Scintigraphic recording of blood volume shifts.
A scintigraphic device consisting of small scintillation probes tightly fixed to the skin was developed to record intravascular blood volume shifts continuously and simultaneously at several sites. The aim of the present study was to ascertain the reliability of the measurements obtained, show the blood shifts induced by common daily activities in healthy subjects and clarify the mechanisms responsible for hemodynamic changes.


METHODS
Measurements were made in three fields of the right lung, the liver, thighs and calves of 16 men during Valsalva maneuver, hyperventilation, various posture changes and treadmill walking. Some tests were repeated.


RESULTS
The measured blood volume shifts were always in the expected direction and in accordance with those reported in the literature; they also were reproducible. Therefore, the measurements were reliable. A pattern of blood volume changes peculiar to some common daily activities was recorded in subjects moving freely. Insights were obtained on the mechanisms responsible for the blood volume shifts.


CONCLUSIONS
Our noninvasive technique provides reliable continuous measurements of blood volume changes at several sites during common daily activities and could be applied not only in healthy subjects but also in patients.
D000203:Activities of Daily Living; D001810:Blood Volume / Q000502:physiology*; D004867:Equipment Design; D004912:Erythrocytes; D018495:Fluid Shifts / Q000502:physiology*; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology; D007866:Leg / Q000098:blood supply / Q000000981:diagnostic imaging; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D008168:Lung / Q000098:blood supply / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology; D011877:Radionuclide Imaging / Q000295:instrumentation*; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000295:instrumentation*; D013667:Technetium; D014636:Valsalva Maneuver / Q000502:physiology; D016138:Walking / Q000502:physiology
D013667:Technetium