• 대한영상의학회지
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• 제82권2호
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• pp.359-370
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• 2021

목적 증상이 있는 123명의 coronavirus disease 2019 (이하 COVID-19) 환자에서 흉부 CT 병변의 소견과 일련의 변화를 분석하였다. 대상과 방법 2020년 2월 19일부터 4월 7일까지 총 123명의 COVID-19 환자(남성, 44명; 여성, 79명; 평균 연령 59.2 ± 18.6)를 후향적으로 연구하였다. 총 234개의 CT 스캔을 검토하여 패턴[급성 폐포 손상(acute alveolar insult) 패턴: 간유리음영, 돌조각보도모양, 혼합된 패턴, 또는 폐경화; 기질화 폐렴(organizing pneumonia) 패턴: 소엽주위 패턴, 띠 음영, 곡선형 음영, 역달무리 음영, 또는 소결절경화; 호전형 패턴: 순수 간유리음영, 잔존 곡선형 음영, 또는 소결절경화]과 폐 이상의 연속적인 변화를 분석하였다. 피어슨 카이 제곱 검정과 피셔의 정확 검정을 사용하여 시간 경과에 따른 급성 폐포 손상 패턴, 기질화 폐렴 패턴, 호전형 패턴의 비율을 비교하고, 패턴과 질병 심각도 간의 연관성을 분석하였다. 결과 초기 입원군(증상 발병 후 0~10일)의 CT 패턴은 급성 폐포 손상 패턴(87%) 이 가장 많았고, 후기 입원군(10일 이상)에서는 기질화 폐렴 패턴(45.7%), 퇴원군(퇴원 시 및 퇴원 후)에서는 호전형 패턴(47.2%; 84.8%)이 가장 많았다. 시간 경과에 따른 우세한 CT 패턴에 대한 비율의 차이는 통계적으로 유의하였다(p < 0.001, 피어슨 카이 제곱 검정). 패턴과 질병 중증도 간에 통계적으로 유의한 연관성은 발견되지 않았다(p = 0.055, 피셔의 정확 검정). 후속 CT 스캔에서 병변의 섬유화는 관찰되지 않았다. 결론 COVID-19 환자의 연속적 CT 스캔은 COVID 폐렴의 폐 손상 및 복구의 단계로서 다양한 CT 영상 소견을 보여주었다.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1066-1076
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• 2018

Objective: The reliability of size measurements of liver metastases from neuroendocrine tumors (NETs) on contrast-enhanced computed tomography (CT) phases made by different readers may be hampered due to transient, variable rim enhancement in arterial phase (AP) or portal venous phase (PVP) images. We aimed to assess the reliability of tumor size measurements in pre- and post-contrast scans. Materials and Methods: The study coordinator selected target lesions according to Response Evaluation Criteria in Solid Tumors 1.1 guidelines in 44 consecutive patients with pathologically confirmed NET liver metastases. Two blinded readers measured the longest diameters of target lesions on pre-contrast, AP, and PVP images twice with a 4-week interval. Inter- and intra-observer agreements were evaluated using Bland-Altman plots and 95% limit of agreement (LOA) calculations. Results: Of the 79 target lesions (approximate mean size of 3 cm), 45 showed rim enhancement. Inter-observer agreement assessed based on LOA was highest in pre-contrast CT images (-6.1-5.7 mm), followed by PVP (-7.9-7.1 mm) and AP (-8.5-7.4 mm) images. Intra-observer agreement showed the same trend: -2.8-2.9 mm and -2.9-2.9 mm for readers 1 and 2, respectively, on pre-contrast CT, -2.8-2.9 mm and -3.0-3.2 mm, respectively, on PVP, and -3.2-4.2 mm and -3.4-3.2 mm, respectively, on AP images. Mean tumor diameters differed significantly among the phases in the following increasing order: pre-contrast CT, PVP, and AP images. Conclusion: There was better inter- and intra-observer agreement in size measurements of NET liver metastases on pre-contrast scans than on AP and PVP scans. Pre-contrast CT may be the optimal for measuring NET liver metastases if its accuracy is proven.

• 대한두경부종양학회지
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• 제4권1호
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• pp.5-11
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• 1988

CT examination has been used in the preoperative examination of patients with head and neck cancer. The accuracy of CT in detecting nodal metastases has not been well established. We studied 35 patients (41 neck specimens) with head and neck cancer who underwent neck dissection. Surgical pathologic findings were compared with preoperative CT scan to establish the diagnostic accuracy for cervical lymph node metastases. The results of physical examination, CT scans of neck and histologic examinations were compared each other. The overall diagnostic accuracy of CT was 83.3%. Comparison with clinical accuracy shows the CT scan to be superior to the clinical examination in spite of careful physical examination, particularly in detecting occult metastases.

• 한국방사선학회논문지
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• 제17권3호
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• pp.285-295
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• 2023

기술의 발전으로 CT 검사에 있어 환자가 받는 피폭선량을 줄이기 위한 노력은 새로운 재구성 기법 개발과 함께 계속 진행되고 있다. 최근에는 반복적 재구성 기법의 한계를 극복하기 위해 딥러닝 재구성 기법이 개발되었다. 본 연구는 소아 흉부 CT 영상에서 재구성 기법에 따른 영상의 유용성을 평가하였다. 환자 실험은 2021년 1월 2일부터 2022년 12월 31일까지 경상남도 P 병원에서 흉부 조영 CT 검사를 받은 소아 환자 중 85명을 대상으로 연구를 진행하였다. 팬텀 실험에 사용된 팬텀은 Pediatric Whole Body Phantom PBU-70이다. 검사 후 FBP, ASIR-V(50%), DLIR(TF-Medium,High)로 영상을 재구성했고, 동일한 크기의 ROI를 설정하여 HU값, SD값을 획득하여 SNR, CNR 값을 산출하여 영상을 평가하였다. 그 결과 DLIR의 TF-H가 모든 실험에서 ASIR-V(50%)와 TF-M에 비해 잡음 값이 가장 낮았으며, SNR과 CNR의 값이 가장 높았다. 소아 흉부 CT 검사에서 DLIR이 적용된 TF 영상이 ASiR-V 영상보다 잡음이 적었고, CNR과 SNR은 높은 것으로 나타났으며 DLIR이 적용되면 기존의 재구성법에 비해 영상의 질이 더 향상될 것으로 판단된다.

