Two hundred million adults worldwide have major surgery every year. A million of these patients will have an obvious stroke after their surgery. Another 10 million patients may have "silent" strokes. Although silent strokes are not diagnosed immediately, they are likely to reduce patients' short-term memory, concentration, and ability to function at home. However, the investigators do not know how common silent strokes are after noncardiac surgery, nor the extent to which they affect brain function.

The investigators will first perform a pilot trial to determine the feasibility of the larger study that will provide the definitive answer to this question. Participating patients will be assessed by questionnaire before and after surgery, and will have a magnetic resonance imaging (MRI) study of the brain after the surgery to look for silent strokes. Combining the results of the MRI and the questionnaires will allow us to determine the frequency of silent strokes after non-cardiac surgery, and their effect on brain function. The NeuroVISION Pilot Study will determine the feasibility of a large study to examine the frequency and the impact of silent stroke in patients who undergo noncardiac surgery.

Inclusion Criteria:

• age 65,
• undergoing noncardiac surgery,
• regional or general anesthetic.

Exclusion Criteria:

-Patients who have a contraindication to MRI.

Patients aged 65 years and older undergoing noncardiac surgery and staying in hospital overnight.