Using a 1.28 ration and a minimum attenuation of 170 HU in dual-energy CT (DECT) postprocessing eliminates the majority of lower limb artifacts, especially clumpy artifacts and beam hardening, according to a study published in Quantitative Imaging in Medicine and Surgery. In an effort to help reduce the frequency of some common artifacts seen in patients with suspected gout—nail bed, skin, beam hardening, submillimeter and vascular artifacts—and, thus, overdiagnosis in this patient population, researchers sought to determine the optimal DECT settings for post-processing. Various post-processing settings were evaluated among patients hospitalized with suspected gout in the feet/ankles and/ or knees who underwent DECT imaging. Nine settings (R1 to R9) were evaluated with a combination of different ratios (1.28, 1.36 and 1.55) and attenuation coefficients (120, 150, 170 HU). “Among the nine settings tested, the R2 setting (170 HU, ratio =1.28) significantly reduced the presence of knee and foot/ankle artifacts compared to the standard R1 setting (85% and 94% decrease in beam hardening and clumpy artifacts in the ankle and foot, respectively (P<0.001); a decrease of 71%, 60% and 88% respectively of meniscal beam hardening, beam hardening and submillimeter artifacts in the knee (P<0.001),” wrote the study authors.
