A hybrid attenuation correction technique to compensate for lung density in 3D total body PET

A hybrid attenuation correction technique (ACT) has been developed for ¹⁸F-FDG Total Body Positron Emission Tomography (PET). With a short transmission scan of the thorax, any time within a few days of the isotope injection, it can correct for attenuation in the entire body. Segmentation, registration, and active contour finding techniques are applied to both emission and short transmission images to locate and map the major attenuating structures in the body. This technique eliminates the need for patient to remain still from the start of the transmission scan to the end of the emission scan without the added noise of simultaneous or post transmission scan measurements. The results of volunteer studies are comparable to standard measured ACT, both visually and quantitatively. Efficient use of scanner and maximum comfort for patients make it a highly desirable technique for clinical imaging