• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.272-279
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• 2007

Purpose: The aim of this study was to evaluate the discriminating nature of $^{123}I-FP-CIT$ SPECT in patients with parkinsonism. Methods: $^{123}I-FP-CIT$ SPECT images acquired from the 18 normal controls; NC ($60.4{\pm}10.0$ yr) and 237 patients with parkinsonism ($65.9{\pm}9.2$ yr) were analyzed. From spatialIy normalized images, regional counts of the caudate, putamen, and occipital lobe were obtained using region of interest method. Binding potential (BP) was calculated with the ratio of specific to nonspecific binding activity at equilibrium. Additionally, the BP ratio of putamen to caudate (PCR) and asymmetric Index (ASI) were measured. Results: BPs of NC $3.37{\pm}0.57,\; 3.10{\pm}0.41,\; 3.23{\pm}0.48$ for caudate, putamen, whole striatum, respectively) had no significant difference with those of essential tremor; ET ($3.31{\pm}0.64,\; 3.06{\pm}0.61,\; 3.14{\pm}0.63$) and Alzheimer's disease; AD (3.33 $\pm$0.60, 3.29$\pm$0.79, 3.31$\pm$0.70), but were higher than those of Parkinson's disease; PD (1.92$\pm$0.74, 1.39$\pm$0.68, 1.64$\pm$0.68), multiple system atrophy; MSA (2.36$\pm$1.07, 2.16$\pm$0.91, 2.26$\pm$0.96), and dementia with Lewy body; DLB (1.95$\pm$0.72, 1.64$\pm$0.65, 1.79$\pm$0.66)(p<0.005). PD had statisticalIy lower values of PER and higher values of ASI than those of NC (p<0.005). And PD had significantIy lower value of PCR, higher ASI and lower BP in the putamen and whole striatum than MSA (p<0.05). Conclusion: Dopamine transporter image of $^{123}I-FP-CIT$ SPECT was a good value in differential diagnosis of parkinsonism.

• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.16-24
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• 2012

Purpose : The purpose of this study was to determine whether there is a significant correlation between vertebral marrow fat fraction measured using Dixon quantitative chemical shift MRI (QCSI) and BMD on dual-energy X-ray absorptiometry (DXA). Materials and Methods: This retrospective study included 68 healthy individuals [mean age, 50.7 years; range, 25-76; male/female (M/F) = 36/32] who underwent DXA of the L-spine and whole body MRI including QCSI of the L-spine and chemical shift MRI of the liver. The enrolled individuals were divided into subgroups according to sex and T-score [i.e., normal bone density (M/F=27/23) and osteopenia (M/F=9/9)]. Vertebral marrow (Dixon QCSI, TR/TE 10.2/4.8 ms) and hepatic fat fractions (chemical shift technique, TR/TE 110/4.9 and 2.2 ms) were calculated on MRI. We evaluated whether there were significant differences in age, body mass index (BMI), vertebral marrow fat fraction, or hepatic fat fraction among the subgroups. Whether or not the participant had reached menopause was also evaluated in females. The correlations among variables (i.e., age, BMI, vertebral marrow and hepatic fat fractions, BMD) were evaluated using Spearman's correlation method. Results: There were no significant differences in age, BMI, or vertebral marrow and hepatic fat fractions between the two male subgroups (normal bone density vs. osteopenia). In female subjects, mean age in the osteopenic subgroup was greater than that in the normal subgroup (p=0.01). Presence of menopause was more common in the osteopenic subgroup [77.8% (7/9)] than the normal subgroup [26.1% (6/23), p<0.05]. The other variables showed no significant difference between female subgroups. The only significant correlation with marrow fat fraction after partial correlation analysis was that with age in the female subjects (r=0.43, p<0.05). Conclusion: The vertebral marrow fat fraction calculated using the Dixon QCSI does not precisely reflect the mild decrease in BMD for either sex.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.59-63
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• 2019

