• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.22-30
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• 1994

Encephalo-duro-arterio-synangiosis (EDAS) is a relatively new surgical procedure for treatment of childhood moyamoya disease. We assessed regional cerebral perfusion in moyamoya patients before (1.3 mo) and after (6.8 mo) EDAS with $^{99m}Tc$-HMPAO brain SPECT. A total of 21 EDAS operations in 17 moyamoya patients was included. Preoperative CT or MRI showed cerebral infarction in 14 patients and carotid angiography showed Suzuki grade I to V stenosis in 6%, 9%, 62%, 12% and 12% of the hemispheres respectively. Preoperative SPECT showed regional hypoperfusion in all patients, bilateral frontal and temporal lobes being the most frequently involved site. $4{\times}4$ pixel sized ROIs were applied on the frontotemporal cortex in 3 slice averaged transverse tomographic images. An index of regional perfusion was measured as: PI (%)=average F-T activity/average cerebellar activity${\times}100$ Pre-EDAS ipsilateral PI ranged from 23.7 to 98.4% (mean: $74.3{\pm}17%$) and increased significantly after operation ($81.4{\pm}17%$, p<0.001). Individual post-EDAS PI improved in 15/21 cases, showed no significant change in 5 and was slightly aggravated in 1. The amount of clinical improvement (${\Delta}CI$) was graded with a scale of 0 to 4 based on frequency and severity of TIA attacks. When patients were grouped according to pre-EDAS PI, group II (PI 70-89) showed a significantly higher ${\Delta}CI$ (3.3) compared to group I (PI< 70, 1.57) or group III (PI >90, 0.5) (P< 0.001). The amount of perfusion improvement (${\Delta}PI$) showed significant correlation with ${\Delta}CI$ (r=0.42, p=0.04). ${\Delta}PI$ did not, however, correlate with the amount of neovascularization assessed angiographically in 8 patients. Serial HMPAO SPECT is an useful noninvasive study for assessing perfusion improvement after EDAS in childhood moyamoya patients.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.32 no.4
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• pp.137-143
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• 2021

Objectives: Despite the growing concern regarding the adverse effects related to problematic smartphone use (PSU), little is known about underlying morphologic changes in the brain. The brainstem is a deep brain structure that consists of several important nuclei associated with emotions, sensations, and motor functions. In this study, we sought to examine the difference in the volume of brainstem substructures among adolescents with and without PSU. Methods: A total of 87 Korean adolescents participated in this study. The PSU group (n=20, age=16.2±1.1, female:male=12:8) was designated if participants reported a total Smartphone Addiction Proneness Scale (SAPS) score of ≥42, whereas the remaining participants were assigned to the control group (n=67, age=15.3±1.7, female:male=19:48). High-resolution T1 magnetic resonance imaging was performed, and the volume of each of the four brainstem substructures [midbrain, pons, medulla, and superior cerebellar peduncle (SCP)] was measured. Analysis of covariance was conducted to reveal group differences after adjusting for effects of age, gender, whole brainstem volume, depressive symptoms, and impulsivity. Results: The PSU group showed a significantly smaller volume of the SCP than the control group (F=8.273, p=0.005). The volume of the SCP and the SAPS score were negatively correlated (Pearson's r=-0.218, p=0.047). Conclusion: The present study is the first to reveal an altered volume of the brainstem substructure among adolescents with PSU. This finding suggests that the altered white matter structure in the brainstem could be one of the neurobiological mechanisms underlying behavioral changes in PSU.

