In MRI, which of the following sequences is MOST appropriate for detecting acute ischemic stroke within the first few hours?
- A T1-weighted spin echo
- B T2-weighted turbo spin echo
- C Diffusion-weighted imaging (DWI) ✓
- D Proton density-weighted sequence
Correct answer: C. Diffusion-weighted imaging (DWI)
Explanation
Diffusion-weighted imaging (DWI) detects cytotoxic edema within minutes of acute infarction by showing restricted diffusion as bright signal. It is the most sensitive MRI sequence for early ischemic stroke. T1 and T2 sequences may appear normal in the first few hours. Proton density weighting does not detect early ischemia reliably. DWI is the standard of care for acute stroke imaging.
Reference: Yousem, Neuroradiology: The Requisites, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.