• The Korean Journal of Pain
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• 제30권3호
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• pp.165-175
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• 2017

Nuclear medicine imaging is widely used in pain medicine. Low back pain is commonly encountered by physicians, with its prevalence from 49% to 70%. Computed tomography (CT) or magnetic resonance imaging (MRI) are usually used to evaluate the cause of low back pain, however, these findings from these scans could also be observed in asymptomatic patients. Bone scintigraphy has an additional value in patients with low back pain. Complex regional pain syndrome (CRPS) is defined as a painful disorder of the extremities, which is characterized by sensory, autonomic, vasomotor, and trophic disturbances. To assist the diagnosis of CRPS, three-phase bone scintigraphy is thought to be superior compared to other modalities, and could be used to rule out CRPS due to its high specificity. Studies regarding the effect of bone scintigraphy in patients with extremity pain have not been widely conducted. Ultrasound, CT and MRI are widely used imaging modalities for evaluating extremity pain. However, SPECT/CT has an additional role in assessing pain in the extremities.

• Journal of Magnetics
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• 제20권3호
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• pp.295-301
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• 2015

We evaluated certain issues related to magnetic resonance imaging (MRI) coupled with the use of active 2.5 GHz radio frequency identification (RFID) tags for patient identification using low field (0.3 T) MRI and computed tomography (CT) scans. We also investigated the performance of the RFID reader located outside the MRI room by considering several factors. A total of ten active RFID tags were exposed to several MRI sequences and X-rays of CT scan. We found that only card type active RFID tags are suitable for patient identification purpose in MRI environment and both wristbands as well as card tags were suitable for the same in CT environment. Severe artifacts were found in the captured MRI and CT images when the area of the imaging was in proximity to the tags. No external factors affected the performance of active RFID reader stationed outside the MRI scan room.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 2002년도 춘계학술대회 및 총회
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• pp.25-27
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• 2002

With the advent of multidetector-row CT, lung cancer imaging is much more promising than before. However, the effectiveness of multidetector-row CT in making an initial diagnosis, staging, and evaluating post-treatment changes of lung cancer still remains to be proved. Fast imaging along with volumetric data set and attendant multi-planar imaging provide much more details on the anatomic changes and pathology associated with lung cancer. However, with images showing anatomic and pathologic changes only, radiologists confront with several questions the answers of which may help evaluate lung cancer more thoroughly. The frequent questions that I have in dally practice of chest CT interpretation are as follows.

• 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.

• Journal of Korean Neurosurgical Society
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• 제52권6호
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• pp.541-546
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• 2012

Objective : The prefabrication of customized cranioplastic implants has been introduced to overcome the difficulties of intra-operative implant molding. The authors present a new technique, which consists of the prefabrication of implant molds using three-dimensional (3D) printers and polymethyl-methacrylate (PMMA) casting. Methods : A total of 16 patients with large skull defects (>100 $cm^2$) underwent cranioplasty between November 2009 and April 2011. For unilateral cranial defects, 3D images of the skull were obtained from preoperative axial 1-mm spiral computed tomography (CT) scans. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of the cranium as a model. For bilateral cranial defects, precraniectomy routine spiral CT scan data were merged with postcraniectomy 3D CT images following a smoothing process. Prefabrication of the mold was performed by the 3D printer. Intraoperatively, the PMMA implant was created with the prefabricated mold, and fit into the cranial defect. Results : The median operation time was $184.36{\pm}26.07$ minutes. Postoperative CT scans showed excellent restoration of the symmetrical contours and curvature of the cranium in all cases. The median follow-up period was 23 months (range, 14-28 months). Postoperative infection was developed in one case (6.2%) who had an open wound defect previously. Conclusion : Customized cranioplasty PMMA implants using 3D printer may be a useful technique for the reconstruction of various cranial defects.

• 한국임상수의학회지
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• 제35권3호
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• pp.93-96
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• 2018

This study aimed to establish an injection protocol to determine the precise CT scan timing in canine abdominal multi-phase CT using the test bolus method. Three dynamic scans with different contrast injection parameters were performed using a crossover design in eight normal beagle dogs. A contrast material was administered at a fixed dose of 200 mg iodine/kg as a test bolus for dynamic scans 1 and 2, and 600 mg iodine/kg as a main bolus for dynamic scan 3. The contrast materials were administered with 1 ml/s in dynamic scan 1, and 3 ml/s in dynamic scan 2 and 3. The mean arrival time to the appearance of aortic enhancement in dynamic scan 3 was similar to that in dynamic scan 2, and different significantly to that in dynamic scan 1. The mean arrival time to the peak aortic and pancreatic parenchymal enhancement in dynamic scan 3 was similar to that in dynamic scan 1, and different significantly to that in dynamic scan 2. In multi-phase CT scan, a test bolus should be injected with the same injection duration of a main bolus, to obtain the precise arrival times to peak of arterial or pancreatic parenchymal enhancement.