scholarly journals Magnetic Resonance Imaging of Acute Stroke

1998 ◽  
Vol 18 (6) ◽  
pp. 583-609 ◽  
Author(s):  
Alison E. Baird ◽  
Steven Warach
Keyword(s):  
Ischemic Stroke ◽  
Magnetic Resonance ◽  
Acute Stroke ◽  
Perfusion Imaging ◽  
Diffusion Weighted Imaging ◽  
Mr Angiography ◽  
Great Promise ◽  
Proton Density ◽  
Diffusion Weighted ◽  
Cerebral Ischemic

In the investigation of ischemic stroke, conventional structural magnetic resonance (MR) techniques (e.g., T1-weighted imaging, T2-weighted imaging, and proton density-weighted imaging) are valuable for the assessment of infarct extent and location beyond the first 12 to 24 hours after onset, and can be combined with MR angiography to noninvasively assess the intracranial and extracranial vasculature. However, during the critical first 6 to 12 hours, the probable period of greatest therapeutic opportunity, these methods do not adequately assess the extent and severity of ischemia. Recent developments in functional MR imaging are showing great promise for the detection of developing focal cerebral ischemic lesions within the first hours. These include (1) diffusion-weighted imaging, which provides physiologic information about the self-diffusion of water, thereby detecting one of the first elements in the pathophysiologic cascade leading to ischemic injury; and (2) perfusion imaging. The detection of acute intraparenchymal hemorrhagic stroke by susceptibility weighted MR has also been reported. In combination with MR angiography, these methods may allow the detection of the site, extent, mechanism, and tissue viability of acute stroke lesions in one imaging study. Imaging of cerebral metabolites with MR spectroscopy along with diffusion-weighted imaging and perfusion imaging may also provide new insights into ischemic stroke pathophysiology. In light of these advances in structural and functional MR, their potential uses in the study of the cerebral ischemic pathophysiology and in clinical practice are described, along with their advantages and limitations.

Diffusion imaging of cerebral diaschisis in childhood arterial ischemic stroke

2016 ◽  
Vol 11 (9) ◽  
pp. 1028-1035 ◽  
Author(s):  
Adam Kirton ◽  
Elizabeth Williams ◽  
Michael Dowling ◽  
Sarah Mah ◽  
Jacquie Hodge ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Ischemic Stroke ◽  
Magnetic Resonance ◽  
Diffusion Weighted Imaging ◽  
Infarct Volume ◽  
Resonance Imaging ◽  
Arterial Ischemic Stroke ◽  
Diffusion Weighted ◽  
Motor Outcome

Background Diffusion-weighted imaging magnetic resonance imaging may detect changes in brain structures remote but connected to stroke consistent with neuropathological descriptions of diaschisis. Early diffusion-weighted imaging demonstrates restriction in corticospinal pathways after arterial ischemic stroke of all ages that correlates with motor outcome. Aim/hypothesis We hypothesized that cerebral diaschisis is measurable in childhood arterial ischemic stroke and explored associations with outcome. Methods This sub-study of the validation of the Pediatric NIH Stroke Scale study prospectively enrolled children with acute arterial ischemic stroke and both acute and early follow-up (5–14 days) diffusion-weighted imaging. Inclusion criteria were (1) unilateral middle cerebral artery arterial ischemic stroke, (2) acute and subacute diffusion-weighted imaging ( b = 1000), and (3) 12 month neurological follow-up (Pediatric Stroke Outcome Measure). A validated method using ImageJ software quantified diffusion-weighted imaging diaschisis in anatomically connected structures. Diaschisis measures were corrected for infarct volume, compared to age, imaging timing, and outcomes (Chi square/Fisher, Mann–Whitney test). Results Nineteen children (53% male, median 8.1 years) had magnetic resonance imaging at medians of 21 and 168 h post-stroke onset. Diaschisis was common and evolved over time, observed in one (5%) on acute but eight (42%) by follow-up diffusion-weighted imaging. Thalamic and callosal diaschisis were most common (5, 26%). Estimates of perilesional diaschisis varied (54 ± 18% of infarct volume). Children with diaschisis tended to be younger (7.02 ± 5.4 vs. 11.82 ± 4.3 years, p = 0.08). Total diaschisis score was associated with poor cognitive outcomes ( p = 0.03). Corticospinal tract diaschisis was associated with motor outcome ( p = 0.004). Method reliability was excellent. Conclusions Diffusion-weighted imaging diaschisis occurs in childhood arterial ischemic stroke. Mistaking diaschisis for new areas of infarction carries important clinical implications. Improved recognition and study are required to establish clinical relevance.

scholarly journals Reliability of Smartphone for Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomography Scores in Acute Ischemic Stroke Patients: Diagnostic Test Accuracy Study

10.2196/15893 ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. e15893
Author(s):  
Kenichiro Sakai ◽  
Teppei Komatsu ◽  
Yasuyuki Iguchi ◽  
Hiroyuki Takao ◽  
Toshihiro Ishibashi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Acute Stroke ◽  
Diffusion Weighted Imaging ◽  
Interrater Agreement ◽  
Great Promise ◽  
Smartphone App ◽  
Test Accuracy ◽  
Computed Tomography Images ◽  
Diffusion Weighted ◽  
Medical App

Background High-quality neuroimages can be viewed using a medical app installed on a smartphone. Although interdevice agreement between smartphone and desktop PC monitor was found to be favorable for evaluating computed tomography images, there are no interdevice agreement data for diffusion-weighted imaging (DWI). Objective The aim of our study was to compare DWI interpretation using the Join smartphone app with that using a desktop PC monitor, in terms of interdevice and interrater agreement and elapsed interpretation time. Methods The ischemic change in the DWI of consecutive patients with acute stroke in the middle cerebral artery territory was graded by 2 vascular neurologists using the Join smartphone app and a desktop PC monitor. The vascular neurologists were blinded to all patient information. Each image was categorized as either Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomography Scores (DWI-ASPECTS) ≥7 or DWI-ASPECTS <7 according to the Japanese Society for Neuroendovascular Therapy. We analyzed interdevice agreement and interrater agreement with respect to DWI-ASPECTS. Elapsed interpretation time was compared between DWI-ASPECTS evaluated by the Join smartphone app and a desktop PC monitor. Results We analyzed the images of 111 patients (66% male; median age=69 years; median National Institutes of Health Stroke Scale score on admission=4). Interdevice agreement regarding DWI-ASPECTS between the smartphone and the desktop PC monitor was favorable (vascular neurologist 1: κ=0.777, P<.001, vascular neurologist 2: κ=0.787, P<.001). Interrater agreement was also satisfactory for the smartphone (κ=0.710, P<.001) and the desktop PC monitor (κ=0.663, P<.001). Median elapsed interpretation time was similar between the smartphone and the desktop PC monitor (vascular neurologist 1: 1.7 min vs 1.6 min; P=.64); vascular neurologist 2: 2.4 min vs 2.0 min; P=.14). Conclusions The use of a smartphone app enables vascular neurologists to estimate DWI-ASPECTS accurately and rapidly. The Join medical smartphone app shows great promise in the management of acute stroke.

Sign in / Sign up

Export Citation Format

Share Document