• The Korean Journal of Nuclear Medicine
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• v.33 no.5
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• pp.439-451
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• 1999

Purpose : It is important to differentiate malignant from benign lesions of intraocular masses in choosing therapeutic plan. Biopsy of intraocular tumor is not recommended due to the risk of visual damage. We evaluated the usefulness of F-18-FDG PET imaging in diagnosing intraocular neoplasms. Materials and Methods: F-18-FDG PET scan was performed in 13 patients (15 lesions) suspected to have malignant intraocular tumors. There were 3 benign lesions (retinal detachment, choroidal effusion and hemorrhage) and 10 patients with 12 malignant lesions (3 melanomas, 7 retinoblastomas and 2 metastatic cancers). Regional eye images ($256{\times}256$ and $128{\times}128$ matrices) were obtained with or without attenuation correction. Whole body scan was also performed in eight patients (3 benign and 6 malignant lesions). Results: All malignant lesions were visualized while all benign lesions were not visualized. The mean peak standardized uptake value (SUV) of malignant lesions was $2.64{\pm}0.57g/ml$. There was no correlations between peak SUV and tumor volume. Two large malignant lesions ($> 1000 mm^3$) showed hot uptake on whole body scan. But two medium-sized lesions ($100-1000mm^3$) looked faint and two small ($<100mm^3$) lesions were not visualized. The images reconstructed with $256{\times}256$ matrix showed lesions more clearly than those with $128{\times}128$ matrix Conclusion: F-18-FDG PET scan is highly sensitivity in detecting malignant intraocular tumor For the evaluation of small-sized intraocular lesions, whole body scan is not appropriate because of low sensitivity. A regional scan with sufficient acquisition time is recommended for that purpose. Image reconstruction in matrix size of $256{\times}256$ produced clearer images than the ones in $128{\times}128$, but it does not affect the diagnostic sensitivity.

• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.233-242
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• 2012

The purposes of this study were to compare psychological profiles, to investigate the differences in the clinical characteristics, and to compare treatment outcomes between myogenous pain and arthrogenous pain subgroups of temporomandibular disorder (TMD) based on Research Diagnostic Criteria for Temporomandibular disorders (RDC/TMD). Two hundred and fifty two patients diagnosed as TMD were divided into three groups based on the RDC/TMD axis I diagnostic guidelines; myogenous pain group, arthrogenous pain group, and mixed pain (both myogenous pain and arthrogenous pain) group. RDC/TMD history questionnaire was administered to each patient and depression, somatization, jaw disability, pain intensity, disability days, and graded chronic pain scale were analyzed. Bruxism, clenching, insomnia, headache, and unilateral chewing were assessed in a standardized TMD dysfunction questionnaire and the duration of onset, chronicity of pain, treatment period, the effectiveness of the treatment, and improvement of symptoms also analyzed. Myogenous pain group had higher depression (p=0.002), and somatization scales (p<0.001) than the arthrogenous pain group. Mixed pain group showed higher pain intensity (p=0.008), disability days (p<0.001), graded chronic pain scale (p=0.005), somatization (p<0.001), and depression scores (p=0.002) than the arthrogenous pain group. Jaw disability did not show any significant differences among the three groups (p=0.058). Arthrogenous pain group reported more limitation of mouth opening than myogenous pain group (p=0.007). Duration of onset showed that the arthrogenous pain group had lowest prevalence of chronicity among three groups (p=0.002). Mixed pain group patients showed lowest symptom improvements among three groups (p=0.007). Multiple linear regression analysis results showed that the treatment effectiveness was significantly associated with somatization score (${\beta}$=-0.251, p=0.03).

• Tuberculosis and Respiratory Diseases
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• v.42 no.1
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• pp.84-92
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• 1995

