MRI clinical trials at UCSF

The goal of this interventional study (clinical trial) is to learn if different breath-holding techniques, with and without extra oxygen, can improve the quality of abdominal Magnetic Resonance Imaging (MRI) images in healthy adults, ages 18-75. The main questions it aims to answer are: - Does breath-holding at end-expiration improve image quality in abdominal MRI scans? - Does adding oxygen while breath-holding further reduce motion artifacts in abdominal MRI scans? Researchers will compare breath-holding with and without oxygen to see if using oxygen improves image quality during MRI scans. Participants will: - Be pre-screened for MRI safety and trained on breath-hold procedures - Have one non-contrast abdominal MRI scan at the University of California San Francisco (UCSF) China Basin Imaging Center - Use two different breath-holding techniques during the scan, with and without oxygen - Complete one study visit lasting about 45 minutes to 1 hour

This study will investigate the how the cerebellum is involved in speech motor learning over time and short-term corrections in patients with cerebellar ataxia and healthy controls. This will be accomplished through three approaches: behavioral studies, magnetic resonance imaging (MRI), and transcranial magnetic stimulation (TMS). During behavioral studies, participants will be asked to speak into a microphone while their voice is played back over earphones, and to do other speaking tasks. MRI will be acquired to perform a detailed analysis on brain function and anatomy related to speech and the cerebellum. In healthy controls, TMS will also be performed to temporarily disrupt the cerebellum before, during, or after the participant performs speaking tasks. Patients with cerebellar ataxia and healthy volunteers will be asked to complete behavioral studies and/or MRI; healthy volunteers may be asked to additionally participate in TMS.