Abstract: A medical or surgical device or tool that is designed to be implanted or inserted inside the human or mammalian body, having at least part of its surface coated whereby the ultrasound visibility of said device or tool in vivo is enhanced, wherein the coating comprises one or more of the following: (i) a matrix material containing a plurality of contrast enhancing elements; (ii) magnesium; (iii) a liquid or polymer which alters its ultrasound imaging properties upon elevating the temperature from ambient to physiological temperature; (iv) a liquid or polymer which alters its ultrasound imaging properties as a result of a change in pH; (v) an essentially non-polymeric bio-compatible compound which forms a discontinuous coating. Preferably the device or tool is a radioactive source for use in brachytherapy, and in particular a radioactive seed.

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: A method of treatment of a human or animal body by sonodynamic therapy in which a sensitizer agent is administered to the body and the body is exposed to ultrasound to achieve a cytopathogenic effect at a site therein, wherein the said sensitizer agent is a physiologically tolerable substance which is capable of enhancing the cytopathogenic efficacy of said sonodynamic therapy. Preferably, the sensitizer agent is a water-soluble polymer compound or a conjugate thereof.

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.