Crushed Early Acquisition Spin Echo (CEASE): a novel technique for positive contrast and spectroscopic imaging of superparamagnetic particles

Introduction There has been increasing interest in using micron-sized iron oxide (MPIO) particles for cell tracking[1]. Traditionally, T2* weighted images have been used to provide negative contrast; however hypointense regions that are not due to iron oxide particles are likely to be present in biological samples. Positive contrast techniques have been shown to be more specific to contrast generated by iron oxide[2] Here, we present a novel positive contrast sequence that consists of an excitation pulse, a crusher, and an early spin-echo acquisition; leading to the name Crushed Early Acquisition Spin Echo or the CEASE sequence.