Vessel segmentation in 4D arterial spin labeling magnetic resonance angiography images of the brain

2017 ◽  
Author(s):  
Renzo Phellan ◽  
Thomas Lindner ◽  
Alexandre X. Falcão ◽  
Nils D. Forkert
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Vessel Segmentation ◽  
The Brain

scholarly journals Vessel-encoded dynamic magnetic resonance angiography using arterial spin labeling

2010 ◽  
Vol 64 (3) ◽  
pp. 698-706 ◽  
Author(s):  
Thomas W. Okell ◽  
Michael A. Chappell ◽  
Mark W. Woolrich ◽  
Matthias Günther ◽  
David A. Feinberg ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Dynamic Magnetic Resonance

Abstract WP61: A Novel Application of Four-dimensional Magnetic Resonance Angiography Using Arterial Spin Labeling for Assessment of Postoperative Cerebral Hemodynamic Changes in Moyamoya Disease

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Haruto Uchino ◽  
Masaki Ito ◽  
Ken Kazumata ◽  
Kiyohiro Houkin
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Moyamoya Disease ◽  
Arterial Spin Labeling ◽  
Early Time ◽  
Spin Labeling ◽  
Postoperative Management ◽  
Cerebral Hemodynamics ◽  
Hemodynamic Changes ◽  
Tof Mra

Introduction: Recently, four-dimensional magnetic resonance angiography without contrast enhancement using arterial spin labeling (ASL-4D MRA) has become available to visualize the intracranial arteries. However, few reports are available about the efficacy of ASL-4D MRA in moyamoya disease (MMD). Hypothesis: We hypothesized that postoperative hemodynamic changes in MMD patients could be evaluated using ASL-4D MRA. Methods: This study included 26 hemispheres of 21 patients who underwent combined direct and indirect revascularization for MMD. ASL-4D MRA was serially performed before and after surgery. We assessed the time phases where signals of the arteries were detected on ASL-4D MRA in order to analyze perioperative changes in cerebral hemodynamics. Results: The signals of the anastomosed arteries on ASL-4D MRA were detected and disappeared at significantly earlier time phase after surgery than before. This change in acute period was moderated in chronic period after surgery. Postoperative hyperperfusion was observed in 12 of 26 hemispheres within 7 days after surgery. The signals of the arteries were detected significantly earlier in hemispheres with hyperperfusion than those without. In cases with hyperperfusion, ASL-4D MRA demonstrated high intensity of peripheral middle cerebral artery (MCA) around anastomosed region in early time phase (Figure). This “early hyperintensity of MCA” was observed in all cases with hyperperfusion and corresponded to the timing of the occurrence of hyperperfusion. Furthermore, this hyperperfusion-specific sign could not be detected by routine TOF MRA. Conclusions: Noninvasive ASL-4D MRA successfully evaluated perioperative dynamic changes of cerebral blood flow and the effect of surgical revascularization in MMD. This next generation modality could also visualize cerebral hemodynamics in cases with postoperative hyperperfusion and would be quite useful for appropriate postoperative management.

scholarly journals Arterial Spin Labeling Imaging of a Giant Aneurysm Leading to Subarachnoid Hemorrhage following Cerebral Infarction

2018 ◽  
Vol 10 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Tatsuya Ueno ◽  
Tatsuya Sasaki ◽  
Masatoshi Iwamura ◽  
Tomoya Kon ◽  
Jin-ichi Nunomura ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Cerebral Infarction ◽  
Arterial Spin Labeling ◽  
Giant Aneurysm ◽  
Spin Labeling ◽  
Left Internal Carotid Artery ◽  
Hyperintense Signal ◽  
Aneurysm Thrombosis

An 83-year-old Japanese man was admitted with dysarthria and right hemiparesis. He had had a large intracranial aneurysm on the left internal carotid artery 5 years before admission and had been followed up under conservative treatment. On admission, diffusion-weighted imaging revealed a hyperintense signal on the left anterior choroidal artery territory. Time-of-flight magnetic resonance angiography demonstrated poor visibility of the middle and anterior cerebral arteries and the inferior giant aneurysm, suggesting distal emboli from aneurysm thrombosis or a reduction of blood outflow due to aneurysm thrombosis. Arterial spin labeling (ASL) signal increased in the giant aneurysm, suggesting blood stagnation within the aneurysmal sac, and decreased in the left hemisphere. We diagnosed cerebral infarction due to aneurysm thrombosis, and started antithrombotic therapy. On day 2, he suddenly died of subarachnoid hemorrhage due to rupturing of the giant aneurysm. When thrombosis occurs in a giant aneurysm, increasing ASL signal within the aneurysm and decreasing ASL signal with poor visibility on magnetic resonance angiography in the same arterial territory may indicate the danger of impending rupture of the giant aneurysm.

scholarly journals Assessment of cerebral perfusional and functional connectivity in schizophrenia using magnetic resonance imaging

2017 ◽  
Vol 11 (2) ◽  
pp. 30
Author(s):  
Icaro Agenor Ferreira de Oliveira ◽  
Tiago M Guimarães ◽  
Roberto M Souza ◽  
Antonio C Dos Santos ◽  
Joao Paulo M Sousa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Neuronal Activity ◽  
Arterial Spin Labeling ◽  
Functional Organization ◽  
Spin Labeling ◽  
Resonance Imaging ◽  
Noninvasive Technique ◽  
The Brain

Schizophrenia is a significant mental disorder that compromises structural and functional aspects of the brain, with an extreme effect on the patient’s thoughts, feelings, and behavior. Physiologically, in addition to functional and structural abnormalities, changes in neuronal activity are reported. Since the cerebral blood flow (CBF) is directly related to neuronal activity, the magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL), which allows the quantification of CBF, is a useful tool in brain perfusional evaluation. In addition, ASL can be used to assess functional connectivity, which is efficient in investigating functional impairment between regions of the brain. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 schizophrenia patients in treatment and 28 age-matched healthy controls. Static CBF and connectivity patterns were assessed. Decreased CBF and functional connectivity were observed in regions that forms two resting brain networks, default mode (DMN) and salience (SN), for schizophrenia patients. Previous studies related the features of this pathology with altered resting CBF and functional disconnections. Therefore, using a noninvasive technique, we were able to find CBF deficits and altered functional organization of the brain in schizophrenia patients that are associated with the symptoms and characteristics of the disorder.

scholarly journals Vessel‐encoded dynamic magnetic resonance angiography using arterial spin labeling

2010 ◽  
Vol 64 (2) ◽  
pp. 430-438 ◽  
Author(s):  
Thomas W. Okell ◽  
Michael A. Chappell ◽  
Mark W. Woolrich ◽  
Matthias Günther ◽  
David A. Feinberg ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Dynamic Magnetic Resonance
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