• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.31-37
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• 2019

The study analyzes Non SEMAC and SEMAC to reduce susceptibility artifacts that may occur when performing magnetic resonance imaging(MRI) of metal patients. The Foot and Ankle Phantom was used as the experimental tool and the 3.8 cm general screw was used to make the magnetic susceptibility artifact. The experimental equipment was used 3.0T Magnetom Skyra and the area was measured with the 17th image where the signal off is the most noticeable in the obtained image. Statistical analysis was performed using the SPSS(Ver.25) program and the significance was assessed by the Wilcoxon Signed Rank Test. As a result, the area of Non SEMAC which is the lowest signal was $289.53{\pm}23.07197mm$. When the Turbo Factor was changed to 3, 4, and 5 after SEMAC use, it decreased to $125.02{\pm}7.45875mm$, $120.96{\pm}12.01704mm$ and $108.79{\pm}16.53498mm$, respectively. In conclusion, this study demonstrates that Using SEMAC with Turbo Factor effectively reduces the susceptibility artifacts.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.232-243
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• 2002

Purpose: We studied whether brain perfusion SPECT is useful in the psychiatric disability evaluation of patients with chronic traumatic brain injury (TBI). Materials and Methods: Sixty-nine patients (M:F=58:11, age $39{\pm}14$ years) who underwent Tc-99m HMPAO brain SPECT, brain MRI and neuropsychological (NP) tests during hospitalization in psychiatric wards for the psychiatric disability evaluation were included; the severity of injury was mild in 31, moderate in 17 and severe in 21. SPECT, MRI, NP tests were peformed $6{\sim}61$ months (mean 23 months) post-injury. Diagnostic accuracy of SPECT and MRI to show hypoperfusion or abnormal signal intensity in patients with cognitive impairment represented by NP test results were compared. Results: Forty-two patients were considered to have cognitive impairment on NP tests and 27 not. Brain SPECT showed 71% sensitivity and 85% specificity, while brain MRI showed 62% sensitivity and 93% specificity (p>0.05, McNemar test). SPECT found more cortical lesions and MRI was superior in detecting white matter lesions. Sensitivity and specificity of 31 mild TBI patients were 45%, 90% for SPECT and 27%, 100% for MRI (p>0.05, McNemar test). Among 41 patients with normal brain MRI, SPECT showed 63% sensitivity (50% for mild TBI) and 88% specificity (85% for malingerers). Conclusion: Brain SPECT has a supplementary role to neuropsychological tests in the psychiatric disability evaluation of chronic TBI patients by detecting more cortical lesions than MRI.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.289-294
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• 2009

Purpose : To assess the usefulness of magnetic resonance imaging (MRI), karyotyping, brainstem auditory evoked potential (BAEP), electroencephalogram (EEG), tandem mass screening test, and newborn metabolic screening test in children with language delay for diagnosing underlying diseases. Methods : From January 2000 to June 2007, a retrospective chart review was performed for 122 children with language delay who visited the Child Neurology Clinic at Yeungnam University Hospital and who underwent neuropsychologic tests and other diagnostic evaluations for underlying diseases. They were grouped into phenomenological diagnostic categories, and test results were analyzed according to the underlying diseases. Results : Of 122 patients, 47 (38.5%) had mental retardation, 40 (32.8%) had developmental language disorders, 23 (18.9 %) had borderline IQ, and 12 (9.8%) had autism spectrum disorder. In 26 (21.3%) cases, the causes or relevant clinical findings to explain language delay were found. Eight (10.4%) of 77 MRIs, 6 (8.0%) of 75 EEGs, and 4 (5%) of 80 BAEPs showed abnormal results. Results directly attributed to diagnosing underlying diseases were 2 hearing defects in BAEPs and 1 bilateral perisylvian cortical dysplasia in MRIs. No abnormal results were found in karyotyping, tandem mass screening tests, and new-born screening tests. Conclusion : Commonly used tests to diagnose the cause of language delay are not very effective and should only be used selectively, according to patient characteristics. However, despite the low diagnostic yields from these tests, because many patients show abnormal results, these tests are useful when conducted in complete evaluation.

