• Investigative Magnetic Resonance Imaging
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• 제14권1호
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• pp.56-63
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• 2010

목적 : 본 논문에서는 DIR 영상을 이용하여 두뇌의 피질두께측정 연구를 수행하는 한편 평행 영상기법 중 하나인 GRAPPA (generalized autocalibrating partially parallel acquisitions)를 이용하여 GRAPPA 인자 (reduction factor, R)가 2일 때와 평행 영상기법을 이용하지 않았을 때의 결과 비교를 통해 3D DIR 영상의 획득시간 단축 가능성을 제시하고자 한다. 대상 및 방법 : 3.0T 자기공명영상장치 (Siemens Tim Trio MRI scanner)의 3D DIR 펄스열을 이용하여 6명(남자 3명, 여자 3명, $25.33{\pm}2.25$살)의 정상인 뇌에 대한 3차원 영상을 얻었다. GRAPPA 시뮬레이션은 R=2 일 때를 가정하여 수행되었고 두뇌 피질두께측정을 위해 Analyze 9.0과 Freesurfer v.4.3.0 프로그램을 사용하였다. 결과로 얻은 데이터를 T-검증을 이용하여 비교분석 하였다. 결과 : GRAPPA 기법을 통하여 복원한 영상이 잡음이 증가하는 경향을 보였으나 두뇌 피질두께 측정에는 별다른 영향을 미치지 않았다. 통계분석을 통해 비교한 결과 대부분의 두뇌 영역에서 참조영상과 GRAPPA 기법을 이용한 영상의 차이가 유의하지 않았다. 결론 : 피질두께측정 연구에 있어서 3D DIR영상의 문제점 중 하나는 긴 영상획득시간이다. 따라서 평행영상 기법 중 하나인 GRAPPA 영상기법을 적용하면 피질두께측정 연구결과의 큰 차이없이 영상 획득 시간을 단축시킬 수 있다.

• Journal of Chest Surgery
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• 제35권9호
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• pp.659-663
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• 2002

이 논문은 비소세포폐암으로 새로이 진단 받은 환자에서 수술 전 병기판정에 통상적으로 골 스캔의 유용성에 대하여 연구하였다. 대상 및 방법: 서울대병원에서 2000년 1월부터 12월까지 비소세포 폐암으로 진단 받은 환자 258명을 대상으로 하였다. 수술 전 병기는 과반수에서(132명) 수술이 불가능할 정도로 진행된 상태였다. 골 원격전이의 임상 평가 항목으로 증상, alkaline phosphatase, calcium 등을 채택하였고 모든 환자의 골 스캔 결과를 검토하여, 각각의 민감도, 특이도, 음성 예측률, 양성 예측률을 산출하였다. 최종적인 골 전이의 판단은 일반 X-lay나 MRI 또는 골 생검을 기준으로 하였다. 골 전이만 없다면 수술이 가능한 (“potentially operable”)환자 126명의 임상 경과를 따로 분석하여 수술 대상 환자에서 골 전이에 대한 임상 평가의 중요성을 검토하였다. 결과: 골 전이에 대한 골 스캔의 민감도는 96%, 특이도는 75% 양성 예측률은 44%, 음성 예측률은 99%였고, 골 스캔에 대한 임상 평가의 민감도, 특이도, 양성 예측률, 음성 예측률은 각각 54%, 73%, 54%, 72%였다. 골 전이에 대한 임상 평가의 경우는 80%, 70%, 38%, 94%였다. 골 전이만 배제하면 수술이 가능하였던 “potentially operable”군 환자 126명에서 골 전이에 대한 임상 평가의 음성 예측률은 99%였다. 결론: 폐암 진단 당시 병기 결정에 있어서, 골 전이에 대한 철저한 임상 평가가 필수적이다. 특히 골 전이 외에 다른 수술 불가능 요인이 없는 환자군에서 임상 평가 결과 특이사항이 없을 경우 골 전이의 확률이 매우 낮아, 통상적인 골 스캔 없이도 근치적 수술을 고려할 수 있음을 확인하였다. 그러나 임상 평가 결과 양성인 경우에는 약 30% 이상의 환자에서 골 전이가 발견되므로 골 전이를 발견하기 위한 골 스캔은 물론 다른 여러 가지 진단법을 적극적으로 검토해야 한다.

