• 한국의학물리학회지:의학물리
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• 제25권2호
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• pp.72-78
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• 2014

연구의 목적은 의사호흡정지(QBH) 바이오 피드백이 의료영상획득 시간의 큰변화 없이 잔류 호흡 운동을 조절함으로써 호흡 운동에 의한 영상 오류를 줄이고, 게이트 3차 흉부 자기 공명 영상을 향상시킬 수 있다는 가설을 실험하는 것이다. 가설을 확인하기 위해 건강한 다섯 사람을 대상으로 3T 지멘스 엠알아이의 호흡 탐색기가 포함된 T2 가중 스페이스 엠알 펄스 시퀀스를 이용해 두번의 게이트 자기공명 영상 연구를 시행 하였다: 자유 호흡 상태와 의사호흡정지 바이오 피드백 호흡상태, 의사호흡정지 바이오 피드백 시스템은 알피엠(RPM) 시스템(실시간 위치 관리시스템, 베리안)을 사용하여, 복부의 외부 위치를 측정하고, 음향과 시각적으로 각각의 호흡주기의 90% 위치에서 2초 숨을 정지하도록 안내하는 방법을 사용했다. 평가방법은 의사호흡정지 바이오 피드백 시스템을 이용시 간 상부의 호흡정지모습의 재현성이 게이팅 영역 내에서 향상되는지를 지원자의 실험을 통해 평가하였다. 자유호흡상태와 의사호흡정지 바이오 피드백상태에서 3차 흉부자기공명영상내에 호흡 운동에 의한 영상 오류와 게이팅영역 내에서의 잔류 호흡 운동 조절여부도 함께 평가했다. 또한, 복부 변위의 RMSE도 (제곱근오차) 조사되었다. 의사호흡정지 바이오 피드백방법을 사용함으로 자유호흡의 경우보다 게이트 3차 흉부 엠알 영상에서 폐와 간에서 호흡운동에 의한 영상오류의 감소 결과를 획득했다(영상획득시간: ~6분). 이는 의사호흡정지 바이오 피드백사용시, 게이팅 영역에서 복부 운동 감소와 횡경막의 잔류 움직임 감소가 일치함을 의미한다. 따라서, 알피엠을 통해 얻은 복부 변위의 전체 자료에서평균 RMSE는 (제곱근오차) 자유 호흡의 2.0 mm에 비해 7 mm (67% 감소, p값=0.02)로 감소하였으며, 게이팅영역만을 고려했을때는 자유 호흡의 1.7 mm가 의사호흡정지 바이오 피드백 호흡을 사용함으로써 0.7 mm (58 % 감소, p값=0.14) 로 개선되었다. 선형 피팅을 사용하여 얻은 평균 기준 이동값은 의사호흡정지 바이오 피드백 을 사용하면 자유 호흡 5.5 mm/분보다 0.6 mm/분(89% 감소, p값=0.017)으로 감소되었다. 이 연구는 의사호흡정지 바이오 피드백을 이용해 게이트 3차 흉부 자기 공명 영상 중에 간 상부의 호흡정지 재현성이 향상되는 것을 보여 주었다. 이 시스템은 내부 해부학의 운동을 조절함으로써 게이트 의료 영상과 방사선 치료에 임상적으로 적용 할 수 있다.

• 대한디지털의료영상학회논문지
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• 제14권1호
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• pp.21-29
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• 2012

