Convolution estimation of spill-down and scatter in dual isotope (99mTc/111In) SPECT

Jian Feng; Bill C. Penney; Xiaochuan Pan

doi:10.1117/12.465618

3 May 2002 Convolution estimation of spill-down and scatter in dual isotope (^99mTc/¹¹¹In) SPECT

Jian Feng, Bill C. Penney, Xiaochuan Pan

Proceedings Volume 4682, Medical Imaging 2002: Physics of Medical Imaging; (2002) https://doi.org/10.1117/12.465618
Event: Medical Imaging 2002, 2002, San Diego, California, United States

Abstract

Accurate attenuation correction in dual isotope single photon emission computed tomography (SPECT) requires spill-down and scatter correction. Convolution methods that allow such correction were investigated. Three energy windows were used: 1) a Compton scatter window placed below the Tc-99m photopeak window, 2) the Tc-99m photopeak, and 3) both In-111 photopeaks. Spill-down of In-111 into the Tc-99m window was measured using a small source of In-111 at depths of 5, 7, 9, and 11cm. From these data, the convolution kernel relating the In-111 image and the Tc-99m window spill-down image was computed for each depth. Using a small Tc-99m source at the same depths, the convolution kernels describing its spill-down into the Compton window were computed. A factor to scale the Tc-99m spill-down estimate by for obtaining the self-scatter estimate was determined from the total counts in the Tc-99m photopeak vs. the Compton scatter window when primary photons were blocked with a small lead disk. Depths of 5 and 9cm were optimal for spill-down and Tc-99m self-scatter correction, respectively. It was demonstrated that the spill-down and scatter correction increased effective attenuation coefficient towards its 'no-scatter' value and dramatically decreased the intensity of an In-111 source in Tc-99m projection images.

Citation Download Citation

Jian Feng, Bill C. Penney, and Xiaochuan Pan "Convolution estimation of spill-down and scatter in dual isotope (^99mTc/¹¹¹In) SPECT", Proc. SPIE 4682, Medical Imaging 2002: Physics of Medical Imaging, (3 May 2002); https://doi.org/10.1117/12.465618

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available