Diffusion-weighted echo-planar MRI of lacunar infarcts

Area of Science:

• Neuroradiology
• Magnetic Resonance Imaging (MRI)

Background:

• Lacunar infarcts are small ischemic strokes.
• Accurate detection of lacunar infarcts is crucial for diagnosis and management.
• Conventional MRI sequences may have limitations in visualizing small or early-stage infarcts.

Purpose of the Study:

• To evaluate the utility of diffusion-weighted echo-planar imaging (DW-EPI) for detecting lacunar infarcts.
• To compare the conspicuity of lesions on DW-EPI with conventional MRI sequences.
• To assess the ability of DW-EPI to characterize infarcts based on their age.

Main Methods:

• Study included 35 patients with lacunar infarcts.
• Utilized 1.5 T MRI with diffusion-weighted echo-planar imaging (DW-EPI).
• Calculated relative apparent diffusion coefficient ratio (ADCR) and compared lesion conspicuity with fast fluid-attenuated inversion recovery and T2-weighted fast spin-echo sequences.

Main Results:

• DW-EPI identified acute infarcts (<3 days) as areas of decreased ADCR and high signal.
• Subacute infarcts (4-30 days) showed high-signal or isointense areas with decreased/normal ADCR.
• Chronic infarcts (>30 days) appeared as low/high-signal areas with normal/increased ADCR.
• DW-EPI detected hyperacute brainstem infarcts (<6h) and fresh infarcts adjacent to old ones, which were missed by other sequences.

Conclusions:

• DW-EPI is a sensitive technique for detecting lacunar infarcts across different age groups.
• DW-EPI offers superior lesion conspicuity compared to conventional MRI sequences for small infarcts.
• DW-EPI is particularly valuable for identifying hyperacute and subtle lacunar infarcts.