The overall goal of this project is to design and integrate instrumentation allowing the next generation of real-time image formation in MRI. The motivation comes from an existing project for forming MR images during continuous motion of the patient table. When applied to peripheral MR angiography the target is the formation of a moving table angiogram in which the table motion is precisely matched to the transit of the contrast bolus through the patient. However, implementation of this requires that a number of mathematical processes be done at high speed, including: (i) time-resolved 3D MRI of an extended field of view (FOV); (ii) determination of localized time-dependent parameters such as bolus arrival time and bolus velocity; (iii) variable ordering of phase encodings over the course of an MRI scan, allowing optimized local resolution; (iv) gradient warping correction for MR acquisition done using a moving patient table; (v) multi-coil reconstruction using the SENSE technique, allowing improved lateral resolution for a given acquisition time; (vi) MR acquisition done using a variable table velocity When implemented, these methods will allow the formation of peripheral MR angiograms with optimized, patient-specific table motion, maximum efficiency, and high spatial resolution.
Specific aims are: 1. Construction of the Next Generation Real-Time Image MR Reconstruction System. The funding will allow the construction of a system enabling the real-time performance of the mathematical algorithms which perform the above processes. System design will allow the data acquisition and reconstruction to be modified in real time. 2. Incorporation of the New System into the Project of Moving Table MRA. Once the hardware is integrated into a useable system it will be interfaced to a clinical MRI scanner at Mayo and used in the formation of peripheral contrast-enhanced MR angiograms using continuous motion of the patient table through the scanner gantry.
