Development of brain infarct volume as assessed by magnetic resonance imaging (MRI): Follow‐up of diffusion‐weighted MRI lesions
ABSTRACT PurposeTo investigate the development of ischemic brain lesions, as present in the acute stroke phase, by diffusion-weighted magnetic resonance imaging (DWI), and in the subacute and chronic phases until up to four months after stroke, in fluid-attenuated inversion recovery (FLAIR)- and T2-weighted (T2W) magnetic resonance (MR) images.Materials and Methods
Twelve consecutive patients with their first middle cerebral artery (MCA) infarction were included. Lesion volumes were assessed on T2W images recorded with a turbo spin echo (TSE) and on images recorded with the FLAIR sequence on average on day 8 and after about four months. They were compared with acute lesion volumes in perfusion and DWI images taken within 24 hours of stroke onset.ResultsOn day 8, lesion volumes in images obtained with FLAIR exceeded the acute infarct volumes in DWI. The chronic lesion volumes were almost identical in T2W and FLAIR images but significantly reduced compared with the acute DWI lesions. The lesion volumes assessed on DWI images correlated highly with the lesions in the images obtained with TSE or FLAIR, as did the lesions in the images obtained with FLAIR and TSE. The secondary lesion shrinkage was accompanied by ventricular enlargement and perilesional sulcal widening, as most clearly visible in the images obtained with FLAIR.Conclusion
Our results show that the acute DWI lesions are highly predictive for the infarct lesion in the chronic stage after stroke despite a dynamic lesion evolution most evident in MR images obtained with FLAIR. J. Magn. Reson. Imaging 2004;20:201–207. © 2004 Wiley-Liss, Inc.
- SourceAvailable from: Olivier Naggara[Show abstract] [Hide abstract]
ABSTRACT: By probing microscopic molecular motions, diffusion-weighted imaging (DWI) is the only method available today that provides noninvasively information on molecular displacements over distances comparable to cell dimensions. Since it measures a parameter different from those assessed by conventional MRI, DWI represents a new imaging technique that goes beyond depiction of neuroanatomy and evaluates function and physiopathology. Image contrast is related to differences in the diffusion rate of water molecules rather than to changes in total tissue water. DWI has proven its high sensitivity in early detection of acute infarction; it is reliable in differentiating acute stroke from other diseases that mimic acute stroke in clinical terms and on conventional MR images. By differentiating lesions with decreased diffusion from those with increased diffusion, DWI is useful in the evaluation of a wide variety of other disease processes including neoplasms, demyelization, traumatic brain injury, intracranial infections. In particular, DWI can distinguish between epidermoid and arachnoid cysts and provides key information for the diagnosis of cerebral abscess. In some clinical situations, DWI data have a prognostic value.EMC - Radiologie 05/2005; 2(2):133-164.
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ABSTRACT: Transient or minor ischemic stroke is associated with an early risk of deterioration. Baseline perfusion-diffusion mismatch may predict clinical deterioration and infarct growth in this population. High-risk transient ischemic attack and minor stroke (National Institutes of Health Stroke Scale ≤3) subjects were prospectively enrolled and imaged with MRI within 24 hours of symptom onset as part of sequential derivation and validation cohorts. Baseline diffusion-weighted imaging, perfusion-weighted imaging (Tmax≥4 s), mismatch (Tmax≥4 s-diffusion-weighted imaging), and follow-up fluid-attenuated inversion recovery infarct volumes were measured. Primary outcome was infarct growth on fluid-attenuated inversion recovery, and secondary outcome was symptom progression. One hundred thirty-seven and 281 subjects were included in the derivation and validation cohorts, respectively. Infarct growth occurred in 18.5% of the derivation and 5.5% of the validation cohorts. Symptom progression occurred in 9.5% of the derivation and 4.5% of the validation cohorts. In the derivation cohort, subjects with baseline mismatch were significantly more likely to show infarct growth on fluid-attenuated inversion recovery (relative risk [RR], 13.5; 95% confidence interval [CI], 4.2-38.9) and symptom progression (RR, 7.0; 95% CI, 2.0-7.3). A baseline mismatch volume of 10 mL in the derivation cohort was the optimal threshold to predict infarct growth (area under the curve, 0.89; 95% CI, 0.80-0.98). This threshold was highly predictive of infarct growth in the validation cohort (P=0.001). Baseline mismatch was associated with clinical deterioration in the derivation (area under the curve, 0.81; 95% CI, 0.67-0.96) and validation cohorts (area under the curve, 0.66; 95% CI, 0.46-0.85). Among subjects with high-risk transient ischemic attack and minor stroke, diffusion-weighted imaging-perfusion-weighted imaging mismatch predicts infarct growth and clinical deterioration. These findings suggest that reperfusion strategies would be beneficial in this population.Stroke 08/2013; · 6.02 Impact Factor
- RöFo - Fortschritte auf dem Gebiet der R 05/2007; 179(5):516-524. · 1.96 Impact Factor