Sdk125 Introducing Health Sciences - Block 4

Front 1

What are the risk factors for breast cancer?

Back 1

* Age - the risk of cancer increases as age increases.
* Gender - 99% of breast cancer occurs in women.
* Diet-a high fat diet has been linked to a higher risk
* Genes - A faulty BRCA1 or BRCA2 gene increases the risk.
Oestrogen - increased exposure to this hormone increases the risk
* Environment - levels of atmospheric radiation.

Front 2

How are X-rays used for imaging?

Back 2

When X-rays pass through soft tissue they are either absorbed, scattered or some pass through the materials.

To form an image a detector, either a photograph film or computer software, is needed to give an image.

The image produced shows high density tissue (bones) as very white as these absorb a high concentration of the X-rays.

Front 3

What are waves?

Back 3

A wave is simply a vibration.

The rate of the vibration gives the frequency,
it's length is measured as the distance between two peaks,
the amplitude is the power and is measured as the distance from the mid point to the wave peak.

Waves include: electromagnetic, X-rays, sound waves etc.

Front 4

What is breast cancer?

Back 4

Oestrogens signal mammary cells to grow and multiply.

During DNA replication mutations can occur. If enough cells mutate without the bodies repair system correcting these errors they block the normal function of the host organ. This is cancer

Front 5

Name 3 other imaging techniques

Back 5

* Ultrasound - High frequency sound waves reflect off tissues and form an image.
* M.R.I - Uses magnetic fields and radiowaves.
*Radionuclide - Radioactive materials are injected into the patient and detected by a 'gamma camera'

Front 6

The electromagnetic spectrum

Back 6

Front 7

What are the 4 possible result categories a patient could receive after a screening?

Back 7

* A true negative - the majority of results, the person does NOT have breast cancer.
* A false positive - the screening shows there may be a cancerous cluster of cells and the person is asked to return for a follow up screening, this usually leads to a true negative result.

True positive - the person has cancerous cells.
False negative - the least likely result received, cancer in the breast is not detected.

Front 8

Describe what is meant by attenuation coefficient

Back 8

The attenuation coefficient of a tissue gives an indication of the reduction in intensity of an x-ray beam passing through that particular tissue.

It can be affected by the intensity of the x-ray beam and by the density of the tissue.