MRI-CT Compatible Dynamic Motion Phantom

Tech ID: yue000920



The use of MRI for radiotherapy is increasingly important, especially with the recent development of MRI-Linacs and other MRI-based therapy systems. With this increase comes the need for equipment to verify and validate research results across imaging modalities (particularly MRI and CT). There is no currently available motion phantom compatible with both CT and MRI modalities. The inventors have created a motion phantom with no metal components in or near the imaging region, making it compatible with MRI as well as CT imaging.



This motion phantom provides equally accurate image contrast for both MRI and CT imaging. A water-gel mixture was used to provide a typical background soft-tissue signal. The phantom consists of a gadolinium gel suspended in a low-concentration gadolinium fluid. The plastic outside of the target was used to ensure a clearly defined boundary for both CT and MRI. These design decisions were successful at minimizing the image quality differences between the two image modalities.

The phantom can produce dynamic motion driven by an air pump which is placed outside the MRI room. The device simulates human respiratory rates (2-20 s/cycle) and breathing depths (3-30mm).


Stage of Development

Working prototype with in-vitro data.



By distancing the pump from the imaging phantom image artifacts and safety hazards caused by electromagnetic motor are eliminated.


Intellectual Property

•       PCT application PCT/US2016/044338 filed.



•       Yue et al. Geometric validation of self-gating k-space-sorted 4D-MRI vs 4D-CT using a respiratory motion phantom. Med Phys. 2015 Oct;42(10):5787. Link

Patent Information:
For Information, Contact:
Julien Brohan
Yong Yue