title: On the impact of physiological noise in spinal cord functional MRI.
abstract: Functional magnetic resonance imaging (fMRI) techniques are widely exploited for the study of brain activation. In recent years, similar approaches have been attempted for the study of spinal cord function; however, obtaining good functional images of spinal cord still represents a technical and scientific challenge. Some of the main limiting factors can be classified under the broad category of "physiological noise," and are related to 1) the cerebrospinal fluid (CSF) flux in the subarachnoid space surrounding the spinal cord; 2) the cord motion itself; and 3) the small area of the cord, which makes it critical to have a high image resolution. In addition, the different magnetic susceptibility properties of tissues surrounding the spinal cord reduce the local homogeneity of the static magnetic field, causing image distortion, reduction of the effective resolution, and signal loss, all effects that are modulated by motion. For these reasons, a number of methods have been developed for the purpose of denoising spinal cord fMRI time series. In this work, after a short introduction on the relevant features of the spinal cord anatomy, we review the main sources of physiological noise in spinal cord fMRI and discuss the main approaches useful for its mitigation.
authors.affiliation: MARBILab - Museo storico della fisica e Centro di studi e ricerche Enrico Fermi, Roma, Italy; Dipartimento di Fisica, Sapienza Universita' di Roma, Roma, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Fratini
authors.forename: Marta
authors.initials: M
authors.lastname: Moraschi
authors.forename: Bruno
authors.initials: B
authors.lastname: Maraviglia
authors.forename: Federico
authors.initials: F
authors.lastname: Giove
mesh_terms: D016477:Artifacts; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D013116:Spinal Cord / Q000033:anatomy & histology* / Q000502:physiology*
keywords: fMRI; physiological noise; spinal cord