• The Korean Journal of Nuclear Medicine Technology
• /
• v.15 no.1
• /
• pp.58-64
• /
• 2011

Objective: The 3-dimensional reconstruction method with resolution recovery modeling has advantages of high spatial resolution and contrast because of its precise modeling of spatial blurring according to the distance from detector plane. The aim of this study was to evaluate one of the resolution recovery reconstruction methods (Astonish, Philips Medical), compare it to other iterative reconstructions, and verify its clinical usefulness. Materials and Methods: NEMA IEC PET body phantom and Flanges Jaszczak ECT phantom (Data Spectrum Corp., USA) studies were performed using Skylight SPECT (Philips) system under four different conditions; short or long (2 times of short) radius, and half or full (40 kcts/frame) acquisition counts. Astonish reconstruction method was compared with two other iterative reconstructions; MLEM and 3D-OSEM which vendor supplied. For quantitative analysis, the contrast ratios obtained from IEC phantom test were compared. Reconstruction parameters were determined by optimization study using graph of contrast ratio versus background variability. The qualitative comparison was performed with Jaszczak ECT phantom and human myocardial data. Results: The overall contrast ratio was higher with Astonish than the others. For the largest hot sphere of 37 mm diameter, Astonish showed about 27.1% and 17.4% higher contrast ratio than MLEM and 3D-OSEM, in short radius study. For long radius, Astonish showed about 40.5% and 32.6% higher contrast ratio than MLEM and 3D-OSEM. The effect of acquired counts was insignificant. In the qualitative studies with Jaszczak phantom and human myocardial data, Astonish showed the best image quality. Conclusion: In this study, we have found out that Astonish can provide more reliable clinical results by better image quality compared to other iterative reconstruction methods. Although further clinical studies are required, Astonish would be used in clinics with confidence for enhancement of images.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.1
• /
• pp.54-60
• /
• 2010

Purpose: Nuclear medicine manufacturers provide various softwares which shorten imaging time using their own image processing techniques such as UlatraSPECT, ASTONISH, Flash3D, Evolution, and nSPEED. Seoul National University Hospital has introduced softwares from Siemens and Philips, but it was still hard to understand algorithm difference between those two softwares. Thus, the purpose of this study was to figure out the difference of two softwares in planar images and research the possibility of application to images produced with high energy isotopes. Materials and Methods: First, a phantom study was performed to understand the difference of softwares in static studies. Various amounts of count were acquired and the images were analyzed quantitatively after application of PIXON, Siemens and ASTONISH, Philips, respectively. Then, we applied them to some applicable static studies and searched for merits and demerits. And also, they have been applied to images produced with high energy isotopes. Finally, A blind test was conducted by nuclear medicine doctors except phantom images. Results: There was nearly no difference between pre and post processing image with PIXON for FWHM test using capillary source whereas ASTONISH was improved. But, both of standard deviation(SD) and variance were decreased for PIXON while ASTONISH was highly increased. And in background variability comparison test using IEC phantom, PIXON has been decreased over all while ASTONISH has shown to be somewhat increased. Contrast ratio in each spheres has also been increased for both methods. For image scale, window width has been increased for 4~5 times after processing with PIXON while ASTONISH showed nearly no difference. After phantom test analysis, ASTONISH seemed to be applicable for some studies which needs quantitative analysis or high contrast, and PIXON seemed to be applicable for insufficient counts studies or long time studies. Conclusion: Quantitative values used for usual analysis were generally improved after application of the two softwares, however it seems that it's hard to maintain the consistency for all of nuclear medicine studies because result images can not be the same due to the difference of algorithm characteristic rather than the difference of gamma cameras. And also, it's hard to expect high image quality with the time shortening method such as whole body scan. But it will be possible to apply to static studies considering the algorithm characteristic or we can expect a change of image quality through application to high energy isotope images.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.1
• /
• pp.9-14
• /
• 2009

