Sodium imaging of human body organs and extremities in vivo

In vivo sodium magnetic resonance (MR) images of various structures--such as the heart, chest wall, kidneys, spine, liver, gallbladder, breasts, knees, hands, and feet--were obtained at 1.9 T. Improved sensitivity relative to standard spin-echo imaging was achieved with use of a modified three-dimensional acquisition sequence with short repetition and gradient-echo times (45 and 6.4 msec, respectively) and with use of special cylindrical and planar radio-frequency coils. Imaging times of 2-30 minutes were sufficient to render good-quality images with high contrast sensitivity. Relatively strong sodium signals were found to emanate from such sources as cerebrospinal fluid, blood serum, interstitial fluid, joint fluid, and cartilage. It is concluded that sodium imaging of body organs and extremities is feasible and is potentially of clinical diagnostic value, as is the more extensively studied sodium imaging of the head.