• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.146-153
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• 1999

Purpose : To evaluate the proton MR spectroscopy (MRS) findings of early and late ischemic infarcts and to compare these MRS findings with clinical symptoms. Materials and Methods : We obtained MRs spectra of 28 consecutive patients with early ischemic infarct (15 me, 13 women) between 2-10 (mean 6.2) days after stroke onset. Follow-up MRS was carried out between 20-32 (mean 25) days in 12 patients. The MRs spectra were acquired at 1.5T MR unit using single voxel technique with PRESS sequence, TR of 2000ms, TE of 288 (144)ms, and voxel size of 2cm x 2cm x 2cm in the three areas; an infarct lesion, the brain parenchyma adjacent to the lesion, and contralateral normal brain parenchyma. The NAA/creatine, choline/creatine, and lactate/creatine ratios were calculated in each spectrum. The spectra of MRS were compared with clinical symptoms. Results : In early infarct, decreased NAA/creatine ratio (n=22) and increased lactate/creatine ratio (n=25) were found in the infarct lesion. Choline/creastine ratio was within normal range (n=25). On follow-up MRS in late stage, NAA/creatine ratio in the infarct lesion decreased further (n=5), did not change (n=6), or increased (n=1). Lactate/creatine ratio became less elevated (n=10), or did not changed (n=2). Choline/creatine ratio had a trend for increase. The decreased NAA/creatine and increased lactate/creatine ratios were correlated well with the severity of symptoms, respectively. Conclusion : Decreased NAA/creatine and increased lactate/creatine ratios were common MRS findings characteristic in early ischemic infarct and correlated well with clinical severity. On follow-up MRS in late stage, NAA/creatine ratio decreased further or did not change, and lactate/creatine ratio became less elevated.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.69-74
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• 2001

Purpose: $^{99m}Tc$-HMPAO is a radiopharmaceutical for imaging cerebral blood flow. HMPAO (RR, SS)-4.8-diaza-3,6,6,9-tetramethylundecan-2,10- dione bisoxime) has three stereoismers such as, meso-. d-, and l-HMPAO. Techentium complexes of meso-HMPAO and d,l-HMPAO are known to have different in vivo brain uptakes. In this study, enantiomers of HMPAO (d-HMPAO and l-HMPAO) were separated from d,l-HMPAO. These enantiomers were labeled with $^{99m}Tc$ and the biodistribution studies were performed in mice. Materials and Methods: An intermediate imine product was produced from 2,3-butanedione monooxime and 2,2-dimethyl-1,3-propanediamine (54% yield) and was reduced into a mixture of three isomers (35% yield). The meso-isomer was separated from d,l-mixture by repeated fractional crystallization (11 % yield). The d- and l-enantiomers were subsequently separated by co-crystallization with optical isomers of tartaric acid (25% and 5% yield. respectively). Each enantiomeric HMPAO was labeled with $^{99m}Tc$ by reacting with $SnCI_2{\cdot}2H_2O\;and\;^{99m}Tc$-pertechnetate. Biodistribution study was performed 1 hr after tail vein injection to ICR mice. Results: Radiochemical purities of each compound were over 80%. In biodistribution study. the brain uptakes of d,l- d- and l-form were 1.34, 1.12 and 1.67% ID/g, respectively. In case of l-lsomer the brain uptake was higher (1.5 fold) than d-isomer. Conclusion: We successfully purified each enantiomeric HMPAO. In biodistribution study of stereoismers of $^{99m}Tc$-HMPAO in mice, l-HMPAO may show better brain image than d,l-HMPAO which was supplied in a commercial kit.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.23-32
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• 2001

