• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.427-433
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• 2013

Recently, 18F-FDG PET based CT scan was a critical examination that the after, before plan diagnosis and treatment of tumors. But, due to the distortion of SUV that should be proportional to the metabolic rate of glucose in the tumor, the other measurement methods are being on study. In this study, compared the degree of distortion of SUV that according to the volume of the tumor analysis ROI and VOI using the NEMA IEC Phantom. The results, the SUVmax, mean value are rapidly decreased with threshold value 500 mm2 interval of the ROI analysis, 1500 mm3 interval of the VOI analysis. When compared SUVmax value SUVmean, ROI and VOI analysis VOI measurements was 1.077 times higher SUVmax was 0.981 times highe compared to the value of the ROI measurement. Compare MTV, SUV 2.0 as measured by the volume of the VOI to Volume showed a slightly higher results(Volume / MTV = $93.4 %{\pm}14.8 %$). Considering the above results, Tumor evaluation by 18F-FDG PET / CT scan Consider each threshold value should be analyzed due to larger SUV's Distortion depending on the size of the tumor. VOI analysis is recommended. because it showed the VOI analysis is higher than the ROI analysis SUVmax and lower SUVmean due to VOI analysis than once as a measure of the wider area as measured ROI analysis. MTV (R2 = 0.999), a result close to the actual size of the tumor. but, more research is needed in this regard, because SUV according to the standards of value are affected.

• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.57-69
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• 2024

Purpose: Quantitative analysis through count measurement in nuclear medicine planar images is limited by analysis techniques that are useful for obtaining various clinical information or by organ overlap or artifacts in actual clinical practice. On the other hand, the use of SPECT tomography images is quantitative analysis using volume rather than planar, which is not only free from problems such as projection overlap, but also has excellent quantitative accuracy. In the use of developing SPECT quantitative analysis technology, this study aims to compare the accuracy of quantitative analysis between ROI of the conventional planar images and VOI of the SPECT tomographic images in evaluating the count change happened by the volume change of the source. Materials and Methods: A ^99mTcO₄^- source(200.17 MBq) was filled with sterilized water in the syringe to create a phantom with an inner diameter volume of 60 cc, and a planar image and a SPECT image were obtained by reducing the volume by 15 cc (25%) respectively. ROI and VOI(threshold: 1~45%, 5% interval) were set for each image obtained to estimate true count and measure the total count, and compared with the preseted volumetric change rate(%). Results: When volume changes of 25%, 50%, and 75% occurred in the initial volume of 60 cc(100%) of the phantom, the average count changes of the measured planar image were 26.8%, 53.2%, 77.5%, and the average count changes of the SPECT image were 24.4%, 50.9%, and 76.8%. In this case, the VOI size(cm³) set showed an average change rate of 25.4%, 51.1%, and 76.6%. The highest threshold value for the accuracy of radioactive concentration by VOI size (average error -1.03%) was 35%, and the VOI size of the same threshold had an error of -17.1% on average compared to the actual volume. Conclusion: On average, the count-based volumetric change rate in nuclear medicine images was able to track changes more accurately using VOI than ROI, but there was no significant difference with relatively similar value. However, the accuracy of radioactive concentration according to individual VOI sizes did not match, but it is considered that a relatively accurate quantitative analysis can be expected when the size of VOI is set smaller than the actual volume.

• Progress in Medical Physics
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• v.21 no.2
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• pp.174-182
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• 2010

In this study, we evaluated feasibility of applying MTV (Metabolic Target Volume) to respiratory gated radiotherapy for more accurate treatment using various SUV (Standard Uptake Value) from PET images. We compared VOI (Volume of Interest) images from 50%, 30% and 5% SUV (standard uptake volume) from PET scan of an artificial target with GTV (Gross Tumor Volume) images defined by percentage of respiratory phase from 4D-CT scan for respiratory gated radiotherapy. It is found that the difference of VOI of 30% SUV is reduced noticeably comparing with that of 50% SUV in longitudinal direction with respect to total GTV of 4D-CT image. Difference of VOI of 30% SUV from 4D-PET image defined by respiratory phase from 25% inhalation to 25% exhalation, and GTV from 4D-CT with the same phase is shown below 0.6 cm in maximum. Thus, it is better to use 4D-PET images than conventional PET images for applying MTV to gated RT. From the result that VOI of 5% SUV from 4D-PET agrees well with reference image of 4D-CT in all direction, and the recommendation from department of nuclear medicine that 30% SUV be advised for defining tumor range, it is found that using less than 30%SUV will be more accurate and practical to apply MTV for respiratory gated radiotherapy.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.11-17
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• 2013

