Background: In a general population of patients with stroke, the rate of new MRI lesions at 1 week was much higher than expected. With patients with minor stroke and TIA having a higher risk of recurrent clinical even...Background: In a general population of patients with stroke, the rate of new MRI lesions at 1 week was much higher than expected. With patients with minor stroke and TIA having a higher risk of recurrent clinical events, the authors examined whether patients with minor stroke and TIA also had a high rate of asymptomatic lesions on repeat MRI scanning. Methods: Patients with minor stroke and TIA presenting within 12 hours of symptom onset with a NIH Stroke Scale score less than six, who had a baseline MRI and a 1-month follow-up, were enrolled in this study. The follow-up study was examined for new diffusion-weighted imaging lesions as compared to the baseline study. Clinical or MRI factors predicting recurrent lesions were examined. Results: A total of 143 patients were enrolled and 14 patients (9.8%; 95%CI 5.4, 15.9) had MR evidence of new lesions at 30 days. Six of these new lesions were clinically asymptomatic (42.9%; 95%CI 17.7, 71.1). A trend to increased likelihood of new lesions at 30 days was seen with progressing baseline scan lesion number (none [2.2%], solitary [12.9%], multiple [19.8%]: p = 0.046). Patients whose mechanism of stroke was large artery or cardioembolic were the most likely to have new lesions on follow-up MRI. Conclusion: Minor stroke and TIA are associated with a 10%risk of new lesions on MRI and half of these new lesions are asymptomatic. This risk is lower than seen in more severely affected patients with stroke. Patients with multiple lesions at baseline are at an increased risk for new ischemic lesions.展开更多
Objectives: In this study we define the probability of vascular abnormality in the middle cerebral artery (MCA) territory according to the extent of ischaemic change seen using computed tomography (CT). We assessed th...Objectives: In this study we define the probability of vascular abnormality in the middle cerebral artery (MCA) territory according to the extent of ischaemic change seen using computed tomography (CT). We assessed the sensitivity and spe cificity of the hyperdense middle cerebral artery (HMCA) and the “dot”sign usi ng magnetic resonance angiography (MRA). Methods: Patients presenting with ischa emic stroke had a CT scan ( < 6h)prior to MRI (< 7 h). A quantitative CT scoring system (ASPECTS) was applied to CT and diffusion weighted images (DWI) at basel ine and follow up (24 h) by five independent observers. The presence of HMCA and the MCA "dot" sign was also evaluated. An expert reader assessed the 3D time of flight (TOF) MRA in the anterior circulation for areas of decreased vascular si gnal in the MCA territory, with an absent signal taken to represent severely red uced or absent flow. Results: A total of 100 consecutive patients had baseline C T and MR scans. The median NIHSS was 9. The median CT ASPECTS was 8 and equalled the median DWI ASPECTS. There were a total of 10 HMCA and 19 MCA “dot”signs, with four patients having both HMCA and “dot”signs. A total of 47 MRA flow sig nal abnormalities were observed in the anterior circulation. Conclusions: In the absence of accessible neurovascular imaging, the extent of CT ischaemia (ASPECT S) is a strong predictor of vascular occlusion. The CT hyperdense artery signs h ave a high positive predictive value but low negative predictive value.展开更多
文摘Background: In a general population of patients with stroke, the rate of new MRI lesions at 1 week was much higher than expected. With patients with minor stroke and TIA having a higher risk of recurrent clinical events, the authors examined whether patients with minor stroke and TIA also had a high rate of asymptomatic lesions on repeat MRI scanning. Methods: Patients with minor stroke and TIA presenting within 12 hours of symptom onset with a NIH Stroke Scale score less than six, who had a baseline MRI and a 1-month follow-up, were enrolled in this study. The follow-up study was examined for new diffusion-weighted imaging lesions as compared to the baseline study. Clinical or MRI factors predicting recurrent lesions were examined. Results: A total of 143 patients were enrolled and 14 patients (9.8%; 95%CI 5.4, 15.9) had MR evidence of new lesions at 30 days. Six of these new lesions were clinically asymptomatic (42.9%; 95%CI 17.7, 71.1). A trend to increased likelihood of new lesions at 30 days was seen with progressing baseline scan lesion number (none [2.2%], solitary [12.9%], multiple [19.8%]: p = 0.046). Patients whose mechanism of stroke was large artery or cardioembolic were the most likely to have new lesions on follow-up MRI. Conclusion: Minor stroke and TIA are associated with a 10%risk of new lesions on MRI and half of these new lesions are asymptomatic. This risk is lower than seen in more severely affected patients with stroke. Patients with multiple lesions at baseline are at an increased risk for new ischemic lesions.
文摘Objectives: In this study we define the probability of vascular abnormality in the middle cerebral artery (MCA) territory according to the extent of ischaemic change seen using computed tomography (CT). We assessed the sensitivity and spe cificity of the hyperdense middle cerebral artery (HMCA) and the “dot”sign usi ng magnetic resonance angiography (MRA). Methods: Patients presenting with ischa emic stroke had a CT scan ( < 6h)prior to MRI (< 7 h). A quantitative CT scoring system (ASPECTS) was applied to CT and diffusion weighted images (DWI) at basel ine and follow up (24 h) by five independent observers. The presence of HMCA and the MCA "dot" sign was also evaluated. An expert reader assessed the 3D time of flight (TOF) MRA in the anterior circulation for areas of decreased vascular si gnal in the MCA territory, with an absent signal taken to represent severely red uced or absent flow. Results: A total of 100 consecutive patients had baseline C T and MR scans. The median NIHSS was 9. The median CT ASPECTS was 8 and equalled the median DWI ASPECTS. There were a total of 10 HMCA and 19 MCA “dot”signs, with four patients having both HMCA and “dot”signs. A total of 47 MRA flow sig nal abnormalities were observed in the anterior circulation. Conclusions: In the absence of accessible neurovascular imaging, the extent of CT ischaemia (ASPECT S) is a strong predictor of vascular occlusion. The CT hyperdense artery signs h ave a high positive predictive value but low negative predictive value.
