A miniature cesium iodide-photodiode detector for ambulatory monitoring of left ventricular function.
The physical characteristics of a portable nonimaging scintillation probe system for continuous ambulatory monitoring of the left ventricular function are described. The detector of the equilibrium radionuclide labeled blood pool is a single cesium iodide (CsI) crystal coupled to a silicium photodiode and interfaced to a microcomputer. The spatial properties of this small CsI crystal (1 x 1 x 1 cm3) were evaluated with various single-hole collimators. Linearity was studied in nonattenuating medium. Saturation began at 3000 cps, count loss was 10% at 4000 cps, maximal count rate was 24,000 cps. In attenuating medium, isocount curve of 5% of the maximal count rate was 100 mm deep and 160 mm wide. The most appropriate tested lead collimator to record the global ejection fraction of the left ventricle was a disc-shaped (thickness 5 mm, diameter 41 mm) single-hole (proximal aperture 8 mm, distal aperture 18 mm) collimator. Sensitivity was similar to the sensitivity of a sodium iodide nuclear probe. The detection performance appeared comparable to other available detector systems. Our results indicate that such a CsI-photodiode probe is a promising candidate for left ventricular function monitoring. The application to an ambulatory multicrystal detector system is presented and discussed.
Millaire
A
A
Division of Cardiology, Hôpital Cardiologique, Centre Hospitalier Régional et Universitaire, Lille, France.
Hossein-Foucher
C
C
Rousseau
J
J
Bedoui
H
H
Ducloux
G
G
Marchandise
X
X
D055592:Biophysical Phenomena; D001703:Biophysics; D002586:Cesium; D005069:Evaluation Studies as Topic; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007454:Iodides; D008838:Microcomputers; D008961:Models, Structural; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D011835:Radiation Protection; D011877:Radionuclide Imaging; D012588:Scintillation Counting / Q000295:instrumentation*; D013667:Technetium; D013679:Technology, Radiologic; D016277:Ventricular Function, Left
D007454:Iodides; D002586:Cesium; D013667:Technetium; C040050:cesium iodide