Background: Nasal applied continuous positive airway pressure(CPAP) is a highly effective method of treatment for obstructive sleep apnea syndrome. More than a decade of accumulated experience with this treatment modality confirmed that it is unquestionably the medical treatment of choice for patients with obstructive sleep apnea syndrome. However it takes long time to reach optimal CPAP pressure. To save the time to reach optimal pressure, it is necessary to clarify the time to reach optimal pressure for treatment of obstructive sleep apnea syndrome. Method: CPAP pressure is titrated during an overnight study according to a standardized protocol. Just before the presleep bio-calibration procedures, the technician applies the nasal mask and switches on the clinical CPAP unit. Initial positive for pressure is typically 3.0 centimeters of water pressure. After sleep onset, the technician gradually increases the pressure until sleep-disordered breathing events disappear or become minimal. The pressure must maintain maximal airway patency during both NREM and REM sleep to be considered effective. Before recommending a final pressure setting, sleep recording and oximetry data are reviewed by an American Board of Sleep Medicine certified Sleep Specialist and a Registrered Polysomnographic Technologist. Results: We examined the time required to reach optimal pressure during routine CPAP titration in 127 consecutively evaluated individuals diagnosed with sleep-disordered breathing. Results indicate that 33% of patients required more than four hours to attain satisfactory titration. This indicates that a four-hour session is marginally enough time, at best, to determine a proper CPAP pressure setting. Moreover, 60 of 127 patients required further adjustment after optimal pressure was reached. These additional pressure trials were needed to confirm that higher pressures were not superior for eliminating sleep-disordered breathing events. Conclusions: The data presented underscore the logistical difficulty of titrating CPAP during split-night studies without modifying the titration procedure. Futhermore, the time needed to reach optimal pressure makes it improbable that proper CPAP titration can be performed during a 2-3 hour nap study.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.230-234
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• 2004

Purpose: The use of laparoscopic surgery for gastric disease has been gaining popularity. However, there has been the controversy over the indications and the standard techniques of laparoscopic gastric surgery in the early gastric cancer (EGC). The purposes of this study were to compare the clinical outcomes among a hand-assisted laparoscopic distal gastrectomy (HALDG), a laparoscopy-assisted distal gastrectomy (LADG), and an open distal gastrectomy (ODG) and to discuss the role of these procedures in the treatment of EGC. Materials and Methods: Between August 2001 and July 2004, laparoscopic surgery was performed in our institution on 25 patients, LADG (n=7) and HALDG (n=18) with EGC. Analysis was performed on clinical data such as the operative time, the hospital stay, the start of oral intake, and the number of harvested lymph nodes. Patients were categorized into early and late groups by using the date of surgery and were also grouped by surgical procedure. To evaluate the feasibility and efficacy of laparoscopic surgery for EGC, we compared the clinical data with those for ODGs performed during the same period. Results: There was no difference in the number of harvested lymph nodes between the laparoscopic group and the open group, but the operation time in the laparoscopic group was longer than that in the open group (P<0.05). Also, no significant differences in other clinical data were found between the two groups. Comparing the early and the late periods of the series, the number of harvested lymph nodes for a HALDS increased from $22.31\pm4.29\;to\;29.40\pm3.21$ (P<0.05). Conclusion: Our early experience with laparoscopic gastric surgery shows that a wide range of possibilities exist for applying laparoscopic gastric surgery to selected gastric cancer patients. However, the surgical procedure should be standardized, and the outcomes of laparoscopic surgery, in comparison to those of open surgery, need to be confirmed based on a large randomized study. (J Korean Gastric Cancer Assoc 2004;4:230-234)

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.251-259
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• 1999

Background: Even though the necessity for premedication has been questioned, some combinations of antisialogogues, sedatives and analgesics are usually employed by most bronchoscopists. The goal of this study was to determine whether fiberoptic bronchoscopy(FOB) could be performed safely and effectively without premedication while using a standardized topical anesthetic. Method: Eighty outpatients were randomized in a double-blind manner into group I(n=20) with 1 ml normal saline, group II(n=20) with 0.5mg of atropine, group III(n=20) with 0.5mg of atropine plus 5mg of midazolam, and group IV(n=20) with 0.5mg of atropine plus 50mg of meperidine, given intramuscularly 30 minutes before FOB as premedication Topical anesthetics administered were same in each group. Each patient was given 5ml(200mg) of 4% nebulized lidocaine and additional intratracheobronchial 2% lidocaine. Oxygen saturation, pulse rate and electrocardiogram were monitored and recorded before, during, just after and 2 minutes after FOB. Immediately after FOB, the bronchoscopists answered four questions such as ease of procedure, extent of coughing, extent of secretion, and overall impression. Before leaving bronchoscopy suite, patients completed similar questions on discomfort during procedure, and willingness to return for a repeat procedure. Results: Age, gender, baseline pulmonary function, dose of 2% lidocaine used for topical anesthesia, and duration of FOB were not significantly different. There was no statistical difference among group I to IV with regard to extent of coughing answered by bronchoscopist. But extent of secretion was significantly different between group I without atropine and group II-IV with atropine. And there was also significant difference in ease of procedure and overall impression among groups. There was no statistical difference in patient's willingness and level of discomfort among the groups. Thirteen patients(16%) showed hypoxemia(arterial oxygen saturation: <90%), and 3 patients(4%) showed significant tachyarrhythmia(heart rate: > l60/min), but the rate of complication was not statistically different among the groups. Conclusion: These results suggest that the value of premedication is questionable for outpatient FOB, although it may be necessary in excessively anxious patient.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.404-411
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• 2006

