Multiwindow scatter correction techniques in single‐photon imaging

Abstract

We studied the performance of linear scatter correction methods for single-photon imaging with Tc-99m and Tl-201, using a numerical model of the Rollo phantom and measurements with a gamma camera modified to record position and energy information in list mode form. We compared the performance of these methods to per-image optimized linear methods and to locally adaptive linear methods, and developed estimates of the limits on accuracy of scatter correction imposed by the presence of Poisson noise. For both Tc-99m and Tl-201 imaging at a fixed depth, particularly at low count rates, the performance of dual-window methods, or of adaptive methods, is near the best possible for linear methods. Smoothing of the scatter estimate results in minor improvement for Tl-201. Substantial gaps between the performance of any of these linear methods and the limits imposed by Poisson noise remain and are due primarily to bias, with the gap for Tl-201 being larger than that for Tc-99m.

123I-Metaiodobenzylguanidine cardiac innervation imaging: methods and interpretation

“…In Europe and US most laboratories use LEHR collimators without any scatter correction, whereas in Japan the low-medium energy collimators are more widely used. Some studies have proposed several scatter compensation methods [24][25][26][27][28] to offset for the resulting corruption of image related to the use of LEHR collimator due to penetration by higher energy photons. Recently, Chen et al [28,29] developed a deconvolution of septal penetration technique, a mathematical method that optimizes acquisition and processing protocols obtaining similar results for LEHR and medium energy all-purpose collimators.…”

Optimization of energy window and evaluation of scatter compensation methods in MPS using the ideal observer with model mismatch

“…A disadvantage of window-based methods is the noise in the scatter estimate that results from acquiring data in these narrow windows. Increasing the width of the scatter window reduces noise in the scatter estimate, but provides, in general, a more biased estimate of scatter in the photopeak window [31].…”

Optimization of energy window and evaluation of scatter compensation methods in myocardial perfusion SPECT using the ideal observer with and without model mismatch and an anthropomorphic model observer

“…Increasing the width of the scatter window reduces the noise in the scatter estimate, but provides, in general, a more biased estimate of scatter in the photopeak window. 31 …”