Learning objectives
Rectangular image artifacts were noted on a few cases of APchest radiographs performed using new high sensitivity digital wireless cassettes.
These artifacts were accentuatedin patients of larger body habitus where elevated kVPs were utilised.
Possible parameters our research team considered included patient positioning,
coning and differences in beam energy.
An e-mail directive from the detector supplier suggested the use of an optionallead backing sheet to reduce artifacts.
Our learning objective is to devise a method to identify the cause of the predescribed image artifacts onchest...
Background
On moving to new high sensitivitywireless digital radiography cassettes,multiple low contrast rectangular shaped image artefacts have been found in AP chest radiographs especially inpatients of larger body habituswhere high kVPs were utilised.
Collimation of the image can reduce how conspicuous these artefacts appear but collimation is not always possible on large patients.An e-mail directive from the detector supplier suggested the addition of an optionallead backing sheet to reduce artifacts.
We endeavoured to create a method toidentify the cause of such artifacts and to test the...
Findings and procedure details
To demonstratethese image artefacts,
we endeavoured to visually enhance them by using 18cm of Perspex as a patient phantom.
This allowed us to create similar realcase beam energy and backscatter but a constant grey scale image,
enabling visual amplification of the artefacts.
The resultant image proved that it was backscatter though the digital cassettecircuitryand battery causing the clinically seen image artefacts.
We then attached a lead backing sheet to the cassette to absorb any backscatter.
Repeating the previous phantom test demonstrated that the artefacts were...
Conclusion
Unlike film or CR cassettes,
modern wireless digital cassettes have circuitry and a battery on the rear of the cassette.
This dense componentry can create a differential absorption of backscatter to the front detector layer causingmultiple regular shapedimage artefacts.
These artefacts are especially conspicuous on new higher sensitivitydigital cassettes and in patients of larger body habitus due to the utilisation of elevated kVP's during image acquisition.
By adding a lead backing sheet to the detector,
these artefacts can be eliminated andwe have also identified the...
References
Naji AT,
Jaafar MS,
Ali EA and Al-Anr SKJ.
X-ray attenuation and reduction of backscattered radiation.
Applied Physics Research [Internet].
2016 [cited 2017 June 12]; 8(4): 92-102.
Available from:https://www.researchgate.net/publication/305761642_X-ray_Attenuation_and_Reduction_of_Backscattered_Radiation
Normal 0 false false false EN-US JA X-NONE
Eaton DJ and Doolan PJ.
Review of backscatter measurement in kilovoltage radiotherapy using novel detectors and reduction from lack of underlying scattering material.
Journal of Applied Clinical Medical Physics [Internet].
2013 [cited 2017 June 10]; 4(6): 5-17.
Available from:http://onlinelibrary.wiley.com/doi/10.1120/jacmp.v14i6.4358/pdf
Naji AT and Jaafar MS.
Reduction of Backscattered Radiation...