Question

Concerning digital radiography: 

a. It does not require the use of an anti-scatter grid 

b. Fixed system noise may be reduced by post-processing 

c. Detector artefacts may occur as a result of variations in image receptor sensitivity 

d. Automatic exposure control is not used with digital radiography 

e. It requires specific post-processing parameters for paediatric patients

Answer 1

a. False. Scatter of radiation occurs irrespective of the imaging system employed. 

b. True. This is a type of internal source of noise (different to X-ray quantum noise) associated with the image receptor. Its contribution to the final image may be corrected for by using a control to obtain average values for the fixed system noise. This can then be used as a map to remove its contribution from subsequent images. 

c. True. This may occur as a result of the manufacturing process. Compensation may occur by taking the average values from adjacent receptors and substituting these. 

d. False. It can be used. 

e. True. Due to decreased patient size, the image will have a different dynamic range than with adult patients and so digital enhancement needs to be varied to compensate for this.