Low-cost MR-compatible moving heart phantom

For the development and evaluation of cardiac magnetic resonance (MR) imagi ng sequences and methodologies, the availability of a periodically moving p hantom to model respiratory and cardiac motion would be of substantial bene fit Given the specific physical boundary conditions in an MR environment, t he choice of materials and power source of such phantoms is heavily restric ted. Sophisticated commercial solutions are available; however they are oft en relatively costly and user-specific modifications may not easily be impl emented. We therefore sought to construct a low-cost MR-compatible motion p hantom that could be easily reproduced and had design flexibility. A commer cially available K'NEX construction set (Hyper Space Training Tower, K'NEX Industries, Inc., Hatfield, PA) was used to construct a periodically moving phantom head The phantom head performs a translation with a superimposed r otation, driven by a motor over a 2-m rigid rod. To synchronize the MR data acquisition with phantom motion (without introducing radiofrequency-relate d image artifacts), a fiberoptic control unit generates periodic trigger pu lses synchronized to the phantom motion. Total material costs of the phanto m are US$ < 200.00, and a total of 80 man-hours were required to design and construct the original phantom. With schematics of the present solution, t he phantom reproduction may be achieved in approximately 15 man-hours. The presented MR-compatible periodically moving phantom can easily be reproduce d, and user-specific modifications may be implemented Such art approach all ows a detailed investigation of motion-related phenomena in MR images.