Analysis of different doses of 18F-FDG to PET image quality

• 作 者: Zhang Xiongwei
• 机 构: PET/CT Center,PLA General Hospital,Beijing 100853,China
• 出 处: The 1st Sino-American Conference on Nuclear Medicine(首届中美核医学
• 发表日期: 2011年12期
• 关键词: PET FDG Dosage PET image

　　Objective: Using qualitative and quantitative methods to analysis and explore the influence of different dosages 18F-FDG to PET model, provides the basis for clinical tracer dosage.Methods: PET/CT of GE (DISCOVERY VCT) and Siemens (Biograph64—HD).Cylindrical organic glass hollow model which is filled with certain dosage of the FDG aqueous solution.According to the half-life calculate time of different dosages(27.8、 20.8、 13.9、 9.71、 6.91、 3.46、1.73、 0.86、 0.43 、 0.22 mCi).Thare are also 16 organic glass hollow balls with different diameter which is filled with very low (0.0005mCi/mL) dosage of the FDG aqueous solution as the background in the cylindrical model.PET-CT acquisition: both of GE and Siemens chose routine clinical parameter for the acquisition.Data analysis: Using qualitative methods to Analysis the reconstructed image.For quantitative methods, same slice was extracted from reconstructed image for doing following analysis: the hot area SUV, the ratio between hot area and cold area, the standard deviation on background area.Results: combine the qualitative methord and the index value of quantitative to choose the appropriate dosage.Discussion: When the dosage is too high, due to the influence of the dead time, each qualitative indexes of the reconstructed image are poorer, quantitative analysis found that each index confusion ; When the dosage is too low, the information of reconstructed image is lower,Noise has very big effect , lead to image distortion.prolong the time Can offset clinical information shortages, but will increase the errors caused by displacement.; When the dosage is appropriate, the resolution, uniformity and contrast of the images are better ,noise within acceptable limits, in clinical the dosage is also acceptable.Conclusion:Combining above result with other consideration, such as radiation exposure,information amount and acquisition time, the optimal dosage of GE is 0.07mCi/Kg~0.14mCi/Kg and 0.10mCi/Kg ~ 0.20mCi/Kg for Siemens.