| Date | May 2013 | Marks available | 2 | Reference code | 13M.3.HL.TZ2.22 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | State | Question number | 22 | Adapted from | N/A |
Question
This question is about nuclear magnetic resonance (NMR) imaging.
Outline the physical principles of NMR imaging.
State two advantages of NMR imaging over computed tomography (CT) imaging.
1.
2.
Markscheme
a magnetic field is applied (eg to a patient);
protons/H nuclei (in patient) have spin/magnetic moment;
which align with the field / have different energy levels;
a radio frequency (RF) field (at resonant/Larmor frequency) is turned on;
which changes the spin orientation/energy levels;
the protons/nuclei then emit an RF pulse (as they de-excite);
which is detected to determine the position of the proton/nuclei;
no exposure to harmful radiation;
better quality image;
Examiners report
Both parts of this question were answered very well. It is clear that previous questions on NMR imaging have reaped benefits as now the majority can list most of the main physical principles involved.
Both parts of this question were answered very well. It is clear that previous questions on NMR imaging have reaped benefits as now the majority can list most of the main physical principles involved.