Purpose: Nowadays in the nuclear medicine, many studies and efforts are being made to reduce the scan time, as well as the waiting time to be needed to execute exams after injection of radionuclide medicines. Several methods are being used in clinic, such as developing new radionuclide compounds that enable to be absorbed into target organs more quickly and reducing acquisition scan time by increase the number of Gamma Camera detectors to examine. Each medical equipment manufacturer has improved the imaging process techniques to reduce scan time. In this paper, we tried to analyze the difference of image quality between FBP, 3D OSEM reconstruction methods that commercialized and being clinically applied, and Astonish reconstruction method (A kind of Iterative fast reconstruction method of Philips), also difference of image quality on scan time. Material and Methods: We investigated in 32 patients that examined the Bone SPECT from June to July 2008 at department of nuclear medicine, ASAN Medical Center in Seoul. 40sec/frame and 20sec/frame images were acquired that using Philips‘ PRECEDENCE 16 Gamma Camera and then reconstructed those images by using the Astonish (Philips’ Reconstruction Method), 3D OSEM and FBP methods. The blinded test was performed to the clinical interpreting physicians with all images analyzed by each reconstruction method for qualitative analysis. And we analyzed target to non target ratio by draws lesions as the center of disease for quantitative analysis. At this time, each image was analyzed with same location and size of ROI. Results: In a qualitative analysis, there was no significant difference by acquisition time changes in image quality. In a quantitative analysis, the images reconstructed Astonish method showed good quality due to better sharpness and distinguish sharply between lesions and peripheral lesions. After measuring each mean value and standard deviation value of target to non target ratio with 40 sec/frame and 20sec/frame images, those values are Astonish (40 sec-$13.91{\pm}5.62$ : 20 sec-$13.88{\pm}5.92$), 3D OSEM (40 sec-$10.60{\pm}3.55$ : 20 sec-$10.55{\pm}3.64$), FBP (40 sec-$8.30{\pm}4.44$ : 20 sec-$8.19{\pm}4.20$). We analyzed target to non target ratio from 20 sec and 40 sec images. And we analyzed the result, In Astonish (t=0.16, p=0.872), 3D OSEM (t=0.51, p=0.610), FBP (t=0.73, p=0.469) methods, there was no significant difference statistically by acquisition time change in image quality. But FBP indicates no statistical differences while some images indicate difference between 40 sec/frame and 20 sec/frame images by various factors. Conclusions: In the circumstance, try to find a solution to reduce nuclear medicine scan time, the development of nuclear medicine equipment hardware has decreased while software has marched forward at a relentless. Due to development of computer hardware, the image reconstruction time was reduced and the expanded capacity to restore enables iterative methods that couldn't be performed before due to technical limits. As imaging process technique developed, it reduced scan time and we could observe that image quality keep similar level. While keeping exam quality and reducing scan time can induce the reduction of patient's pain and sensory waiting time, also accessibility of nuclear medicine exam will be improved and it provide better service to patients and clinical physician who order exams. Consequently, those things make the image of department of nuclear medicine be improved. Concurrent Imaging - A new function that setting up each image acquisition parameter and enables to acquire images simultaneously with various parameters to once examine.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.21 no.2
• /
• pp.55-64
• /
• 2017

Purpose Recently, with the spread of SPECT/CT, various image correction methods can be applied quickly and accurately, which enabled us to expect quantitative accuracy as well as image quality improvement. Among them, the Collimator Detector Response(CDR) recovery is a correction method aiming at resolution recovery by compensating the blurring effect generated from the distance between the detector and the object. The purpose of this study is to find out quantitative change depending on the change in detection distance in SPECT/CT images with CDR recovery applied. Materials and Methods In order to find out the error of acquisition count depending on the change of detection distance, we set the detection distance according to the obit type as X, Y axis radius 30cm for circular, X, Y axis radius 21cm, 10cm for non-circular and non-circular auto(=auto body contouring, ABC_spacing limit 1cm) and applied reconstruction methods by dividing them into Astonish(3D-OSEM with CDR recovery) and OSEM(w/o CDR recovery) to find out the difference in activity recovery depending on the use of CDR recovery. At this time, attenuation correction, scatter correction, and decay correction were applied to all images. For the quantitative evaluation, calibration scan(cylindrical phantom, $^{99m}TcO_4$ 123.3 MBq, water 9293 ml) was obtained for the purpose of calculating the calibration factor(CF). For the phantom scan, a 50 cc syringe was filled with 31 ml of water and a phantom image was obtained by setting $^{99m}TcO_4$ 123.3 MBq. We set the VOI(volume of interest) in the entire volume of the syringe in the phantom image to measure total counts for each condition and obtained the error of the measured value against true value set by setting CF to check the quantitative accuracy according to the correction. Results The calculated CF was 154.28 (Bq/ml/cps/ml) and the measured values against true values in each conditional image were analyzed to be circular 87.5%, non-circular 90.1%, ABC 91.3% and circular 93.6%, non-circular 93.6%, ABC 93.9% in OSEM and Astonish, respectively. The closer the detection distance, the higher the accuracy of OSEM, and Astonish showed almost similar values regardless of distance. The error was the largest in the OSEM circular(-13.5%) and the smallest in the Astonish ABC(-6.1%). Conclusion SPECT/CT images showed that when the distance compensation is made through the application of CDR recovery, the detection distance shows almost the same quantitative accuracy as the proximity detection even under the distant condition, and accurate correction is possible without being affected by the change in detection distance.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.18 no.1
• /
• pp.115-121
• /
• 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
• /
• v.16 no.2
• /
• pp.110-114
• /
• 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.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.18 no.1
• /
• pp.122-126
• /
• 2014

