Abstract: Non-invasive imaging methods and minimally invasive sensing methods are used for assessing the viability of cells implanted in the central nervous system for therapeutic purposes and for detecting the transformation of such cells, including embryonic stem cells, into brain tumors. In particular, the present invention provides an imaging means for differentiating normal cell proliferation and angiogenesis following a cell implant from abnormal tumor growth and neovascularization associated with teratoma-inducing implanted embryonic stem cells.

Abstract: The invention provides a method of imaging a blood vessel in a body using magnetic resonance (MR) imaging. The method includes the step of acquiring images of a region of the body in which the blood vessel is located. It also includes the step of administering an MR contrast agent into the vascular system of the body at a dose and a time selected so that the MR contrast agent passing through the blood vessel is present therein during acquisition of the images thereof for at least part of the acquiring step.

Abstract: The invention provides a method of monitoring the vasodilatory or vasoconstrictive effects of a physiologically active substance administered to a human or non-human animal body, said method comprising the steps of: administering said substance into said body; administering into the systemic vasculature of said body a contrast enhancing amount of an intravascular paramagnetic metal containing magnetic resonance imaging contrast agent; subjecting said body to a magnetic resonance imaging procedure capable of generating from magnetic resonance signals from said body a series of temporally spaced images of at least a part of said body into which said agent passes, said procedure being a fast imaging procedure having an image acquisition time of less than five seconds; and detecting temporal variations in said signals or images whereby to monitor the vasoconstriction or vasodilation induced by said substance.