The subject area is Diagnostic Radiography. The essay should include graphs and tables; and consider also ionising versus non-ionising radiation.
Its aim is to explain radiation effects not how many slices and sequencies are done.

Each explanation should include how and why each modality affects the cell (deterministic effect and stochastic effect).
Contrast agents use should not be mentioned.
In MRI, please mention and explain how and why different coils affect the fetus.

References should be within the last 5 years, main sources to use are Society of Radiographers, Medicines and Healthcare Products Regulatory Agency, COMARE and peer reviewed journals..