Purpose The motion due to respiration of patients undergoing PET/CT is a cause of artifacts in image and registration error between PET and CT images. The degree of displacement and distortion for tumor, which affects the measurement of Standard Uptake Value (SUV) and lesion volume, is especially higher for tumors that is small or located at the base of lungs. The purpose of this study was to evaluate the usefulness of prone position in the correction of image distortion due to respiration of patients in PET/CT. Materials and Methods The imaging equipment used in this study was PET/CT Discovery 600 (GE Healthcare, MI, USA). 20 patients whose lesions were identified in the middle and lower lungs from May to August 2018 were enrolled in this study. After acquiring whole body image in the supine position, additional images of the lesion area were obtained in the prone position with the same conditions. SUVmax, SUVmean, and volume of the lesion were measured for each image, and the displacement of the lesion on PET and CT images were measured, compared, and analyzed. Results The SUVmax, SUVmean, and volume, and displacement of the lesion were $4.72{\pm}2.04$, $3.10{\pm}1.38$, $4.68{\pm}3.20$, and $4.64{\pm}1.88$, respectively for image acquired in the supine position and $5.89{\pm}2.42$, $3.97{\pm}1.65$, $2.13{\pm}1.09$, and $2.24{\pm}0.84$, respectively for image acquired in the prone position, indicating that, for all the lesions imaged, SUVmax and SUVmean were higher and volume and displacement were smaller in the images acquired in prone position compared to those acquired in supine one(p<0.05). Conclusion These results showed that the prone position PET/CT imaging improves the quality of the image by increasing the SUV of the lesion and reducing the respiratory artifacts caused by registration error between PET and CT images. It is considered that the PET/CT imaging in the prone position is helpful in the diagnosis of the disease as an economical and efficient methods that correct registration error for the lesions in basal lung and reduce artifacts.

• Radiation Oncology Journal
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• v.26 no.2
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• pp.96-103
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• 2008

Purpose: To conduct a nationwide academic hospital patterns of the practice status and principles of radiotherapy for prostate cancer. The survey will help develop the framework of a database of Korean in Patterns of Case Study. Materials and Methods: A questionnaire about radiation treatment status and principles was sent to radiation oncologists in charge of prostate cancer treatment at thirteen academic hospitals in Korea. The data was analyzed to find treatment principles among the radiation oncologists when treating prostate cancer. Results: The number of patients with prostate cancer and treated with radiation ranged from 60 to 150 per academic hospital in Seoul City and 10 to 15 outside of Seoul City in 2006. The primary diagnostic methods of prostate cancer included the ultrasound guided biopsy on 6 to 12 prostate sites(mean=9), followed by magnetic resonance imaging and a whole body bone scan. Internal and external immobilizations were used in 61.5% and 76.9%, respectively, with diverse radiation targets. Whole pelvis radiation therapy(dose ranging from 45.0 to 50.4 Gy) was performed in 76.9%, followed by the irradiation of seminal vesicles($54.0{\sim}73.8$ Gy) in 92.3%. The definitive radiotherapy doses were increased as a function of risk group, but the range of radiation doses was wide(60.0 to 78.5 Gy). Intensity modulated radiation therapy using doses greater than 70 Gy, were performed in 53.8% of academic hospitals. In addition, the simultaneous intra-factional boost(SIB) technique was used in three hospitals; however, the target volume and radiation dose were diverse. Radiation therapy to biochemical recurrence after a radical prostatectomy was performed in 84.6%; however, the radiation dose was variable and the radiation field ranged from whole pelvis to prostate bed. Conclusion: The results of this study suggest that a nationwide Korean Patterns of Care Study is necessary for the recommendation of radiation therapy guidelines of prostate cancer.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.60-64
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• 2010

Purpose: Until now the general study for breast cancer patient has been mammography, breast sonography for anatomic diagnostics and $^{18}F$-FDG whole body PET for functional one. But the PEM (Positron Emission Mammography) was developed to increase sensitivity, specificity and accuracy to improve the disadvantage of each study. Therefore this present study aims to describe availability of PEM for improving diagnosis of breast cancer. Materials and Methods: During 3 months from January in 2010, PEM was performed on 100 patients who had history of breast cancer. Using Naviscan's PEM Flex Solo II scanner, PEM images of breast were acquired. And then we evaluated sensitivity, specificity and accuracy of PEM data by comparing results of PEM images with postoperative pathologic finding. Results: On the 100 patients, it could reveal 89 true positive, 9 false positive, 7 false negative and 87 true negative. Thus the results of sensitivity, specificity and accuracy for PEM was evaluated 92.7%, 90.6% and 91.7%. Conclusion: The sensitivity, specificity and accuracy have been reported 83.7%, 68.5% and 77.1% in mammography, and that was 89.1%, 79.1% and 83.4% in breast sonography. However the results of PEM were more increased than others. Therefore the results of this study will be available that PEM used diagnosis with breast cancer, used preoperative operation plan and helps to discovery of a part recurrence.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.15-21
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• 2004

