University of California

Hologic, Inc.

Sutter West Bay Hospitals

John A Shepherd

Kevin E Wilson

Howard P Weiss

Steven R Cummings

Jay A Stein

Thomas L Kelly

Karla Kerlikowske

Vincent E Quinn

Wei Wang

Richard E Cabral

Mark Guetersloh

Joel B Weinstein

Bennett K Ng

Serghei Malkov

Chao Huang

Systems and methods for determining body composition by combining dual-energy x-ray (DXA) technology with three-dimensional (3D) optical technology and/or bioimpedance technology. A multi-modality scanning system may include a dual-energy x-ray source and an x-ray detector mounted to opposing sides a c-arm and configured to scan a patient on a optically translucent table. The system may also include one or more 3D optical imaging devices to capture 3D optical images of the patient substantially concurrently with the emission of the dual energy x-rays. A bioimpedance machine may also be included in the multi-modality scanning system. Data based on the dual-energy x-rays may be combined with the data from the 3D optical images and/or the bioimpedance data to generate values of at least three compartments selected from: bone, fat tissue, lean tissue, dehydrated lean tissue, and water.

Multiple modality body composition analysis

The present invention provides an apparatus and methods for measuring proportions of body materials in body parts. The apparatus includes a device for retaining the body part, at least one reference material with at least two thicknesses positioned adjacent to the device, and at least three radiopaque markers positioned on the reference material(s). The reference material(s) each have an attenuation characteristic that is selected in correspondence to the body materials in the body part. The apparatus further includes a radiation device to simultaneously irradiate the body part, the reference material(s) and the radiopaque markers as well as a detector to detect attenuated beams of radiation and a pattern projected from the irradiated radiopaque markers. A calculation device determines the thickness of the body part based on this projected pattern and compares the attenuation values of the body part and the reference material(s) at the determined thickness.

Methods and apparatus for determining proportions of body materials

The present invention provides a radiation device that includes a device for retaining therein the body part in a uniform position. In addition, at least two reference materials that have attenuation characteristics are used and retained in the retaining device. The reference materials are being positioned for the comparative determination during a simultaneous irradiation of the body part and the reference materials. The attenuation characteristics of the reference materials are selected in correspondence to the attenuation characteristics of the body materials in the body part. A radiation device for simultaneously irradiating the body part and the reference materials is used to create attenuated beams. A detector is used to detect the attenuated beams as attenuated values. A calculating device is included for calculating the proportion of the body materials that define a particular body part of interest based on the attenuated values of the materials and the body part.

Device and method for determining proportions of body materials

A method of measuring bone mineral density (BMD) of a selected region of bone in a small body portion (such as a limb or extremity), using a mini C-arm x-ray fluoroscopic imaging system to acquire the data from which the BMD is calculated. Apparatus for performing the method includes a tray for positioning the small body portion in the x-ray beam path of the imaging system and a sample of bone of predetermined density supported by the tray in side-by-side relation to the selected region of bone.

Method of assessing bone characteristics using digital 2-dimensional x-ray detector

True body composition is estimated using a dual-energy, fan-shaped distribution of x-rays and signal processing that corrects for mass magnification and other effects due to the geometry of the measurement system. To avoid inaccuracies due to beam hardening and certain other effects, the thickness of attenuating material along respective raypaths is obtained through using a four-dimensional look-up table derived experimentally from step-wedge measurements. To correct for mass magnification effects due to using a fan-shaped distribution of x-rays, another look-up table and interpolation between table entries are used to convert projected mass to true mass.

Determining body composition using fan beam dual-energy x-ray absorptiometry

Bone densitometry using x-ray imaging systems

Growing community of inventors

Novato, CA, United States of America

John A Shepherd