• Journal of Digestive Cancer Research
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• v.1 no.1
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• pp.48-51
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• 2013

We report an unusual case of postoperative early gastric cancer with liver metastasis mimicking pancreaticobiliary carcinoma. A 73-year-old man with early gastric cancer was transferred for endoscopic treatment. The patient underwent endoscopic submucosal dissection for the treatment of the early gastric cancer. The pathological diagnosis was adenocarcinoma with extension to the deep submucosa and some lymphatic invasion. Therefore, subsequent a subtotal gastrectomy was performed. The histological results demonstrated residual adenocarcinoma confined to the mucosa. The resection margin and lymph node metastasis were negative. Thus, he was closely monitored for recurrence every 6 months. After 2 years, he was suddenly suspected of developing liver metastasis and local recurrence. He received a liver biopsy, and the pathological result was poorly differentiated adenocarcinoma. Immunohistochemical staining suggested pancreaticobiliary carcinoma rather than metastatic adenocarcinoma from the stomach or colon, but primary focus was not found. We were sure that the recurrent stomach cancer metastasized to the liver because stomach cancer can show heterogeneous cytokeratin (CK) expression pattern with various histological features. Therefore, no single CK expression pattern has diagnostic value for distinguishing gastric carcinoma. The patient underwent chemotherapy for metastatic stomach cancer.

• Korean Journal of Radiology
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• v.20 no.5
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• pp.791-800
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• 2019

Objective: To compare various models of diffusion-weighted imaging including monoexponential apparent diffusion coefficient (ADC), biexponential (fast diffusion coefficient [D_f], slow diffusion coefficient [D_s], and fraction of fast diffusion), stretched-exponential (distributed diffusion coefficient and anomalous exponent term [α]), and kurtosis (mean diffusivity and mean kurtosis [MK]) models in the differentiation of renal solid masses. Materials and Methods: A total of 81 patients (56 men and 25 women; mean age, 57 years; age range, 30-69 years) with 18 benign and 63 malignant lesions were imaged using 3T diffusion-weighted MRI. Diffusion model selection was investigated in each lesion using the Akaike information criteria. Mann-Whitney U test and receiver operating characteristic (ROC) analysis were used for statistical evaluations. Results: Goodness-of-fit analysis showed that the stretched-exponential model had the highest voxel percentages in benign and malignant lesions (90.7% and 51.4%, respectively). ADC, D_s, and MK showed significant differences between benign and malignant lesions (p < 0.05) and between low- and high-grade clear cell renal cell carcinoma (ccRCC) (p < 0.05). α was significantly lower in the benign group than in the malignant group (p < 0.05). All diffusion measures showed significant differences between ccRCC and non-ccRCC (p < 0.05) except D_f and α (p = 0.143 and 0.112, respectively). α showed the highest diagnostic accuracy in differentiating benign and malignant lesions with an area under the ROC curve of 0.923, but none of the parameters from these advanced models revealed significantly better performance over ADC in discriminating subtypes or grades of renal cell carcinoma (RCC) (p > 0.05). Conclusion: Compared with conventional diffusion parameters, α may provide additional information for differentiating benign and malignant renal masses, while ADC remains the most valuable parameter for differentiation of RCC subtypes and for ccRCC grading.

• Investigative Magnetic Resonance Imaging
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• v.8 no.2
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• pp.94-99
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• 2004

Purpose : To investigate the signal enhancement ratio by NOE effect on in vivo $^{31}P$ MRS in human heart muscle and liver. we also evaluated the enhancement ratios of different phosphorus metabolites, which are important in 31P MRS for each organ. Materials and Methods : Ten normal subjects (M:F = 8:2, age range = 24-32 yrs) were included for in vivo $^{31}P$ MRS measurements on a 1.5 T whole-body MRI/MRS system using $^1H-^{31}P$ dual tuned surface coil. Two-dimensional Chemical Shift Imaging (2D CSI) pulse sequence for $^{31}P$ MRS was employed in all $^{31}P$ MRS measurements. First, $^{31}P$ MRS performed without NOE effect and then the same 2D CSI data acquisitions were repeated with NOE effect. After postprocessing the MRS raw data in the time domain, the signal enhancements in percent were estimated from the major metabolites. Results : The calculated NOE enhancement for liver $^{31}P$ MRS were $\alpha-ATP\;(7\%),\;\beta-ATP\;(9\%),\;\gamma-ATP\;(17\%),\;Pi\;(1\%),\;PDE\;(19\%)$ and $PME\;(31\%)$. Because there is no creatine kinase activity in liver, PCr signal is absent. For cardiac $^{31}P$ MRS, whole body coil gave better scout images and thus better localization than surface coil. In $^{31}P$cardiac multi-voxel spectra, DPG signal increased from left to right according to the amount of blood included. The calculated enhancement for cardiac $^{31}P$ MRS were : $\alpha-ATP\;(12\%),\;\beta-ATP\;(19\%),\;\gamma-ATP\;(30\%),\;PCr\;(34\%),\;Pi\;(20\%),\;(PDE)\;(51\%),\;and\;DPG\;(72\%)$. Conclusion : Our results revealed that the NOE effect was more pronounced in heart muscle than in liver with different coupling to 1H spin system and thus different heteronuclear cross-relaxation.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.9-16
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• 2004

