Data-driven denoising in spinal cord fMRI with principal component analysis.

Numerous approaches have been used to denoise spinal cord functional magnetic resonance imaging (fMRI) data. Principal component analysis (PCA)-based techniques, which derive regressors from a noise region of interest (ROI), have been used in both brain (e.g.

EPISeg: Automated segmentation of the spinal cord on echo planar images using open-access multi-center data.

Functional magnetic resonance imaging (fMRI) of the spinal cord is relevant for studying sensation, movement, and autonomic function. Preprocessing of spinal cord fMRI data involves segmentation of the spinal cord on gradient-echo echo planar imaging (EPI) images. Current automated segmentation methods do not work well on these data, due to the low spatial resolution, susceptibility artifacts causing distortions and signal drop-out, ghosting, and motion-related artifacts.

Variable Cerebral Blood Flow Responsiveness to Acute Hypoxic Hypoxia.

Cerebrovascular reactivity (CVR) to changes in blood carbon dioxide and oxygen levels is a robust indicator of vascular health. Although CVR is typically assessed with hypercapnia, the interplay between carbon dioxide and oxygen, and their ultimate roles in dictating vascular tone, can vary with pathology. Methods to characterize vasoreactivity to oxygen changes, particularly hypoxia, would provide important complementary information to established hypercapnia techniques.

Quantitative mapping of cerebrovascular reactivity amplitude and delay with breath-hold BOLD fMRI when end-tidal CO quality is low.

Cerebrovascular reactivity (CVR), the ability of cerebral blood vessels to dilate or constrict in order to regulate blood flow, is a clinically useful measure of cerebrovascular health. CVR is often measured using a breath-hold task to modulate blood CO levels during an fMRI scan. Measuring end-tidal CO (PCO) with a nasal cannula during the task allows CVR amplitude to be calculated in standard units (vascular response per unit change in CO, or %BOLD/mmHg) and CVR delay to be calculated in seconds.

Early Findings of Helpline Inquiries From Youth and Young Adults With Concerns About Their Sexual Thoughts, Behaviors, and Experiences.

Most self-reported victims of child sexual abuse are harmed by peers or known older youth with the average age of first-time sexual perpetration being between 11 and 16 years. In this retrospective review of inquiries made to the WhatsOK helpline over an 18.5-month period, we examine the characteristics of contacts to a helpline for youth with questions about their sexual interests and behaviors.