Diagnosis of acute ischaemic stroke with fluid-attenuated inversion recovery and diffusion-weighted sequences

Abstract

We evaluated the feasibility and use of diffusion-weighted and fluid-attenuated inversion-recovery pulse sequences performed as an emergency for patients with acute ischaemic stroke. A 5-min MRI session was designed as an emergency diagnostic procedure for patients admitted with suspected acute ischaemic stroke. We reviewed routine clinical implementation of the procedure, and its sensitivity and specificity for acute ischaemic stroke over the first 8 months. We imaged 91 patients (80 min to 48 h following the onset of stroke). Clinical deficit had resolved in less than 3 h in 15 patients, and the remaining 76 were classified as stroke (59) or stroke-like (17) after hospital discharge. Sensitivity of MRI for acute ischaemic stroke was 98%, specificity 100%. MRI provided an immediate and accurate picture of the number, site, size and age of ischaemic lesions in stroke and simplified diagnosis in stroke-like episodes. The feasibility and high diagnostic accuracy of emergency MRI in acute stroke strongly support its routine use in a stroke centre.

Prediction of Malignant Middle Cerebral Artery Infarction by Diffusion-Weighted Imaging

“…14 With the advent of diffusion-weighted imaging (DWI) in clinical MRI units, this technique is increasingly being used to image acute-stroke patients. Despite the thoroughly documented diagnostic power of DWI for diagnosing acute stroke, [15][16][17][18] its ability to identify the extent of the so-called ischemic penumbra (by the combination of DWI and perfusion imaging), 19 and its prognostic value on clinical outcome, 20,21 the use of DWI for the early prediction of malignant MCA infarction has not been reported. We compared the DWI obtained within 14 hours after stroke onset in MCA infarction between a group of patients who subsequently developed malignant MCA infarction and a group of patients who did not.…”

Ischaemic Stroke - Clinical Profile and Evaluation With Electroencephalography and Mri Brain

“…[25] Acutely ischaemic lesions demonstrate high signal of DWI (Diffusion Weighted Imaging) and low signal on ADC (Apparent Diffusion Coefficient) maps within minutes. [26] FLAIR images demonstrate abnormal signal sooner than T2WI and have been shown to detect infarcts within 3 hours after onset of acute stroke. [27] …”

Prognostic Value of Hyperintense Vessel Signals on Fluid-Attenuated Inversion Recovery Sequences in Acute Cerebral Ischemia

“…In almost 50% of stroke patients who undergo MRI with the first 24 h after stroke onset, they also reveal hyperintense vessel signals (HVS) [5]. HVS are associated with vessel occlusion on TOF sequences [6]. They have been identified from 35 min up to 13 days after stroke onset [8] and are associated with cerebral infarction as a result of large-vessel occlusion with inadequacy of collateral circulation [4].…”

“…National Institute of Health Stroke Scale (NIHSS) scores are higher in patients with HVS involving the whole (middle cerebral artery) MCA territory [4], and resolution of HVS is associated with improvement of transcranial Doppler velocities and decrease in NIHSS scores [4]. The significance of HVS on FLAIR sequences remains unknown: HVS may be related to severe flow reduction, intra-luminal thrombus or emboli [6] or retrograde collateral circulation [5, 7, 9]. The most likely hypothesis is a sluggish blood flow within dilated blood vessels located near ischemic tissue, explaining why HVS may also be present in symptomatic patients with multiple intracerebral acute stenosis [10].…”

“…Fluid-attenuated inversion recovery (FLAIR) sequences identify pre-existing cerebral lesions (such as old infarcts), white matter changes and non-ischemic lesions mimicking infarcts (such as intra-cerebral hemorrhages, demyelinating lesions or tumors) [4,5,6,7]. In almost 50% of stroke patients who undergo MRI with the first 24 h after stroke onset, they also reveal hyperintense vessel signals (HVS) [5].…”