Abstract: The nucleoside analog 2′-fluoro-5-methyl-1-&bgr;-D-arabinofuranosyluracil (FMAU) has been found to have an especially desirable combination of properties for use as an imaging agent, including in particular limited in vivo catabolism. Methods for the preparation of the [11C]-and [18F]-labeled FMAU and for the use of the labeled material are also provided.

Abstract: The nucleoside analog 2'-fluoro-5-methyl-1-.beta.-D-arabinofuranosyluracil (FMAU) has been found to have an especially desirable combination of properties for use as an imaging agent, including in particular limited in vivo catabolism. Methods for the preparation of the ?.sup.11 C!-labelled FMAU and for the use of the labelled material are also provided.

Abstract: Certain ones of a total array of ultrasonic transducers constitute a small aperture and are so energized as to project acoustic energy onto predetermined parts of a scene. Reflections of the transmitted signals are received by certain ones of the array, are converted to electrical signals and are appropriately delayed to enable additive combination of the amplitude of the received signals emanating from the same points in the scene ("targets"). The phase (or time delay) as well as the amplitude information of the reflective signals are stored. Next, the same transmitting elements ("subarray") project acoustic energy upon the remaining parts of the scene in sequence and the reflected signals are similarly processed and stored. This continues until all the parts of the predetermined scene have been interrogated by insonification from that subarray and the reflected signals have been similarly processed.

Abstract: An array of acoustic receiving transducers is placed next to the body to be imaged. Acoustic energy is initially projected through the body, picked up by these receiving transducers, and processed to determine any time domain deviations which exist in the paths actually followed by that energy from those paths which would have been followed if the body were substantially homogeneous and the transducer array substantially fixed. Further acoustic energy is also picked-up by the transducers, after reflection within the body to be imaged. The image of any given point within the body is then formed by selecting from each transducer output signal that portion which corresponds to the image forming energy emanating from that point, as corrected in accordance with the previously determined deviations.