Antenne de surface supraconductrice pour la microscopie par résonance magnétique nucléaire de la peau in vivo à 1,5 teslas

Abstract

For in vivo micro-imaging of the human skin in a whole body by magnetic resonance imaging (MRI) system at 1.5 teslas, the internal noise of a conventional copper coil limits the signal-to-noise ratio (SNR). A high-temperature superconducting (HTS) surface coil recently designed in our laboratory was used for this application. Inductive measurements of the HTS coil parameters were carried out without mobilisation of a NMR unit. The preliminary measurements indicated that using such an HTS coil at 77 K can provide a significant gain in SNR, reaching a factor of 3 to 5, depending on the observed anatomical region. The existence of an optimal distance, dependent on the load, from the body surface to the coil was highlighted. In vivo images of the calf skin produced with the HTS coil showed highly resolved details and a threefold improvement in SNR over that obtained with a conventional copper coil at room temperature. The improved SNR associated with the high spatial resolution leads to an effective spatial resolution which has never before been obtained on a whole-body NMR scanner.