Pant G S, Kumar R, Gupta A K, Sharma S K, Pandey A K
Departments of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi-110029, India.
Nucl Med Commun. 2003 Jul;24(7):743-8. doi: 10.1097/00006231-200307000-00002.
scintigraphic method for the estimation of the thyroid mass in patients with Graves' disease is described. The method was first standardized using thyroid phantoms with eight different volumes ranging from 5 to 110 cm(3). The planar and single photon emission computed tomography (SPECT) images of each phantom were acquired with four different activities [3.7 MBq (100 microCi), 11.1 MBq (300 microCi), 22.2 MBq (600 microCi) and 37 MBq (1.0 mCi) of 99mTc-pertechnetate] with a 20% window symmetrically placed over the photopeak of 99mTc. The thyroid lobes were enclosed with the help of regions of interest (ROI) tools and a threshold was selected to identify the thyroid boundaries. The same threshold was used in all slices of an image. In the phantom study, a 20% threshold for planar images and a 30% threshold for SPECT were found to be optimum for measuring the thyroid volume. The volume from planar images was calculated by the formula described by Allen and Goodwin (The scintillation counter as an instrument for in-vivo determination of thyroid weight. Radiology 1952; 58: 68-79), whereas, in SPECT images, the sum of the slice areas was multiplied by the slice thickness. The estimated volume of each phantom was compared and correlated with its actual volume. After standardization of the technique with phantom studies, planar scintigraphy (with 20% threshold) in 51 patients and SPECT (with 30% and 35% threshold) in 40 patients with Graves' disease were performed to estimate the thyroid size. The thyroid size was also estimated by ultrasonography, which showed good agreement with the scintigraphic method, particularly with SPECT.
描述了一种用于评估格雷夫斯病患者甲状腺质量的闪烁扫描法。该方法首先使用体积从5到110立方厘米不等的8种不同甲状腺模型进行标准化。使用四种不同活度[3.7兆贝可（100微居里）、11.1兆贝可（300微居里）、22.2兆贝可（600微居里）和37兆贝可（1.0毫居里）的99m锝高锝酸盐]采集每个模型的平面和单光子发射计算机断层扫描（SPECT）图像，在99m锝的光电峰上对称放置一个20%的窗。借助感兴趣区域（ROI）工具勾勒出甲状腺叶，并选择一个阈值来确定甲状腺边界。在一幅图像的所有切片中使用相同的阈值。在模型研究中，发现平面图像的20%阈值和SPECT的30%阈值最适合测量甲状腺体积。平面图像的体积通过艾伦和古德温描述的公式计算（闪烁计数器作为体内测定甲状腺重量的仪器。放射学1952；58：68 - 79），而在SPECT图像中，切片面积之和乘以切片厚度。将每个模型的估计体积与其实际体积进行比较并建立相关性。在用模型研究对该技术进行标准化后，对51例格雷夫斯病患者进行了平面闪烁扫描（阈值为20%），对40例患者进行了SPECT（阈值为30%和35%）以估计甲状腺大小。还通过超声检查估计了甲状腺大小，其与闪烁扫描法显示出良好的一致性，特别是与SPECT。
