Can the anode heel effect be used to optimise radiation dose and image quality for AP pelvis radiography?

Abstract

A study was conducted to determine whether the anode heel effect can be used to influence optimisation of radiation dose and image quality (IQ) for AP pelvis radiography. Methods:ATOM dosimetry phantom and an anthropomorphic phantom were positioned for AP pelvis. Using a CR system, images were acquired and doses were measured with phantom feet toward anode and then feet toward cathode. Exposure factors (kVp, mAs and SID) were systematically generated using a factorial design. Images were scored visually for quality using relative visual grading together with a 3 point Likert scale. Signal to noise ratio was also calculated as a physical measure of image quality. Dosimetry data were collected for the ovaries and testes. Results:The optimum technique for male, which resulted in lower dose and suitable image quality, was with feet positioned toward the anode (0.80±0.03 mGy; SNR of 38±2.9; visual IQ score 3.13± 0.35). The optimum technique for female was with feet toward anode (0.23±0.02 mGy; SNR of 34.7±2.6; visual IQ score 3.15± 0.26). kVp had the biggest effect on both visual and physical image quality metrics (p˂0.001) for both tube orientations, whereas SID had the lowest effect on both visual and physical image quality metrics compared with mAs and kVp (p˂0.001). The effect of SID on the SNR was not significant (p>0.05) with feet toward anode. Conclusion:Positioning the patient with feet toward the anode, as opposed to the cathode, has no adverse effect on visual image quality assessment but it does have an effect on physical image quality.

Evaluation of Non-Uniform Image Quality Caused by Anode Heel Effect in Digital Radiography Using Mutual Information

“…However, there were limited previous works quantifying the influence of anode heel effect on image quality in digital radiographs [ 16 ]. Previous studies demonstrated that the heel effect significantly impacted the signal-to-noise ratio (SNR) using an anthropomorphic phantom, but the image quality was not significantly different between pelvic radiographs with the head towards the anode and cathode directions [ 17 , 18 ]. Moreover, some previous studies performed post-processing heel effect correction (HEC) to minimize the inhomogeneous intensity in radiographs [ 19 , 20 , 21 ].…”

Differences of Radiation Dose and Image Contrast on Anode Heel Effect Application with Thoracal Examination with Cathode Location in Proximal and Distal

“…The same thing was also expressed [4] who measured radiation doses, there was a significant difference in the dose to the testes between the anode in the distal part and the anode in the proximal part, while the anode was in the distal part and the anode in the proximal part, there was no significant difference for the ovaries.…”

Development of an application to visualise the spread of scattered radiation in radiography using augmented reality

“…The irradiation conditions for the supine and sitting positions were the same. The pelvic irradiation conditions were a tube voltage of 80 kV with 2.7 mm Al specific filtration, focus-detection surface distance of 120 cm, tube current-time product of 22 mAs, and irradiation field size of 43 × 35.4 cm 2 [22]. An x-ray tube, an x-ray source, a bed (height 60 cm, length 240 cm, width 120 cm), portable x-ray equipment, and a phantom simulating a patient were prepared in a virtual hospital room filled with air consisting of density 0.001293 (g cm −3 ), composition 14 N (79.6%), 15 N (0.4%), 16 O (20%).…”