Original ArticleReduced administered activity, reduced acquisition time, and preserved image quality for the new CZT camera
Section snippets
Background
Myocardial perfusion single photon emission computed tomography (MPS) is an established non-invasive imaging technique for detection of myocardial perfusion defects. The conventional technology with a NaI-crystal was introduced more than 50 years ago and is the most widely used nuclear medicine imaging technique. Conventional MPS is associated with time-consuming image acquisition and a relatively high administered activity is required to enable adequate image quality.
Recently, a new generation
Study Design
The study group comprised 150 consecutive patients referred for MPS due to known or suspected coronary artery disease. All patients underwent a 1-day 99mTc-tetrofosmin stress protocol according to clinically established protocols. Exclusion criteria were a patient weight more than 100 kg, patients undergoing a 2-day protocol and patients undergoing the rest examination before the stress examination.
The patients were consecutively included into three different subgroups. The first 50 patients
Results
Patient characteristics and MPS study results are shown in Table 1. All 150 patients successfully underwent stress examination with mean activity of 318, 238, and 203 MBq at stress for the 4, 3, and 2.5 MBq/kg protocols, respectively (Table 2). Examination at rest was performed in 97 patients (65%) based on the interpretation of the stress images. The mean duration between stress and rest activity administration was 3.5 ± 1.1 hour resulting in a mean administered activity for the rest
Discussion
This study shows that it is possible to perform MPS with the new CZT technology with both a significantly reduced effective dose and a shorter scan time with a preserved image quality as compared to conventional MPS technology and the EANM guidelines.
There was no statistically significant difference in image quality between the three activity groups. Also, the image quality was graded as “good” or “excellent” in the vast majority of the studies by both expert readers. These results are
Conclusions
The effective radiation dose and the acquisition time can be considerably decreased with preserved high image quality when MPS is performed with the novel CZT technology. A stress and rest examination, using a 1-day protocol, can be performed with an effective dose of 37% compared to the dose recommended in international guidelines.
Acknowledgments
The authors would like to thank Christel Kullberg for excellent technical assistance. This study was supported in part by research funding from Region of Scania, Swedish Research Council, Swedish Heart and Lung Foundation, and Lund University Faculty of Medicine.
Conflict of interest
None.
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