Abstract: The invention relates to a method of generating an image of an animate human or non-human animal body or part thereof. The method comprises administering to said body a physiologically tolerable contrast agent comprising a radiation absorbing component and/or a pressure inducing component, exposing said body to radiation, detecting pressure waves generated in said body by said radiation and generating an optoacoustic image therefrom of at least a part of said body containing the administered contrast agent.

Abstract: This invention relates to a set of aqueous marker compositions, each composition having a selected 1/Ti value which is substantially invariant over an at least 10° C. temperature range between 15 and 40° C. and preferably over an at least ±2% magnetic field strength range about a selected field strength value between 0.01 and 5T and comprising an aqueous matrix material having a non-zero 1/Ti temperature dependence within said temperature range with distributed therein a first paramagnetic material having a Ti relaxivity which is substantially invariant within said range(s) and/or a second paramagnetic material having within said ranges(s) and T1 relaxivity which has a non-zero temperature dependence of opposite polarity to the temperature dependence of 1/Ti of said matrix material, said set containing a plurality of said compositions with different selected 1/Ti values preferably encompassing at least the range 1.0 to 2.

Abstract: This invention provides a physiologically tolerable light imaging contrast agent compound having a molecular weight in the range 500 to 5000000 and containing at least two chromophores having delocalized electron systems as well as at least one polyalkylene oxide (PAO) moiety having a molecular weight in the range 60 to 100000.

Abstract: The invention provides polymeric polychelants containing polymer repeat units of formula ?L--Ch--L--B! (where Ch is a polydentate chelant moiety; L is an amide or ester linkage; B is a hydrophobic group providing a carbon chain of at least 4 carbon atoms between the L linkages it interconnects) or a salt or chelate thereof, with the proviso that where Ch is 2,5-biscarboxymethyl-2,5-diazahex-1,6-diyl, the polychelant is metallated with lanthanide or manganese ions or B provides a carbon chain of at least 10 carbon atoms between the L linkages it interconnects and their salts and chelates. The paramagnetic polychelates of the polychelants of the invention have remarkably high R.sub.1 relaxivities.