The purpose of this study is to evaluate the mutual relations by measuring SNR from T2 weighted image and ADC values on the basis of the stiffness values from liver tissues. This study was conducted that total 37 people(23 of males and 11 of females) were taken the liver MRI examination and average age was $54.5{\pm}12.7$ years old. The equipment was MAGNETOM Skyra 3.0T (SIEMENS, Erlangen, Germany) and 32 channel body-array coil. The examination were conducted with HASTE T2 weighted image by axial plane, Spin-echo EPI (echo planner image) DWI (b-value = 800) and Magnetic resonance elastography. The ROIs (region of interest: 200-300 $mm^2$) were established on the basis of the first axial stiffness image corresponded 95% confidence interval from axial stiffness image and then were measured values. After drawing the grid lines, signals were measured SNR from T2 weighted image and ADC values on the same locations that were analysed other 3 planes respectively. The results were showed correlation (0.057) that were increased to SNR from T2 weighted image by increasing stiffness value that no significant difference statistically p = 0.003. Other results were showed correlations (-0.301) that were decreased to ADC values by increasing stiffness values that no significant difference statistically p = 0.088. In the 3.0T equipment, the results may be error in much the same fashion as the 1.5T from ADC values by evaluation of fibrosis stage. However, Magnetic resonance elastography would be useful method that is used to diagnose exactly liver fibrosis stages in the 3.0T.

• Journal of Preventive Medicine and Public Health
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• 제27권4호
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• pp.735-745
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• 1994

The incidence data (1991. 7. 1$\sim$1992. 6. 30) from the Implementation Study of Seoul Cancer Registry (ISSCR) were evaluated in terms of its completeness and validity. Two indicators for the completeness, Mortality/Incidence ratio (M/I ratio) and Age-specific Incidence Curve, showed fairy good registration throughout the age-sex specific strata, except the strata aged over 75 years old. The strata had very high M/I ratio (over 100%) and decreasing pattern of incidence, which suggested incomplete registration of cancer in this group. The active surveillance by a ISSCR staff improved the registration rate especially among elderlies. From the site specific M/I ratio, we found that liver cancer had oddly high M/I ratio. Since this high M/I ratio of liver cancer appears consistently in other reliable cancer registries, it is more like to be due to the high fatality of it rather than incomplete registration. The validity of the incidence data was assessed by three indicators; Histological Verification (HV%), Primary Site Unknown (PSU%), and Age Unknown (Age UNK%). The average HV% were 77% for men and 85% for women, which were slightly lower than those of other reliable cancer registries. This low HV% might be due to the considerable size of relative frequency of liver cancer in Korea, regarding the fact that the diagnosis of liver cancer is made mostly by non-biopsical radiologic methods (CT, Ultrasono, Angiography, MRI etc.). The level of PSU% and Age UNK% were in acceptable range, but not low enough, especially in terms of Age UNK%. Although ISSCR data had acceptable quality in general, it is needed to have more hospitals participate in the registry surveillance, to make registery data merged with death certificate data regulary, and educate the registration stans to be more competent and dedicated.

• 대한방사선기술학회지:방사선기술과학
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• 제20권2호
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• pp.73-78
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• 1997

The goal of this paper is that we know the usefulness of echo-planar imaging(EPI) for discriminate between hepatocellular carcinoma(HCC) and hemangioma. We get a time signal intensity curve for liver diseases from the dynamic contrast enhancement images and compared and analyze both the contrast ratio(CR) and the contrast to noise ratio(CNR) using echo planar imaging. The obtained results are follows : 1. Hepatocellular carcinoma was shown the best contrast after about 20 seconds when Is the earlist time in the main artery, and then reduced. The center where is disease was shown the characteristic that the best contrast is appeared after about 35-45 seconds and then slowly reduced. Liver parenchyma was shown the best contrast and reduced after 60 seconds. 2. The peripheral nodular of hemangioma was shown the better contrast soon. On the other hend, the contrast of center where is disease started to increase after 60 seconds and was equal to that of liver parenchyma. Increasing of the contrast continued after. 3. Turbo SE technic was used, the average of CR for hepatocellular carcinoma was $36.7{\pm}1.2$ and the average of CNR was $2.4{\pm}3.2$, while the average of CNR for hemangioma was $54.9{\pm}1.0$ and the average of CNR was $9.7{\pm}1.3$. 4. EPI technic was used, the average of CR for hepatocellular carcinoma was $47.8{\pm}1.2$ and the average of CNR was $3.4{\pm}2.1$, while the average of CNR for hemangioma was $75.7{\pm}2.2$ and the average of CNR was $9.5{\pm}1.1$. According to above we can find that hemangioma is more bright than hepatocellular carcinoma and the difference of brightness between hepatocellular carcinoma and hemangioma is useful sequence.