Purpose: The new reconstruction algorithms (NRA) provided by vendor aim to shorten the acquisition scan time. Whereas depending on the installed version AutoQuant program used for myocardial SPECT quantitative analysis did not contain the normal data that NRA is applied. Thus, the purpose of this paper is to compare the results according to AutoQuant versions in myocardial SPECT applied NRA and half-time scan (HT). Materials and Methods: Rest Tl and stress MIBI data of total 80 (40 men, 40 women) patients were gathered. Data were applied HT acquisition and ASTONISH (Philips) software which is NRA. Modified autoquant of SNUH and old version of AutoQuant (full-time scan) provided by company were compared. Comparison groups were classified as coronary artery disease (CAD), 24 hrs delay and almost normal patients who have a simple pain patient. Perfusion distribution aspect, summed stress score (SSS), summed rest score (SRS), extent and total perfusion deficit (TPD) of each 25 patient who have above diseases were compared and evaluated. Results: The case of CAD, when using re-edited AutoQuant (HT) SSS and SRS showed about 30% reduction (P<0.0001), Extent showed about 38% reduction and TPD showed about 30% reduction in the tendency (P<0.0001). In the score of the perfusion, especially on the part of infero-medium, infero-apical, lateral-medium and lateral-apical regions were the biggest change. The case of the 24 hrs delay patient SRS (P=0.042), Extent (P=0.018) and TPD (P=0.0024) showed about 13-18% reduction. And the case of simple pain patient, comparison of 4 results showed about 5-7% reduction. Conclusion: This study was started based on expectation that results could be affected by normal patient data. Normal patient data is possible to change by race and gender. It was proved that combination of new reconstruction algorithm for reducing scan time and analysis program according to scan protocol with NRA could also be affected to results. Clinical usefulness of gated myocardial SPECT is possibly increased if each hospital properly collects normal patient data for their scan acquisition protocol.

• The Korean Journal of Archival Studies
• /
• no.14
• /
• pp.289-323
• /
• 2006

The first organization of the 'national Archives of France' was defined by a law voted during the Revolution, the law of June 25, 1794 which is remained into force during nearly two century-until with the law of January 3, 1979. This law is regarded as the text founder of the national Archives of France, mainly thanks to its article 48 which posed the principle of the free communicability of the whole of the documents of national Archives of France. But it had initially as an aim to organize and frame sortings of the documents gathered in great number since the beginning of the French revolution. Its principal provision does not leave astonish us: it envisaged a separation between the documents to be eliminated, the useful documents has the administration, only intended to be preserved in national Archives of France?, and the documents interesting for the history, which were intended for the national Library.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.19 no.2
• /
• pp.93-101
• /
• 2015