• Journal of the Korean Magnetics Society
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• v.26 no.6
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• pp.219-225
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• 2016

In this study, for assessment of degenerative knee joint cartilage disease we acquired images by fat suppressed 3D spoiled gradient recalled (SPGR) and fat suppressed 3D $T2^*$ weighted imaging techniques. To do a quantitative evaluation, the knee joint cartilage was divided into medial femoral cartilage (MFC), medial tibial cartilage (MTC), lateral femoral cartilage (LFC), lateral femoral cartilage (LFC) and patella cartilage (Pat) to measure their respective signal intensity values, signal-to-noise ratio, and contrast-to-noise ratio. As for the measured values, statistical significance between two techniques was verified by using Mann-Whitney U-Test. To do a qualitative evaluation, two radiologists have examined images by techniques after which image artifact, cartilage surface, tissue contrast, and depiction of lesion distinguishing were evaluated based on 4-point scaling (1: bad, 2: appropriate, 3: good, 4: excellent), and based on the result, statistical significance was verified by using Kappa-value Test. 3.0T MR system and HD T/R 8ch knee array coil were used to acquire images. As a result of a quantitative analysis, based on SNR values measured by using two imaging techniques, MFC, LFC, LTC, and Pat showed statistical significance (p < 0.05), but MTC did not (p > 0.05). As a result of verifying statistical significance for measured CNR value, MFC, LFC, and Pat showed statistical significance (p < 0.05), while MTC and LTC did not show statistical significance (p > 0.05). As a result of a qualitative analysis, by comparing mean values for evaluated image items, 3D $T2^*$ weighted Image has indicated a slightly higher value. As for conformance verification between the two observers by using Kappa-value test, all evaluated items have indicated statistically significant results (p < 0.05). 3D $T2^*$ weighted technique holds a clinical value equal to or superior to 3D SPGR technique with respect to evaluating images, such as distinguishing knee joint cartilages, comparing nearby tissues contrast, and distinguishing lesions.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.10-12
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• 2006

U-Health에 대한 연구는 환자, 의료장비에 대한 위치 추적을 통한 의료업무 지원관리 분야로 집중되고 있다. 본 논문에서는 RFID Tag를 의료 측정에 적용한다. 즉, RFID Tag를 이용하여 방사선치료에서 사용되는 결손조직 보상체의 체표 윤곽을 모델링하는 방법을 제안한다. 기존의 모델링 방법은 환자의 체표 윤곽을 컴퓨터단층촬영이나 자기공명촬영을 사용한 의료영상을 이용해왔다. 이러한 방법은 고가의 비용이 소요되고 방사선치료에 따른 체표윤곽의 변화에 대응하지 못한다. 본 연구에서는 U-Health에서 기본적으로 사용하는 RFID Tag를 환자의 체표윤각에 고정하여 3차원 위치정보를 획득한다. 체표윤곽에 위치한 RFID의 상대적 위치를 통해 결손조직 보상체를 제작하고 이의 유용성 평가를 위해 기하학적, 선량학적 평가를 수행하였다.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.96-103
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• 1998

Purpose : To assess the clinical utility of turbo contrast-enhanced magnetic resonance angiography(CE MRA) in the evaluation of the aortic arch and its major branches and to compare the image quality of CE MRA among different coils used. Materials and Methods : Turbo three-phase dynamic CE MRA encompassing aortic arch and its major branches was prospectively performed after manual bolus IV injection of contrast material in 29 patients with suspected cerebrovascular diseases at 1.0T MR unit. the raw data were obtained with 3-D FISH sequence (TR 5.4ms, TE 2.3ms, flip angle 30, slab thickness 80nm, effective slice thickness 4.0mm, matrix size $100{\times}256$, FOV 280mm). Total data acquisition time was 4. to 60 seconds. We subjectively evaluated the imge quality with three-rating scheme : "good" for unequivocal normal finding, "fair" for relatively satisfactory quality to diagnose 'normal' despite intravascular low signal, and "poor" for equivocal diagnosis or non-visualization of the origin or segment of the vessels due to low signal or artifacts which needs catheter angiography. At the level of the carotid bifurcation, it was compared with conventional 2D-TOF MRA image. Overall image quality was also compared visually and quantitatively by measuring signal-to-noise ratios (SNRs) of the ascending aorta, the innominate artery and both common carotid arteries among the three different coils used(CP body array(n=12), CP neck array(n=9), and head-and-neck(n=8). Results : Demonstration of the aortic arch and its major branches was rated as "good" in 55% (16/29) and "fair" in 34%(10/29). At the level of the carotid bifurcation, image quality of turbo CE MRA was same as or better than conventional 2D-TOF MRA in 65% (17/26). Overall image quality and SNR were significantlygreater with CP body array coil than with CP neck array or head-and-neck coil. Conclusions : Turbo CE MRA can be used as a screening exam in the evaluation of the major branches of the aortic arch from their origin to the skull base. Overall imagequality appears to be better with CP body array coil than with CP neck array coil or head-and-neck coil.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.501-506
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• 2008

