• The Korean Journal of Nuclear Medicine
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• v.18 no.2
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• pp.17-23
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• 1984

For nearly a century it has been known that chemical activity accompanies mental activity, but only recently has it been possible to begin to examine its exact nature. Positron-emitting radioactive tracers have made it possible to study the chemistry of the human mind in health and disease, using chiefly cyclotron-produced radionuclides, carbon-11, fluorine-18 and oxygen-15. It is now well established that measurable increases in regional cerebral blood flow, glucose and oxygen metabolism accompany the mental functions of perception, cognition, emotion and motion. On May 25, 1983 the first imaging of a neuroreceptor in the human brain was accomplished with carbon-11 methyl spiperone, a ligand that binds preferentially to dopamine-2 receptors, 80% of which are located in the caudate nucleus and putamen. Quantitative imaging of serotonin-2, opiate, benzodiazapine and muscarinic cholinergic receptors has subsequently been accomplished. In studies of normal men and women, it has been found that dopamine and serotonin receptor activity decreases dramatically with age, such a decrease being more pronounced in men than in women and greater in the case of dopamine receptors than serotonin-2 receptors. Preliminary studies in patients with neuropsychiatric disorders suggests that dopamine-2 receptor activity is diminished in the caudate nucleus of patients with Huntington's disease. Positron tomography permits quantitative assay of picomolar quantities of neuro-receptors within the living human brain. Studies of patients with Parkinson's disease, Alzheimer's disease, depression, anxiety, schizophrenia, acute and chronic pain states and drug addiction are now in progress. The growth of any scientific field is based on a paradigm or set of ideas that the community of scientists accepts. The unifying principle of nuclear medicine is the tracer principle applied to the study of human disease. Nineteen hundred and sixty-three was a landmark year in which technetium-99m and the Anger camera combined to move the field from its latent stage into a second stage characterized by exponential growth within the framework of the paradigm. The third stage, characterized by gradually declining growth, began in 1973. Faced with competing advances, such as computed tomography and ultrasonography, proponents and participants in the field of nuclear medicine began to search for greener pastures or to pursue narrow sub-specialties. Research became characterized by refinements of existing techniques. In 1983 nuclear medicine experienced what could be a profound change. A new paradigm was born when it was demonstrated that, despite their extremely low chemical concentrations, in the picomolar range, it was possible to image and quantify the distribution of receptors in the human body. Thus, nuclear medicine was able to move beyond physiology into biochemistry and pharmacology. Fundamental to the science of pharmacology is the concept that many drugs and endogenous substances, such as neurotransmitters, react with specific macromolecules that mediate their pharmacologic actions. Such receptors are usually identified in the study of excised tissues, cells or cell membranes, or in autoradiographic studies in animals. The first imaging and quantification of a neuroreceptor in a living human being was performed on May 25, 1983 and reported in the September 23, 1983 issue of SCIENCE. The study involved the development and use of carbon-11 N-methyl spiperone (NMSP), a drug with a high affinity for dopamine receptors. Since then, studies of dopamine and serotonin receptors have been carried out in over 100 normal persons or patients with various neuropsychiatric disorders. Exactly one year later, the first imaging of opitate receptors in a living human being was performed [1].

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.247-261
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• 1999

Purpose: The aim of this study was to evaluate the normal values of regional cerebral blood flow (rCBF) and cerebrovascular reserve (CVR) in normal children to aged volunteers using Tc-99m HMPAO, Materials and Methods: Thirty four right-handed normal volunteers (20 males, 14 females, mean age $40.3{\pm}24.9$ years, range 4 to 82 years) were underwent rost/acetazolamide (ACZ) brain SPECT using Tc-99m HMPAO and the sequential injection and subtraction method. rCBF was estimated on the basis of a semiquantitative approach by means of right/left ratio, region/cerebellum and region to whole brain ratios in (rental, parietal, temporal, and occipital lobes, basal ganglia, thalami, and cerebellum. CVR was measured by means of % perfusion increase calculated as % mean count change compared to rest rCBF in each regions. Results: Mean values of right to left ratios range from 1.004 to 1.018, rCBF was highest in cerebellum and lowest in basal ganglia and thalami. Frontal and temporal rCBF decreased while occipital and thalamic rCBF increased according to age. No sexual difference of rCBF was noted. Mean CVR was $29.9{\pm}12.9%$. Mean CVR significantly increased to late teens, and declined thereafter. After 6th decade, CVR in both frontal lobes, left parietal lobe and right basal ganglia decreased significantly with advancing age. There was no sexual difference of CVR. Conclusion: Quantitative assessment of CVR was possible by ACZ Tc-99m HMPAO brain SPECT. It revealed that rCBF and CVR changed according to age in normal Korean volunteers. There was no sexual difference.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.213-221
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• 2005

