J Clin Neurol.  2006 Jun;2(2):107-112. 10.3988/jcn.2006.2.2.107.

Diffusion Weighted Imaging Findings in the Acute Lateral Medullary Infarction

• Seo MJ
• Roh SY
• Kyun YS
• Yu HJ
• Cho YK

• KMID: 1700742
• DOI: http://doi.org/10.3988/jcn.2006.2.2.107

Abstract

BACKGROUND AND PURPOSE
Negative findings on diffusion-weighted imaging (DWI) does not exclude the possibility of brainstem infarction, particularly in the acute stage of medullary lesion. Our aim was to investigate the false-negative rate of DWI in patients with acute lateral medullary infarction.
METHODS
We applied DWI to 26 patients with a clinical diagnosis of lateral medullary infarction within 72 h of the onset. We assessed relationships between initial DWI findings and time-to-MRI (the time between onset of symptoms and initial DWI), number of clinical symptoms and signs, and final lesion volume.
RESULTS
There were 8 cases (31%) of false negatives in the initial DWI results. The occurrence of false-negative DWI findings decreased significantly as the time-to-MRI increased (P=0.014). However, the false-negative rate was not significantly correlated with the number of clinical symptoms and signs or the final lesion volume.
CONCLUSIONS
The diagnosis of lateral medullary infarction should not be ruled out on the basis of early negative DWI. To confirm the lesion, follow-up DWI or further MRI should be performed in cases with early negative DWI results

Keyword

Lateral medullary infarction; False-negative DWI; Time-to-MRI

MeSH Terms

Brain Stem Infarctions
Diagnosis
Diffusion*
Follow-Up Studies
Humans
Infarction*
Magnetic Resonance Imaging

Figure

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  Figure 1 Case 1: A 69-year-old male patient with acute lateral medullary infarction. (A, B) At 8 h after onset of symptoms, initial diffusion-weighted imaging (DWI) shows no abnormal signal intensity. (C, D) At 63 h after onset of symptoms, the follow-up DWI and FLAIR imaging show a clear hyperintensity in the right lateral medullar area, matching the clinical presentation.

• 

  Figure 2 Case 22: A 67-year-old female patient with acute lateral medullary infarction. (A) At 6 h after onset of symptoms, initial DWI shows no abnormal signal intensity. (B) At 96 h after onset of symptoms, FLAIR imaging shows hyperintensity in the right lateral medullar area, matching the clinical presentation. In comparison, the follow-up DWI is considered normal (C, D).

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