A new Compton densitometer for measuring pulmonary edema

Conference · Sat Feb 01 04:00:00 EST 1986 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:5886631

Loo, B W; Goulding, F S; Simon, S

Pulmonary edema (PE) is the pathological increase of extravascular lung water found most often in patients with congestive heart failure and other critically ill patients who suffer from intravenous fluid overload. The chest x-ray, the standard method for validating the presence of PE, is neither quantitative nor sensitive. A non-invasive lung density monitor that is accurate, easily portable, safe and inexpensive is needed for clinical use. To deal with the problem of attenuation along the beam paths, previous gamma-ray techniques require simultaneous measurement of transmitted and scattered beams. Since multiple scattering is a strong function of the density of the scattering medium and the mass distribution within the detection geometry, there will be inherent uncertainties in the system calibration unless it is performed on a body structure closely matched to that of each individual patient. Other researchers who have employed Compton scattering techniques generally used systems of extended size and detectors with poor energy resolution. This has resulted in significant systematic biases from multiply-scattered photons and larger errors in counting statistics at a given radiation dose to the patient. We are proposing a patented approach in which only backscattered photons are measured with a high-resolution HPGe detector in a compact system geometry. By proper design and a unique data extraction scheme, effects of the variable chest wall on lung density measurements are minimized. Preliminary test results indicate that with a radioactive source of under 30 GBq, it should be possible to make an accurate lung density, measurement in one minute, with a risk of radiation exposure to the patient a thousand times smaller than that from a typical chest x-ray.

• Research Organization: Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720
• OSTI ID: 5886631
• Report Number(s): CONF-851009-
• Conference Information: Journal Name: IEEE Trans. Nucl. Sci.; (United States) Journal Volume: NS-33:1
• Country of Publication: United States
• Language: English

Related Subjects

440101 -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ATTENUATION
BODY
COMPTON SCATTERING TOMOGRAPHY
DATA PROCESSING
DENSITOMETERS
DENSITY
DESIGN
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
DOSES
EDEMA
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
GAMMA RADIATION
GE SEMICONDUCTOR DETECTORS
HIGH-PURITY GE DETECTORS
IONIZING RADIATIONS
LUNGS
MASSLESS PARTICLES
MEASURING INSTRUMENTS
MONITORING
ORGANS
PATHOLOGICAL CHANGES
PHOTOMETERS
PHOTONS
PHYSICAL PROPERTIES
PROCESSING
RADIATION DETECTORS
RADIATION DOSES
RADIATIONS
RADIOACTIVITY
RESPIRATORY SYSTEM
RISK ASSESSMENT
SEMICONDUCTOR DETECTORS
SYMPTOMS
TOMOGRAPHY