A method is described which overcomes the problems of multipath propagation and range ambiguity that is suffered by the single-frequency continuous-wave microwave-imaging system described in part I. This technique is essentially a variation of chrip radar techniques, which have been adapted to time delay and attenuation measurements through a target. The feasibility of discriminating between paths whose differential time delay is on the order of 100 ps is demonstrated. Further, the need for small physical aperture in the transmitting and receiving antennas is demonstrated.

Electric Conductivity↗

PubMedDate not supplied

Microwave scattering parameter imagery of an isolated canine kidney.

This paper describes a method for imaging biosystems using radiation in the microwave frequency range (3.9 GHz). The advantages of interrogation with microwave radiation are discussed in terms of its physiological significance. An electromechanical scanning system for imaging isolated organs and the subsequent image processing techniques are described. Imagery is presented for a phantom target and an isolated canine kidney. The kidney images are interpreted in terms of the known anatomical and functional organization of the organ. It does appear to be possible to distinguish cortex corticis corresponding to a high proportion of proximal and distal convoluted tubules, deeper cortical layers corresponding to a high population density of glomeri, a medullary outer zone corresponding to the loops of Henle as well as the collecting system, and the region of calyces/renal pelvis.

Animals↗

PubMedDate not supplied

Microwave time delay spectroscopic imagery of isolated canine kidney.

A method for producing microwave images that are improved through the reduction of multipath propagation effects is described. This method employs water immersed antennas and microwave time delay spectroscopy (TDS) at S-band. It is shown that objects as small as 6 mm in diameter can be detected. Objects 10 mm apart appear as separate responses on the image. It is also shown that is possible to generate a physiologically and anatomically relevant image of an isolated canine renal specimen.

Animals↗