Premium
A miniature cesium iodide‐photodiode detector for ambulatory monitoring of left ventricular function
Author(s) -
Millaire A.,
HosseinFoucher C.,
Rousseau J.,
Bedoui H.,
Ducloux G.,
Marchandise X.
Publication year - 1994
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.597171
Subject(s) - collimator , photodiode , preamplifier , detector , sodium iodide , materials science , scintillation , optics , nuclear medicine , photomultiplier , optoelectronics , physics , medicine , nuclear physics , amplifier , cmos
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 (1×1×1 cm 3 ) 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.