1.02

A multicenter evaluation of a new post-processing method with depth-dependent collimator resolution applied to full-time and half-time acquisitions without and with simultaneously acquired attenuation correction

“…7 The application to 32 projections was described in prior reports. 8,9 For all attenuation map reconstructions, a uniform initial estimate and 30 iterations of a Bayesian algorithm 7 applied to the downscatter-compensated projection data was used. Truncation compensation for artifacts occurring in the small field of view transmission images as described earlier 10 was applied to the 32-and 64-projection stress-only images.…”

Multicenter investigation comparing a highly efficient half-time stress-only attenuation correction approach against standard rest-stress Tc-99m SPECT imaging

“…We recently studied the transmission maps attained using half-time acquisition times to establish lower limits for fast imaging. 13,14 We showed in phantoms and retrospective analysis of patient studies that the attenuation maps were equivalent to full time acquisitions including quantitative attenuation coefficient values for all key tissue regions and important boundaries for registration were equivalent. We also demonstrated that the downscatter correction method developed for fulltime acquisition was accurate when applied to fast acquisitions showing no difference when compared to studies with no Tc-99m activity present, especially important for the higher amounts of downscatter from stress activity levels.…”

“…17 The application to 32 projections was described in prior reports. 13,14 For all studies, a uniform initial estimate and 30 iterations were applied to the downscatter compensated projection data. 17 Truncation compensation for any artifacts occurring when the patient's body becomes outside of the small field of view in the transmission images as described earlier 18 was applied to the 32 and 64 projection stress-only images identically.…”

“…9,12 Preliminary data have demonstrated adequacy of simultaneously acquired line-source transmission maps for attenuation correction using one of these rapid-acquisition protocols (Astonish, Philips, Milpitas, CA). 13,14 To date, reduced acquisition time with new algorithms has not been evaluated with stress-only imaging techniques. Important considerations include image quality, interpretive confidence, diagnostic accuracy, and comparability of extent and severity of defects and quantitative function parameters.…”

Highlights of the 2007 Scientific Sessions of the American Society of Nuclear Cardiology

“…24, 2007 image reconstruction with filtered back projection (3). Studies of attenuation correction demonstrated that the attenuation maps obtained from gadolinium-153 transmission scans are not adversely affected by "half-time" acquisition protocols (4,5). A study of hybrid imaging with a PET/CT system in patients with chest pain recruited from emergency department patients found that the absence of CAC was predictive of a normal adenosine stress rubidium-82 scan, suggesting that stepwise imaging with CT for CAC performed first might reduce overall radiation exposure (6).…”