This paper describes the development of $^{99m}Tc$ tricarbonyl cysteine as potential renal function diagnostic radiopharmaceutical and evaluation of its biological characteristics using experimental animals. l-Cysteine was labeled efficiently with $^{99m}Tc$ tricarbonyl precursor $([^{99m}Tc(CO)_3(H_2O)_3)]^{+})$ under 30 min heating at ${75^{\circ}C}$. Labeling yield and stability were analyzed by high performance liquid chromatography (HPLC). The biodistribution property of $^{99m}Tc$ tricarbonyl cysteine in mice and its dynamic imaging profiles in rabbits were carried out. To investigate the excretion mechanism of $^{99m}Tc$ tricarbonyl cysteine, tubular transport inhibition test with probenecid was adopted. $^{99m}Tc$ tricarbonyl cysteine was obtained with a high labeling yield under the moderate condition. The results of biodistribution experiments of $^{99m}Tc$ tricarbonyl cysteine in ICR mice at 3 and 90 min provided that $^{99m}Tc$ tricarbonyl cysteine was very highly accumulated in the kidney and bladder, thereby almost 99% of $^{99m}Tc$ tricarbonyl cysteine was excreted within 90 min post injection. The same results were confirmed by the whole body dynamic images for 30 minutes and static images in rabbits at given time intervals after injection. Renogram of $^{99m}Tc$ tricarbonyl cysteine in rabbits showed that its $T_{max}$ and $T_{1/2}$ of $^{99m}Tc$ tricarbonyl cysteine were $2.33{\pm}0.56$ and $4.30{\pm}0.79$ min, respectively. The $T_{max}$ of $^{99m}Tc$ tricarbonyl cysteine with probenecid pretreatment was $2.30{\pm}0.17$ min, whereas $T_{1/2}$ of that with probenecid pretreatment was $17.0{\pm}32.47$ min. $T_{1/2}$ of $^{99m}Tc$ tricarbonyl cysteine with probenecid pretreatment was significantly different, as compared to the result without probenecid (p<0.0001). The results showed that the excretion of $^{99m}Tc$ tricarbonyl cysteine was extremely affected by probenecid. Therefore, $^{99m}Tc$ tricarbonyl cysteine was rapidly excreted from the kidney principally by the tubular secretion.

• Progress in Medical Physics
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• v.10 no.1
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• pp.23-32
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• 1999

Combined MRI and Relaxogram approach was introduced as a very useful tool for fat study. The phantoms simulating homogeneous mixture of fat and non-fat environments were measured with spin echo pulse sequence on a 0.15 T whole body imager. From 45 scans, the Tl values were obtained by fitting the data to continuous distribution (CONTIN) of relaxation time. This relaxogram gives broad distributions of relaxation time, which are characterized by a number of peaks with characteristic T1 values. Two distinct peaks in relaxogram were observed and identified as signals from com oil and gelatin gel. This model system can be served as simulating the distribution of fat in muscle. Also the relative ratio of two components, which is proportional to the area under the peak, is estimated and compared to nominal values. Based on the good agreement between two predictions, the values from our proposed method agreed with nominal values within $\pm$7 % error. The effects of different concentration of contrast agent and different region of interest are presented. To optimize total scan times, the minimum required data points and so further reduction in total scan times are discussed.

• Journal of Acupuncture Research
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• v.21 no.6
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• pp.177-186
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• 2004