Purpose : Urachal anomalies are rare but are known to develop several complications, especially infection. Moreover, uniform guidelines for management have not been presented because of the variable clinical characteristics of these anomalies. The purpose of this report is to review our experience with urachal anomalies and attempt to determine the optimal management. Methods : We retrospectively reviewed the records of fourteen children with a variety of urachal anomalies who had been treated from January 1996 to June 2005 at Dong Kang General Hospital. Results : The age distribution of the patients(mean age; 3.8 years) was six neonates, one infant, five preschool-age and two school-age children. The male to female ratio was 1:1. Six cases of urachal cyst, four cases of patent urachus, two cases of urachal sinus and two cases of urachal diverticulum were found. Three patients with patent urachus and one with urachal cyst had hydronephrosis. Other associated anomalies included an inguinal hernia in one patient with urachal sinus and a vesicoureteral reflux in one patient with urachal diver ticulum. As a first-line diagnostic tool, high-resolution ultrasound examination was performed in thirteen cases and computed tomography in one case. Surgical excision was performed in nine patients with urachal anomaly. Five cases out of six neonatal cases experienced spontaneous improvement during a three-month follow up period. Due to frequent infection of the umbilicus, surgical excision was performed on one neonate with urachal sinus. Conclusion : All patients with urachal anomalies should undergo investigation for associated anomalies. The neonate with urachal anomalies, especially patent urachus, do not require surgical excision unless the patient has multiple episodes of recurrent infection. (J Korean Soc Pediatr Nephrol 2005;9:213-221)

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.417-425
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• 2018

The psychological anxiety of radiologists, as well as the patients, is growing with the increasing use of CT contrast agent side effects and the process of extravasation. In this study, a satisfaction survey was conducted regarding the wireless signal device after CT examination in patients and radiologists by employing a wireless signal device during a contrast-enhanced CT examination in order to determine its usefulness to the relieve psychological anxiety, such as anxiety and fear, of patients and radiologists when using contrast agents. The use of a wireless signal device was also intended to help radiologists in dealing with the side effects of contrast agents that may occur during a CT examination and preventing extravasation. Patients aged 20 years or older, who visited the C university hospital in Jeonnam province for 4 months from August to November in 2017, were surveyed. A total number of 90 patients (57 males and 33 females),who agreed to the study after CT examination, were included in the questionnaire survey. Meanwhile, 15 radiologists, who were working at a CT room and had an experience in using a wireless signal device, were surveyed. Patient satisfaction was $6.01{\pm}0.88$ before the use of a wireless signal device and $8.20{\pm}1.06$ after use, thereby showing an increased satisfaction after its use. Radiologist satisfaction was $8.46{\pm}1.06$ after use, thereby not showing a big difference from the mean patient satisfaction. The satisfaction was high at over 8 points in both groups. The contribution to psychological stability with the use of a wireless signal device was $8.98{\pm}0.65$ in patients with prior experience of side effects and $8.00{\pm}1.21$ in patients without prior experience of side effects. In conclusion, it is considered to improve satisfaction with the examination by helping the radiologists in taking immediate action with calling via the wireless signal device and providing the patients and radiologists with psychological stability by reducing their anxiety.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.403-407
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• 2018

Currently, the highest cancer death rate in Korea is lung cancer, which is a typical cancer that is difficult to detect early. Low-dose chest CT is being used for early detection, which has a greater lung cancer diagnosis rate of about three times than regular chest x-ray images. However, low-dose chest CT not only significantly reduces image resolution but also has a weak signal and is sensitive to noise. Also, air filled lungs are low-density organs and the presence of noise can significantly affect early diagnosis of cancer. This study used Visual C++ to set a circle inside a large circle with a density of 2.0, with a density of 1.0, which is the density of water, in which five small circle of mathematics have different densities. Gaussian noise was generated by 1%, 2%, 3%, and 4% respectively to determine the effect of noise on the mean value, the standard deviation value, and the relative noise ratio(SNR). In areas where the density difference between the large and small circles was greatest in the event of 1 % noise, the SNR in the area with the greatest variation in noise was 4.669, and in areas with the lowest density difference, the SNR was 1.183. In addition, the SNR values can be seen to be high if the same results are obtained for both positive and negative densities. Quality was also clearly visible when the density difference was large, and if the noise level was increased, the SNR was reduced to significantly affect the noise. Low-density organs or organs in areas of similar density to cancers, will have significant noise effects, and the effects of density differences on the probability of noise will affect diagnosis.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.573-578
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• 2006

