Quantitative evaluation of the effectiveness of metal artifact reduction using a dedicated phantom across cone-beam
Tomoyuki Sadakane1, Ataru Yabe1
1J. Morita MFG. Corp.
Purpose:
To propose and validate the residual ratio of the metal artifact area (ResRaMAA) as an objective and practical metric for quantitative evaluation of the effectiveness of metal artifact reduction (MAR) in cone-beam computed tomography (CBCT) using a dedicated phantom.
Methods:
A phantom enabling variation in the number and positioning of titanium rods was scanned under four rod configurations using three CBCT systems. The metal artifact area (MAA) was measured with MAR turned off (MAR-Off) and on (MAR-On), and the two values were used to determine the ResRaMAA.
Results:
MAA values indicated a proportional relationship between MAR-Off and MAR-On. The proportionality coefficient, total ResRaMAA, ranged from 14% to 18%, significantly differing from 0% and 100%. Lower and upper ResRaMAA distributions differed significantly within the same device. Device-related differences were suggested, but not confirmed statistically. Additionally, titanium rod shapes in MAR-On data varied by device and metal rod configuration.
Conclusion:
ResRaMAA was able to quantify MAR effectiveness in reducing metal artifacts (MAs) caused by titanium rods and revealed significant differences between the lower and upper MA regions. ResRaMAA provides a simple, practical metric for objective evaluation of MAR performance.
Related Concept Videos
01:10Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
01:27Imaging Studies III: Computed Tomography