Efforts to Improve the Images from ⁶⁷Ga Whole-Body Scintigraphy

Kyoko Saito¹, Yasuyuki Takahashi^1*, Naomi Ogano², Hirotaka Shimada², Takao Kanzaki², Hiroki Okada², Kei Yokota³, Kaori Hatano⁴, Yuki Yoshida⁵, Tetsuya Higuchi⁶

¹Department of Nuclear Medicine Technology, Gunma Prefectural College of Health Sciences, Maebashi, Japan.
²Department of Radiological Technology, Gunma University Hospital, Maebashi, Japan.
³Department of Radiological Technology, JA Hiroshima General Hospital, Hatsukaichi, Japan.
⁴Department of Radiological Technology, Nakamura Memorial Hospital, Sapporo, Japan.
⁵Department of Radiological Technology, Gunma Children’s Medical Hospital, Shibukawa, Japan.
⁶Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan.

DOI: 10.4236/wjnst.2015.51001                

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.

Keywords

⁶⁷Ga Imaging, LME Collimator, MDW Scatter Correction

Conflicts of Interest

The authors declare no conflicts of interest.

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