Abstracts of Reports and Presentations
Concerning the BVA-100

PRESENTATION GIVEN AT THE SOCIETY OF NUCLEAR MEDICINE CONFERENCE,
JUNE 6-10, 1999, LOS ANGELES, CALIFORNIA

K.F. Smith, I.S. Seo, W.M. Sy, C.J. Homs, P.C. Sze, J.G. McBride, C. Morton

Blood volume (BV) measurements utilizing 1-131 human serum albumin (HSA) are useful in a variety of clinical and surgical situations. The aim of this work was to evaluate the technical aspects of a computerized blood volume analyzer, the BVA-100 (Daxor Corporation, New York, NY).

The BVA-100 is a computer-controlled instrument consisting of a gamma counter with a 2-inch thick Nal crystal coupled to a multichannel analyzer (NICA). The instrument contains an automatic sample feed mechanism and a computer with dedicated software, which drives the entire system. A built in algorithm provides a predicted norm for a specific individual of 8%. Measurements are based on the indicator dilution principle, Following injection (if 0.92 mBq of 1-131 USA, five separate blood samples are taken at measured intervals. After obtaining hematocrit and centrifuging to obtain plasma, the BVA-100 automatically counts each sample and calculates BV. The BVA-100 also provides a pre-calibrated single dose injection in addition to a precisely matched standard.

A predicted norm for a specific individual of 8% represents a significant improvement over those based purely on body weight or surface area. The use of a 2-inch thick Nal crystal increases counting efficiency, permitting a smaller dose to be administered to the patient. Provision of a precisely matched standard eliminates the time consuming step of preparing a standard. The use of multiple sampling reduces errors that may occur from improper or inadequate collection and permits BV determinations to within accuracy of 0.5%. In conclusion, The BVA-100 provides accurate, reproducible determinations of BV, at minimal radiation dose to the patient.