SPECT Gama Kemera Sistemi için Çekim Parametre Değişikliğinin Görüntü Kalitesine Etkisi

GİRİŞ: Bu çalışmada amacımız gama kamera çekim parametre değişikliklerinin görüntü kalitesi üzerine etkilerini araştırmaktır. YÖNTEM: Miyokard perfüzyon sintigrafisi ve tiroid sintigrafisi tetkiki için gönderilen toplam 48 hastanın (K:29, E:19, Yaş ortalaması: 47,4±11,1) çift başlı gama kamerada çekimleri yapıldı. Ardından gama kamera çekim parametreleri değiştirilerek (Miyokard perfüzyon sintigrafisi için 64x64 ve 128x128 matrix değişikliği, tiroid sintigrafisi için 5cm ve 10cm uzaklık değişikliği) hastaların yeniden çekimleri yapıldı. Hastaların görüntüleri analiz edildi. BULGULAR: 64x64 matrikste sol ventrikül ejeksiyon fraksiyonu (EF) değeri: %62,7±8,8 olarak hesaplandı. Aynı hastaların 128x128 matrikste yapılan görüntülemesinde ise EF değeri: %48,9±10,3 olarak düşük bulundu. 10 cm uzaklıktan yapılan 99mTc-perteknetat uptake sonucu %3,8±2,3 olarak bulundu. Aynı hastaların 5 cm uzaklıktan yapılan uptake sonucu ise %6,2±3,6 olarak yüksek bulundu. SONUÇ: SPECT gama kamera sisteminde doğru görüntüleme yapabilmek için intrinsic flood-field uniformite ve relative sensitivite değerleri yanında, doğru çekim parametreleri de göz önünde bulundurulmalıdır.

Anahtar Kelimeler:

SPECT gama kamera, 99mTeknesyum, kalite kontrol test, çekim parametreleri

Effect of Acquisition Parameters of SPECT Gamma Camera System on Image Quality

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. 99mTc-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.

Keywords:

SPECT gamma camera, 99mTechnetium, quality control test, acquisition parameters,

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