Calculations of total activity and relative radiolysis product yields for selected photonuclear reaction target systems used for production of clinically useful, short-lived, positron-emitting radionuclides.

The potential performance of certain photonuclear target systems designed to produce short-lived positron emitters for nuclear medicine applications was evaluated. Included were calculations of photonuclear target activity yields, relative radiolysis product yields and relative specific activities of products as a function of photonuclear target shapes, dimensions, spacing from the bremsstrahlung photon source, and the energy of the electron beam using the reactions 12C(gamma,n)11C, 14N(gamma,n)13N, and 16O(gamma,n)15O. Results indicate that substantial activity yields can be achieved in these photonuclear target systems and that specific activity of the product varies widely as a function of the energy of the electron beam used to produce the bremsstrahlung and the included angle from the central beam axis that the photonuclear target occupies.

A system for quantitatively assessing certain performance parameters of gamma camera systems from reflective print and film transparency final images.

Past efforts at routine evaluation of gamma camera systems performance, using final product images, primarily resulted in qualitative assessments. This paper describes a system for quantitatively determining certain performance parameters of gamma camera systems using paper-backed print and transparent film test images of the same type used for viewing by the nuclear medicine physician. By use of appropriate transmission and line source phantoms, the gamma camera system's spatial resolution, distortion, and flood field uniformity as a function of position in the image field, are determined using a semiautomated image scanning and data reduction system.

Measurements of the distribution of technetium-99m sulfur colloid and technetium-99m HEDP in normal humans.

Technetium-99m sulfur colloid and technetium-99m hydroxyethylidene diphosphonate (HEDP) are two radiopharmaceuticals that have been widely used in nuclear medicine. Radiation dose estimates for both materials have been published in the literature and are found in the package inserts of the commercial kits. However, these estimates were made without the benefit of quantitative human organ uptake data.

Lack of specificity for detection of breast lesions with radioactive cesium chloride.

Detection of breast disease at an early stage was evaluated with 131CsCl. The tissue distribution study showed that malignant tumors could be distinguished from both benign and normal tissue by the degree of 131Cs concentration. However, the external counting method was not sensitive enough to warrant general application to patients with a suspected malignant tumor of the breast.