• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.115-121
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• 2014

Purpose: In addition to improving the quality of the PET image, through much research, the development of various programs are performed. Astonish TF reconstruction techniques by Philips can confirm the improved contrast of the lesion. Also, It's image reconstruction of 2 mm is possible with rapid reconstruction rate than conventional. In this study, we compared and evaluated Standardized Uptake Value (SUV) in accordance with the 2 mm reconstruction techniques and traditional 4 mm from the $^{18}F-FDG$ PET whole body image. Materials and Methods: In the phantom experiment, NEMA IEC body phantom (sphere: 10, 13, 17, 22, 28, 37 mm) was used to obtain images by using GEMINI TF 64 PET/CT (Philips, Cleveland, USA). Also, In the clinical images, we performed $^{18}F-FDG$ PET/CT examination to 30 women (age: $55.1{\pm}11.3$, BMI: $24.1{\pm}2.9$) with a diagnosis of breast cancer. After that, we reconstructed images in 2 mm and 4 mm respectively. The region of interest was drawn to acquired images. Since then, we measured SUV and statistically analyzed with SPSS ver.18 by using EBW (Extended Brilliance Workstation) NM ver.1.0. Results: After analyzing the result of the phantom study, there was a tendency that the bigger hot sphere size, the higher SUV. If you compared the 2 mm reconstruction techniques to 4 mm, it increased 95.78% in 10 mm, 50.60% in 13 mm, 25.00% in 17 mm, 30.04% in 22 mm, 31.81% in 28 mm, and 27.84% in 37 mm. Through the result of the analysis of the 2 mm reconstruction techniques and 4 mm in clinical images, it appeared that SUV of 2 mm was higher than that of 4 mm. Also the smaller the volume was, the more the change rate increased. Conclusion: After analyzing the result of the clinical picture and phantom experiments applied by Astonish TF reconstruction techniques, as the size of the volume was small, the change rate of the SUV increased. Therefore, it was necessary to further research about the SUV correction for accurate and active utilization of 2 mm reconstruction techniques which had excellent lesion discrimination ability and contrast in clinic.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.110-114
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• 2012

Purpose : PET/CT is widely used for early checking up of cancer and following up of pre and post operation. Image reconstruction method is advanced with mechanical function. We want to evaluate image quality of each reconstruction program based on time of flight (TOF). Materials and Methods : After acquiring phantom images during 2 minutes with Gemini TF (Philips, USA), Biograph mCT (Siemens, USA) and Discovery 690 (GE, USA), we reconstructed image applied to Astonish TF (Philips, USA), ultraHD PET (Siemens, USA), Sharp IR (GE, USA) and not applied. inside of Flangeless Esser PET phantom (Data Spectrum corp., USA) was filled with $^{18}F$-FDG 1.11 kBq/ml (30 Ci/ml) and 4 hot inserts (8. 12. 16. 25 mm) were filled with 8.88 kBq/ml (240 ${\mu}Ci/ml$) the ratio of background activity and hot inserts activity was 1 : 8. Inside of triple line phantom (Data Spectrum corp., USA) was filled with $^{18}F$-FDG 37 MBq/ml (1 mCi). Three of lines were filled with 0.37 MBq (100 ${\mu}Ci$). Contrast ratio and background variability were acquired from reconstruction image used Flangeless Esser PET phantom and resolution was acquired from reconstruction image used triple line phantom. Results : The contrast ratio of image which was not applied to Astonish TF was 8.69, 12.28, 19.31, 25.80% in phantom lid of which size was 8, 12, 16, 25 mm and it which was applied to Astonish TF was 6.24, 13.24, 19.55, 27.60%. It which was not applied to ultraHD PET was 4.94, 12.68, 22.09, 30.14%, it which was applied to ultraHD PET was 4.76, 13.23, 23.72, 31.65%. It which was not applied to SharpIR was 13.18, 17.44, 28.76, 34.67%, it which was applied to SharpIR was 13.15, 18.32, 30.33, 35.73%. The background variability of image which was not applied to Astonish TF was 5.51, 5.42, 7.13, 6.28%. it which was applied to Astonish TF was 7.81, 7.94, 6.40 6.28%. It which was not applied to ultraHD PET was 6.46, 6.63, 5.33, 5.21%, it which was applied to ultraHD PET was 6.08, 6.08, 4.45, 4.58%. It which was not applied to SharpIR was 5.93, 4.82, 4.45, 5.09%, it which was applied to SharpIR was 4.80, 3.92, 3.63, 4.50%. The resolution of phantom line of which location was upper, center, right, which was not applied to Astonish TF was 10.77, 11.54, 9.34 mm it which was applied to Astonish TF was 9.54, 8.90, 8.88 mm. It which was not applied to ultraHD PET was 7.84, 6.95, 8.32 mm, it which was applied to ultraHD PET was 7.51, 6.66, 8.27 mm. It which was not applied to SharpIR was 9.35, 8.69, 8.99, it which was applied to SharpIR was 9.88, 9.18, 9.00 mm. Conclusion : Image quality was advanced generally while reconstruction program which is based on time of flight was used. Futhermore difference of result compared each manufacture reconstruction program showed up, however this is caused by specification of instrument of each manufacture and difference of reconstruction algorithm. Therefore we need further examination to find out appropriate reconstruction condition while using reconstruction program used for advance of image quality.