Is it possible to miss a stroke on ct scan? is mri always done?

Most often MRI done: An early stroke or a small stroke are the two most common strokes missed on a ct scan. An MRI is almost always done on every stroke patient as it gives a clearer picture of the stroke.

Not always: Ct is not good for stroke in the first 6-24 hrs, especially in small strokes. It is always done however because it is more accessible, is cheaper, and because it is necessary to exclude a brain bleed. Mri is far superior in stroke detection, assuming the patient has no contraindications, like a pacemaker.