NMR in medecine

Question 1

What is the use of NMR in body scanning?

Answer 1

Nuclear magnetic resonance has been developed into the medical scanning technique known as magnetic resonance imaging, MRI. MRI has been developed rapidly and is now used routinely for the diagnosis of medical conditions.

Question 2

What happens in the atoms of a patients body when in an MRI scan?

Answer 2

The patient is the sample being analysed. The patient is placed inside a large, cylindrical electromagnet and radio waves are then sent through the body. Protons align with or against the strong magnetic field and they resonate in response to pulses of radio-frequency radiation. Despite this resonance, patients receiving an MRI scan report that they do not feel anything, even though protons in their bodies are resonating in response to the magnetic field and radio waves.

Question 3

What are the hazards of MRI?

Answer 3

• Patients with ferromagnetic metal (Fe,Co,Ni) implatns that would be attracted towards the magnet within the scanner.
• Heart pacemakers area affected by the strong magnetic field.
• Nothing metal should be near the MRI area such as knives,glasses and furniture.
• The MRI can wipe a credit card.

Question 4

Explain how MRI is used in the diagnosis of medical problems.

Answer 4

• MRI produces a 3d image of the protons in water and other hydrogen-containing molecules. Many diseases change the water content within tissues and organs, and the scanner detects these differences.

Question 5

Explain how the NMR picks up different tissue parts in the body.

(eg, does it pick of soft tissue brighter or darker?)

Answer 5

• MRI can make images from almost all parts of the body.
• Bones contain the fewest hydrogen atoms and produce a dark image. Tissues such as fat contain lots of hydrogen atoms and produce a bright image.

Question 6

Why is it easy to detect brain disorders using NMR?

Answer 6

Most brain disorders result in changes to water content and this is reflected in the MR image.