A catheter-based radiation detector for endovascular detection of atheromatous plaques.
OBJECTIVE
Although various radiopharmaceuticals have been developed for the detection of atheromas, external imaging techniques have limitations when it comes to the detection of small plaques. In this study, we developed a charged particle-sensitive detector for the endovascular detection of small plaques.


METHODS
The device consists of a probe, an automatic pullback unit and a controller. The probe, which consists of a plastic scintillator and flexible optical fibres, is 1.0 mm in diameter. The probe was inserted into a catheter placed on (18)F point sources, and then the radioactivity was measured as the probe was pulled out stepwise.


RESULTS
The sensitivity for (18)F was 9.3 cps/kBq, and there was a close linear correlation between the peak counts and source dose until at least 0.8 MBq. Furthermore, this device showed low background counts (<0.1 cps) and a low detection limit (0.21 kBq). To investigate the effect of background radioactivity on the measurement at the point sources, a ball phantom was prepared and five (18)F point sources were set on the ball's surface. Even though 298 MBq of (18)F-fluorodeoxyglucose was injected into the ball, the point sources located every 10 mm on the ball's surface were detectable separately.


CONCLUSIONS
The data gathered suggest that a catheter-based radiation detector in combination with charged particle-emitting radiopharmaceuticals is useful for the endovascular detection of small lesions such as coronary plaques.
Mukai
Takahiro
T
Department of Nuclear Medicine and Diagnostic Imaging, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Nohara
Ryuji
R
Ogawa
Mikako
M
Ishino
Seigo
S
Kambara
Naoshige
N
Kataoka
Kazuaki
K
Kanoi
Toru
T
Saito
Kazuhiro
K
Motomura
Hiroshi
H
Konishi
Junji
J
Saji
Hideo
H
D000818:Animals; D016893:Carotid Stenosis / Q000000981:diagnostic imaging; D002404:Catheterization / Q000295:instrumentation*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019788:Fluorodeoxyglucose F18; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation / Q000379:methods; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18