A calibration phantom for absolute quantitation of radionuclide uptake by SPECT
A calibration phantom for absolute quantitation of radionuclide uptake by SPECT
复制标题
用于通过 SPECT 绝对定量放射性核素吸收的校准模型
DOI：
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
H. Hines
中科院分区：
文献类型：
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作者：
D. Macey;G. Nardo;S. D. Nardo;H. Hines
小体积或器官中放射性核素摄取的绝对定量是核医学程序的兴趣，包括放射免疫治疗中辐射剂量的估计。使用校准模体的绝对定量放射性核素在小体积的横切面图像的SPECT模体与旋转伽玛相机进行了研究。校准模体是一组4个管，其中装满了溶液中放射性核素的适当比活度范围。这是与SPECT幻象或患者同时扫描的。这些管可以放置在患者边界的适当点上，也可以被封闭在一个组织等效的新月形幻影中，该幻影要么附着在SPECT台的底部，要么放置在患者身上以保留椭圆以进行衰减补偿。在横切面图像中，每个管和体积的感兴趣区域（ROI）被定义为大约10%的适当阈值，并且在1到100亩的范围内，感兴趣区域的计数随特定活动的变化呈线性变化。Ciml / 1 /一同坐席。然而，从校准模体中得到的计数取决于横切面的总活度，更取决于横切面的大小和有效衰减系数，所使用的重构滤波器以及衰减补偿的边界检测精度。初步结果表明，如果衰减补偿令人满意，该SPECT校准模体可用于体内选定部位的放射性核素摄取的绝对定量。此外，该方法将简化辐射剂量计算中累积活度的测定。«少
Absolute quantitation of radionuclide uptake in small volumes or organs is of interest for nuclear medicine procedures including the estimation of radiation dose in radioimmunotherapy. The use of a calibration phantom for absolute quantitation of a radionuclide in small volumes in a transverse section image of a SPECT phantom with a rotating gamma camera has been investigated. The calibration phantom is a set of 4 tubes filled with a suitable range of specific activity of the radionuclide in solution. This is scanned simultaneously with the SPECT phantom or patient. The tubes can either be placed at appropriate points on the patient boundary or enclosed in a tissue equivalent crescent-shaped phantom which is either attached to the underside of the SPECT table or placed on the patient to preserve the ellipse for attenuation compensation. A region of interest (ROI) for each tube and volume in the transverse section image was defined with an appropriate threshold of about 10% and the variation of counts in the ROI versus specific activity was found to be linear over the range 1 to 100..mu..Ciml/sup -1/. However, the counts from the calibration phantom were found to depend on the total activity in the transverse section slice,more » the size and effective attenuation coefficient of the transverse section, the reconstruction filter used and the accuracy of boundary detection for attenuation compensation. Preliminary results indicate that this SPECT calibration phantom can be used for absolute quantitation of radionuclide uptake in a selected site in the body, provided attenuation compensation is satisfactory. Also, the method will simplify determination of cumulated activity for radiation dose calculations.« less