Concepts and clinical utility of the measurement of cerebral blood flow

Use of radiopharmaceuticals in diagnostic nuclear medicine in the United States: 1960-2010

To reconstruct reliable nuclear medicine-related occupational radiation doses or doses received as patients from radiopharmaceuticals over the last five decades, the authors assessed which radiopharmaceuticals were used in different time periods, their relative frequency of use, and typical values of the administered activity. This paper presents data on the changing patterns of clinical use of radiopharmaceuticals and documents the range of activity administered to adult patients undergoing diagnostic nuclear medicine procedures in the U.S. between 1960 and 2010. Data are presented for 15 diagnostic imaging procedures that include thyroid scan and thyroid uptake; brain scan; brain blood flow; lung perfusion and ventilation; bone, liver, hepatobiliary, bone marrow, pancreas, and kidney scans; cardiac imaging procedures; tumor localization studies; localization of gastrointestinal bleeding; and non-imaging studies of blood volume and iron metabolism. Data on the relative use of radiopharmaceuticals were collected using key informant interviews and comprehensive literature reviews of typical administered activities of these diagnostic nuclear medicine studies. Responses of key informants on relative use of radiopharmaceuticals are in agreement with published literature. Results of this study will be used for retrospective reconstruction of occupational and personal medical radiation doses from diagnostic radiopharmaceuticals to members of the U.S. radiologic technologists' cohort and in reconstructing radiation doses from occupational or patient radiation exposures to other U.S. workers or patient populations.

Regional arm-brain mean transit time in the diagnostic evaluation of patients with cerebral vascular disease

By analyzing time-activity curves over selected brain regions, following intravenous administration of non-diffusible radionuclide, it is possible to assess regional arm-brain mean transit time (rABmtT). By evaluating this parameter in normal subjects a relatively small range of differences between asymmetrical regions can be found (0.30 +/- 0.14 sec, mean +/- SD). An increase of this difference above statistical limits was found in 82% of patients with acute complete stroke, in 56% of patients with chronic complete stroke in 21% of patients with transient ischemic attacks.