[Diffusion-weighted magnetic resonance imaging (MRI) in acute brain stem infarction]

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Context:

• Diffusion-weighted imaging (DWI) is a key MRI technique for detecting acute ischemic lesions.
• Technical limitations of DWI can lead to missed diagnoses in the early stages of stroke.
• Brain stem infarctions present unique diagnostic challenges due to their location and potential for subtle imaging findings.

Purpose:

• To evaluate the sensitivity of initial diffusion-weighted imaging (DWI) in detecting acute brain stem infarctions within 24 hours of symptom onset.
• To determine the rate of missed ischemic lesions on acute DWI in patients with confirmed brain stem infarctions.
• To assess the utility of follow-up MRI in diagnosing brain stem infarctions initially not visualized on DWI.

Summary:

• This retrospective study analyzed 28 patients with confirmed brain stem infarctions who underwent DWI within 24 hours of onset.
• Only 57.1% of acute brain stem infarctions were clearly visualized on initial DWI; 12 cases showed no obvious lesions.
• Follow-up MRI, performed an average of 127 hours later, confirmed infarction in 11 of the 12 initially negative DWI cases, predominantly in the medulla oblongata.

Impact:

• Acute DWI has limited sensitivity for detecting brain stem infarctions, especially in the medulla oblongata.
• Negative acute DWI findings do not rule out brain stem infarction and warrant further investigation with follow-up imaging.
• Understanding DWI limitations is crucial for timely diagnosis and management of acute stroke in the brain stem.