Middle Cerebral Artery (MCA) Susceptibility Sign at Susceptibility-based Perfusion MR Imaging: Clinical Importance and Comparison with Hyperdense MCA Sign at CT<sup>1</sup>

SUMMARY:Vascular hyperintensities have been noted on FLAIR sequences obtained in the setting of acute stroke and intracranial steno-occlusive disease. The presence of FVHs likely represents disordered blood flow, often from collaterals distal to arterial occlusion or stenosis. As opposed to other vessel signs seen in arterial insufficiency, FVH is unique in that it does not represent thrombus, but rather sluggish or disordered blood flow through vessels. This review will discuss the diagnostic and prognostic value of FVH and its impact on clinical decision-making.ABBREVIATIONS: DWI ϭ diffusion-weighted imaging; FLAIR ϭ fluid-attenuated inversion recovery; FVH ϭ FLAIR vascular hyperintensity; GRE-BA ϭ gradient-echo susceptibility vessel blooming artifacts; HMCAS ϭ hyperdense MCA sign seen on CT; HVS ϭ hyperintense vessel sign; MCA ϭ middle cerebral artery; MRA ϭ MR angiography; MRI ϭ MR imaging; NIHSS ϭ National Institutes of Health Stroke Scale; PWI ϭ perfusion-weighted imaging; rtPA ϭ recombinant tissue plasminogen activator; TOF ϭ time of flight; TIA ϭ transient ischemic attacks A dvances in MR imaging have allowed better characterization of tissue and vessel status in cerebrovascular diseases, including acute stroke. Although the particular MR imaging sequences used for evaluation of stroke vary among institutions, FLAIR sequences are usually obtained. FLAIR sequences have a high sensitivity and specificity for the evaluation of brain parenchyma pathology and the subarachnoid spaces. 1,2One frequently encountered imaging finding in acute ischemic stroke is high signal intensity within blood vessels on FLAIR sequences (Fig 1). We aimed to review the current understanding of the etiology, physiology, and clinical significance of FVH. This underappreciated neuroimaging sign may have important clinical implications.In the past decade, FVHs have been associated with largevessel occlusion 3-7 or stenosis. 8 This finding has been termed "FVH," "hyperintense vessel sign," "hyperintense vessels on FLAIR," and the "ivy sign" (Table). For this review, it will be referred to exclusively as FVH. FVHs are described as focal, tubular, or serpentine hyperintensities seen, often transiently, in the subarachnoid space against the relative hypointensity of CSF. As opposed to other vessel signs seen in arterial insufficiency, FVH is unique in that it does not represent thrombus but rather is a representation of the sluggish or disordered blood flow through vessels, most often leptomeningeal collaterals.9,10 Its presence indicates regions of abnormal blood flow and potentially salvageable brain tissue in acute stroke. This review will discuss the diagnostic and prognostic value of FVH and its impact on clinical decision-making. Identification of FVHThe key to identification of FVH is to be aware of its appearance and of the clinical conditions in which it appears with greater frequency. Although the most frequent location is within the Sylvian fissure, FVH has been noted within distal branches of the anterior, middle, and posteri...

Section: Prognostic Valuementioning

confidence: 99%

Fluid-Attenuated Inversion Recovery Vascular Hyperintensities: An Important Imaging Marker for Cerebrovascular Disease

Azizyan

Sanossian²,

Mogensen³

et al. 2010

“…A gradient recalled-echo (GRE) MR imaging sequence is commonly used to identify brain hemorrhage, and it may also differentiate fibrin-rich from erythrocyte-rich thrombus on the basis of the presence of a susceptibility vessel sign (SVS). 5,6 There has been no study addressing the prognostic value of SVS in predicting good clinical recovery after MT, to our knowledge. The goal of our study was, therefore, to investigate whether the presence of the SVS is related to better clinical outcomes after MT with stent retrievers in patients presenting with ACAS.…”

mentioning

confidence: 99%

Susceptibility Vessel Sign on MRI Predicts Favorable Clinical Outcome in Patients with Anterior Circulation Acute Stroke Treated with Mechanical Thrombectomy

Bourcier¹,

Volpi²,

Guyomarch

et al. 2015

“…[4][5][6][7][8] Thromboembolus in the MCA is known to create the MCA susceptibility vessel sign (SVS) on gradient recalled-echo (GRE) MR imaging. 9,10 This sign results from a T2-shortening effect of intracellular deoxyhemoglobin in the acute stage of a red blood cell clot. 9 Thus, the MCA SVS is more commonly seen in red blood cell-dominant and mixed clots and can reflect the clot composition.…”

mentioning

confidence: 99%

Potential for the Use of the Solitaire Stent for Recanalization of Middle Cerebral Artery Occlusion without a Susceptibility Vessel Sign

Bae¹,

Jung²,

Kim³

et al. 2013

BACKGROUND AND PURPOSE:Absence of the MCA susceptibility vessel sign (negative MCA susceptibility vessel sign) on gradient recalled-echo MR imaging in acute stroke is commonly associated with in situ stenosis and thrombotic occlusion. We evaluated the effectiveness and safety of the Solitaire stent as the first-line device for the recanalization of MCA occlusion with a negative MCA susceptibility vessel sign.