• Journal of radiological science and technology
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• v.42 no.4
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• pp.301-308
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• 2019

This study reviewed whether radiology-related pictograms listed on the website of hospitals deliver clearly, accurately and quickly the necessary information. TOPSIS was carried out to select the most fitting pictograms for the department of radiology, department of radiation oncology, and department of nuclear medicine. The finally selected pictogram for the department of radiology shows an image of the chest (lungs), while that for the department of radiation oncology shows the process of treatment using equipment. Using these pictograms as standards seem to be appropriate to a certain level. However, the pictogram for department of nuclear medicine has a symbol for a nucleus and is thus inappropriate to meet the standards for a hospital pictogram. This study is meaningful in that it has established evaluation methods and procedures relaetd to radiation pictograms.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.241-252
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• 2004

Purpose: Population based structural and functional maps of the brain provide effective tools for the analysis and interpretation of complex and individually variable brain data. Brain MRI and PET standard templates and statistical probabilistic maps based on image data of Korean normal volunteers have been developed and probabilistic maps based on cytoarchitectonic data have been introduced. A quantification method using these data was developed for the objective assessment of regional intensity in the brain images. Materials and Methods: Age, gender and ethnic specific anatomical and functional brain templates based on MR and PET images of Korean normal volunteers were developed. Korean structural probabilistic maps for 89 brain regions and cytoarchitectonic probabilistic maps for 13 Brodmann areas were transformed onto the standard templates. Brain FDG PET and SPGR MR images of normal volunteers were spatially normalized onto the template of each modality and gender. Regional uptake of radiotracers in PET and gray matter concentration in MR images were then quantified by averaging (or summing) regional intensities weighted using the probabilistic maps of brain regions. Regionally specific effects of aging on glucose metabolism in cingulate cortex were also examined. Results: Quantification program could generate quantification results for single spatially normalized images per 20 seconds. Glucose metabolism change in cingulate gyrus was regionally specific: ratios of glucose metabolism in the rostral anterior cingulate vs. posterior cingulate and the caudal anterior cingulate vs. posterior cingulate were significantly decreased as the age increased. 'Rostral anterior'/'posterior' was decreased by 3.1% per decade of age ($P<10^{-11}$, r=0.81) and 'caudal anterior'/'posterior' was decreased by 1.7% ($P<10^{-8}$, r=0.72). Conclusion: Ethnic specific standard templates and probabilistic maps and quantification program developed in this study will be useful for the analysis of brain image of Korean people since the difference in shape of the hemispheres and the sulcal pattern of brain relative to age, gender, races, and diseases cannot be fully overcome by the nonlinear spatial normalization techniques.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.368-380
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• 1999

Purpose: The purpose of this study was to evaluate and compare the scintigraphic findings and diagnostic accuracy of double-phase Tc-99m sestamibi scan in primary and secondary hyperparathyroidism (HPT). Materials and Methods: We retrospectively reviewed 16 cases of primary (18 lesions) and 11 cases of secondary HPT (44 lesions) who underwent Tc-99m-sestamibi scan before the surgical intervention. Scan was performed using LEM camera (Siemens, Germany) after the injection of 740MBq of Tc-99m sestamibi. Routine image consisted of baseline and 3-hour delayed images and each image was obtained using both parallel and pine hole collimator. The study population was 27 patients (male/female=5/22, age: $49.1{\pm}10.8$). Results: Eighteen lesions of primary HPT consisted of 13 adenomas and S hyperplasias, while all lesions of secondary HPT were hyperplasias. Among the case of primary HPT, we could detect all the lesions of 13 adenomas but only 2 lesions of 5 hyperplasias (40%) could be detected by double phase scintigraphy. Three cases of primary lesion showed decreased uptake in delayed images compared with baseline. The sensitivity, specificity, positive predictive value and accuracy of primary and secondary HPT were 58.8% (10/17), 83.3% (10/12), 83.3% (10/12), 75.9% (22/29), and 37.5% (15/40), 50% (2/4), 88.2% (15/17), 38.6% (17/44), respectively. Overall sensitivity, specificity, positive predictive value and accuracy were 43.9% (25/57), 75% (12/16), 86.2% (25/29), and 53.4% (39/73). There were no statistical difference between the weight of primary and secondary HPT lesion (p>0.05). Conclusion: Tc-99m sestamibi scan is fairly good modality to detect parathyroid lesion in patient with primary HPT before the surgical intervention. However, since some of cases may reveal decreased uptake in delayed image, a careful attention to the findings of baseline images may be helpful. Still the low accuracy of sestamibi scan in diagnosis of secondary HPT prohibits routine use of it for this disease.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.81-82
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• 2001

