PHYSIOLOGICAL MOTION PHANTOM FOR MRI APPLICATIONS

To address the need for a complex physiologic motion phantom for use i n MR applications, such as the verification of techniques for measurin g myocardial motion dynamics and motion insensitive pulse sequences, a computer-controlled motion phantom has been designed, The phantom, wh ich consists of a deformable silicone gel annulus mounted on a transla tion stage, can undergo a range of bulk motions and deformations. Avai lable motions include bulk rotation and translation, rotational shear, axial shear, and combinations of some or all of these motions, In thi s paper, the capability of the phantom to produce accurate constant an d time-varying waveforms is demonstrated. In the current implementatio n, peak linear translation and rotation rates are 175 mm s(-1) and 10 rad s(-1), respectively. Cycle-to-cycle reproducibility is excellent, with variations of less than .003 radians over the period of hours whi le undergoing rotational shear, The phantom has been designed in a fle xible fashion so that various test objects can be scanned while underg oing bulk translation and can be adapted to produce different deformat ions.