Background: Generally hernia is diagnosed with simple chest or gastrointestinal x-ray. Sometimes CT or MRI can give lots of information for the diagnosis. However, there was no study for the differentiation with using CT findings between Morgagni hernia and pleuropericardial fat. The aim of this study was to evaluate the useful CT findings for differentiating Morgagni hernia from pleuropericardial fat. Material and Method: We retrospectively analyzed CT scans of eight patients with Morgagni hernia and 20 patients with abundant pleuropericardial fat without peridiaphragmatic lesions. All CT scans were performed with coverage of the whole diaphragm in the inspiration state. We evaluated 1) the presence of the defect of the anterior diaphragm, 2) the interface between the lung and fat, 3) the angle between the chest wall and fat, 4) the continuity between the extrapleural fat and fat, 5) the presence of the vessels within fat, and 6) the presence of a thin line surrounding fat. Result: In all cases with Morgagni hernia, the defect of the anterior diaphragm was seen. The interface was well-defined, smooth, and convex to the lung. The angle with the chest wall was acute. The continuity with the extrapleural fat was not seen. In the cases with abundant pleuropericardial fat, the defect of the anterior diaphragm was seen in three (15%). The interface was usually irregular (n=10) and flat (n=17). The angle with the chest wall was variable. The continuity with the extrapleural fat, that was markedly increased in amount, was usually seen (n=16). The thin line surrounding fat was seen in four cases with Morgagni hernia, however, not seen in all cases with pleuropericardial fat. All of the above findings were statistically significant, however, vessels within fat was not significant to differentiate Morgagni hernia (n=8/8) from pleuropericardial fat (n=14/20). Conclusion: The useful CT findings of Morgagni hernia were fatty mass with sharp margin, convexity toward lung, acute angle with chest wall, and thin line surrounding hernia. Branching structure within fatty mass representing omental vessels that has been known as a characteristic finding of Morgagni hernia was not useful for differentiating Morgagni hernia from pleuropericardial fat.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.626-632
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• 2006

Background: Pulmonary hypertension caused by chronic pulmonary embolism is underrecognized and carries a poor prognosis. Medical therapy is generally unsatisfactory and palliative. With the improvement of operative technique and postoperative management, pulmonary endarterectomy has been the treatment of choice for this condition. Material and Method: Between January 2001 and December 2005, eleven patients were received pulmonary endarterectomy. All patients had chronic dyspnea and exercise intolerance. Diagnosis was made with cardiac echocardiography, lung perfusion scan and computed tomography. Before the operation, Greenfield vena cava filter were placed in all patient except one. Deep hypothermic circulatory arrest was used for the distal-most portion of the endarterectomy procedure. More than moderate degree of tricuspid reguirgitation was repaired during operation. Result: There was no early and late death. Right ventricular systolic pressure was reduced significantly after operation from $91{\pm}21$ mmHg to $40{\pm}17$ mmHg on echocardiography (p=0.001). NYHA class and tricuspid reguirgitaion were improved postoperatively. Although mild reperfusion injury in three case and postoperative delirium in one case were observed, all of them recovered without complication. Conclusion: Pulmonary thromboendarterctomy offers to patient an acceptable morbidity rate and anticipation of clinical improvement. This method is safe and effective operation for pulmonary hypertension caused by chronic pulmonary thromboembolism.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.776-780
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• 1998