Purpose : The purpose of this study was to assess supplementary motor area (SMA) activation during motor, sensory, word generation, listening comprehension, and working memory tasks using functional magnetic resonance imaging (fMRI). Materials and Methods : Sixteen healthy right-handed subjects (9M, 7F) were imaged on a Siemens 1.5T scanner. Whole brain functional maps were acquired using BOLD EPI sequences in the axial plane. Each paradigm consisted of five epochs of activation vs. the control condition. The activation tasks consisted of left finger complex movement, hot sensory stimulation of the left hand, word generation, listening comprehension, and working memory. The reference function was a boxcar waveform. Activation maps were thresholded at an uncorrected p=0.0001. The thresholded activation maps were placed into MNI space and the anatomic localization of activation within the SMA was compared across tasks. Results : SMA activation was observed in 16 volunteers for the motor task, 11 for the sensory task, 15 for the word generation task, 5 for the listening comprehension task, and 15 for the working memory task. The rostral aspects of the SMA showed activity during the word generation and working memory tasks, and the caudal aspects of the SMA showed activity during the motor and sensory tasks. Right (contralateral) SMA activation was observed during the motor and sensory tasks, and left SMA activation during the word generation and memory tasks. Conclusion : Our results suggest that SMA is involved in a variety of functional tasks including motor, sensory, word generation, and working memory. The results obtained also support the notion that functionally specific subregions exist within the region classically defined as the SMA.

• Journal of the Korean Magnetics Society
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• v.15 no.2
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• pp.100-105
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• 2005

$Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticles have been prepared by a sol-gel method. The structural and magnetic properties have been investigated by DTA/TGA, XRD, SEM, and $M\ddot{o}ssbauer$ spectroscopy, VSM. $Ni_{0.9}Zn_{0.1}Fe_2O_4$ powder that was annealed at $300^{\circ}C$ has spinel structure and behaved superparamagnetically. The estimated size of superparammagnetic Ni-Zn ferrite nanoparticle is around 10 nm. The hyperfine fields at 13 K for the A and B patterns were found to be 533 and 507 kOe, respectively. The blocking temperature ($T_B$) of superparammagnetic $Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticle is about 250 K. The magnetic anisotropy constant and relaxation time constant of $Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticle were calculated to be $1.6\times10^6\;ergs/cm^3$ and ${\tau}_0=5.0{\times}10^{-13}$ s, respectively. Also, Temperature increased up to $43^{\circ}C$ within 10 minutes under AC magnetic field of 7 MHz. It is considered that $Ni_{0.9}Zn_{0.1}Fe_2O_4$ powder that was annealed at $300^{\circ}C$ is available for biomedicine application such as hyperthermia, drug delivery system and contrast agents in MRI.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.1
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• pp.7-12
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• 2014

