Almquist H, Palmer J, Ljungberg M, Wollmer P, Strand S E, Jonson B
Department of Clinical Physiology, University of Lund, Sweden.
Eur J Nucl Med. 1990;16(8-10):587-94. doi: 10.1007/BF00998154.
A method for measuring attenuation coefficients in single-photon emission tomography (SPECT) is described and evaluated, together with a method for attenuation correction using these measured attenuation coefficients. Build-up, caused by scattered photons, is corrected for by a simple substitution in the algorithms. Transmission studies are performed with a 99mTc- or 57Co flood source, and emission phantom studies with 99mTc line sources. The method is evaluated with variable but well-defined phantoms. The result is accurate attenuation coefficients for different densities, dimensions and geometries, and an accuracy of corrected emission activities of better than +/- 10% in most cases. The present limitations of the method for attenuation correction are discussed.
本文描述并评估了一种在单光子发射断层扫描（SPECT）中测量衰减系数的方法，以及一种使用这些测量得到的衰减系数进行衰减校正的方法。算法中通过简单替换对由散射光子引起的积累效应进行了校正。使用99mTc或57Co泛源进行透射研究，使用99mTc线源进行发射体模研究。该方法通过可变但定义明确的体模进行评估。结果得到了不同密度、尺寸和几何形状下准确的衰减系数，并且在大多数情况下，校正后发射活度的准确度优于±10%。文中还讨论了该衰减校正方法目前存在的局限性。
