Improving 99mTc-tetrofosmin Myocardial Perfusion Images by Time Subtraction Technique

Authors: Yasuyuki Takahashi, Hayato Ishimura, Masao Miyagawa, Teruhito Mochizuki

Abstract:

Quantitative measurement of myocardium perfusion is possible with single photon emission computed tomography (SPECT) using a semiconductor detector. However, accumulation of ^99mTc-tetrofosmin in the liver may make it difficult to assess that accurately in the inferior myocardium. Our idea is to reduce the high accumulation in the liver by using dynamic SPECT imaging and a technique called time subtraction. We evaluated the performance of a new SPECT system with a cadmium-zinc-telluride solid-state semi- conductor detector (Discovery NM 530c; GE Healthcare). Our system acquired list-mode raw data over 10 minutes for a typical patient. From the data, ten SPECT images were reconstructed, one for every minute of acquired data. Reconstruction with the semiconductor detector was based on an implementation of a 3-D iterative Bayesian reconstruction algorithm. We studied 20 patients with coronary artery disease (mean age 75.4 ± 12.1 years; range 42-86; 16 males and 4 females). In each subject, 259 MBq of ^99mTc-tetrofosmin was injected intravenously. We performed both a phantom and a clinical study using dynamic SPECT. An approximation to a liver-only image is obtained by reconstructing an image from the early projections during which time the liver accumulation dominates (0.5~2.5 minutes SPECT image-5~10 minutes SPECT image). The extracted liver-only image is then subtracted from a later SPECT image that shows both the liver and the myocardial uptake (5~10 minutes SPECT image-liver-only image). The time subtraction of liver was possible in both a phantom and the clinical study. The visualization of the inferior myocardium was improved. In past reports, higher accumulation in the myocardium due to the overlap of the liver is un-diagnosable. Using our time subtraction method, the image quality of the ^99mTc-tetorofosmin myocardial SPECT image is considerably improved.

Keywords: 99mTc-tetrofosmin, dynamic SPECT, time subtraction, semiconductor detector.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1125819

References:

[1] G. Germano, T. Chua, H. Kiat, J. S. Areeda, D. S. Berman, “A quantitative phantom analysis of artifacts due to hepatic activity in technetium-99m myocardial SPECT studies,” J Nucl Med, vol. 35, no. 2, pp. 356–359, Feb. 1994.
[2] Y. Takahashi, Y. Yuyama, S. Yagi, M. Kitagawa, Y. Kimura, M. Abe, et al, “Influence of hepatic accumulation of 123I-MIBG on myocardial imaging,” Ehime JM, vol. 30, no. 1, pp. 13–18, Apr. 1994 (in Japanese).
[3] B. A. Herzog, R. R. Buechel, R. Kats, M. Brueckner, L. Husmann, I. A. Burger, et al, “Nuclear myocardial perfusion imaging with a cadmium-zinc-telluride detector technique: optimized protocol for scan time reduction,” J Nucl Med, vol. 51, no. 1, pp. 46–51, Jan. 2010.
[4] Y. Takahashi, M. Miyagawa, Y. Nishiyama, H. Ishimura, T. Mochizuki, “Performance of a semiconductor SPECT system: comparison with conventional Anger-type SPECT,” Ann Nucl Med, vol. 27, no. 1, pp. 11–16, Jan. 2013.
[5] K. Erlandsso, K. Kacperski, D. van Gramberg, B. F. Hutton. “Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology,” Phys. Med. Biol, vol. 9, no. 54, pp. 2635–2649, Sep. 2009.
[6] R. R. Buechel, B. A. Herzog, L. Husmann, I. A. Burger, A. P. Pazhenkottil, V. Treyer, et al. “Ultrafast nuclear myocardial perfusion imaging on a new gamma camera with semiconductor detector technique: first clinical validation,” Eur J Nucl Med Mol Imaging, vol. 4, no. 37, pp. 773–778, Apr. 2010.
[7] T. Hebert, R. Leath. “A generalized EM algorithm for 3D Bayesian reconstruction from Poisson data using Gibbs priors,” IEEE Trans Med Imaging, vol. 2, no. 8, pp. 194–202, Jun. 1989.
[8] G. Germano, H. Kiat, P. Kavanagh, M. Moriel, M. Mazzanti, H. Su, et al. “Automatic quantification of ejection fraction from gated myocardial perfusion SPECT,” J Nucl Med, vol. 11, no. 36, pp. 2138–2124, Nov. 1995.
[9] NEMA Standards publication NU 1-2001, “Performance measurements of scintillation cameras,” 2001.
[10] A. Takaki, K. Okada, J. Urata, H. Matsuda, Y. Takao, “Reduction of the influence of the liver uptake to the myocardial uptake on technetium-99m myocardial SPECT : Usefulness and problems of a mask processing method,” Jpn J Nucl Med, vol. 36, no. 5, pp. 459–465, Jul. 1999 (in Japanese).
[11] M. Funahashi, T. Shimonagata, K. Mihara, K. Kashiyama, R. Shimizu, S. Machida, et al, “Application of pixel truncation to reduce intensity artifacts in myocardial SPECT imaging with Tc-99m tetrofosmin,” J Nucl Cardiol, vol. 9, no. 6, pp. 622–631, Nov. 2002 (in Japanese).