Loading...
Impact of body part thickness on AP pelvis radiographic image quality and effective dose
Alzyoud, K. Hogg, P. Flintham, K. England, A.
Alzyoud, K.
Hogg, P.
Flintham, K.
England, A.
Publication Date
2018-10-03
End of Embargo
Supervisor
Rights
© 2018 Elsevier. Reproduced in accordance with the publisher's self-archiving policy. This manuscript version is made available under the CC-BY-NC-ND 4.0 license.
Peer-Reviewed
Yes
Open Access status
openAccess
Accepted for publication
2018-09-06
Institution
Department
Awarded
Embargo end date
Collections
Additional title
Abstract
Within medical imaging variations in patient size can generate challenges, especially when
selecting appropriate acquisition parameters. This experiment sought to evaluate the impact of
increasing body part thickness on image quality (IQ) and effective dose (E) and identify optimum
exposure parameters.
Methods: An anthropomorphic pelvis phantom was imaged with additional layers (1e15 cm) of animal
fat as a proxy for increasing body thickness. Acquisitions used the automatic exposure control (AEC),
100 cm source to image distance (SID) and a range of tube potentials (70e110 kVp). IQ was evaluated
physically and perceptually. E was estimated using PCXMC software.
Results: For all tube potentials, signal to noise ratio (SNR) and contrast to noise ratio (CNR) deceased as
body part thickness increased. 70 kVp produced the highest SNR (46.6e22.6); CNR (42.8e17.6). Visual
grading showed that the highest IQ scores were achieved using 70 and 75 kVp. As thickness increases, E
increased exponentially (r ¼ 0.96; p < 0.001). Correlations were found between visual and physical IQ
(SNR r ¼ 0.97, p < 0.001; CNR r ¼ 0.98, p < 0.001).
Conclusion: To achieve an optimal IQ across the range of thicknesses, lower kVp settings were most
effective. This is at variance with professional practice as there is a tendency for radiographers to increase
kVp as thickness increases. Dose reductions were experienced at higher kVp settings and are a valid
method for optimisation when imaging larger patients.
Version
Accepted manuscript
Citation
Alzyoud K, Hogg P, Snaith B et al (2018) Impact of body part thickness on AP pelvis radiographic image quality and effective dose. Radiography. 25(1): e11-e17.
Link to publisher’s version
Link to published version
Link to Version of Record
Type
Article