The main purpose of this study is to assess the induction of neuroinflammation in brain regions of interest for learning and memory in adult patients undergoing urological surgery under general anesthesia

The investigators aim to study immune cell activation as a biomarker for neuroinflammation using the cell specific [11C]PBR28 probe as detected by PET imaging techniques.

Inclusion Criteria:

1. Patients 60-75 years of age. American Society for Anesthesiologist' criteria (ASA) physical status I-III
2. Lower abdominal surgery (hysterectomy/prostatectomy) under general anaesthesia
3. Obtained consent within 3 months before execution of the study.

Exclusion Criteria:

1. Patient's refusal to participate in the trial
2. Ongoing smoking, snuff or other nicotine compound treatment
3. Disabling neuropsychiatrical disorder (a Mini mental State Examination (MMSE) score ≤ 24, diagnosis of dementia, Mb Alzheimer, Mb Parkinson, schizophrenia, or mental depression) or other signs of significant cognitive decline.
4. History of stroke with neurological sequelae
5. Surgical procedure scheduled for regional anaesthesia.
6. Severe cardia and/or renal and/or hepatic impairment.
7. Coagulopathy.
8. Terminal phase of a chronic disease.
9. Patient on steroidal or non-steroidal anti-inflammatory drugs.
10. Admission B-Glucose > 15 mmol/litre or poorly controlled diabetes mellitus.
11. Presumed uncooperativeness or legal incapacity.
12. Preoperative or later postoperative B-hemoglobin < 90 g/L.