Syllabus: Topic 3D
Physics GCE syllabus: Topic 3C
D1 Nuclear medicine
- Radioisotopes for nuclear
medicine; metastable radionuclides. Production by neutron irradiation and elution methods: in particular
123I, 131I and 99mTc.
- Radionuclides as tracers. Dilution studies; measurement of body
fluids. Uptake studies; use of model or ‘phantom’. Imaging body parts.
- Physiological effects
of radiation. Range and effects of alpha, beta and gamma
radiation. Destruction and mutation of cells.
- Radioactive and biological
half-lives; effective half-lives. Basic principles of radiological protection. 1/te = 1/tr + 1/tb
- Gamma camera. Principles of collimator, scintillation
counter and photomultiplier.
- Use of gamma radiation
for therapy. 60Co sources for destruction of tissue.
- Energy of radioactive
emissions. keV and MeV as measures of the energy of
X-rays and ultrasonics
- X-ray production. The rotating anode X-ray tube. Energy
of accelerated electrons in eV. Efficiency. (Photons and a knowledge of E
= hf are not required.)
- MeV X-rays for therapy. Absorption not strongly dependent on proton
number. Multiple beams and rotational treatment. Alignment devices.
Criticality of dose.
- keV X-rays for diagnosis. Absorption strongly dependent on proton
number. Detection with photographic plates. Radiographs of bones,
tissues and air spaces.
- X-ray geometry. Point source, shadows, use of a lead
anti-scatter grid. Inverse square law.
- Ultrasonics in medicine. The sonar principle. Knowledge of c =
fλ expected: small wavelengths give rise to better
- Scanning methods for ultrasonic
diagnosis. Basic principles only. A-scans and B-scans.
- Reflection and absorption. Acoustic
impedance Z. Dependence of Z on speed of wave and density of medium; Z
= cρ; Reflection coefficient = (Z1 – Z2)2/(Z1 + Z2)2; The need for a coupling medium.
- Comparison of ultrasonic and X-ray
techniques in diagnosis. Health and safety aspects of the use of ultrasound and X-rays.
an informative book is 'Medical Physics' by Martin Hollins
to be included in medical physics web pages