Purpose: Cortical dysplasia (CD) designates a diverse group of malformations resulting from one or more abnormalities in the development of the cerebral cortex. We investigated the findings of interictal SPECT and the diagnostic usefulness of interical and ictal SFECT according to pathological grading (PG) in comparison with MRI. Materials and Methods: This study included 16 patients (M:F=9:7, age: $19.9{\pm}11.8$ yrs) with pathologically proven CD. Tc-99m ECD SPECT was performed in all patients: interictal 11, interictal and ictal 3, ictal 2. MRI were obtained in all patients and image analysis was done blindly as to the result of SPECT. Pathologic findings of CD were classified into grade 1 G1, dyslamination), grade 2 (G2, dysplastic neurons) and grade 3 (G3, balloon cells). We compared SFECT with MRI in lesions-to-lesions and analyzed the result according to PG. Results: In SFECT and MRI. 38 and 27 lesions were visually recognized. In 14 interictal SPECT, variable findings in 35 lesions were demonstrated: 25 were hypoperfusion, 7 hyperperfusion, 2 heterotopic perfusion in the white matter. By comparison between two studios, missed lesions were founded: SPECT were 1 lesion, MRI 12. Review of missed 12 lesions of MRI were followed according to PG: G1 patients were 16.7% (4/19), G2 40.0% (6/15), and G3 50% (2/4). Conclusion: Interictal SFECT in CD showed variable findings such as hypoperfusion, hyperperfusion or heterotopic perfusion. However, for detection of missed CD on MRI, SFECT may help to detect a functional abnormality of the lesion with high PG.

• Journal of Internet Computing and Services
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• v.17 no.1
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• pp.101-107
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• 2016

Due to the recent advancement in digital imaging technology, development of intervention equipment has become generalize. Video arbitration procedure is a process to insert a tiny catheter and a guide wire in the body, so in order to enhance the effectiveness and safety of this treatment, the high-quality of x-ray of image should be used. However, the increasing of radiation has become the problem. Therefore, the studies to improve the performance of x-ray detectors are being actively processed. Moreover, this intervention is based on the reference of the angiographic imaging and 3D medical image processing. In this paper, we propose a guidance system to support this intervention. Through this intervention, it can solve the problem of the existing 2D medical images based vessel that has a formation of cerebrovascular disease, and guide the real-time tracking and optimal route to the target lesion by intervention catheter and guide wire tool. As a result, the system was completely composed for medical image acquisition unit and image processing unit as well as a display device. The experimental environment, guide services which are provided by the proposed system Brain Phantom (complete intracranial model with aneurysms, ref H+N-S-A-010) was taken with x-ray and testing. To generate a reference image based on the Laplacian algorithm for the image processing which derived from the cerebral blood vessel model was applied to DICOM by Volume ray casting technique. $A^*$ algorithm was used to provide the catheter with a guide wire tracking path. Finally, the result does show the location of the catheter and guide wire providing in the proposed system especially, it is expected to provide a useful guide for future intervention service.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.171-180
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• 1992

The precise role of radiotherapy for low grade gliomas including the optimal radiation dose and timing of treatment remains unclear. The information given by a retrosepctive analysis may be useful in the design of prospective randomized studies looking at radiation dose and time of surgical and radiotherapeutic treatment. The records of 56 patients (M:F = 29:27) with histologically verified cerebral low grade gliomas (47 cases of grade 1 or 2 astrocytomas and 9 oligodendrogliomas) diagnosed between 1979 and 1989 were retrospectively reviewed. The extent of surgical tumor removal was gross total or radical subtotal in 38 patients ($68\%$) and partial or biopsy only in the remaining 18 patients ($32\%$). Postooperative radiation therapy was given to 36 patients ($64\%$) of the total 56 patients with minimum dose of 5000 cGy (range=1250 to 7220 cGy). The 5-and 10-year survival rates for the total 56 patients were $44\%$ and $32\%$ respectively with a median survival of 4.1 years. According to the histologic grade the 5- and 10-year survivals were $52\%$ and $35\%$ for the 24 patients respectively with grade I astrocytomas compared to $20\%$ and $10\%$ for the 23 patients with grade II astrocytomas. Survival of oligodendroglioma patients was greater than those with astrocytoma ($65\%$ vs $36\%$ at 5 years), and the difference was also remarkable in the long term period of follow up ($54\%$ vs $23\%$ at 10 years). Those who received high-dose radiation therapy ($\geq$5400 cGy) had significant better survival than those who received low-dose radiation (< 5400cGy) or surgery alone (p<0.05). The 5- and 10-year survival rates were, respectively $59\%$ and $46\%$ for the 23 patients receiving high-dose radiation, $36\%$ and $24\%$ for the 13 patients receiving low-dose radiation, and $35\%$ and $26\%$ for the 20 patients with surgery alone. Survival rates by the extent of surgical resection were similar at 5 years ($46\%$ vs $41\%$), but long term survival was quite different (p<0.01) between total/subtotal resection and partial resection/biopsy ($41\%$ and $12\%$, resepctively). Previously published studies have identified important prognostic factors in these tumor: age, extent of surgery, grade, performance status, and duration of symptoms. But in our cases statistical analysis revealed that grade I histology (p<0.025) and young age (p<0.001) were the most significant good prognostic variables.