Purpose: The use of SUV which should be normalized by lean body mass (LBM) is recommended for PET response criteria in solid tumors. LBM which was determined by whole body CT was used for SUV normalization (SUL) in this study. The purpose of the present study was to assess interobserver and intraobserver reproducibility of SUL measurements in reference organs. Materials and Methods: F-18 FDG PET/CT was conducted on 52 subjects and LBMs were directly determine by whole body CT for normalization of SUV. The 3 cm diameter spherical VOI, $1\times2$ cm cylindrical VOI, 2 cm diameter spherical VOI were placed in the liver, descending aorta and spleen, respectively. Experienced two observers measured SULmax and SULmean in each organ. Repeated measurements were conducted two weeks apart by observer 1 blind to previous results. Similarly, measurements were conducted on the same patients by observer 2. For assessing reproducibility(or repeatability), the paired t-test, Pearson's correlation coefficients (CC), and technical error of measurement (TEM) were calculated. Results: For interobserver reproducibility in liver SULmax and SULmean, no significant differences were found between observers(paired t-test, P=0.536, 0.293, respectively). CC and TEM for liver SULmean were 0.909 (P=0.000) and 0.067 SUL unit, respectively. Corresponding figures for liver SULmax were 0.882 (P=0.000) and 0.117 SUL unit, respectively. For intraobserver reproducibility in liver SULmax and SULmean, no significant differences were observed within observer1 (paired t-test, P=0.374, 0.268, respectively). CC and TEM for liver SULmean were 0.924 (P=0.000) and 0.061 SUL, respectively. Corresponding figures for liver SULmax were 0.908 (P=0.000) and 0.104 SUL, respectively. Similarly, no significant differences were found in SULmax and SULmean of the spleen and aorta between observers. Conclusion: The current study demonstrated that both SULmean and SULmax measurements in normal reference organs are highly reproducible. Reproducibility of SULmean in reference organs were slightly better than SULmax. Interobsever technical error of measurement was less than 0.10 SUL unit for liver SULmean, and 0.12 SUL unit for liver SULmax. Intraobsever technical error of measurement was less than 0.07 SUL unit for liver SULmean, and 0.11 SUL unit for liver SULmax.

• Progress in Medical Physics
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• v.24 no.1
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• pp.68-75
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• 2013

The purpose of this research is to compare and analyze $SUV_{LBM}$-maximum of normal regions using VOI (the volume of interest) in order to enhance the diagnostic level in whole body images of PET/CT and PET/MRI for 26 health check-up participants. In particular, we try to set up $SUV_{LBM}$-maximum data that can be used in synchronous evaluation for PET/CT and PET/MRI without contrast media. The evaluation of $SUV_{LBM}$-maximum for normal regions of whole body PET/CT and whole body PET/MRI shows that the image of PET/MRI differs very significantly from the reference image of PET/CT (p<0.0001). However, they exhibit high correlations in view of statistics (R>0.8). From this research, we suggest that the decision in the evaluation of $SUV_{LBM}$-maximum for PET/MRI should be made with the reduction of about 26.3%, while one should decide with the reduction of about 29.3% when the contrast media is used. It is helpful to interpret all image of PET/CT and PET/MRI using $SUV_{LBM}$-maximum for convenience and efficiency.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.56-58
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• 2004

MRI analysis and weights of molecular differences of Volume of Interest(VOI) was studied in animal. The appearance of tiny voxels significant objects for evaluate of disease or irregular function of cells is simplified remodeling before making image. The method of Marquardt, A method of Non-linear mathematical approach can be used to get a quick calculations in arbitrary space. Results shows the relationships between accurate vivo signal and biochemical molecular solutions,

