MAGNETIC-RESONANCE-IMAGING OF LEAVES

Several aspects of leaf anatomy and morphology make it difficult to image leaves with magnetic resonance imaging. Since most fully expanded leaves contain much intercellular air space and are often thin in one plane, relatively few water protons are available to provide signal. Their heterogeneous structure and the presence of many air-water interfaces cause imaging problems as a result of differences in magnetic susceptibility of tissues and cells. Significant progress has been made in overcoming these difficulties, primarily by greatly reducing the echo time, permitting in vivo imaging of leaves at 7 and 9.4 Tesla with an in-plane resolution of less than 15 mum2. Examples are shown and the potential for gaining information regarding in vivo water relations of leaves is discussed.