ViP MRI: virtual phantom magnetic resonance imaging.

Abstract : OBJECT: The ability to generate reference signals is of great benefit for quantitation of the magnetic resonance (MR) signal. The aim of the present study was to implement a dedicated experimental set-up to generate MR images of virtual phantoms. MATERIALS AND METHODS: Virtual phantoms of a given shape and signal intensity were designed and the k-space representation was generated. A waveform generator converted the k-space lines into a radiofrequency (RF) signal that was transmitted to the MR scanner bore by a dedicated RF coil. The k-space lines of the virtual phantom were played line-by-line in synchronization with the magnetic resonance imaging data acquisition. RESULTS: Virtual phantoms of complex patterns were reproduced well in MR images without the presence of artifacts. Time-series measurements showed a coefficient of variation below 1 % for the signal intensity of the virtual phantoms. An excellent linearity (coefficient of determination r (2) = 0.997 as assessed by linear regression) was observed in the signal intensity of virtual phantoms. CONCLUSION: Virtual phantoms represent an attractive alternative to physical phantoms for providing a reference signal. MR images of virtual phantoms were here generated using a stand-alone, independent unit that can be employed with MR scanners from different vendors.