Introduction : Recent studies Suggested that there is a strong correlation between acupuncture stimulation and its related cortical activation. Anther study showed that either positive or negative BOLD effects could be observed depending on anatomical structure in acupuncture stimulation. In ttis study, we investigated a new acupoint $KI_6$ (照海), which was known as motor-related acupoint and obtained an evidence that the stimulation of $KI_6$ resulted in either negative or positive BOLD response to stimulation. Methods & Results : 1. Subjects and paradigms : Two separate stimulation paradigms were performed on five healthy (aged 22-23 yrs) in this study. First, the paradigm of acupuncture stimulation was that the acupuncture needle was inserted in acupoints $KI_6$, which is located in lateral side of the foot and then continuously twisted(補瀉를 除外한 捻轉法) for 70 seconds for 10 cycles of activation. During rest period (70 seconds), the needle was completed removed from acupoint. Total 60 cycles were performed and 10 images were obtained per cycle. Second, nonacupoint was randomly selected and the same paradigm was performed as acupoint stimulation. The stimulation protocol comprised 10 cycles of alternating. activation and rest (10 images per cycle). Total 60 cycles were performed and each cycle take about 1.5 sec for motor task. Subjects take an at least 15 minutes break before starting anther paradigm. 2. fMRI mapping : Multi-slice functional images were obtained on a 1.5T Magnetom Vision MRI scanner (Simens Medical, Erlangen, Germany) equipped with high performance whole-body gradients. The BOLD T2 * - weighted images were acquired with acho planar imaging sequence (TR = 1.2 sec, TE = 60 msec, and flip angle = $90_{\circ}$). The other sequence parameter are : FOV = 210 mm, matrix=$64{\times}128$ or $64{\times}64$, slice number=10 and slice thickness = 5 or 8 mm. the anatomic images were obtained with Spin-echo T1-weighted images. The resulting images were then anaiyzed with STIMULATE (CMRR, U. of Minnesota) to generate functional maps using a student T-test (p < 0.005) and cluster analysis. Both positive and negative response were evaluated. Conclusions : We have observed the activation of the motor cortex by stimulating motor-related acupoint ($KI_6$). Among five subjects, negative BOLD response was shown in four and positive response in one. All subjects showed positive response to conventional finger flexion-extension task. To understand the detailed mechanisms of correlation between acupuncture stimulation and BOLD fMRI changes and two typs of response, further study strongly required.

• Investigative Magnetic Resonance Imaging
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• v.7 no.2
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• pp.108-115
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• 2003

Purpose : To evaluate the effect of the gradient switching noise on the ECD source localization with the EEG data recorded during the MRI scan. Materials and Methods : We have fabricated a spherical EEG phantom that emulates a human head on which multiple electrodes are attached. Inside the phantom, electric current dipole(ECD) sources are located to evaluate the source localization error. The EEG phantom was placed in the center of the whole-body 3.0 Tesla MRI magnet, and a sinusoidal current was fed to the ECD sources. With an MRI-compatible EEG measurement system, we recorded the multi channel electric potential signals during gradient echo single-shot EPI scans. To evaluate the effect of the gradient switching noise on the ECD source localization, we controlled the gradient noise level by changing the FOV of the EPI scan. With the measured potential signals, we have performed the ECD source localization. Results : The source localization error depends on the gradient switching noise level and the ECD source position. The gradient switching noise has much bigger negative effects on the source localization than the Gaussian noise. We have found that the ECD source localization works reasonably when the gradient switching noise power is smaller than $10\%$ of the EEG signal power. Conclusion : We think that the results of the present study can be used as a guideline to determine the degree of gradient switching noise suppression in EEG when the EEG data are to be used to enhance the performance of fMRI.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.89-95
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• 1998

Purpose : To investigate the phosphorus metabolic abnormalities in skeletal muscle of patients with mitochondrial myopathy using in vivo $^{31}P$ magnetic resonance spectroscopy(MRS). Materials and Methods : Patients with mitochondrial myopathy(N=10) and normal control subjects (N=10) participated. All in vivo $^{31}P$ MRS examinations were performed on 1.5T whole-body MRI/MRS system by using an image selected in vivo spectroscopy (ISIS) pulse sequence that provided a $4{\times}4{\times}4{\;}cm^{3}$ volume of interest (VOI) in the right thigh muscle tissue. Peak areas for each phophorus methabolite were measured using a Marquart algorithm. Results : The specific features in patients with mitochondrial myopathy were a significant increase of Pi/PCr ratio (p=0.003) and a significant decrease of ATP/PCr ratio (p=0.004) as compared with normal controls. In particular, the ${\beta}-ATP/PCr$ ratio between controls and patients with mitochondrial myopathy was predominantly altered. Conclusions : In vivo $^{31}P$ MRS may be a useful modality in the clinical evaluation of patients with mitochondrial myopathy based on ATP/PCr and Pi/PCr ratios in skeletal muscle tissue and provides a valuable information in further understanding disorders of muscle metabolism.