• 한국방사선학회논문지
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• 제11권7호
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• pp.619-625
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• 2017

본 연구는 조영제 주입 전 복부 검사 시 필수적으로 적용되고 있는 HASTE, HASTE(f/s), FFE(in, out)를 중심으로 두 기기에 대한 복부장기의 신호 대 잡음비(SNR; Signal to Noise Ratio)와 대조도 대 잡음비(CNR; Contrast to Noise Ratio)를 정량적으로 평가함으로서 최적의 장비선택을 알아보고자 하였다. 데이터분석은 1.5T 와 3.0T 자기공명영상기기(Philips medical system, Netherland)를 이용하여 검사한 복부영상을 무작위로 선정하여 분석을 하였다. 정량적 분석결과 간(Liver), 신장(Kidney), 비장(Spleen)에서는 1.5와 비교했을 때 3.0T가 SNR, CNR 값이 높게 나타났고(p<0.05), 위(Stomach), 복부지방(Abdominal Fat), 췌장(Pancreas)에서는 1.5T 가 높은 결과를 얻었다(p<0.05). 결론적으로 두기기별 장기에 대한 정량적 평가를 했을 때 인체의 바같 부분 조직은 전반적으로 3.0T 가 높게 나타났고 가스를 포함하여 자화율의 차이를 많이 발생시키는 안쪽부분의 장기는 1.5T 가 높은 결과를 얻었다. 이러한 결과는 환자상태에 따라 조영제를 사용하지 못하고 MRI 검사를 하는 경우 정확한 진단학적 정보를 제공하는데 가이드라인이 될 것이다.

• Investigative Magnetic Resonance Imaging
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• 제25권3호
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• pp.172-182
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• 2021

Purpose: We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. Materials and Methods: We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). Results: PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). Conclusion: In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

• Korean Journal of Radiology
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• 제22권11호
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• pp.1786-1796
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• 2021

Objective: To evaluate the prognostic implications of preoperative magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with a focus on those with targetoid appearance based on the Liver Imaging Reporting and Data System (LI-RADS), as well as known microvascular invasion (MVI) features. Materials and Methods: This retrospective study included 242 patients (190 male; mean age, 57.1 years) who underwent surgical resection of a single HCC (≤ 5 cm) as well as preoperative gadoxetic acid-enhanced MRI between January 2012 and March 2015. LI-RADS category was assigned, and the LR-M category was further classified into two groups according to rim arterial-phase hyperenhancement (APHE). The imaging features associated with MVI were also assessed. The overall survival (OS), recurrence-free survival (RFS), and their associated factors were evaluated. Results: Among the 242 HCCs, 190 (78.5%), 25 (10.3%), and 27 (11.2%) were classified as LR-4/5, LR-M with rim APHE, and LR-M without rim APHE, respectively. LR-M with rim APHE (vs. LR-4/5; hazard ratio [HR] for OS, 5.48 [p = 0.002]; HR for RFS, 2.09 [p = 0.042]) and tumor size (per cm increase; HR for OS, 6.04 [p = 0.009]; HR for RFS, 1.77 [p = 0.014]) but not MVI imaging features (p > 0.05) were independent factors associated with OS and RFS. Compared to the 5-year OS and RFS rates in the LR-4/5 group (93.9% and 66.8%, respectively), the LR-M with rim APHE group had significantly lower rates (68.0% and 45.8%, respectively, both p < 0.05), while the LR-M without rim APHE group did not significantly differ in the survival rates (91.3% and 80.2%, respectively, both p > 0.05). Conclusion: Further classification of LR-M according to the presence of rim APHE may help predict the postoperative prognosis of patients with a single HCC.

