Browsing by Author "Vaghela, Viratsinh"

Now showing 1 - 3 of 3
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    Functional magnetic resonance imaging of the brain: a quick review.
    (Neurology India, 2010)
    Ability to non-invasively map the hemodynamic changes occurring focally in areas of brain involved in various motor, sensory and cognitive functions by functional magnetic resonance imaging (fMRI) has revolutionized research in neuroscience in the last two decades. This technique has already gained clinical use especially in pre-surgical evaluation of epilepsy and neurosurgical planning of resection of mass lesions adjacent to eloquent cortex. In this review we attempt to illustrate basic principles and techniques of fMRI, its applications, practical points to consider while performing and evaluating clinical fMRI and its limitations.
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    Spontaneous intracranial hypo and hypertensions: an imaging review.
    (Neurology India, 2011)
    Cerebrospinal fluid (CSF) pressure changes can manifest as either intracranial hypertension or hypotension. The idiopathic forms are largely under or misdiagnosed. Spontaneous intracranial hypotension occurs due to reduced CSF pressure usually as a result of a spontaneous dural tear. Idiopathic intracranial hypertension (IIH) is a syndrome of elevated intracranial tension without hydrocephalus or mass lesions and with normal CSF composition. Neuroimaging plays an important role in excluding secondary causes of raised intracranial tension. As the clinical presentation is varied, imaging may also help the clinician in arriving at the diagnosis of IIH with the help of a few specific signs. In this review, we attempt to compile the salient magnetic resonance imaging findings in these two conditions. Careful observation of these findings may help in early accurate diagnosis and to provide appropriate early treatment.
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    'Susceptibility sign' on susceptibility-weighted imaging in acute ischemic stroke
    (NEUROLOGY INDIA, 2012)
    Background and Aim: Acute intra-arterial thrombus produces susceptibility artifact on gradient echo images (susceptibility sign). Our aim was to study the sensitivity and specificity of the susceptibility sign in various major intracranial arteries on susceptibility-weighted imaging (SWI) in patients with acute stroke. We also compared it with the 'hyperintensity sign' on fluid-attenuated inversion recovery (FLAIR) and 'hyperdense artery sign' on computed tomography (CT) for middle cerebral artery (MCA) occlusion. Materials and Methods: We have retrospectively studied 48 patients with ischemic stroke in various stages, due to intracranial arterial occlusions, for presence of 'hyperdense artery sign' (CT), 'hyperintense arterial sign' (FLAIR sequence) and 'susceptibility sign' (SWI). The sensitivity and specificity of each sign to detect intracranial arterial occlusion were calculated using the contrast-enhanced magnetic resonance (MR) angiogram as reference standard. Results: The sensitivity and specificity of the 'susceptibility sign' for detecting the MCA occlusion were 77% and 100% respectively (10 of 13). The sensitivity of the 'susceptibility sign' for detecting anterior cerebral artery (ACA) occlusion was 50% (1 of 2), 66.6% for posterior cerebral artery (2 of 3) and 75% for basilar artery (3 of 4). All the vertebral artery occlusions showed 'susceptibility sign' (6 of 6). Overall sensitivity and specificity of the 'susceptibility sign' for all acute major intracranial arterial occlusions were 82% and 100% respectively. Only one of the two cases of subacute infarcts studied showed a positive susceptibility sign. None of the 11 chronic intracranial occlusions and seven internal carotid occlusions showed the sign intracranially. Conclusion: 'Susceptibility sign' is more sensitive in detecting the acute MCA thrombus as compared to 'hyperdense MCA sign' on CT and 'hyperintense artery' sign on FLAIR images. It also has high sensitivity and specificity for other intracranial acute arterial occlusions.