Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · May 2012
ReviewVascular disorders: insights from arterial spin labeling.
The introduction of high-field magnetic imaging (≥3 T) has made noninvasive arterial spin labeling (ASL) a realistic clinical option for perfusion assessment in vascular disorders. Combined with the advances provided by territorial imaging of individual intracerebral arteries and the measurement of vascular reactivity, ASL is a powerful tool for evaluating vascular diseases of the brain. This article evaluates its use in chronic cerebrovascular disease, stroke, moyamoya disease, and arteriovenous malformation, but ASL may also find applications in related diseases such as vascular dementia.
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Neuroimaging Clin. N. Am. · May 2012
ReviewCurrent state-of-the-art 1.5 T and 3 T extracranial carotid contrast-enhanced magnetic resonance angiography.
Recent advances in magnetic resonance (MR) hardware and software have improved the resolution and spatial coverage of head and neck first-pass contrast-enhanced (CE) MR angiography. Despite these improvements, high-quality submillimeter-resolution 1.5 T and 3 T carotid CE MR angiography is not consistently available in the general radiology practice. This article reviews the important imaging parameters and potential pitfalls that affect carotid CE MR angiography image quality, and the dose and timing of the gadolinium-based contrast agent, and summarizes vendor-specific protocols for high-quality submillimeter-resolution carotid CE MR angiography at 1.5 and 3 T.
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Epileptogenic lesions are often subtle, do not change during life, and are easily overlooked, if spatial resolution and signal to noise ratio are inappropriate. 2D or more recently 3D-FLAIR sequences are best suited to detect small cortical dysplasias which are often located at the bottom of a sulcus. 3D-T1-weighted gradient echo sequences are used for multiplanar, curved surface reformations, and voxel-based analyses. 3 T MR imaging is currently the state-of-the-art imaging modality for patients with suspected structural epilepsies in which an epileptogenic lesion has not yet been found.
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Neuroimaging Clin. N. Am. · May 2012
ReviewCurrent status and future perspectives of magnetic resonance high-field imaging: a summary.
There are several magnetic resonance (MR) imaging techniques that benefit from high-field MR imaging. This article describes a range of novel techniques that are currently being used clinically or will be used in the future for clinical purposes as they gain popularity. These techniques include functional MR imaging, diffusion tensor imaging, cortical thickness assessment, arterial spin labeling perfusion, white matter hyperintensity lesion assessment, and advanced MR angiography.
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Neuroimaging Clin. N. Am. · May 2012
ReviewVascular disorders--magnetic resonance angiography: brain vessels.
Magnetic resonance angiography (MRA) of the brain obtained at 3 T imaging has made a significant clinical impact. MRA benefits from acquisition at higher magnetic field strength because of higher available signal-to-noise ratio and improved relative background suppression due to magnetic field strength-related T1 lengthening. Parallel imaging techniques are ideally suited for high-field MRA. Many of the developments that have made 3 T MRA of the brain successful can be regarded as enabling technologies that are essential for further development of 7 T MRA, which brings additional challenges.