• Journal of Chest Surgery
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• v.38 no.8 s.253
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• pp.545-550
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• 2005

Background: Discrete subaortic stenosis is known to recur frequently even after surgical resection. We retrospectively reviewed the preoperative and postoperative changes in pressure gradient through left ventricular outflow tract, and the recurrence rate. Material and Method: Between September 1984 and December 2004, 34 patients underwent surgical treatment. Mean age of patients was $17.1\pm15.2$ years and 19 patients $(55.9\%)$ were male, 16 patients $(47.1\%)$ had previous operations and associated diseases were aortic regurgitation (11), coarctation of aorta (3), and others. Result: Immediate postoperative peak pressure gradient was significantly lower than preoperative peak pressure gradient (21.8 mmHg vs 75.8 mmHg, p<0.04). Peak pressure gradient measured after 50.3 months of follow up was 20.2 mmHg which was also significantly lower than that of preoperative value but not significantly different from that of immediate postoperative value. There was no surgical mortality but one patient developed cerebral infarction. Mean follow up duration was $69.8\pm54.6\;months$. During this period, 5 patients $(14.7\%)$ had reoperation, 3 $(8.8\%)$ of whom were due to recurred subaortic stenosis. We found no risk factors for recurrence and survival for free from reoperation was $76.4\%$. Conclusion: Excision of subaortic membrane combined with or without myectomy in discrete subaortic stenosis showed sufficient relief of left ventricular outflow tract obstruction with low mortality and morbidity, but careful long term follow up is necessary for recurrence, since it is not predictable.

• Journal of Chest Surgery
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• v.34 no.11
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• pp.848-853
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• 2001

Background: Sternal infection or dehiscence after cardiac surgery through median sternotomy is rare. If suitable treatment is not performed for the complication, however, the mortality is high. For 12 patients with sternal dehiscence or infection, we performed wide excision of the infected and necrotic tissue and covered with muscle flap(s) to obliterate the mediastinal dead space. Material and method: Sternal infection or dehiscence occurred in 13 of patients who underwent cardiac surgery One patient, who died of cerebral infarction before the sternal complication was treated, was excluded in this study. The sternal wound complication occurred in 6 of patients with valve replacement and 6 of patients with coronary bypass surgery, respectively. Since 1991, 9 patients underwent definite surgical debridement and muscle transposition as soon as fever was controlled with closed irrigation and drainage. The necrotic tissue and bone was widely excised and the sternal dead space was eradicated with the single flap or the combined flaps of right pectoralis flap(turnover flap), left pectoralis flap(turnover flap or rotation-advancement flap), and right rectus muscle flap. Result : There was no mortality in 12 patients with coverage of muscle flap(s) for sternal infection or dehiscence The mean interval between the diagnosis of sternal complication and the myoplasty was 6.6$\pm$3.9 days. In 4 patients, one pectoralis muscle flap was used, and in 8 patients both pectoralis muscle flaps were used. For each 1 patient and 2 patients in each group, right rectus muscle flap was added. For the last 3 patients, a single pectoralis flap was used to eradicate the mediastinal dead space and the longer placement of the mediastinal drain catheter was needed. One patient, who had suffered from necrosis of left pectoralis flap(rotation-advancement flap) with subsequent chest wall abscess after coverage of both pectoralis flaps, was managed with reoperation using right rectum flap. Conclusion : Sternal dehiscence or infection after cardiac operation can be readily managed with wide excision of necrotic infected tissue(including bone) and muscle flap coverage after short-term irrigation of sternal wound. The sternal(mediastinal) dead space may be completely eradicated with right pectoralis major muscle flap alone.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.482-489
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• 1998