• Progress in Medical Physics
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• v.24 no.3
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• pp.176-182
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• 2013

Through this research, we measure the data for several SUVs such as SUVLBM, SUVBW, and SUVBSA using volume of interest in order to enhance the diagnostic level in whole-body image for healthy examinees via F-18 FDG PET/CT. Maximum value, mean value, standard deviation, and threshold value for each SUVs are shown. The measurement of SUVs are carried out with 31 examinees who have taken whole-body examination with F-18 FDG PET/CT from July, 2012 to August, 2012. To secure the preciseness of measurement, we selected 26 healthy examinees as a subject of measurement according to diagnostic view of a nuclear-medical doctor. We see from the measurement of SUVs of PET/CT that the value of SUVBW is hightest and followed by SUVLBM and SUVBSA in turn regardless of the use of contrast media. By comparing the SUVLBM-maximum data for the group used contrast media with those for the group used no contrast media, there found a trend that the measured values increase when the contrast media are used. Among them, liver, aorta, lumbar-5, and Cerebellum exhibit significant difference (p<0.05). We conclude that our data for SUVs would be basic references in overall image interpretation, and hope that the research using VOI would be active.

• International journal of advanced smart convergence
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• v.7 no.2
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• pp.1-6
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• 2018

In this paper, we propose an automatic left ventricle segmentation method in computed tomography angiography (CTA) using separating energy function. First, we smooth the images by applying anisotropic diffusion filter to remove noise. Secondly, the volume of interest (VOI) is detected by using k-means clustering. Thirdly, we divide the left and right heart with split energy function. Finally, we extract only left ventricle from left and right heart with optimizing cost function including orientation term.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.67-71
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• 2015

Purpose At recently, we enter into the aging society and a age-related disease is increasing. Among that, prevalence of degenerative brain disease like Parkin's disease will be increased. So, many radiopharmaceuticals is developed to diagnosis early and to evaluate the performance of therapeutic drugs. Especially $^{18}F-DOPA$ which involved at dopamine synthesis and function of storage is widely used to the diagnosis of Parkinson's disease as well as brain tumors. in the study, we will evaluate the distribution pattern of $^{18}F-DOPA$ at the striatum by using dynamic study. Materials and Methods We used Biograph Truepoint(Siemens, Germany) as PET/CT scanner, injected a $^{18}F-DOPA$ ($600{\pm}30MBq$) to patient (4men, 6women. $67{\pm}11age$) who visited our hospital from June to September, started 95min dynamic study at same time. after finishing acquisition, we reconstructed PET data with 19 frame every 5 minutes, analysed a average counts at ROI's where set at both striatums, anterior putamen, posterior putamen Results Counts in the cerebellum as the background formed a plateau after 90 minutes from the highest out rapidly reduced to 15 minutes. Counts of anterior putamen and posterior gradually increased but formed a plateau after 60min. A count ratio of Striatum to cerebellum was continuously increased up to more than 95 minutes, A count ratios of an anterior putamen to posterior one formed a plateau after 85 minutes. Conclusion The dynamic acquisition can be possible to evaluate a distribution of the $^{18}F-DOPA$ in the striatum and the VOI analysis through a dynamic acquisition and a variety of patterns. Futhermore, to make a uniformed distribution and count ratio of striatum to cerebellum, a static acquisition will have to start 90minutes later after injection.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.19-24
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• 2017

In this paper, we propose an automatic segmentation method of left and right heart in computed tomography angiography (CTA) using separating energy function. First, we smooth the images by applying anisotropic diffusion filter to remove noise. Then, the volume of interest (VOI) is detected by using k-means clustering. Finally, we extract the left and right heart with separating energy function which we proposed to split the heart. We tested our method in ten CT images and they were obtained from a different patient. For the evaluation of the computational performance of the proposed method, we measured the total processing time. The average of total processing time, from first step to third step, was $14.39{\pm}1.17s$. We expect for our method to be used in cardiac diagnosis for cardiologist.