SDX introduction - Zero in on a moving target

ABGT, Lda.; SDX® Respiratory Gating System, DYN’R, SAS, a spirometry-based system.

Computed tomography (CT) versus magnetic resonance imaging (MRI) "shades of grey"

Drawing created and kindly provided by @instant.oncology: Wang, L., 2020. Login • Instagram. [online] Instagram.com. Available at: <https://www.instagram.com/p/B-d8KlUAhCP/> [Accessed 30 October 2020].

∝: proportional to; DWI: diffusion-weighted imaging; STIR: short-T1 inversion recovery; Rx: x-rays; Z: atomic number or proton number.

"CT (...) uses kilovoltage x-rays, which interact with matter via photoelectric interactions, and are attenuated depending on the Z-number of the material. (...). Metalwork (such as hip prostheses or dental implants) can also lead to substantial artifacts because they attenuate the x-rays so much that a surrounding “shadow” is created. (...).

MRI (...) does not involve radiation exposure, but (...) [is] also highly prone to artifact by metal implants, even more so than CT. Artifacts tend to affect only CT axial slices containing the implant; but with MRI the distortion can extend to several slices above and below the implant. (...)."

Bibliographic reference: Wang, L., 2020. Login • Instagram. [online] Instagram.com. Available at: <https://www.instagram.com/p/B-d8KlUAhCP/> [Accessed 30 October 2020].