the reference standard for intracranial stenosis assessment before and after angioplasty and stenting in patients with middle cerebral artery (MCA) stenosis.Materials and Methods: Sixty-two patients with MCA stenosis (age 53 ± 12 years, 43 males) underwent MRA and DSA within a week for pre-intervention evaluation and 32 of them had intracranial angioplasty and stenting performed. The MRAs' image quality, flow visualization within the stents, and susceptibility artifact were graded on a 1–4 scale (1 = poor, 4 = excellent) independently by three radiologists. The degree of stenosis was measured by two radiologists independently on DSA and MRAs.Results: There was an excellent inter-observer agreement for stenosis assessment on PETRA-MRA, 3D-TOF-MRA, and DSA (ICCs > 0.90). For pre-intervention evaluation, PETRA-MRA had better image quality than 3D-TOF-MRA (3.87 ± 0.34 vs. 3.38 ± 0.65, P < 0.001), and PETRA-MRA had better agreement with DSA for stenosis measurements compared to 3D-TOF-MRA (r = 0.96 vs. r = 0.85). For post-intervention evaluation, PETRA-MRA had better image quality than 3D-TOF-MRA for in-stent flow visualization and susceptibility artifacts (3.34 ± 0.60 vs. 1.50 ± 0.76, P < 0.001; 3.31 ± 0.64 vs. 1.41 ± 0.61, P < 0.001, respectively), and better agreement with DSA for stenosis measurements than 3D-TOF-MRA (r = 0.90 vs. r = 0.26). 3D-TOF-MRA significantly overestimated the stenosis post-stenting compared to DSA (84.9 ± 19.7 vs. 39.3 ± 13.6%, p < 0.001) while PETRA-MRA didn't (40.6 ± 13.7 vs. 39.3 ± 13.6%, p = 0.18).Conclusions: PETRA-MRA is accurate and reproducible for quantifying MCA stenosis both pre- and post-stenting compared with DSA and performs better than 3D-TOF-MRA.

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Time-of-Flight Magnetic Resonance Angiography (TOF MRA) and MRV: Clinical Applications

Vascular Imaging of the Central Nervous System ◽

10.1002/9781118434550.ch9 ◽

2013 ◽

pp. 146-160

Author(s):

Mauricio Castillo ◽

Juan Camilo Márquez ◽

Francisco José Medina

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Time Of Flight ◽

Clinical Applications ◽

Tof Mra

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Evaluation of cerebral arteriovenous shunts: a comparison of parallel imaging time-of-flight magnetic resonance angiography (TOF-MRA) and compressed sensing TOF-MRA to digital subtraction angiography

Neuroradiology ◽

10.1007/s00234-020-02581-y ◽

2020 ◽

Author(s):

Akihiko Sakata ◽

Yasutaka Fushimi ◽

Tomohisa Okada ◽

Satoshi Nakajima ◽

Takuya Hinoda ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Compressed Sensing ◽

Digital Subtraction Angiography ◽

Parallel Imaging ◽

Time Of Flight ◽

Digital Subtraction ◽

Tof Mra ◽

Imaging Time ◽

Arteriovenous Shunts

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Time-of-flight magnetic resonance angiography (TOF-MRA) of the normal equine head

Equine Veterinary Journal ◽

10.1111/j.2042-3306.2012.00621.x ◽

2012 ◽

Vol 45 (2) ◽

pp. 187-192 ◽

Cited By ~ 6

Author(s):

G. MANSO-DÍAZ ◽

M. I. GARCÍA-REAL ◽

C. CASTELEYN ◽

F. SAN-ROMÁN ◽

O. TAEYMANS

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Time Of Flight ◽

Tof Mra

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Contrast-Enhanced and Time-of-Flight MR Angiographic Assessment of Endovascular Coiled Intracranial Aneurysms at 1.5 T

Interventional Neuroradiology ◽

10.15274/inr-2014-10064 ◽

2014 ◽

Vol 20 (6) ◽

pp. 686-692 ◽

Cited By ~ 5

Author(s):

Akin Levent ◽

Ihsan Yuce ◽

Suat Eren ◽

Omer Ozyigit ◽

Mecit Kantarci

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Sensitivity And Specificity ◽

Intracranial Aneurysms ◽

Interobserver Agreement ◽

Three Dimensional ◽

Time Of Flight ◽

Selective Embolization ◽

Tof Mra ◽

Contrast Enhanced

This study evaluated contrast-enhanced magnetic resonance angiography (CE-MRA) and three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) through comparisons with digital subtraction angiography (DSA) for the follow-up of intracranial aneurysms treated with detachable coils. Sixty-seven patients with 79 aneurysms underwent 3D-TOF-MRA, CE-MRA, and catheter angiography one year after coiling. Two independent observers classified recanalization status on images as neck or body remnant or no recanalization. For 3D-TOF-MRA and CE-MRA, the intermodality agreement, interobserver agreement, and correlation with angiography were assessed. Sixty-seven patients with 79 coiled aneurysms agreed to participate in the study. Three aneurysms could not be detected on 3D-TOF-MRA, so they were excluded from this study. Interobserver agreement was very good for 3D-TOF-MRA and CE-MRA (kappa (κ): 0.87, 0.94, respectively). Correlation of TOF-MRA with angiography was good (κ: 0.76). Correlation of CE-MRA with angiography was excellent (κ: 0.91). The sensitivity and specificity of TOF-MRA were 92% and 98%, respectively. The sensitivity and specificity of CE-MRA were 96% and 98%, respectively. After selective embolization of intracranial aneurysms, CE-MRA is useful and comparable to DSA in the assessment of aneurysmal recanalization. Agreement with the gold standard is stronger with CE-MRA than with 3D-TOF-MRA.

