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Digital subtraction angiography is the preferred imaging modality in suspected cases of primary CNS vasculitis and has greater specificity than magnetic resonance angiography or CT angiography (which have reduced accuracy for assessment of luminal irregularities of medium sized vessels or the posterior circulation of the brain). [5] Typical ...
Cerebral edema and venous infarction may be apparent on any modality, but for the detection of the thrombus itself, the most commonly used tests are computed tomography (CT) and magnetic resonance imaging (MRI), both using various types of radiocontrast to perform a venogram and visualise the veins around the brain.
Magnetic resonance angiography (MRA) is a group of techniques based on magnetic resonance imaging (MRI) to image blood vessels. Magnetic resonance angiography is used to generate images of arteries (and less commonly veins) in order to evaluate them for stenosis (abnormal narrowing), occlusions, aneurysms (vessel wall dilatations, at risk of rupture) or other abnormalities.
The key to Phase-contrast MRI (PC-MRI) is the use of a bipolar gradient. [4] A bipolar gradient has equal positive and negative magnitudes that are applied for the same time duration. The bipolar gradient in PC-MRI is put in a sequence after RF excitation but before data collection during the echo time of the generic MRI modality.
The first MR images of a human brain were obtained in 1978 by two groups of researchers at EMI Laboratories led by Ian Robert Young and Hugh Clow. [1] In 1986, Charles L. Dumoulin and Howard R. Hart at General Electric developed MR angiography, [2] and Denis Le Bihan obtained the first images and later patented diffusion MRI. [3]
Rarely, coexisting vasculitis may cause neurological complications. These occurrences can start with mild headaches that steadily worsen in pain and onset, and can include attacks of dysesthesia. This type of deterioration happens usually if the lesions involve the fovea. [2] [15]
CT scan (computed tomography) of the brain (without any iodinated contrast), is the initial imaging choice because of its high speed, good accessibility in hospitals, high sensitivity in detecting brain injuries or brain diseases, thus helping to triage patients in emergency department in a timely manner and urgent neurosurgical intervention ...
An MRI with special sequences called diffusion-weighted MR imaging (DWI), is very sensitive for locating areas of an ischemic based stroke, such as a watershed stroke. Further diagnosis and evaluation of a stroke includes evaluation of the blood vessels in the neck using either Doppler ultrasound, MR-angiography or CT-angiography, or formal ...