SPECT Gama Kemera Sistemi için Çekim Parametre Değişikliğinin Görüntü Kalitesine Etkisi

OBJECTIVE: Quality control testing of a SPECT gamma camera is crucial in assessing the suitability of the camera for use in nuclear medicine department. The aim of the present study was to investigate the effect of gamma camera acquisition parameters on image quality. METHODS: Camera scanning was carried out using a double-headed gamma cameraon a total of 48 patients (29 female and 19 male, mean age: 47.4±11.1) referred to our department for myocardial perfusion scintigraphy and thyroid scintigraphy. Then, camera acquisition parameters were changed (for myocardial perfusion scintigraphy from 64x64 to 128x128 matrix change and for thyroid scintigraphy from 5 cm to 10 cm distance change), and scanning was repeated and images were analyzed. RESULTS: Left ventricle ejection fraction (EF) value in 64x64 matrix was calculated to be 62.7±8.8%. Smaller EF value of 48.9±10.3% was obtained in 128x128 matrix for the same patients. 99m Tc-pertechnetate uptake percentage was 3.8±2.3% in measurements carried out at a distance of 10 cm. On the other hand, a higher uptake percentage of 6.2±3.6% was found for the same patients measured at a distance of 5 cm. CONCLUSION: In order to obtain proper imaging in SPECT gamma camera system, correct acquisition parameters should be used along with quality control tests for intrinsic flood-field uniformity and relative sensitivity.