Motion-Compensation Techniques in Neonatal and Fetal MR Imaging

Fetal and neonatal MR imaging is increasingly used as a complementary diagnostic tool to sonography. MR imaging is an ideal technique for imaging fetuses and neonates because of the absence of ionizing radiation, the superior contrast of soft tissues compared with sonography, the availability of different contrast options, and the increased FOV. Motion in the normally mobile fetus and the unsettled, sleeping, or sedated neonate during a long acquisition will decrease image quality in the form of motion artifacts, hamper image interpretation, and often necessitate a repeat MR imaging to establish a diagnosis. This article reviews current techniques of motion compensation in fetal and neonatal MR imaging, including the following: 1) motion-prevention strategies (such as adequate patient preparation, patient coaching, and sedation, when required), 2) motion-artifacts minimization methods (such as fast imaging protocols, data undersampling, and motion-resistant sequences), and 3) motion-detection/correction schemes (such as navigators and self-navigated sequences, external motion-tracking devices, and postprocessing approaches) and their application in fetal and neonatal brain MR imaging. Additionally some background on the repertoire of motion of the fetal and neonatal patient and the resulting artifacts will be presented, as well as insights into future developments and emerging techniques of motion compensation

Effect of cognitive-only and cognitive-motor training on preventing falls in community-dwelling older people: protocol for the smart +/- step randomised controlled trial

BACKGROUND: Physical and cognitive impairments are important risk factors for falls in older people. However, no studies have been adequately powered to examine whether cognitive or cognitive-motor training can prevent falls in older people. This is despite good evidence of improvements in fall-related cognitive and physical functions following both intervention types. This manuscript describes the study protocol for a three-arm randomised controlled trial to evaluate the effectiveness of home-based cognitive and cognitive-motor training interventions, compared to a minimal-intervention control group, in preventing falls in older people. This trial was prospectively registered with the Australia New Zealand Clinical Trial Registry, number ACTRN12616001325493. METHODS AND ANALYSIS: Community-dwelling adults aged 65 years and over, residing in Sydney Australia, will be recruited. Participants (n=750) will be randomly allocated to (1) cognitive-only training, (2) cognitive-motor training or (3) control groups. Both training interventions involve the use of the smart±step home-based computerised game playing system for a recommended 120 min/week for 12 months. Cognitive training group participants will use a desktop electronic touch pad to play games with the smart±step system while seated and using both hands. The cognitive-motor training group participants will use a wireless electronic floor step mat that requires accurate stepping using both legs for playing the same smart±step games, hence incorporating balance exercises. All groups will receive an education booklet on fall prevention. The primary outcome will be rate of falls, reported by monthly diaries during the 12-month duration of the study and analysis will be by intention-to-treat. Secondary outcomes include the proportion of fallers, physical and cognitive performance in 300 participants, and brain structure and function in 105 participants who will undertake MRI scans at baseline and 6 months. Cost-effectiveness will be determined using intervention and health service costs. ETHICS AND DISSEMINATION: Ethical approval was obtained from UNSW Ethics Committee in September 2015 (ref number HC15203). Outcomes will be disseminated through publication in peer-reviewed journals and presentations at international conferences. TRIAL REGISTRATION NUMBER: ACTRN12616001325493