Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Winter;3(1):43-9.

Dual radioisotopes simultaneous SPECT of (99m)Tc-tetrofosmin and (123)I-BMIPP using a semiconductor detector

Yasuyuki Takahashi  1 , Masao Miyagawa  2 , Yoshiko Nishiyama  2 , Naoto Kawaguchi  2 , Hayato Ishimura  3 , Teruhito Mochizuki  2
Affiliations

Dual radioisotopes simultaneous SPECT of (99m)Tc-tetrofosmin and (123)I-BMIPP using a semiconductor detector

Yasuyuki Takahashi et al. Asia Ocean J Nucl Med Biol. 2015 Winter.

Abstract

Objectives: The energy resolution of a cadmium-zinc-telluride (CZT) solid-state semiconductor detector is about 5%, and is superior to the resolution of the conventional Anger type detector which is 10%. Also, the window width of the high-energy part and of the low-energy part of a photo peak window can be changed separately. In this study, we used a semiconductor detector and examined the effects of changing energy window widths for (99m)Tc and (123)I simultaneous SPECT.

Methods: The energy "centerline" for (99m)Tc was set at 140.5 keV and that for (123)I at 159.0 keV. For (99m)Tc, the "low-energy-window width" was set to values that varied from 3% to 10% of 140.5 keV and the "high-energy-window width" were independently set to values that varied from 3% to 6% of 140.5 keV. For (123)I, the "low energy-window-width" varied from 3% to 6% of 159.0 keV and the high-energy-window width from 3% to 10% of 159 keV. In this study we imaged the cardiac phantom, using single or dual radionuclide, changing energy window width, and comparing SPECT counts as well as crosstalk ratio.

Results: The contamination to the (123)I window from (99m)Tc (the crosstalk) was only 1% or less with cutoffs of 4% at lower part and 6% at upper part of 159KeV. On the other hand, the crosstalk from (123)I photons into the (99m)Tc window mostly exceeded 20%. Therefore, in order to suppress the rate of contamination to 20% or less, (99m)Tc window cutoffs were set at 3% in upper part and 7% at lower part of 140.5 KeV. The semiconductor detector improves separation accuracy of the acquisition inherently at dual radionuclide imaging. In, this phantom study we simulated dual radionuclide simultaneous SPECT by (99m)Tc-tetrofosmin and (123)I-BMIPP.

Conclusion: We suggest that dual radionuclide simultaneous SPECT of (99)mTc and (123)I using a CZT semiconductor detector is possible employing the recommended windows.

Keywords: Breast cancer; Myocardial perfusion; Radiotherapy; SPECT.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Geometric arrangement of the c cardiac phantom study
Figure 2
Figure 2
The energy spectrum of 99mTc and 123I by the Discoverly NM530c. Intensity was made similar to the clinical study
Figure 3
Figure 3
Schema is the image of the cardiac phantom with injection radionuclide. This static image was acquired by an Anger type gamma camera. The count ratio of single radionuclide and a mixture of both radionuclides to which concentration was changed. X-axis: Concentration of 99mTc or 123I in a single radionuclide (100%) and a mixture of both radionuclides (20, 40, 60 and 80%). Y-axis: The count of the point source per pixel
Figure 4
Figure 4
In crosstalk measurement using cardiac phantom, the crosstalk into various-sized windows was determined for both 99mTc and 123I.
Figure 5
Figure 5
Bull’s eye map for the cardiac phantom with anterior defect in single- and dual-radionuclide. The defect is 1.5 cm (upper right), 3.0 cm (lower left) and left anterior descending (lower right). Upper left image was without defect
Figure 6
Figure 6
99mTc-tetrofosmin and 123I-BMIPP are displayed (top: 99mTc-tetrofosmin, middle: 123I-BMIPP in early phase, and bottom: 123I-BMIPP in delayed phase)
See this image and copyright information in PMC

References

    1. Dobbeleir AA, Hambys ASE, Franken PR. Influence of methodology on the presence and extent of mismatching between 99mTc-MIBI and 123I-BMIPP in myocardial viability studies. J Nucl Med. 1999;40:707–14. - PubMed
    1. Tamaki N, Tadamura E, Kawamoto M Magata, Yonekura Y, Fujibayashi Y, et al. Decreased uptake of iodinated branched fatty acid analog indicates metabolic alterations in ischemic myocardium. J Nucl Med. 1995;36:1974–80. - PubMed
    1. Kumita S, Mizumura S, Kijima T, Machida M, Kumazaki T, Tetsuou Y, et al. ECG-gated dual isotope myocardial SPECT with 99mTc-MIBI and 123I-BMIPP in patiens with ischemic heart disease. Kaku Igaku. 1995;32:547–55. - PubMed
    1. Standards publication NU-1–1994. Washington, DC: NEMA; 1994. National Electric Manufacturers Association (NEMA). Performance Measurements of Scintillation Cameras.
    1. USA, Rosslyn: National Electrical Manufacturers Association; 2001. NEMA Standard Publication NU 1-001, Performance Measurements of Scintillation Cameras.

LinkOut - more resources