Reduced administered activity, reduced acquisition time, and preserved image quality for the new CZT camera

Abstract

Reduced administered activity, reduced acquisition time, and preserved image quality for the new CZT camera. Link to publication Citation for published version (APA): Oddstig, J., Hedeer, F., Jögi, J., Carlsson, M., Hindorf, C., & Engblom, H. (2013). Reduced administered activity, reduced acquisition time, and preserved image quality for the new CZT camera. Journal of Nuclear Cardiology, 20(1), 38-44. DOI: 10.1007/s12350-012-9634-6 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Abstract BackgroundFor a 1-day myocardial perfusion SPECT (MPS) the recommendations for administered activity stated in the EANM guidelines results in an effective dose of up to 16 mSv per patient. Recently, a gamma camera system, based on cadmium zinc telluride (CZT) technology, was introduced. This technique has the potential to reduce the effective dose and scan time compared to the conventional NaI gamma camera. The aim of this study was to investigate if the effective dose can be reduced with a preserved image quality using CZT-technology in MPS. MethodsIn total, 150 patients were included in the study. All underwent a 1-day 99m Tc-tetrofosmin stress-rest protocol and were divided into three subgroups (n=50 in each group) with 4 MBq/kg, 3 MBq/kg and 2.5 MBq/kg body weight of administered activity in the stress examination, respectively. The acquisition time was increased in proportion to the decrease in administered activity. All examinations were analysed for image quality by visual grading on a 4-point scale (1 = poor, 2 = adequate, 3 = good, 4 = excellent), by two expert readers. ResultsThe total effective dose (stress + rest) decreased from 9.3 mSv to 5.8 mSv comparing 4 MBq/kg to 2.5 MBq/kg body weight. For the patients undergoing stress examination only (35%) the effective dose, administrating 2.5 MBq/kg, was 1.4 mSv. The image acquisition times for 2.5 MBq/kg body weight were 475 s and 300 s (stress and rest) compared to 900 s for each when using conventional MPS. The average image quality was 3.7±0.5, 3.8±0.5 and 3.8±0.4 for the stress images and 3.5±0.6, 3.6±0.6 and 3.5±0.6 for the rest images and showed no statistically significant difference (p=0.62) between the 4 MBq/kg, 3 MBq/kg and 2.5 MBq/kg groups. ConclusionsThe new CZT technology can be used to considerably decrease the effective dose and acquisition time for MPS with preserved high image quality. KeywordsMyocardial perfusion imaging, SPECT, CZT detector, effective dose, image quality 2 Background Myocardial p...

It’s about time we think about lowering radiation dose in obese patients too

“…Based on their prior study of a low-dose protocol for nonobese patients using 2.5 MBq/kg body weight, they projected this concept for patients who were obese in an attempt to expand the 2.5 MBq/kg to all types of patients. 20 In this prospective study, patients weighing less than 110 kg received 2.5 MBq/kg of 99Tc-tetrofosmin, while for patients weighing 110 to 120 kg and [120 kg, a fixed dose of 430 and 570 MBq, respectively, were used. Images were obtained using a conventional gamma camera with resolution recovery software or a newer CZT cameras, with about half of the subjects imaged in each of the two groups.…”

Effect of a patient-specific minimum activity in stress myocardial perfusion imaging using CZT-SPECT: Prognostic value, radiation dose, and scan outcome

“…As longer scan times were used in the PLAP group, this automatically lowered the required activity. 15 We therefore did not only compare the administered activity between both protocols but also the PAST, as this metric accounts for changes in both activity and scan time. Patients in the PLAP group received a 25% lower PAST during stress MPI.…”

The radiation dose to overweighted patients undergoing myocardial perfusion SPECT can be significantly reduced: validation of a linear weight-adjusted activity administration protocol

“…7,8 Furthermore, a new generation of reconstruction methods for the conventional gamma cameras was recently introduced referred to as Ordered Subset Expectation Maximization with depth-dependent Resolution Recovery (OSEM-RR). 9 Both CZT detectors and OSEM-RR can be used to reduce the radiation exposure to nonobese patients [10][11][12] in accordance with ALARA (As Low As Reasonably Achievable). 13 A large body size may cause a higher proportion of emitted photons being attenuated and scattered within the patient resulting in reduced number of primary photons reaching the detector.…”

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