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Carotid artery stenosis with a high-intensity signal plaque on time-of-flight magnetic resonance angiography and association with evidence of intraplaque hypoxia

Journal of Neurosurgery ◽

10.3171/2016.4.jns16349 ◽

2016 ◽

Vol 126 (6) ◽

pp. 1873-1878 ◽

Cited By ~ 2

Author(s):

Atsushi Ogata ◽

Masatou Kawashima ◽

Tomihiro Wakamiya ◽

Masashi Nishihara ◽

Jun Masuoka ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Carotid Artery ◽

High Intensity ◽

Time Of Flight ◽

University Hospital ◽

Intraplaque Hemorrhage ◽

Carotid Plaques ◽

Tof Mra ◽

The Relationship

OBJECTIVEHypoxia induces angiogenesis and plays a major role in the progression of carotid plaques. During carotid intervention, plaques with high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) often cause ischemic stroke and embolic complications. However, the role of intraplaque hypoxia before carotid endarterectomy (CEA) and carotid artery stenting is not presently understood. In this study the authors aimed to investigate the relationship between intraplaque hypoxia and MRA findings.METHODSNineteen consecutive patients with 20 carotid artery stenoses who underwent CEA at Saga University Hospital between August 2008 and December 2014 were enrolled in the study. The expressions of hypoxia-inducible transcription factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were analyzed by immunohistochemical analysis. In addition, the relationship between the findings on TOF MRA and pathology for the carotid plaques was analyzed.RESULTSHigh-intensity plaques on TOF MRA showed higher expression levels of HIF-1α (p = 0.015) and VEGF (p = 0.007) compared with isointensity plaques. The rate of intraplaque hemorrhage (IPH) on TOF MRA was also significantly higher in the high-intensity plaques than in the isointensity plaques (p = 0.024). Finally, the mean number of neovessels was significantly higher in those without plaque hemorrhage than in those with plaque hemorrhage (p = 0.010).CONCLUSIONSPlaques with high-intensity signals on TOF MRA were associated with IPH and evidence of intraplaque hypoxia. This fact may represent an opportunity to establish novel therapeutic agents targeting intraplaque hypoxia.

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Multiband multislab 3D time-of-flight magnetic resonance angiography for reduced acquisition time and improved sensitivity

Magnetic Resonance in Medicine ◽

10.1002/mrm.25774 ◽

2015 ◽

Vol 75 (4) ◽

pp. 1662-1668 ◽

Cited By ~ 11

Author(s):

Jenni Schulz ◽

Rasim Boyacioğlu ◽

David G Norris

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Time Of Flight ◽

Acquisition Time

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Using the Region of Interest from Time-of-Flight Magnetic Resonance Angiography to Differentiate Between Intracranial Arterial Dissection and True Atherosclerotic Stenosis

Cerebrovascular Diseases ◽

10.1159/000496505 ◽

2019 ◽

Vol 47 (1-2) ◽

pp. 8-14 ◽

Cited By ~ 2

Author(s):

Jung Won Hwang ◽

Jin-Man Jung ◽

Jae Hyung Cha ◽

Il Eok Jung ◽

Moon Ho Park ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Time Of Flight ◽

Region Of Interest ◽

Arterial Stenosis ◽

Arterial Dissection ◽

Intracranial Arterial Stenosis ◽

Tof Mra ◽

Significant Difference ◽

Focal Stenosis

Background: Noncontrast three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) is commonly used to examine intracranial arterial stenosis, although it can be difficult to identify the etiology of the stenosis. Our aim was to determine the effectiveness of 3D TOF MRA in differentiating an intracranial arterial dissection from atherosclerosis. Methods: During 2015–2017, 356 patients had confirmed intracranial arterial stenosis based on high resolution-magnetic resonance imaging. This study ultimately included 51 patients with severe focal stenosis that was caused by dissection and atherosclerosis. We compared the dissection group with the atherosclerotic narrowing group by measuring the region-of-interest (ROI) values 3 mm proximal and 3 mm distal from sites of severe focal stenosis. Results: A significant difference was observed between the median ROI difference values in the dissection group (n = 18) and the atherosclerosis group (n = 33; 35.6 [20.9–78.4] vs. 165.5 [99.8–328.5]; p < 0.001). A receiver operating characteristic curve was prepared to distinguish between dissection and atherosclerosis using the ROI difference values. The area under the curve was 0.919 (sensitivity 75.8%, specificity 94.4%). The optimal cutoff value for using ROI to distinguish between dissection and atherosclerosis was found to be 99.0 based on the Youden’s index. Conclusion: The ROI difference value from 3D TOF MRA could help distinguish between dissection and atherosclerosis. If the ROI difference value from 3D TOF MRA is small (< 99.0), detailed testing should be performed to identify dissection.

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