• Archives of Plastic Surgery
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• 제35권5호
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• pp.603-606
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• 2008

Purpose: Sclerosing lipogranuloma is an unusal benign condition of the genitalia following injections into the genitalia with exogenous paraffin or mineral oil. A few cases have been reported in which sclerosing lipogranuloma of the lid was caused by paraffin-containing ointment plugs after the endonasal sinus surgery. A 52-year-old man presented with a painless hard mass of the right lower lid after the MRI scan at the Ophthalmology department. Nine months before, he had undergone right maxilla sinus surgery through the oral incision. And he was also gotten nasal packing with Vaseline gauze after the surgery. Methods: The round shaped two masses in the Right lower lid were approximately $1.0{\times}1.0cm$ in size. There were no size or color change, bleeding and ulceration. The MRI scan showed a suspicious part of an abscess of benign tumor. Also, He was planned cyst remove through the endonasal surgery due to the mucoid cyst in the right maxillary sinus in the ENT dept. Under the general anesthesia, the patient underwent surgical excision through a subcilliary incision with endonasal sinus surgery. The masses were in deep subcutaneous orbital fat with no connection with right maxillary sinus. Results: The masses were excised $2.1{\times}0.7cm$ in size including surrounding necrotic fatty tissue. Histopathological diagnosis was 'sclerosing lipogranuloma' due to paraffin or similar substance with fat necrosis and cystic change. This tissue was positive in PAS, S-100, CD68 reaction. Conclusion: It is extremely rare to find a granulomatous orbital lesion arising to a endonasal surgery. In conclusion, if sclerosing lipogranuloma is suspected excisional biopsy should be undertaken. Surgery should be reserved for recurrent or refractory cases when steroids have failed as first-line treatment at the 6-month follow-up examination, There was no complication or recurrence.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권3호
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• pp.139-144
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• 2012

This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from $34.5{\pm}2.1$ mm to $37.2{\pm}3.5$ mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. Conclusion: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).

• Investigative Magnetic Resonance Imaging
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• 제18권3호
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• pp.253-257
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• 2014

부유비장은 희귀한 임상질환으로서 느슨한 비장현수인대에 의해 발생하며 이는 비장혈관줄기의 비틀림을 유발한다. 복통이 있는 7세 여자 환아의 전산화 단층촬영에서 하복부에 조영증강되지 않는 종괴 소견이 있었고 소장은 우측 복부에 대장은 좌측 복부에 위치하였다. 자기공명영상 스캔에서 비틀린 비장혈관줄기와 함께 조영증강 되지 않는 불균질 신호강도의 종괴가 있었다. 지금까지 자기공명영상으로 진단된 부유비장의 증례 보고는 매우 드물게 보고되어 있다.

• Radiation Oncology Journal
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• 제11권1호
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• pp.91-96
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• 1993

From September 1989 to June 1992,22 patients with nasopharyngeal carcinoma were treated in Asan Medical Center with an external beam of 60 Gy followed by a boost dose of 15 Gy HDR brachytherapy. There were 5 females and 17 males with median age of 44 years (range: 20-69 years). All patients were histologically confirmed and staged by physical examination, CT scan and/or MRI. By the AJCC TNM staging system, there were 2 patients with stge II (T2NO), 4 with stage III (T3NO, T1-3N1), and 16 with stage IV (T4 or N2-3). Four patients received chemotherapy with 5-FU and cisplatin prior to radiotherapy. All patients were followed up periodically by a telescopic examination and radiologic imaging study of CT scan or MRI with a median follow-up time of 13 months (range: 3-34 months). Twenty one patients showed a complete response ore month after completing therapy and one patient showed a complete response after three months. At the time of this analysis, seventeen patients remain alive without evidence of disease, but four patients developed distant metastasis and one patient died a month after treatment. The local control rate was $100{\%}$ in a median follow-up time of 13 months. The two year overall and disease free survival rates by the Kaplan-Meier method were $94{\%}$ and $67{\%}$, respectively. Serious radiation sequelae have not been observed yet. Although longer follow-up is needed, this retrospective analysis suggests that HDR brachytherap. given as a boost therapy for nasoharyngeal carcinoma may improve the local control. To reduce the incidence of distant metastasis, we need to develop a more effective systemic chemotherapy.

