We propose to purchase a state of the art 3T MRI scanner (Siemens MAGNETOM Prisma) in order to replace our end-of-life 3 Tesla Philips research scanner at the F.M. Kirby Research Center of the Hugo Moser Research Institute at Kennedy Krieger (KKI), which cannot be upgraded to the newest digital Philips Achieva system. This scanner replacement is necessary to address the needs of many investigators at the KKI and Johns Hopkins University (JHU) who have 15 NIH-funded grants with specific aims that strongly benefit from the improved technical capabilities provided by this upgrade. These investigators use the 3T system for structural MRI, functional MRI (fMRI), quantitative physiological MRI, magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI), and diffusion tensor imaging (DTI) for the study of human behavior and a large range of diseases and developmental disabilities. The main features of importance for us on the Prisma are availability of 1) magnetic field gradient hardware with the highest simultaneous strength (80 mT/m) and slew rate (200 mT/m/s), 2) a completely digital radiofrequency (RF) transmit/receive system with 3) 128 receive channels; 4) a 64-channel head and neck coil; 5) improved field and frequency stability; 6) availability of advanced simultaneous multi-slice (SMS) and multiband (MB) packages both from Siemens and from advanced Siemens users leading the human connectome project (HCP); 7) we will have the fastest reconstruction computer available on an MRI scanner with full user control. This scanner will provide a large range of benefits for our users, including but not limited to: improved signal to noise ratio (SNR) for all applications due o reduced noise in the digital receive system, which can be used for better detection of small signals, finer spatial resolution, and/or faster scans. SNR is further increased for DTI scans due to shorter echo time (TE) attainable with higher gradient strength (shorter diffusion time) and slew rate (shorter readout time). The availability of 128 receive channels provides a future path to high-end connectome-type RF hardware. The first commercially available 64-channel coil is expected to provide modestly improved SNR compared to 32-channel as well as an improved g-factor for parallel imaging, especially for controlled aliasing in SMS/MB imaging. Improved frequency stability compared to our current system will provide benefits for a) improved signal intensity stability for dynamic scans; b) absence of spatial image drift under high duty cycle gradient use such as in diffusion spectrum imaging (DSI) with many orientations and strong diffusion weighting; c) improved spectral editing with selective pulse excitation; d) improved CEST-MRI frequency referencing. Finally, user control of the reconstruction computer allows on- scanner processing of HCP-type acquisition sequences and real-time motion-correction algorithms.
We propose to purchase a state of the art 3T MRI scanner that will benefit a large group of researchers using the F.M. Kirby Research Center for Functional Brain Imaging at the Hugo Moser Research Institute at Kennedy Krieger. The Center provides a core magnetic resonance facility within an interdisciplinary environment for the investigation of human brain anatomy, function and physiology. These are studied in conditions such as ADHD, Alzheimer's Disease, cancer, stroke, aphasia, multiple sclerosis, schizophrenia, preterm babies, obesity, adrenoleukodystrophy, dyslexia, autism spectrum disorder, Down syndrome, cerebellar syndromes, sturge weber syndrome and traumatic brain injury.