Purpose:The effectiveness of transdermal buprenorphine patch on the patients with frozen state of frozen shoulder was evaluated. Materials and Methods: Between March and September in 2013, 127 patients with pain and limited range of motion in shoulder joint over 6 months were included. Every patient was confirmed the diagnosis through MRI or ultrasonogram and each patient received intra-articular injection of steroid once. After 2~4 weeks, every patient was interviewed via telephone survey and finally 105 patients were included, 54 patients received only oral NSAIDs (NP group) while 51 patients received additional transdermal buprenorphine patch (BP group). Pain and functional visual analog scale (PVAS, FVAS), American Shoulder Elbow Society (ASES) score was checked. Results: Generally, every outcome variables showed improvements in both groups (p<0.001). PVAS score after treatment showed superior result in NP group but it was not significant (p=0.088). In ASES score, NP group had superior result than BP group and it had significant difference. Similarly in FVAS, NP group showed superior result but the data before treatment was significantly different (p=0.028) Conclusion: Transdermal buprenorphine patch didn't show superior treatment result in the patient with frozen state of frozen shoulder which was applied with oral NSAIDs after single intra-articular glenohumeral steroid injection in short-term follow-up.

• Clinical and Experimental Pediatrics
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• v.50 no.11
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• pp.1116-1124
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• 2007

Purpose : Juvenile dermatomyositis (JDM) is the most common of the idiopathic inflammatory myopathies in children. The purpose of this study is to observe demographic, initial presentations, duration of time between disease onset and diagnosis, clinical manifestations and laboratory findings at diagnosis of patients with JDM. Methods : Forty seven patients identified at Seoul National University Children's Hospital from January 1986 to May 2007. Medical records were reviewed retrospectively focusing on initial presentations, clinical manifestations and laboratory findings at the time of diagnosis of patients with JDM. Results : Male and female patients were 25 and 22, respectively and sex ratio was 1.14:1. The average age at the time of diagnosis was 6.51 years. Skin rash (94%) was the most common symptom, followed by the proximal muscle weakness (89%). The disease activity score was 10.8. The duration between the onset of the skin rash and the muscle weakness and diagnosis was 7.18 and 4.70 months, respectively. The serum muscle enzymes, LDH, AST, CK and aldolase, were elevated in the patient with JDM. Autoimmune antibodies, antinuclear antibody, anti SSA antibody and anti SSB antibody, were negative findings. Electromyography findings were consistent with JDM in 88% of the patients, the muscle biopsy was in 91% and all MRI findings were compatible with those of patients with JDM. The most common symptom besides musculocutaneous lesions was the calcinosis (62.5%). The most common site of calcinosis was the pelvic area and buttocks. Conclusion : This study shows that the major symptoms are proximal muscle weakness and cutaneous lesion, and they are important to diagnose JDM.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.168-175
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• 2003

Fracture about proximal humerus may be classified as the articular segment or the anatomical neck, the greater tuberosity, the lesser tuberosity, and the shaft or surgical neck. Now, usually used, Neer's classification is based on the number of segments displaced, over 1cm of displaced or more than 45 degrees of angulation , rather than the number of fracture line . Absolute indication of a operative treatment a open fracture, the fracture with vascular injury or nerve injury , and unreductable fracture-dislocation . Inversely, the case that are severe osteoporosis, and eldly patient who can't be operated by strong internal fixation is better than arthroplasty used by primary prosthetic replacement and early rehabilitation program than open reduction and internal fixation. The operator make a decision for the patient who should be taken the open reduction and internal fixation, because it's different that anatomical morphology, bone density, condition of patient. The operator decide operation procedure. For example, percutaneous pinning, open reduction, plate & screws, wire tension bands combined with some intramedullary device are operation procedure that operator can decide . The poor health condition for other health problem, fracture with unstable vital sign and severe osteoporosis , are the relative contraindication. The stable fracture without dislocation is not the operative indication . The radiologic film of the prokimal humerus before the operation can not predict for fracture evaluation. It's necessary to good radiologic film for evaluation of fracture form. The trauma serise is better than the other radiologic film for evaluation. The accessary radiologic exam is able to help for evaluation of bone fragment and anatomy. The CT can be helpful in evaluating these injury, especially if the extract fracture type cannot be determined from plain roenterogram of the proximal humerus, bone of humerus head. If the dislocation is severe anatomically , we could consider to do three dimentional remodelling. The MRI doing for observing of bony morphology before the operation is not better than CT If we were suspicious of vascular injury, we could consider the angiography.