A study on the effects of an extended CT field of view (FOV) on the standardized uptake value (SUV) in a PET/CT scan using 18F-fluoro-2deoxy-D-glucose

This study examined the effect of an extended CT field of view (FOV) on the standardized uptake value (SUV) of positron emission tomography — computed tomography (PET/CT) when the image extended beyond the CT FOV. CT images were reconstructed at different FOV sizes (500 mm and 700 mm). Two sets of CT images were reconstructed from the CT projection data by using the two FOV sizes. Twenty patients were examined in this study. The PET images were reconstructed from attenuation maps with a 500 mm CT FOV and a 700 mm extended CT FOV images. The regions of interest (ROIs) were drawn on the PET images. In addition, in the twenty patients, the PET images reconstructed by using a 500-mm CT FOV and 700-mm extended CT FOV were compared with the standardized uptake value (SUVmax). When attenuation maps with the 700-mm extended CT FOV were used, the SUVmax analyses of the liver (p = 0.000), lung (p = 0.007) and mediastinum (p = 0.001) produced statistically significant result. A 700 mm extended CT FOV help recover the true activity distribution in the PET emission data and affected the SUV measurements of the liver, lung and mediastinum.