• Nuclear Medicine and Molecular Imaging
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• 제41권4호
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• pp.339-341
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• 2007

A 22-year-old woman with a history of acute lymphoblastic leukemia was hospitalized for headache and vomiting. CT scan showed a well-defined, ring like enhancing mass in the left frontal lobe with surrounding edema and midline shift. Magnetic resonance imaging demonstrated a round homogeneous mass with a ring of enhancement in the left frontal lobe. Tl-201 brain SPECT showed increased focal uptake coinciding with the CT and MRI abnormality. Aspiration of the lesion performed through a burr hole yielded many neutrophils, a few lymphocytes and histiocytes with some strands of filamentous microorganism-like material. Modified AFB stained negative for norcardia. Gram stain showed a few white blood cells and no microorganism. Antibiotics were started and produced a good clinical response. After one month, CT scan showed markedly reduction in size and extent was observed.

• Imaging Science in Dentistry
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• 제30권2호
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• pp.127-131
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• 2000

A 19-year-old man was referred to Seoul National University Dental Hospital for evaluation of a large painless swelling of the left mandibular angle area in August, 1999. The growth had been first noted 6 years ago. He had visited other hospital in 1997. In spite of the treatment given at the hospital, the mass continued to grow rapidly. Conventional radiographs in 1999 showed an expansile, lobulated, and destructive lesion of the left mandibular body. CT scan demonstrated an expansile mass with a corticated margin. Bony septa were seen within the lesion. Internal calcification noted on the bone-setting CT image, and corresponded to the hypointense area in T1-weighted MRI image. MRI clearly delineated the extent of the lesion which had heterogenous intermediate signal intensity in T1-weighted images and heterogenous hyperintense signal intensity in T2-weighted images. The lesion was well-enhanced. Histopathologically, the lesion was well demarcated. Multinucleated giant cells were presented in a fibrous background, demonstrating a storiform pattern. Areas of osteoid rimmed by a few osteoblasts were scattered throughout the lesion. Inflammatory cells, blood vessels, and hemosiderin deposition were also shown. CGCG may show lots of internal calcification foci on the CT, and varied signal intensity in MRI. More cases will be needed to understand the features of the CT & MR finding of CGCG.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.375-385
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• 2016

Recently, several implantable hearing aids such as cochlear implant, middle ear implant, etc., which have a module receiving power and signal from outside the body, are frequently used to treat the hearing impaired patients. Most of implantable hearing aids are adopted permanent magnet pairs to couple between internal and external devices for the enhancement of power transmission. Generally, the internal device which containing the magnet in the center of receiving coil is implanted under the skin of human temporal bone. In case of MRI scanning of a patient with the implantable hearing aid, however, homogeneous magnetic fields of the MRI might be interfered by the implanted magnet. For the above reasons, the MR image is degraded by large area of artifact, so that diagnostics are almost impossible in deteriorated region. In this paper, we proposed an external coil system that can reduce the artifact of MR image due to the internal coupling magnet. By finite element analysis estimating area of MR artifact according to varying current and shape of the external coil, optimal coil parameters were extracted. Finally, the effectiveness of the proposed external coil system was verified by confirming the artifact at real MRI scan.

• 생물정신의학
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• 제9권2호
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• pp.152-158
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• 2002

Background & Purpose:Neuropsychological disorders after traumatic brain injury(TBI) are poorly correlated with structural lesions detected by structural neuroimaging techniques such as computed tomography(CT) scan or magnetic resonance imaging(MRI). It is well known that patients with TBI have cognitive and behavioral disorders even in the absence of structural lesions of the brain. This study investigated whether there are abnormalities of regional cerebral blood flow(rCBF) in TBI patients without structural abnormality on MRI, using technetium 99m ethyl cysteinate dimer(Tc-99m-ECD) single photon emission computed tomography(SPECT) scans. Materials and Methods:Twenty-eight TBI patients without structural abnormality on MRI(mild, n=13/moderate, n=9/severe, n=6) and fifteen normal controls were scanned by SPECT. A voxel-based analysis using statistical parametric mapping(SPM) was performed to compare the patients with the normal controls. Results:rCBF was reduced in the right uncus and the right lateral orbitofrontal gyrus in the TBI patients. However, no increase of rCBF was noted in the patients in comparison to the normal controls. Conclusions:These results suggest that the TBI patients, even in the absence of structural lesion of the brain, may have dysfunction of the brain, particularly of the orbitofrontal and anterior pole of the temporal cortex. They also suggest that SPECT can be a useful method to identify brain dysfunctions in combination with structural brain imaging and neuropsychological tests.