Which statement best describes noncontrast CT in stroke evaluation?

Which statement best describes noncontrast CT in stroke evaluation?

• A. Cannot detect hemorrhage
• B. More widely available than MRI and quickly detects acute brain hemorrhage; may not identify ischemia in the first hours
• C. Always identifies early ischemia
• D. Is more expensive than MRI

Answer: (B)

In acute stroke evaluation, the first imaging step is noncontrast CT because it can be performed rapidly, is widely available, and is the fastest way to determine if there is a brain bleed. Detecting acute hemorrhage quickly is crucial since it guides safe treatment decisions, especially regarding thrombolysis or other reperfusion therapies. While noncontrast CT excels at ruling in or out hemorrhage, its sensitivity for identifying early ischemic changes in the first hours after onset is limited, so a normal scan does not rule out an ischemic stroke. If there’s still high suspicion for ischemia despite a negative CT, MRI with diffusion weighting can detect early infarct more reliably, and perfusion imaging can help assess tissue at risk. The idea that noncontrast CT always identifies early ischemia isn’t correct, and CT is generally less expensive and more accessible than MRI, which is why this modality is the standard initial study.

In acute stroke evaluation, the first imaging step is noncontrast CT because it can be performed rapidly, is widely available, and is the fastest way to determine if there is a brain bleed. Detecting acute hemorrhage quickly is crucial since it guides safe treatment decisions, especially regarding thrombolysis or other reperfusion therapies. While noncontrast CT excels at ruling in or out hemorrhage, its sensitivity for identifying early ischemic changes in the first hours after onset is limited, so a normal scan does not rule out an ischemic stroke. If there’s still high suspicion for ischemia despite a negative CT, MRI with diffusion weighting can detect early infarct more reliably, and perfusion imaging can help assess tissue at risk. The idea that noncontrast CT always identifies early ischemia isn’t correct, and CT is generally less expensive and more accessible than MRI, which is why this modality is the standard initial study.