Efforts to Improve the Images from 67Ga Whole-Body Scintigraphy
Author(s)
Kyoko Saito1,
Yasuyuki Takahashi1*,
Naomi Ogano2,
Hirotaka Shimada2,
Takao Kanzaki2,
Hiroki Okada2,
Kei Yokota3,
Kaori Hatano4,
Yuki Yoshida5,
Tetsuya Higuchi6
Affiliation(s)
1 Department of Nuclear Medicine Technology, Gunma Prefectural College of Health Sciences, Maebashi, Japan. 2 Department of Radiological Technology, Gunma University Hospital, Maebashi, Japan. 3 Department of Radiological Technology, JA Hiroshima General Hospital, Hatsukaichi, Japan. 4 Department of Radiological Technology, Nakamura Memorial Hospital, Sapporo, Japan. 5 Department of Radiological Technology, Gunma Children’s Medical Hospital, Shibukawa, Japan. 6 Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan.
1 Department of Nuclear Medicine Technology, Gunma Prefectural College of Health Sciences, Maebashi, Japan. 2 Department of Radiological Technology, Gunma University Hospital, Maebashi, Japan. 3 Department of Radiological Technology, JA Hiroshima General Hospital, Hatsukaichi, Japan. 4 Department of Radiological Technology, Nakamura Memorial Hospital, Sapporo, Japan. 5 Department of Radiological Technology, Gunma Children’s Medical Hospital, Shibukawa, Japan. 6 Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan.
ABSTRACT
The acquisition method for planar 67Ga imaging has hardly changed for 30 years. In this study, in order to improve image quality and diagnostic accuracy, we take steps to optimize the acquisition method, and to choose a scatter correction. First, we acquired individual images from the 93 keV, 185 keV, and 300 keV photopeak; then the images were added together and compared to the individual images. Second, we compared results from a low-medium-energy (LME) collimator with those from a conventional medium-energy (ME) collimator. Also, we examined whether to combine the data from all three of the usual window locations (set about 93 keV, 185 keV, and 300 keV) or to use the data from only two. Third, we compared results from a conventional photopeak ± 10％ window with those from a photopeak ± 9 keV window. Fourth, for scatter correction we compared results using the triple energy window (TEW) method with those using the multi-photopeak dual window (MDW) method. The phantoms studied were cold rods in a uniform background, and hot spheres within a cylinder containing uniformly radioactive water. The clinical study involved 22 patients with lung lesions. By the comparison by the contrast ratio in cold rods phantom, 15.6% is improved in LME (2 peaks) than ME (3 peaks), and 3.2% is improved in photopeak ± 9 keV than photopeak ± 10%, 10.2% is improved in TEW than MDW. However, the TEW scatter correction method recognized unstable to the contrast ratio in a clinical study. In addition, a body outline might disappear.
The acquisition method for planar 67Ga imaging has hardly changed for 30 years. In this study, in order to improve image quality and diagnostic accuracy, we take steps to optimize the acquisition method, and to choose a scatter correction. First, we acquired individual images from the 93 keV, 185 keV, and 300 keV photopeak; then the images were added together and compared to the individual images. Second, we compared results from a low-medium-energy (LME) collimator with those from a conventional medium-energy (ME) collimator. Also, we examined whether to combine the data from all three of the usual window locations (set about 93 keV, 185 keV, and 300 keV) or to use the data from only two. Third, we compared results from a conventional photopeak ± 10％ window with those from a photopeak ± 9 keV window. Fourth, for scatter correction we compared results using the triple energy window (TEW) method with those using the multi-photopeak dual window (MDW) method. The phantoms studied were cold rods in a uniform background, and hot spheres within a cylinder containing uniformly radioactive water. The clinical study involved 22 patients with lung lesions. By the comparison by the contrast ratio in cold rods phantom, 15.6% is improved in LME (2 peaks) than ME (3 peaks), and 3.2% is improved in photopeak ± 9 keV than photopeak ± 10%, 10.2% is improved in TEW than MDW. However, the TEW scatter correction method recognized unstable to the contrast ratio in a clinical study. In addition, a body outline might disappear.
