Neurological Imaging Indications

Imaging is a question-and-clock decision, not a search for the most detailed picture. When intracranial bleeding or a treatable arterial occlusion is possible, the first test must be fast enough to protect a treatment window: non-contrast CT answers whether acute blood is present, while CT angiography shows the relevant vessels. MRI, particularly diffusion-weighted imaging, is more sensitive for early infarction and many posterior fossa or white-matter lesions, but its longer acquisition and safety screening can make it the wrong first test in an unstable emergency. The same symptom therefore leads to different pathways depending on onset, neurological examination, trauma history, age, and red flags.