Microembolic signals and diffusion-weighted MR imaging abnormalities in acute ischemic stroke

Area of Science:

• Neuroimaging
• Cerebrovascular Disease
• Diagnostic Ultrasound

Background:

• The clinical significance of microembolic signals (MESs) detected via transcranial Doppler sonography (TCD) in acute ischemic stroke is not fully understood.
• Assessing MESs in conjunction with advanced imaging may clarify their role in stroke pathophysiology.

Purpose of the Study:

• To evaluate diffusion-weighted MR imaging (DWI) findings and clinical characteristics in acute ischemic stroke patients with detected MESs.
• To correlate MES detection with stroke etiology and early imaging markers.

Main Methods:

• Transcranial Doppler (TCD) and diffusion-weighted MRI (DWI) were performed on 28 acute brain infarction patients within 48 hours and 7 days of stroke onset, respectively.
• The study examined the relationship between MESs, DWI findings, stroke risk factors, NIHSS scores, and arterial disease.

Main Results:

• Ten patients (MES group) had detectable MESs, while 18 (control group) did not. No significant differences were observed in stroke risk factors or NIHSS scores between groups.
• Arterial disease was more prevalent in the MES group.
• Small, multifocal ischemic lesions (<10 mm) on DWI were significantly more frequent in the MES group, often undetected by conventional CT/MRI.

Conclusions:

• Patients with MESs detected by TCD and evidence of large-vessel occlusive disease showed a higher frequency of small DWI abnormalities compared to stroke patients without MESs.
• Combined TCD and DWI may offer early insights into acute stroke mechanisms, particularly in cases involving large vessel disease.