Three-dimensional magnetic resonance imaging of rigid polymeric materials using single-point ramped imaging with T1 enhancement (SPRITE)

A new MRT method, recently employed in porous-media studies, is introduced for the imaging of rigid polymeric materials. The method, Single-Point Ramped Imaging with T-1, Enhancement (SPRITE), is designed to spatially encode short lifetime, T-2*, signals characteristic of rigid materials. We investigate the advantages of the SPRITE technique over conventional imaging methods by comparing a 2D SPRITE image of four common polymers to a 2D spin-echo image of the same substances. We demonstrate the general applicability of SPRITE by imaging two commercial products, a stop-valve made of chlorinated polyvinyl chloride and a solid-core, multilayer golf ball, both containing synthetic materials with effective H-1 spin-spin relaxation times, T-2*, well under 300 mu s. Three-dimensional images of millimeter resolution reveal internal physical differentiation and chemical inhomogeneities that cannot be observed using conventional MRI methods. We also consider the incorporation of active spoiler gradients in SPRITE for visualization of samples with long spin-spin relaxation times,T-2.