Purpose : Multidrug-resistant tuberculosis (MDR-TB) is an emerging threat to human beings. However, there is little data on the current status of MDR-TB in Korea. This study investigated the current status of MDR-TB in Korea using a survey of all the data from drug susceptibility tests (DST) performed across the country over the last three years. Method : The DST results between Jan. 2000 and Dec. 2002 from 7 laboratories, which were in charge of all antituberculous DSTs across the country as of March 2002, were collected and analyzed to determine the actual number of drug-resistant or MDR-TB patients, annual trend, degree and pattern of resistance against anti-TB drugs, etc. Results : Six laboratories used the absolute concentration method for DST and one used the proportional method. 59, 940 tests had been performed over the 3 year study period. The number of DST performed annually was 18,071, 19,950, and 21,919 in 2000-2002, respectively. The number of resistant tuberculosis patients (resistant against at least one anti-TB drug) had increased by 16.9% from 6,338 in 2000 to 7,409 in 2002. The rate of resistant tuberculosis among all DST results was 35.1% in 2000, 34.5% in 2001, and 33.8% in 2002. The number of MDR-TB patients (resistant against at least both isoniazid and rifampin) showed an increasing trend (14.5%) from 3,708 in 2000 to 4,245 in 2002. Conclusion : Approximately 4,000 MDR-TB cases are newly identified by DST annually and the number is showing an increasing trend. This study suggests that in order to cope with the current MDR-TB situation, the DST methods will need to be standardized and more aggressive measures will be required.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.90-101
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• 1997

The purpose of this study is to evaluate the diagnostic accuracy of various quantitative indices for the differentiation of benign from malignant primary soft tissue tumors by FDG-PET. A series of 32 patients with a variety of histologically or clinically confirmed benign (20) or malignant (12) soft tissue lesions were evaluated with emission whole body (5min/bed position) PET after injection of [$^{18}F$]FDG. Regional 20min transmission scan for the attenuation correction and calculation of SUV was performed in 16 patients (10 benign, 6malignant) followed by dynamic acquisition for 56min. Postinjection transmission scan for the attenuation correction and calculation of SUV was executed in the other 16 patients (10 benign, 6 malignant). The following indices were obtained. the peak and average SUV (pSUV, aSUV) of lesions, tumor-to-background ratio acquired at images of 51 min p.i. ($TBR_{51}$), tumor-to-background ratio of areas under time-activity curves ($TBR_{area}$) and the ratio between the activities of tumor ROI at 51 min p. i. and at the time which background ROI reaches maximum activity on the time-activity curves ($T_{51}/T_{max}$). The pSUV, aSUV, $TBR_{51}$, and $TBR_{area}$ in malignant lesions were significantly higher than those in benign lesions. We set the cut-off values of pSUV, aSUV, $TBR_{51},\;TBR_{area}$ and $T_{51}/T_{max}$ for the differentiation of benign and malignant lesions at 3.5, 2.8, 5.1, 4.3 and 1.55, respectively. The sensitivity, specificity and accuracy were 91.7%, 80.0%, 84.4% by pSUV and aSUV, 83.3%, 85.0%, 84.4% by $TBR_{51}$, 83.3%, 100%, 93.8% by $TBR_{area}$ and 66.7%, 70.0%, 68.8% by $T_{51}/T_{max}$. The time-activity curves did not give additional information compared to SUV or TBR. The one false negative was a case with low-grade fibrosarcoma and all four false positives were cases with inflammatory change on histology. The visual, analysis of FDG-PET also detected the metastatic lesions in malignant cases with comparable accuracy In conclusion, all pSUV, aSUV, $TBR_{51}$, and $TBR_{area}$ are useful metabolic semi-quantitative indices with good accuracy for the differentiation of benign from malignant soft-tissue lesions.

• The Korean Journal of Nuclear Medicine
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• v.32 no.4
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• pp.332-343
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• 1998

