In vivo determination of bone blood flow
Quantitative measurement of bone blood flow is vital to understand the hemodynamics of bone systems especially in the study of asceptic bone necroses. These ''silent bends'' result from micro-emboli in femoral arterioles from small nitrogen bubbles released from lipids during a diver's ascent. A technique to determine bone blood flow in vivo has been developed by measuring the rate of inert gas washout of Ar-41 (t /sub 1/2/ = 1.83 h, E = 1293 keV) from the bone mineral matrix. Argon gas is formed in vivo by neutron activation of Ca-44 using 14.3 MeV neutrons, following the reaction Ca-44(n, ..cap alpha..)Ar-41. The blood flow in the irradiated bone is determined by measuring the clearance rate of Ar-41 using gamma-ray spectroscopy. To date, measurements have been made on dead and living rats (weight 300g). The results indicated that in the no-flow situation the clearance rate is consistent with the physical half-life of Ar-41, while for the live rats the clearance rate for argon is dependent on the flow of blood in the bone. The observed clearance times correspond to flows greater than 3 ml of blood per 100 ml of argon distribution volume/min (F/pV), with the bone-blood partition coefficient for argon approximately one. In addition, measurements of the partitioning of argon and other gases with bone have been measured in order to understand blood-bone systems more fully.
- Research Organization:
- Dept. of Medical Physics, Univ. of Wisconsin, Madison, WI
- OSTI ID:
- 6575239
- Report Number(s):
- CONF-840619-; TRN: 87-018899
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
- Country of Publication:
- United States
- Language:
- English
Similar Records
Bone blood flow measured by /sup 41/Ar clearance formed by /sup 44/Ca(n,. cap alpha. )/sup 41/Ar
Hepatic and muscle clearance of physostigmine in the rat after i. v. administration
Related Subjects
BLOOD VESSELS
BLOOD FLOW
BONE MARROW
RADIONUCLIDE KINETICS
BONE TISSUES
ACTIVATION ANALYSIS
ARGON 41
BLOOD CIRCULATION
BUBBLES
CALCIUM 44
CARDIOVASCULAR SYSTEM
EMBOLI
GAMMA SPECTROSCOPY
IN VIVO
NECROSIS
NEUTRON REACTIONS
OSTEOPOROSIS
RADIOPHARMACEUTICALS
RETENTION FUNCTIONS
ALKALINE EARTH ISOTOPES
ANIMAL TISSUES
ARGON ISOTOPES
BARYON REACTIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCIUM ISOTOPES
CHEMICAL ANALYSIS
CONNECTIVE TISSUE
DISEASES
DRUGS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FUNCTIONS
HADRON REACTIONS
HEMATOPOIETIC SYSTEM
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOTOPES
LABELLED COMPOUNDS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
ORGANS
PATHOLOGICAL CHANGES
RADIOISOTOPES
SKELETAL DISEASES
SPECTROSCOPY
STABLE ISOTOPES
TISSUES
550601* - Medicine- Unsealed Radionuclides in Diagnostics