Department of Radiology, Kantonsspital Baden, Baden, Switzerland.
Hospital Pharmacy, Kantonsspital Baden, Baden, Switzerland.
In Vivo. 2021 Nov-Dec;35(6):3147-3155. doi: 10.21873/invivo.12609.
BACKGROUND/AIM: The quantitative evaluation of fat tissue, mainly for the determination of liver steatosis, is possible by using dual-energy computed tomography. Different photon energy acquisitions allow for estimation of attenuation coefficients. The effect of variation in radiation doses and reconstruction kernels on fat fraction estimation was investigated.
A six-probe-phantom with fat concentrations of 0%, 20%, 40%, 60%, 80%, and 100% were scanned in Sn140/100 kV with radiation doses ranging between 20 and 200 mAs before and after calibration. Images were reconstructed using iterative kernels (I26,Q30,I70).
Fat fractions measured in dual-energy computed tomography (DECT) were consistent with the 20%-stepwise varying actual concentrations. Variation in radiation dose resulted in 3.1% variation of fat fraction. Softer reconstruction kernel (I26) underestimated the fat fraction (-9.1%), while quantitative (Q30) and sharper kernel (I70) overestimated fat fraction (10,8% and 13,1, respectively).
The fat fraction in DECT approaches the actual fat concentration when calibrated to the reconstruction kerneö. Variation of radiation dose caused an acceptable 3% variation.
背景/目的：双能计算机断层扫描（DECT）可定量评估脂肪组织，主要用于测定肝脂肪变性。不同的光子能量采集可用于估计衰减系数。本研究旨在探讨辐射剂量和重建核函数的变化对脂肪分数估计的影响。
使用带有 0%、20%、40%、60%、80%和 100%脂肪浓度的六探头体模，在 Sn140/100 kV 下分别以 20-200 mAs 的辐射剂量进行扫描，扫描前和扫描后进行校准。使用迭代核（I26、Q30、I70）进行图像重建。
DECT 测量的脂肪分数与逐步变化的 20%实际浓度一致。辐射剂量的变化导致脂肪分数变化 3.1%。较软的重建核（I26）低估了脂肪分数（-9.1%），而定量（Q30）和较锐利的核（I70）高估了脂肪分数（分别为 10.8%和 13.1%）。
经重建核校准后，DECT 的脂肪分数接近实际脂肪浓度。辐射剂量的变化导致可接受的 3%变化。