Purpose: The purpose of this study was to assess the diagnostic accuracy of various quantitation methods using F-18-fluorodeoxyglucose (FDG) in patients with malignant or benign lung lesion. Materials and Methods: 22 patients (13 malignant including 5 bronchoalverolar cell cancer; 9 benign lesions including 1 hamartoma and 8 active inflammation) were studied after overnight fasting. We performed dynamic PET imaging for 56 min after injection of 370 MBq (10 mCi) of FDG. Standardized uptake values normalized to patient's body weight and plasma glucose concentration (SUVglu) were calculated. The uptake rate constant of FDG and glucose metabolic rate were quantified using Patlak graphical analysis (Kpat and MRpat), three compartment-five parameter model (K5p, MR5p), and six parameter model taking into account heterogeneity of tumor tissue (K6p, MR6p). Areas under receiver operating characteristic curves (ROC) were calculated for each method. Results: There was no significant difference of rate constant or glucose metabolic rate measured by various quantitation methods between malignant and benign lesions. The area under ROC curve were 0.73 for SUVglu, 0.66 for Kpat, 0.77 for MRpat, 0.71 for K5p, 0.73 for MR5p, 0.70 for K6p, and 0.78 for MR6p. No significant difference of area under the ROC curve between these methods was observed except the area between Kpat vs. MRpat (p<0.05). Conclusion: Quantitative methods did not improve diagnostic accuracy in comparison with nonkinetic methods. However, the clinical utility of these methods needs to be evaluated further in patients with low pretest likelihood of active inflammation or bronchoalveolar cell carcinoma.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.738-743
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• 2009

Background: There is no standardized tool and parameter that can accurately assess the sympathetic function before and after performing sympathectomy in patients with primary palmar hyperhidrosis. We examined the effective-ness of the sympathetic skin response (SSR) study for documenting the change of sympathetic denervation before and after performing selective thoracic sympathicotomy. Material and Method: We prospectively investigated the SSR from 12 healthy subjects who were diagnosed with primary hyperhidrosis. Each SSR was recorded on the right palm or sole with electrical stimuli applied to the skin at the left wrist and foot and vice versa for the controlateral side. This test was performed before, 2 weeks and 1 year after selective thoracic sympathicotomy. The data was corrected for the onset latency and the amplitude of the SSR (n=24). Result: The mean age of the 12 patients was $24.6{\pm}0.4$ years (range: 19~36) and the gender ratio was 1 : 0.7. The mean values of the preoperative, postoperative 2 weeks and postoperative 1 year onset latency and amplitude of the palmar side (n=24) were $1.46{\pm}0.24$ msec and $6,043{\pm}2,339{\mu}V$, $1.63{\pm}0.42$ msec and $823{\pm}638{\mu}V$, and $1.44{\pm}0.39$ msec and $2,412{\pm}1,546{\mu}V$, respectively. The mean values of the plantar side (n=38) were $1.83{\pm}0.42$ msec and $2,816{\pm}1,694{\mu}V$, $2.16{\pm}0.39$ msec and $1,445{\pm}1,281{\mu}V$ and $1.95{\pm}0.25$ msec and $1,622{\pm}865{\mu}V$, respectively. Among the documented parameters, only the palmar amplitude (p=0.002) showed statistical significance in recording the change of the sympathetic system within the same individual for the pre and postoperative period. Conclusion: The SSR amplitude ratio may be a useful parameter for documenting the efficacy of sympathetic denervation after selective sympathicotomy.

• Sleep Medicine and Psychophysiology
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• v.26 no.1
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• pp.23-32
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• 2019

Objectives: Insomnia is not only the most common sleep-related disorder, but also is one of the most important. Knowledge of the comorbidities of insomnia is essential for proper treatment including pharmacological and non-pharmacological methods to prevent disease chronification. This study aimed to determine sleep clinic patients' knowledge of insomnia. Methods: This study recruited 44 patients (24 males and 20 females; mean age $54.11{\pm}16.30years$) from the sleep clinic at National Center for Mental Health. All subjects were asked to complete a self-report questionnaire about their reasons for visiting a sleep clinic and about their knowledge of treatment and comorbidities of insomnia. Results: The reasons for visiting the sleep clinic were insomnia symptoms of daytime sleepiness, irregular sleeping time, nightmares, snoring, and sleep apnea, in that order. Of the responders, 72.7% had a comorbidity of insomnia, and 22.7% showed high-risk alcohol use. In addition, 70.5% of responders chose pharmacological treatment of insomnia as the first option and reported collection of information about treatment of insomnia mainly from the internet and medical staff. More than half (52.3%) of the respondents reported that they had never heard about non-pharmacological treatments of insomnia such as cognitive behavioral treatment (CBT-I) or light therapy. The response rate about comorbidities of varied, with 75% of responders reporting knowledge of the relation between insomnia and depression, but only 38.6% stating awareness of the relation between insomnia and alcohol use disorder. Of the total responders, 68.2% were worried about hypnotics for insomnia treatment, and 70% were concerned about drug dependence. Conclusion: This study showed that patients at a sleep clinic had limited knowledge about insomnia. It is necessary to develop standardized insomnia treatment guidelines and educational handbooks for those suffering from insomnia. In addition, evaluation of alcohol use disorders is essential in the initial assessment of sleep disorders.