Keywords:
Education and training, Diagnostic procedure, Digital radiography, Musculoskeletal bone
Authors:
K. McNally, K. Matthews; Dublin/IE
DOI:
10.26044/ecr2019/C-3387
Aims and objectives
Accurate centring carries a number of implications,
including accurate projection of radiographic anatomy,
consistent function of automatic exposure control (AEC) and accurate and optimal collimation [1].
The use of explicit centring points is taught and encouraged by authoritative texts.
However,
it is reported that the teaching of certain centring points differs in clinical practice and may introduce a level of confusion to students [2].
Beyond any differences in teaching,
centring points may also vary for other reasons.
Centring points may be changed purposely by radiographers in order to better visualise anatomy [3].
For example,
since the central beam should be directed into the concavity of the lateral lumbar spine [4],
the centring may be varied slightly with the degree of patient's curvature,
especially scoliotic patients.
Another consideration arises with rising global obesity rates [5],
the radiographer's ability to palpate necessary landmarks may be diminished.
In these situations,
the radiographer must depend on his/her own experience to estimate anatomy to position the central beam,
and the centring may be less than optimal.
It can also be argued that radiographers' centring technique may be adversely affected due to reduced examination time arising from increasing demand on radiographic departments [6].
This aim of this study was to investigate how various centring points affect the image quality of a radiograph.
The objectives were to:
- Conduct a series of focus groups to establish projections where a wide variation in used centring points was apparent;
- Apply selected centring points in a cadaver study and harvest the images;
- Conduct an evaluation of the images to determine any effects of variation in centring point.