Comparative assessment of different energy mapping methods for generation of 511-keV attenuation map from CT images in PET/CT sy

The use of X-ray CT images for CT-based attenuation correction (CTAC) of PET data results in the decrease of overall scanning time and creates a noise-free attenuation map (μmap). The linear attenuation coefficient (LAC) measured with CT is calculated at the x-ray energy rather than at the 511 keV. It is therefore necessary to convert the linear attenuation coefficients obtained from the CT scan to those corresponding to the 511 keV. Several conversion strategies have been developed including scaling, segmentation, hybrid, bilinear and dual-energy decomposition methods. The aim of this study is to compare the accuracy of different energy mapping methods for generation of attenuation map form CT images. An in-house made polyethylene phantom with different concentrations of K2HPO4 was used in order to quantitatively measure the accuracy of the nominated methods, using quantitative analysis of created μmaps. The generated μmaps using different methods compared with theoretical values ...

• Type: Conference
• Year: 2008
• Where: ISBI
• Authors: Maryam Shirmohammad, Mohammad Reza Ay, Saeed Sarkar, Hossein Ghadiri, Arman Rahmim
• Keywords: Attenuation, Attenuation Maps, ISBI 2008, Linear Attenuation Coefficients, Medical Imaging