본 연구에서는 가상현실을 이용한 단서노출치료가 흡연자의 니코틴 갈망수준을 감소시키는지를 알아보았다. 이를 위하여 8명의 흡연청소년을 대상으로 6회기의 가상환경 단서노출치료를 실시하였다. 또한 단서노출치료 실시전과 후에 흡연관련 사진과 중립사진을 제시하는 동안 참가자들의 뇌를 기능성 자기공명영상장치(fMRI)로 측정하였다. 그 결과 단서노출실시 전에는 prefrontal cortex(PFC), Anterior cingulate gyrus(ACC) 영역을 비롯한 7개의 영역이 활성화되었고, 단서노출치료 후에는 right middle frontal gyrus, right uncus, left medial frontal gyrus, right fusiform gyrus, 그리고 right superior frontal gyrus 영역이 활성화되었다. 단서노출치료 전과 후의 비교에 서는 PFC가 관찰되었다. 본 연구의 결과로 흡연자의 흡연 갈망은 감소되었으며, 가상현실단서노출치료는 흡연자들 뿐 아니라 여러 물질의존자들의 치료에 유용한 방법이 될 것이라는 것을 시사한다.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.385-392
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• 2023

Caroli's disease is a fibrocystic liver disease. Autosomal recessive disorder is characterized by congenital multiple dilatation of the bile duct. Computerized tomography, magnetic resonance imaging, cholangiography and ultrasound are among the methods for diagnosing caroli disease. Computerized tomography is essential for detecting and distinguishing fibroplastic liver disease and is useful for determining intrahepatic bile duct dilatation. However, awareness of the possible side effects of using contrast mediums is necessary. A typical method of magnetic resonance cholangiography is used for magnetic resonance imaging. A non-invasive examination can reduce the pain of the patient, and the anatomical structure of the bile pancreatic duct and the presence or absence of lesions can be easily and quickly observed. Biliary contrast is an effective diagnostic method that can directly visualize various cystic dilatations throughout the enlarged bile duct. However, since this procedure is also an invasive procedure, it is recommended not for diagnosis but for treatment purposes. Ultrasonography can confirm similar findings to computerized tomography. The hepatic artery root is difficult to prove with conventional grayscale ultrasound. However, it is of clinical value in that it can not only describe dilated bile ducts with vascular roots in the tube but also easily identify color Doppler signals in the tube. With the development of video diagnostics, early diagnosis has become possible through computerized tomography, magnetic resonance imaging, cholangiography, and ultrasound. In order to further contribute to the development of video diagnostics so that long-term prognosis can be improved after treatment through early diagnosis, we examined what aspects of each test's caroli disease appear.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.1 no.1
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• pp.27-30
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• 2008

Snapping triceps syndrome is a rare condition in which a distal portion of triceps and ulnar nerve dislocate over the medial epicondyle as the elbow is flexed or extended from flexed position. Because it is frequently misdiagnosed as other elbow pathologies, accurate diagnosis is essential and imaging study is often needed to confirm the abnormal movement of ulnar nerve and triceps. Ultraonography is a convenient and effective method which is able to allow continual visualization of soft tissue movement compared to the other imaging modality including MRI. We reported one patient of snapping triceps syndrome who was diagnosed with the use of dynamic ultrasonography and treated with ulna nerve anterior transposition and repositioning of medial head of triceps. And we also provide the usefulness of musculoskeletal ultrasonography for the diagnosis of snapping triceps syndrome.

• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.232-238
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• 2013

Purpose : We investigated the possible added value of magnetic resonance imaging (MR) in staging of malignant pleural mesothelioma (MPM) compared to computed tomography (CT). Materials and Methods: We retrospectively enrolled 20 patients (M;F = 14:6; mean age, 53.5 yrs) who diagnosed as MPM by histology and underwent CT and MR at initial evaluation from Jan 1997 to Dec 2012. Two radiologists performed clinical staging by using CT alone or MR alone in consensus. In patients underwent surgery (n = 13), we evaluated the diagnostic accuracy of CT and MR in terms of staging compared to surgical staging. In all patients, we compared clinical staging of CT only and CT with MR. Results: The diagnostic accuracy for T staging of CT only was 23.1% (3/13) and that of combined CT and MR was 38.5% (5/13), respectively. Among 13 patients underwent surgery, surgical stage was higher than combined CT and MR stage in 5 patients, but lower in 3 patients. CT only and combined CT and MR agreed in 85.0% (17/ 20). In cases of disagree (15.0%, 3/20), combined CT and MR showed higher stage than CT only. Conclusion: Combined CT and MR increases the diagnostic accuracy in staging of MPM compared to CT only and is important in determining the appropriate treatment in patients being considered for surgery.