Cha Sijin, Chae Yeon, Yun Taesik, Kim Hakhyun, Kang Byeong-Teck
Laboratory of Veterinary Internal Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea.
Front Vet Sci. 2024 Oct 21;11:1453441. doi: 10.3389/fvets.2024.1453441. eCollection 2024.
Small-field-of-view (SFOV) gamma cameras can offer higher sensitivities than conventional gamma cameras. However, there are currently no reports on the efficacy and safety of thyroid scintigraphy using SFOV gamma cameras in veterinary medicine. Therefore, we aimed to evaluate the efficacy and radiation safety of an SFOV gamma camera for feline thyroid scintigraphy.
Three veterinary staff members (operator, staff 1, and staff 2) performed thyroid scintigraphy on 10 healthy cats in this study. The operator administered either 2 or 4 mCi of technetium-99m pertechnetate (TcO ) through the cephalic vein. At 20, 40, and 60 min after injection, thyroid images were obtained using a SFOV gamma camera under various acquisition conditions (100,000, 150,000, and 200,000 counts and 30 and 60 s). Thyroid scintigraphy images were analyzed by calculating the thyroid-to-salivary ratios (TSR) and thyroid-to-background ratios (TBR). Surface and ambient radiation were measured hourly from immediately after injection to 6 h. The cumulative occupational radiation doses were measured during the procedure.
The TSR and TBR median values aligned with the previously reported normal range obtained using a large-field-of-view gamma camera. There were no notable differences in TSR and TBR between the two doses of TcO , nor across acquisition conditions and timelines. The 4-mCi group consistently emitted more ambient ( < 0.05) and surface ( < 0.05) radiation than did the 2-mCi group. Staff 1 consistently received higher cumulative radiation doses than did staff 2 and the operator ( < 0.05).
The SFOV gamma camera demonstrated adequate image quality for thyroid scintigraphy in healthy cats even with relatively low doses and short acquisition conditions. Radiation exposure during the procedure posed minimal safety concerns. Therefore, the SFOV gamma camera could be a valuable tool for evaluating thyroid glands in cats.
小视野（SFOV）γ相机比传统γ相机具有更高的灵敏度。然而，目前尚无关于在兽医学中使用SFOVγ相机进行甲状腺闪烁扫描的有效性和安全性的报道。因此，我们旨在评估SFOVγ相机用于猫甲状腺闪烁扫描的有效性和辐射安全性。
在本研究中，三名兽医工作人员（操作员、工作人员1和工作人员2）对10只健康猫进行了甲状腺闪烁扫描。操作员通过头静脉注射2或4毫居里的高锝[99mTc]酸盐（TcO）。在注射后20、40和60分钟，使用SFOVγ相机在各种采集条件下（100,000、150,000和200,000计数以及30和60秒）获取甲状腺图像。通过计算甲状腺与唾液比值（TSR）和甲状腺与背景比值（TBR）来分析甲状腺闪烁扫描图像。从注射后立即开始，每小时测量表面和环境辐射，持续6小时。在操作过程中测量累积职业辐射剂量。
TSR和TBR的中位数与先前报道的使用大视野γ相机获得的正常范围一致。两种剂量的TcO之间，以及在采集条件和时间线上，TSR和TBR均无显著差异。4毫居里组始终比2毫居里组发出更多的环境辐射（P<0.05）和表面辐射（P<0.05）。工作人员1始终比工作人员2和操作员接受更高的累积辐射剂量（P<0.05）。
即使在相对低剂量和短采集条件下，SFOVγ相机也能为健康猫的甲状腺闪烁扫描提供足够的图像质量。操作过程中的辐射暴露对安全性的影响极小。因此，SFOVγ相机可能是评估猫甲状腺的有价值工具。
