Biomedical subjects

J H Ewins

Publications and source records attributed to J H Ewins.

3 recordsLinked to original sources

PubMed1975

In vivo measurement of 32P in the brain of a freely moving rat.

A new method for measuring the uptake of materials labeled with radioactive phosphorus (32P) in the brain of a freely moving rat is described. The rate of uptake in the brain of a single animal of 32P-labeled phosphate was compared to the uptake rate in the animal's blood or liver. A comparison was made between the uptake following an intravenous (IV) or an intraperitoneal (IP) injection. The effect of convulsions caused by injections of metrazol on the kinetics of 32P uptake in the brain is described.

Animals↗

PubMedDate not supplied

Imaging characteristics of a small germanium camera.

A high purity germanium gamma-camera has been developed and is currently being evaluated. This camera incorporates unique performance parameters such as a 2 mm full-width spatial response function with rejection of multiple-scatter in the detector, a 2.2% FWHM energy resolution for 99 mTc, a 180 nsec paralyzable dead-time, and a 2 mu sec non-paralyzable dead-time. Imaging studies demonstrate the superior capabilities of this instrument.

Animals↗

PubMedDate not supplied

Biomedical probe using a fiber-optic coupled scintillator.

A high-sensitivity biomedical radiation probe which employs a fiber-optic coupled NaI(Tl) scintillator as a detector is described. It was developed for in vivo counting of low-energy 239Pu photons from material located in the tracheobronchial lymph nodes.-This probe is 20 times as sensitive as a solid-state probe (avalanche diode) previously developed for this application. Tests with 99mTc show a sensitivity more than 90 times greater than biomedical probes using DcTe of GaAs; however, the improved sensitivity is largely due to an increased sensitive volume. Probes were evaluated in animals and phantoms for detection of 239Pu and for location of lung tumors labeled with 111In.

Animals↗