• Imaging Science in Dentistry
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• 제44권4호
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• pp.307-314
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• 2014

Primitive neuroectodermal tumor (PNET), which belongs to the Ewing's sarcoma (ES) family of tumors, is mainly seen in children and young adults. PNETs are extremely rare in the maxilla. Here, we report a case of PNET of the left maxillary sinus in an elderly male. Magnetic resonance imaging (MRI) revealed a slightly enhanced solid mass occupying the left maxillary sinus and infiltrating into the retroantral space. A partial maxillectomy was performed. Despite postoperative chemotherapy, follow-up computed tomography (CT) and MRI revealed a nodal metastasis in the submandibular space. Neck dissection was performed. However, the patient died 10 months after the second surgery because of distant metastasis to the liver. MRI and CT were particularly useful in detecting the extent of the tumor, recurrence, and metastasis. Further, a literature review of the previously reported PNET cases of the maxilla was carried out. In this paper, we also discuss the current approach for the diagnosis and management of these tumors.

• Investigative Magnetic Resonance Imaging
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• 제17권4호
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• pp.259-266
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• 2013

목적: DTPA-bis-amide (L3) Gd(III) 복합체의 약동학 및 생체내 분포특성을 조사하고자 하였다. 대상과 방법: Sprague-Dawley 쥐의 꼬리정맥을 통하여 0.1 mmol Gd/kg의 DTPA-bis-amide (L3) Gd(III) 복합체를 주사한 후 약동학 및 생체내 분포 특성을 조사하였다. 조직 및 장기 그리고 혈중 Gd 농도를 ICP-AES를 사용하여 정량 측정하였으며 혈중 약동학적 파라미터는 two-compartment 모델을 사용하여 계산하였다. 결과: DTPA-bis-amide (L3) Gd(III) 복합체의 혈중 반감기는 ${\alpha}$-phase의 경우 $2.286{\pm}0.11$ min 그리고 ${\beta}$-phase의 경우 $146.1{\pm}7.5$ min 이었다. 생체내 분포특성은 주요 배설 경로는 신장을 통한 배설이 주요 경로였으며 일부 담도계를 통한 배설이 확인되었다. 또한 Gd(III)의 농도비는 다른 장기에 비해 간과 비장에서 매우 높은 농도를 보였으며 일부 Gd(III)이 정맥주사 후 7일후에 혈액 및 일부 장기에서 매우 소량 검출되었다. 결론: 새로운 조영제인 DTPA-bis-amide (L3) Gd(III) 복합체는 혈중 잔류시간이 상대적으로 길면서도 체내 축적없이 체외로 배출되는 특성을 나타내었다. 따라서 친지질성과 친수성의 균형이 잘 이루어진 가돌리늄 조영제의 합성은 향후 blood pool MRI 조영제로써의 가능성이 매우 높은 것으로 판단된다.

• 대한핵의학회지
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• 제30권4호
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• pp.516-523
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• 1996

목 적 : 신경내분비종양 진단에 대한 I-123 MIBG 스캔의 4시간 조기 영상과 SPECT 영상의 임상적 유용성을 평가하고자 시행하였다. 대상과 방법 : CT 또는 MRI를 시행하여 신경내분비종양이 의심되었던 21예를 대상으로 I-123 MIBG 스캔을 시행하였으며 4시간에 전신 평면 영상과 SPECT 영상을 얻고, 17예에서는 12-24시간 사이에 지연 평면 영상도 얻었다. 결 과 : 21예중 12예에서 신경내분비종양으로 확진되었고, 4시간 I-123 MIBG 스캔의 진단적 예민도는 75%, 특이도는 89%였다. SPECT 영상은 CT나 MRI와의 비교 분석에 용이하였다. 지연 영상은 일부 진양성을 소견을 보인 예에서 종양 대 배후 방사능의 비가 증가하여 병변 확인에 도움이 되었으나 4시간 평면 영상과 진단율에 차이는 없었다. 결 론 : I-123 MIBG 스캔은 4시간 조기 영상으로도 신경내분비종양의 진단에 유용했으며, SPECT 영상은 다른 진단매체와의 비교 분석이 용이하였고 향후 종양의 종류에 따라 더 많은 예의 연구가 필요할 것으로 생각하였다.