Purpose In SPECT image, scatter count is the cause of quantitative count error and image quality degradation. Thus, a wide range of scatter correction(SC) methods have been studied and this study is to evaluate the accuracy of CT based SC(CTSC) used in SPECT/CT as the comparison with existing energy window based SC(EWSC). Materials and Methods SPECT/CT images were obtained after filling air in order to acquire a reference image without the influence of scatter count inside the Triple line insert phantom setting hot rod(74.0 MBq) in the middle and each SPECT/CT image was obtained each separately after filling water instead of air in order to derive the influence of scatter count under the same conditions. In both conditions, Astonish(iterative : 4 subset : 16) reconstruction method and CT attenuation correction were commonly applied and three types of SC methods such as non-scatter correction(NSC), EWSC, CTSC were used in images filled with image. For EWSC, 9 sub-energy windows were set additionally in addition to main(=peak) energy window(140 keV, 20%) and then, images were acquired at the same time and five types of EWSC including DPW(dual photo-peak window)10%, DEW(dual energy window)20%, TEW(triple energy window)10%, TEW5.0%, TEW2.5% were used. Under the condition without fluctuations in primary count, total count was measured by drawing volume of interest (VOI) in the images of the two conditions and then, the ratio of scatter count of total counts was calculated as percent scatter fraction(%SF) and the count error with image filled with water was evaluated with percent normalized mean-square error(%NMSE) based on the image filled with air. Results Based on the image filled with air, %SF of images filled with water to which each SC method was applied is NSC 37.44, DPW 27.41, DEW 21.84, TEW10% 19.60, TEW5% 17.02, TEW2.5% 14.68, CTSC 5.57 and the most scattering counts were removed in CTSC and %NMSE is NSC 35.80, DPW 14.28, DEW 7.81, TEW10% 5.94, TEW5% 4.21, TEW2.5% 2.96, CTSC 0.35 and the error in CTSC was found to be the lowest. Conclusion In SPECT/CT images, the application of each scatter correction method used in the experiment could improve the quantitative count error caused by the influence of scatter count. In particular, CTSC showed the lowest %NMSE(=0.35) compared to existing EWSC methods, enabling relatively accurate scatter correction.

• Cross-Cultural Studies
• /
• v.51
• /
• pp.329-356
• /
• 2018

Types of emotional expressions are comprised of vocabulary that describes emotion and composition of sentences to express emotion such as an exclamatory sentence and a rhetorical question, expressions of interjection, adverbs of attitude for an idea, and a style of writing. This study is focused on vocabulary that describes emotion and analyzes the aspect of translation when emotional expression of 'Kyo(驚)' is shown in "Kokoro". As a result, the aspect of translation for expression of 'Kyo(驚)' showed that it was translated to vocabulary as suggested in the dictionary in some cases. However, it was not always translated as suggested in the dictionary. Vocabulary that describes the emotion of 'Kyo(驚)' in Japanese sentences is mostly translated to corresponding parts of speech in Korean. Some adverbs needed to add 'verbs' when they were translated. Different vocabulary was added or used to maximize emotion. However, the corresponding part of speech in English was different from Korean. Examples of Japanese sentences expressing 'Kyo(驚)' by verbs were translated to expression of participles for passive verbs such as 'surprise' 'astonish' 'amaze' 'shock' 'frighten' 'stun' in many cases. Idioms were also translated with focus on the function of sentences rather than the form of sentences. Those expressed in adverbs did not accompany verbs of 'Kyo(驚)'. They were translated to expression of participles for passive verbs and adjectives such as 'surprise' 'astonish' 'amaze' 'shock' 'frighten' 'stun' in many cases. Main agents of emotion were showat the first person and the third person in simple sentences. Translation of emotional expressions when a main agent was the first person showed that the fundamental word order of Japanese was translated as in Korean. However, adverbs of time and adverbs of degree were ended to be added. The first person as the main agent of emotion was positioned at the place of subject when it was translated in English. However, things or causes of events were positioned at the place of subject in some cases to show the degree of 'Kyo(驚)' which the main agent experienced. The expression of conjecture and supposition or a certain visual and auditory basis was added to translate the expression of emotion when the main agent of emotion was the third person. Simple sentences without the main agent of emotion showed that their subjects could be omitted even if they were essential components because they could be known through context in Korean. These omitted subjects were found and translated in English. Those subjects were not necessarily human who was the main agent of emotion. They could be things or causes of events that specified the expression of emotion.