This study has investigated the relationship between linear attenuation coefficients (μ) and Hounsfield units (HUs) for six materials covering the range of values found clinically. Narrow-beam μ values were measured by performing radionuclide transmission scans using 99mTc, 123I, 131I, 201Tl and 111In. The μ values were compared to published data. The relationships between μ and HU were determined. These relationships can be used to convert computed tomography (CT) images to μ-maps for single photon emission computed tomography (SPECT) attenuation correction.
- Attenuation correction