Korean J Nucl Med.  1997 Sep;31(3):330-338.

Optimization of Subtraction Brain Perfusion SPECT with Basal / Acetazolamide Consecutive Acquisition

• Lee DS
• Lee TH
• Kim KM
• Chung JK
• Lee MC
• Koh CS

Abstract

This study investigated the method to adjust acquisition time(a) and injection dose(i) to make the best basal and subtraction images in consecutive SPECT. Image quality was assumed to be mainly affected by signal to noise ratio(S/N). Basal image was subtracted from the second image consecutively acquired at the same position. We calculated S/N ratio in basal SPECT images(S1/N1) and subtraction SPECT images(Ss/Ns) to find a(time) and i(dose) to maximize S/N of both images at the same time. From phantom images, we drew the relation of image counts and a(time) and i(dose) in our system using fanbeam-high-resolution collimated triple head SPECT. Noise by imaging process depended on Poisson distribution. We took maximum tolerable duration of consecutive acquisition as 30 minutes and maximum injectible dose as 1,850MBq(50 mCi)(sum of two injections) per study. Counts of second-acquired image(S2), counts(Ss) and noise(Ns) of subtraction SPECT were as follows. C1 was the coefficient of measurement with our system.

Keyword

Subtraction SPECT; Optimization; Rest/acetazolamide study; Signal to noise ratio

MeSH Terms

Acetazolamide*
Brain*
Head
Noise
Perfusion*
Signal-To-Noise Ratio
Tomography, Emission-Computed, Single-Photon*
Acetazolamide