An MRI is needed when doctors think there is inflammation, a tumor, or something medically wrong with the brain that we can't see on the outside.
Cardiovascular is probably your answer
Cardio- the heart
Vascular- vessels
Circulatory- blood
Organs or organ systems are directly below the hierarchical organization of life. For an organism to act or function properly organ systems are needed to exist. The following are examples of organ systems that are needed by an organism:
1. Nervous System
2. Digestive System
3. Reproductive System
4. Respiratory System
5. Muscular System
6. Skeletal System
7. Endocrine System
8. Immune System
9. Excretory System
10. Circulatory System
11. Integumentary System
There are more than 3 million US cases per year