Cite this paper
Saito, K. , Takahashi, Y. , Ogano, N. , Shimada, H. , Kanzaki, T. , Okada, H. , Yokota, K. , Hatano, K. , Yoshida, Y. and Higuchi, T. (2015) Efforts to Improve the Images from 67Ga Whole-Body Scintigraphy. World Journal of Nuclear Science and Technology, 5, 1-5. doi: 10.4236/wjnst.2015.51001.
Saito, K. , Takahashi, Y. , Ogano, N. , Shimada, H. , Kanzaki, T. , Okada, H. , Yokota, K. , Hatano, K. , Yoshida, Y. and Higuchi, T. (2015) Efforts to Improve the Images from 67Ga Whole-Body Scintigraphy. World Journal of Nuclear Science and Technology, 5, 1-5. doi: 10.4236/wjnst.2015.51001.
References
[1] Vorster, M., Maes, A., Jacobs, A., Malefahlo, S., Pottel, H., Wiele, C.V. and Sathekge, M.M. (2014) Evaluating the Possible Role of 68Ga-Citrate PET/CT in the Characterization of Indeterminate Lung Lesions. Annals of Nuclear Medicine, 28, 523-530. [2] Togawa, T., Yui, N., Kinoshita, F., Ichihara, H., Hiyoshi, K., Fujigasaki, K. and Narita, Y. (2000) Clinical Application of Whole Body 67Ga SPECT (WB SPECT) as a NEW Tumor Imaging Method. Japanese Journal of Clinical Radiology, 45, 1079-1087. [3] Inoue, Y., Abe, Y., Itoh, Y., Asano, Y., Kikuchi, K., Sakamoto, Y., Matsunaga, K., Ogino, Y., Iizuka, T. and Mochizuki, H. (2013) Acquisition Protocols and Correction Methods for Estimation of the Heart-to-Mediastium Ratio in 123I-Metaiodobenzylguanidine Cardiac Sympathetic Imaging. Journal of Nuclear Medicine, 54, 707-713.
http://dx.doi.org/10.2967/jnumed.112.111955 [4] Ogawa, K. (1994) Simulation Study of Triple-Energy-Window Scatter Correction in Combined Tl-201, Tc-99m SPECT. Annals of Nuclear Medicine, 8, 277-281.
http://dx.doi.org/10.1007/BF03165031 [5] Yanagisawa, M., Kinoshita, F., Morisada, M. and Ichihara, Y. (1998) Study of Gallium-67 Imaging Using the Triple Energy Window (TEW) Method. Japanese Journal of Radiological Technology, 54, 630-637.
[1] Vorster, M., Maes, A., Jacobs, A., Malefahlo, S., Pottel, H., Wiele, C.V. and Sathekge, M.M. (2014) Evaluating the Possible Role of 68Ga-Citrate PET/CT in the Characterization of Indeterminate Lung Lesions. Annals of Nuclear Medicine, 28, 523-530. [2] Togawa, T., Yui, N., Kinoshita, F., Ichihara, H., Hiyoshi, K., Fujigasaki, K. and Narita, Y. (2000) Clinical Application of Whole Body 67Ga SPECT (WB SPECT) as a NEW Tumor Imaging Method. Japanese Journal of Clinical Radiology, 45, 1079-1087. [3] Inoue, Y., Abe, Y., Itoh, Y., Asano, Y., Kikuchi, K., Sakamoto, Y., Matsunaga, K., Ogino, Y., Iizuka, T. and Mochizuki, H. (2013) Acquisition Protocols and Correction Methods for Estimation of the Heart-to-Mediastium Ratio in 123I-Metaiodobenzylguanidine Cardiac Sympathetic Imaging. Journal of Nuclear Medicine, 54, 707-713.
http://dx.doi.org/10.2967/jnumed.112.111955 [4] Ogawa, K. (1994) Simulation Study of Triple-Energy-Window Scatter Correction in Combined Tl-201, Tc-99m SPECT. Annals of Nuclear Medicine, 8, 277-281.
http://dx.doi.org/10.1007/BF03165031 [5] Yanagisawa, M., Kinoshita, F., Morisada, M. and Ichihara, Y. (1998) Study of Gallium-67 Imaging Using the Triple Energy Window (TEW) Method. Japanese Journal of Radiological Technology, 54, 630-637.