The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 1990
Filed:
Nov. 23, 1988
Walter W Lindstrom, Shaker Hts., OH (US);
Picker International, Inc., Highland Hts., OH (US);
Abstract
A xenon gas system (B) introduces xenon gas into a patient's blood. The xenon concentration in the patient's blood is monitored (26) periodically as the concentration builds toward a saturation level (32). The absorption data is divided into at least three curved segments (32, 34, 36) each of which are approximated by a curve segment to determine absorption curve characteristics. The amplitude of the saturation curve segment is determined as first characteristic; the slope of the second curve segment is a second characteristic; and an end amplitude and time constant of an exponential third curve segment provide third and fourth characteristics indicative of blood xenon absorption. A CT scanner (A) generates a plurality of time displaced image representations, each of which is subtracted (52) from a reference image (30) to determine difference image representations. Each image representation includes a plurality of pixels that correspond to subregions of a region of interest within the patient. A look-up table (60) is addressed by the absorption curve characteristics and corresponding pixel values to retrieve corresponding partition coefficient, blood flow, and fit or confidence values for each pixel. A video display (76) displays images indicative of the partition coefficient, blood flow rate, or confidence value of the imaged pixels.