Background: In patients with coronary artery disease, dysfunctional hypoperfused myocardium at rest may represent either nonviable or viable hibernating myocardium. Two-dimensional echocardiography can detect regional wall motion abnormalities resulting from myocardial ischemia by dobutamine infusion. The purpose of the present study was to identify the prediction of improvement of regional left ventricular(LV) function after surgical revascularization. Materials and methods: Sixteen patients with chronic regional LV dysfunction underwent dobutamine stress echocardiography(DSE) (dobutamine: baseline, 5, 10, 20$\mu$g/kg/min) before coronary artery bypass grafting(CABG) and underwent echocardiography at least 2 months after CABG. Results: All patients were male with mean age of 58 years ranging from 42 to 73 years. The mean LV ejection fraction was 41.8% with a range from 19% to 55%. During DSE, there were no complications, also, there were no operative morbidities or mortalities. Improvement of wall motion within the dysfunctional myocardium was found in 8(50%) of 16 patients in DSE. Among them, 6 patients(75%) showed functional recovery after CABG. Another 8 patients did not show improvement of wall motion in DSE. But among them, 3 patients(38%) showed functional recovery after CABG. 84 dysfunctional segments were found in 256 segments of 16 patients. Improvement of wall motion was found in 34 of 84 segments in DSE. Among them, 23 segments(74%) showed functional recovery after CABG. Another 53 segments did not show improvement of wall motion in DSE. But among them, 12 segments(23%) showed functional recovery after CABG. The sensitivity and specificity of DSE for the prediction of postoperative improvement of segmental wall motion were 66% and 84%, respectively. The positive and negative predictive value of DSE were 74% and 77%, respectively. In patients with chronic regional LV dysfunction, think that DSE is a good predictor of the improvement of dysfunctional segments after CABG.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.733-744
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• 2007

Background: There is a controversy regarding the pathogenesis and management principle of an acute intramural hematoma (IMH) of the aorta, Recent studies have reported intimal defects in many patients diagnosed with IMH, and suggested that intimal defects play important roles in the pathogenesis, progression of the pathology, and prognosis. Material and Method: This study reviewed the preoperative and postoperative computed tomography (CT) scan images of 36 patients who underwent surgical treatment for Stanford type A acute IMH of the aorta. The surgical findings were also reviewed retrospectively from the medical records. Result: In 15 patients (41.7%), the findings suggestive of the intimal defects were found in the preoperative CT. During the operation, 20 patients (72.2%) were found to have small intimal defects in the ascending aorta or the arch, of which 13 patients (50.5%) did not have the CT findings suggestive of intimal defects. In 17 patients, the intimal defects were located in the aortic arch or distal ascending aorta, where a gross examination would have been impossible without total circulatory arrest. In all patients, the intimal defects identified were included in the resected aortic segment, or locally closed. Follow-up CT at 4 months or longer after surgery showed that the IMH in the descending aorta had disappeared or was markedly improved. Conclusion: Most patients undergoing surgical treatment for acute type A IMH had intimal defects. This suggests that a large proportion of IMH might have a similar pathogenic mechanism as classic dissection. Consequently, it is believed that those two entities of acute aortic syndrome should be treat-ed using the same principles.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.573-579
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• 2008

Background: Composite valve graft replacement is currently the treatment of choice for a wide variety of the lesions of aortic root disease. The purpose of this study was to explore the results of aortic root replacement after using the Cabrol technique over a 13-year period at our institution, and we analyzed the results to help surgeons make better decisions when repairing aortic root disease. Material and Method: Between January 1994 and December 2006, twenty-five patients underwent a Cabrol technique operation at our institution. The mean patient age was $43.7{\pm}14.1$ years old (range: $6{\sim}65$ years) and the male and female ratio was 21:4 (84% : 16%). The patients' follow-up was 100% complete, and the mean follow-up period was $60.7{\pm}50.4$ (range:$1{\sim}162$) months. Annuloaortic ectasia (n=18) was the most frequent cause of aortic disease in this series, followed by aortic dissection (n=7). The mean cardiopulmonary bypass time was $177.2{\pm}44.9$ minutes and the mean aortic cross clamping time was $123.4{\pm}34.1$ minutes. Nine patients were checked with MDCT (Multidetector computed tomography) for evaluating a well functioning secondary graft and the coronary anastomosis site. Result: The early mortality rate was 4% (1 of 25 patients). A significant stenosis, kinking or occlusion of the secondary graft was detected by MDCT in 4 patients. The overall survival rate was 88%. Conclusion: The Cabrol technique demonstrated a significant incidence of long-term complications such as secondary graft stenosis or obstruction. It could be used when the modified Bentall technique is not feasible.