A 47-year-old man with end-stage renal disease due to diabetic nephropathy underwent a peritoneal scintigraphy to evaluate the cause of recently developed scrotal swelling. Two liters of dialysate mixed with 111 MBq of Tc-99m sulfur colloid were administered into the peritoneal cavity via the dialysis catheter. Various anterior images of the abdomen and pelvis were obtained at 15 min, 2 hr and 4 hr after the tracer instillation. At 15 min, anterior images of the abdomen and pelvis demonstrated linear tracts of activity through both inguinal canals, which were more prominent in the right side (A). Images at 2 hr revealed a passage of the radioactive fluid into the right hemiscrotum. At the same time, there was a considerable accumulation of activity in the right inguinal canal (B). In the delayed image, there was a progressive accumulation of activity in the inguinal canals and a prominent passage of the tracer into the scrotum (C). Both abdominal and inguinal hernias are commonly associated with continuous ambulatory peritoneal dialysis (CAPD). Overall incidence of CAPD-induced hernia ranges from 2.7% to 25%.$^{1)}$ Inguinal hernias were frequently manifested as scrotal swelling. Leakages of dialysate fluid into the scrotum has been noted in CAPD patients with scrotal swelling, with or without clinical findings of inguinal hernia.$^{1,2)}$ In the present case, the right side had leakage from a clinical inguinal hernia and the left side, leakage from a subclinial inguinal hernia. A subclinical inguinal hernia was easily demonstrable with peritoneal scintigraphy. Peritoneal scintigraphy is extremely helpful in the evaluation of scrotal swelling in a patient on CAPD.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.360-364
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• 1992

Treatment for the brain tumors consist of surgery, chemotherapy, and a variety of methods of irradiation. Therapy is aimed to destroy the tumor, but necrosis and edema occur concurrently. Conventional structural imaging techniques such as CT or MRI are unable to reliably distinguish persistent and recurrent tumor from necrosis or edema. T1-201 has been shown to be useful in the evaluation of the myocardial viability by comparing the early uptake and redistribution image. The aim of this study is to evaluate the clinical usefulness of the early uptake and delayed washout images of the T1-201 brain SPECT in the brain tumors. In the pathologically diagnosed various brain tumor patients, brain SPECT was done with rotating gamma camera 15 minutes and 3 hours after T1-201 injection, and the T1-201 uptake in the tumor was compared with the skull and scalp activity. In the glioblastoma multiforme, meningioma and metastatic tumor, the T1-201 uptake was higher than low grade glioma in both 15 minute and 3 hour images (p<0.02). In the low grade glioma,3 hour T1-201 uptake was significantly lower than 15 minute uptake (p<0.05) but in the glioblastoma, meningioma and metastatic tumor there was no significant difference. There was no significant difference in the T1-201 uptake among the glioblastoma, meningioma and metastatic tumors. In one matastatic tumor, T1-201 uptake was decreased after radiation therapy. T1-201 brain SPECT could distinguish the benign and malignancy, and seems to be useful in the follow-up after treatment. But one of the early or delayed SPECT seems not to be necessary for these purposes.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.27-31
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• 2016

Purpose $^{99m}Tc-DMSA$ renal scan is a test for the comparison of the function by imaging the parenchyma of the kidneys by the cortex of a kidney and by computing the intake ratio of radiation by the left and right kidney. Since the distance between the kidneys and the bladder is not far given the bodily structure of an infant, the bladder is included in the examination domain. Research was carried out with the presumption that counts of bladder would impart an influence on the kidneys at the time of this renal scan. In consideration of the special feature that only a trace amount of a RI is injected in a pediatric examination, research on the method of injection was also carried out concurrently. Materials and Methods With 34 infants aged between 1 month to 12 months for whom a $^{99m}Tc-DMSA$ renal scan was implemented on the subjects, a Post IMAGE was acquired in accordance with the test time after having injected the same quantity of DMSA of 0.5mCi. Then, after having acquired an additional image by shielding the bladder by using a circular lead plate for comparison purposes, a comparison was made by illustrating the percentile of (Lt. Kidney counts + Rt. Kidney counts)/ Total counts, by drawing the same sized ROI (length of 55.2mm X width of 70.0mm). In addition, in the format of a 3-way stopcock, a Heparin cap and direct injection into the patient were performed in accordance with RI injection methods. The differences in the count changes in accordance with each of the methods were compared by injecting an additional 2cc of saline into the 3-way stopcock and Heparin cap. Results The image prior to shielding of the bladder displayed a kidney intake rate with a deviation of $70.9{\pm}3.18%$ while the image after the shielding of the bladder displayed a kidney intake rate with a deviation of $79.4{\pm}5.19%$, thereby showing approximately 6.5~8.5% of difference. In terms of the injection method, the method that used the 3-way form, a deviation of $68.9{\pm}2.80%$ prior to the shielding and a deviation of $78.1{\pm}5.14%$ after the shielding were displayed. In the method of using a Heparin cap, a deviation of $71.3{\pm}5.14%$ prior to the shielding and a deviation of $79.8{\pm}3.26%$ after the shielding were displayed. Lastly, in the method of direct injection into the patient, a deviation of $75.1{\pm}4.30%$ prior to the shielding and a deviation of $82.1{\pm}2.35%$ after the shielding were displayed, thereby illustrating differences in the kidney intake rates in the order of direct injection, a Heparin cap and the 3-way methods. Conclusion Since a substantially minute quantity of radiopharmaceuticals is injected for infants in comparison to adults, the cases of having shielded the bladder by removing radiation of the bladder displayed kidney intake rates that are improved from those of the cases of not having shielded the bladder. Although there are difficulties in securing blood vessels, it is deemed that the method of direct injection would be more helpful in acquisition of better images since it displays improved kidney intake rate in comparison to other methods.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.122-127
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• 2010

