3401 preliminary investigation of ultrashort t 2 * in healthy cervical cord grey matter and white matter in vivo at 3 t

INTRODUCTION: Pathological studies have shown that diseases such as amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS) and neuromyelitis optica (NMO) can affect grey matter (GM) and white matter (WM) differentially in the spinal cord [1-3]. Therefore, tissue-specific (i.e. GM and WM) quantitative MR investigations in the spinal cord have real potential to provide clinically relevant information in conditions like these. Ultrashort echo time (UTE) MRI is a method more commonly used to study tissue components that have very short T2* relaxation times i.e. < 5ms (e.g. bone, tendons) and which are usually undetected with the echo times (TE) used in conventional clinical imaging [4]. Recently, the use of UTE has been proposed for the study of nerve tissue showing potential for probing myelin content [5]. In this work we present a pilot investigation into the feasibility of measuring ultrashort T2* in healthy cervical GM and WM using 3D UTE MRI by sampling two ultrashort echo times, chosen such that any signal decay between these would depend predominantly on the ultrashort T2* components, with negligible influence from the longer T2* components.