Purpose: Radionuclide cisternography may be helpful in understanding pathophysiology of postural head-ache and low CSF pressure in patients with spontaneous intracranial hypotension. The purpose of this study was to characterize radionuclide cisternographic findings of spontaneous intracranial hypotension. Materials and Methods: The study population consists of 15 patients with spontaneous intracranial hypotension. Diagnosis was based on their clinical symptoms and results of lumbar puncture. All patients underwent radionuclide cisternography following injection of 111 to 222 MBq of Tc-99m DTPA into the lumbar subarachnoid space. Sequential images were obtained between 112 hour and 24 hour after the injection of Tc-99m DTPA. Radioactivity of the bladder, soft tissue uptake, migration of radionuclide in the subarachnoid space, and extradural leakage of radionuclide were evaluated according to the scan time. Results: Radionuclide cisternogram showed delayed migration of radionuclide into the cerebral convexity (14/15), increased soft tissue uptake (11/15), and early visualization of bladder activity at 30min (6/10) and 2hr (13/13). Cisternography also demonstrated leakage site of CSF in 4 cases and 2 of these were depicted at 30min. Epidural blood patch was done in 11 patients and headache was improved in all cases. Conclusion: The characteristic findings of spontaneous intracranial hypotension were delayed migration of radionuclide and early visualization of the soft tissue and bladder activity. These scintigraphic findings suggest that CSF leakage rather than increased CSF absorption or decreased production may be the main pathophysiology of spontaneous intracranial hypotension. Early and multiple imaging including the bladder and soft tissue is required to observe the entire dynamics of radionuclide migration.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.204-213
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• 2005

In spite of the improvement in the quality of artificial heart valves and surgical techniques, the incidence of the complications following valve replacement is still high. We reviewed the clinical results of the valve replacements peformed in Korean University Anam Hospital during the last 26 years. Material and Method: The data of 571 patients who received valve replacement between December 1976 and December 2003 were reviewed. Result: There were 304 cases of MVR which was the most common procedure performed. There were 122 cases of AVR, and 111 cases of AVR with MVR. Among the 47 patients who received redo operation 38 cases were redo cases including 31 cases of MVR. $32.5\%$ of the patients who had tissue valve replacement had second valve replacement with 10.2 $\pm$ 3.9 years interval. $24.3\%$ (139/571) of the patients developed valve related complications and cerebral infarction was the highest in frequency. Atrial fibrillation was related with increased complication rates and the mechanical valve replaced group had higher hemorrhagic complication rate than tissue valve replaced group. The operative mortality was $3.68\%$ and the most common cause of the failure was low output syndrome. The operative mortality was higher in the patient group who had valve replacement before the year 1990. The patient group who had mechanical valve replacement had higher operative mortality rate th;3n the tissue valve group. The 5-year survival rate was $92.2\%$ and 10 year survival rate was $85.7\%$. Conclusion: The operative mortality of valve replacement has been improved. The mechnical valve replaced patients had higher hemorrhagic complication rate than the tissue valve replaced patients and more tissue valve replaced patients received redo valve replacement.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.875-882
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• 1996

Multlvalvular heart surgery was performed In 78 cases, in the Department of Thoracic & Cardiovascu far Surgery of Chonbuk national University Hospital from november 1983 to March 1994. There Where 31 men and 47 women. whose ranged from 14 to 63 years. The causes of the valvular lesions were 57 rheumatic origin, 18 degenerative, 1 previous endocarditls, 1 prosthetic valve mal-function. There were 25 double valve replacement with or wit out tricuspid valve repair, i M VR and aortic valve repair, 18 MVR and tricuspid valve repair, 1 MVR and aortic and tricuspid valve repair, 10 AVR and mi- tral valve repair, 1 AVR and tricuspid valve repair, 8 mitral aortic valve repair, 13 mitral and tricuspid valve repair. They were improved mean New York Heart Association functional cldss, from 2.72% 121 Early deaths were 5 cases(6.4%). The cause of death wet'e low cArdiac output syndrome. veritricular tachycardia, massive bleeding and cerebral thromboembolism. All the survivors belonged to New York Heart Association functional class I or ll at discharge. The patients who had had valve replacement operation were medicated with warfarin to maintain the level of 30∼ 50% of normal prothrombin time. During follow-up(93.6%, mean 49.9 months), 2 late deaths were developed. One was due to intracranial hemorrhage and the other congestive heart failure. The pre-operative New York Heart Association Functional class IV was statistically sig ificant operat- ive risk factors(p< 0.05).