Which imaging modality is very accurate for differentiating ischemic from hemorrhagic stroke?

Which imaging modality is very accurate for differentiating ischemic from hemorrhagic stroke?

• A. MRI of the brain
• B. CT angiography
• C. Noncontrast CT
• D. PET scan

Answer: (C)

The main idea is to quickly distinguish hemorrhagic from ischemic stroke in the acute setting, since this determines immediate management decisions like thrombolysis. Noncontrast CT of the head is the best initial test for this purpose because it rapidly detects acute intracranial bleeding as a visible hyperdense area. If blood is seen, the diagnosis is hemorrhagic stroke and thrombolysis is contraindicated. If no hemorrhage is detected, ischemic stroke is considered more likely, allowing timely consideration of reperfusion therapy within the appropriate window. MRI can be more sensitive for detecting early ischemia, but it isn’t as fast or widely available in many emergency settings, which is why noncontrast CT remains the standard first-line study to differentiate the two stroke types. CT angiography adds vascular detail but isn’t necessary for distinguishing hemorrhage from ischemia in most urgent cases.

The main idea is to quickly distinguish hemorrhagic from ischemic stroke in the acute setting, since this determines immediate management decisions like thrombolysis. Noncontrast CT of the head is the best initial test for this purpose because it rapidly detects acute intracranial bleeding as a visible hyperdense area. If blood is seen, the diagnosis is hemorrhagic stroke and thrombolysis is contraindicated. If no hemorrhage is detected, ischemic stroke is considered more likely, allowing timely consideration of reperfusion therapy within the appropriate window.

MRI can be more sensitive for detecting early ischemia, but it isn’t as fast or widely available in many emergency settings, which is why noncontrast CT remains the standard first-line study to differentiate the two stroke types. CT angiography adds vascular detail but isn’t necessary for distinguishing hemorrhage from ischemia in most urgent cases.