Purpose: The Xpress3.$cardiac^{TM}$ which is a kind of wide beam reconstruction (WBR) method developed by UltraSPECT (Haifa, Israel) enables the acquisition of at quarter time while maintaining image quality. The purpose of this study is to investigate the usefulness of WBR method for decreasing scan times and to compare to it with filtered back projection (FBP), which is the method routinely used. Materials and Methods: Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on an equality with counts from patient's body. The Tl-201 concentrations in the compartments were 74 kBq (2 ${\mu}Ci$)/cc in myocardium, 11.1 kBq (0.3 ${\mu}Ci$)/cc in soft tissue, and 2.59 kBq (0.07 ${\mu}Ci$)/cc in lung. The non-gated Tl-201 myocardial perfusion SPECT data were acquired with the phantom. The former study was scanned for 50 seconds per frame with FBP method, and the latter study was acquired for 13 seconds per frame with WBR method. Using the Xeleris ver. 2.0551, full width at half maximum (FWHM) and average image contrast were compared. In clinical studies, we analyzed the 30 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center from January to April 2010. The patients were imaged at full time (50 second per frame) with FBP algorithm and again quarter-time (13 second per frame) with the WBR algorithm. Using the 4D MSPECT (4DM), Quantitative Perfusion SPECT (QPS), and Quantitative Gated SPECT (QGS) software, the summed stress score (SSS), summed rest score (SRS), summed difference score, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were analyzed for their correlations and statistical comparison by paired t-test. Results: As a result of the phantom study, the WBR method improved FWHM more than about 30% compared with FBP method (WBR data 5.47 mm, FBP data 7.07 mm). And the WBR method's average image contrast was also higher than FBP method's. However, in result of quantitative indices, SSS, SDS, SRS, EDV, ESV, EF, there were statistically significant differences from WBR and FBP(p<0.01). In the correlation of SSS, SDS, SRS, there were significant differences for WBR and FBP (0.18, 0.34, 0.08). But EDV, ESV, EF showed good correlation with WBR and FBP (0.88, 0.89, 0.71). Conclusion: From phantom study results, we confirmed that the WBR method reduces an acquisition time while improving an image quality compared with FBP method. However, we should consider significant differences in quantitative indices. And it needs to take an evaluation test to apply clinical study to find a cause of differences out between phantom and clinical results.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.216-226
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• 2020

In this paper, a stacked convolutional autoencoder model is proposed in order to classify Alzheimer's disease with high accuracy in PET/CT images. The proposed model makes use of the latent space representation - which is also called the bottleneck, of the encoder-decoder architecture: The input image is sent through the pipeline and the encoder part, using stacked convolutional filters, extracts the most useful information. This information is in the bottleneck, which then uses Softmax classification operation to classify between Alzheimer's disease, Mild Cognitive Impairment, and Normal Control. Using the data from Dong-A University, the model performs classification in detecting Alzheimer's disease up to 98.54% accuracy.

• The Korean Journal of Nuclear Medicine
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• v.23 no.1
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• pp.19-25
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• 1989

To assess the usefulness of myocardial SPECT imaging to detect post-myocardial infarction ventricular aneurysms, we analyzed the Technetium-99m MIBI myocardial SPECT images of 16 patients with anterior and/or apical infarction, 9 had the previously reported findings of failure of convergence of the left ventricular walls toward the apex on SPECT images and 8 of them also had ventricular aneurysms. The ventriculography of the 2 patients with mixed pattern revealed 1 case of ventricular aneurysm and 1 case without aneurysm. Among the remaining 5 pateints with converging pattern, none had ventricular aneurysm. Of the other 11 pateints with inferior and/or lateral wall infarction, 1 patient had ventricular aneurysm and the SPECT image couldn't detect the aneurysm. $Department of Internal Medicine, College of Medicine, Seoul National University$ myocardial SPECT images for the detection of ventricular aneurysm had a sensitivity of 90 %, a specificity of 88%, and an accuracy of 89%. Thus we could get the information about presence of ventricular aneurysm as well as the status of the myocardial perfusion from the Tc-99m MIBI myocardial SPECT images.

• 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.