3D MRI and angiography of human extremities using a local gradient coil

The limits of the spatial resolution achievable on a standard GE Signa 1.5-T imaging machine have been explored by interfacing a 12-cm-diameter local gradient set to such a system. Using a range of purpose-built radio-frequency (RF) coils, 3D gradient echo images with a spatial resolution of 100×100×500 μ have been routinely obtained on the finger. Also produced were 100×200×500 μ, resolution angiograms of the finger detailing submillimeter vessels, with a velocity encoding of 6 cm s-1. High-resolution fat/water suppressed images and isotropic data sets with a resolution of 170 μ are also demonstrated. With regard to the investigation of the mechanics of the human finger, isotropic data sets are desirable if accurate segmentation is to be implemented. A preliminary study illustrating the potential for producing a magnetic-resonance-based computer simulation of the mechanics of the human finger shows the distal interphalangeal joint extended and then in flexion. © 1994 Chapman & Hall.