%0 Journal Article %J Review of Scientific Instruments %D 2010 %T Permanent magnet desktop magnetic resonance imaging system with microfabricated multiturn gradient coils for microflow imaging in capillary tubes %A Sahebjavaher, Ramin %A Walus, Konrad %A Stoeber, Boris %I American Institute of Physics %N 2 %P 9 %U http://link.aip.org/link/RSINAK/v81/i2/p023706/s1 %V 81 %X A prototype for a desktop high-resolution MRI velocimetry instrument to characterize flow fields in a capillary tube is demonstrated. This inexpensive compact system is achieved with 0.6 T permanent magnetic configuration (Larmor frequency of 25 MHz) and temperature compensation using off-the-shelf NdFeB permanent magnets. A triaxial gradient module with micro-fabricated copper coils using a lithographic fabrication process has been developed. This gradient module is capable of generating fast switching gradients (< 50 Ás) with sensitivities up to 1.7 T/m using custom made current amplifiers, and was optimized for microflow imaging. The RF probe is integrated with the gradient module and is driven by custom electronics. A 2D cross-sectional static image of the inside of a capillary tube with an inner diameter of 1.67 mm is acquired at an in-plane spatial resolution of better than 40 Ám. Time-of-flight flow measurements were also obtained using this MRI system to measure the velocity profile of water flowing at average velocities of above 40 mm/s. The flow profile for slower flow velocities was obtained using phase-encoded techniques, which provides quantitative velocity information in 2D. %8 02/2010 %@ 0034-6748