• 한국의학물리학회지:의학물리
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• 제16권1호
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• pp.47-51
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• 2005

전산화단층검사에서 조영제를 자동주입기를 이용해 주입하여 검사하는 경우에 혈관 외 유출된 성인환자를 대상으로 하였다. 환자의 혈관외유출 사고의 조영제 양은 47 ml로 오른쪽 손목 부위가 부종을 동반하였다. 혈관외유출된 손상부위를 axial 스캔하여 MPR (multi-planar reformation), MIP (maximum intensity protection), volume rendering, SSD (shaded-surface display) 기법으로 구성하였다. 이러한 3D 영상은 조영제의 혈관외유출 환자의 예방 및 사후 조치에 적절한 치료계획의 방법으로 기대된다.

• 한국방사선학회논문지
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• 제14권1호
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• pp.61-68
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• 2020

본 연구에서는 CT 혈관조영 영상에서 조영제 희석비율에 따른 Blooming 인공물 발생의 상관성에 대하여 알아보고자 한다. 3D 프린터를 이용하여 PLA(Poly Lactic Acid)재질의 구형 팬텀을 자체 제작하였고 구형 팬텀 내부에 조영제와 식염수의 비율을 100:0부터 10:90으로 희석하여 총 10세트를 준비하였다. 이후 CT 횡단면 영상을 얻고 raw 데이터를 최대강도투사법, 다중평면 재구성 기법으로 재구성하여 각각 횡단면, 시상면, 관상면의 영상을 얻었다. 검사 후 얻은 영상의 구형 팬텀의 직경을 각각 30회씩 총 1800회 측정하였다. 측정결과, 다중 평면 재구성 기법 중 관상면에서 20:80으로 희석하였을 때 20.47±0.05 mm로 가장 작게 측정되었다(p<0.05). 마찬가지로 최대강도투사법 중 시상면에서 20:80으로 희석하였을 때 20.39±0.08 mm로 가장 작게 측정되었다(p<0.05). 희석비율과 측정 크기의 상관성 분석에서는 모든 재구성 영상에서 강한 음의 상관성을 확인하였다(p<0.05). 결론적으로 조영제 희석비율이 높을수록 혈관의 실측을 측정하기 어려우며 이에 대한 원인으로 Blooming 인공물이 있음을 확인하였다. 따라서 실측에 관한 추후 연구에서 본 연구가 기초자료를 제공할 수 있을 것이라 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제41권2호
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• pp.123-128
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• 2018

Recently, the use of contrast agents has been increasing as a broader range of tests and dynamic tests have become common due to the development of equipment and imaging techniques such as Multi-Detector CT. However, the side effects of using contrast agents have been reduced by the development of non-ionic contrast agents, but they are still occurring often. The purpose of this study was to propose a method to minimize the side effect of contrast agent by using the amount of contrast agent injected to the brain angiography test to suppress excessive use of contrast agent and analyze the amount of contrast agent. Patients who were prescribed Brain Angiography due to cerebrovascular disease, According to the results of the comparison of the results obtained by dividing into 4 groups of 10ml each according to the amount of contrast medium injected with contrast agent according to the BMI of the patient, BA and SNR were not different between groups, and even if the amount of contrast injection was reduced, there was no problem in the evaluation of CT angiography through 3D reconstruction. This result shows that even if the contrast medium is injected into the blood vessels of the patient first and then the contrast medium is used as the physiological saline solution, the contrast medium is reduced by 40% it can be expected to minimize.

• 대한방사선기술학회지:방사선기술과학
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• 제24권2호
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• pp.13-17
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• 2001

When most patients are diagnosed with the quiet progressed hepatoma which often would make the operation impossible, the Interventional Radiology hepatic artery embolization is an extremely useful method for such patients. An existence of the malfunction is evaluated by gaining a portal vein image as a delayed phase image after injecting a contrast media into the superior mesenteric artery. However, it is difficult to make a definite judgement due to the extended exposure time with the peristalsis and the intestine gas obstructing the sharpness of the image when the Patient exposure time increases and due to the increased usage of contrast media and its side effect. The portal vein can be evaluated by obtaining the MIP image after reconstructing a 3-dimensional personal computer setting using the 2-dimensional from an enhancement abdomen CT image that is almost a requisite in operation to a hepatoma patient. Such method nay prevent a decrease in the quality of image based upon the time delay and intestine gas; also, because the patient exposure dose and contrast media usage may be reduced, it is a new, valuable way to decide the operational matter of hepatic artery embolization on a pre-angiography.

• 대한디지털의료영상학회논문지
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• 제10권2호
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• pp.17-22
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• 2008

It is to improve customer satisfaction measurement and CT Scan process without delay of examination time when is using Scan positioning time(Planning time) that time is happened always between research reactor CT examination to increase fear and examination satisfaction by the customer's comprehension tribe which get the latest contrast enhancement CT examination. Needs and interests that customer wants to compose visual and auditory Contents to be played to Scan positioning time did questionnaire about curiosity later before CT examination to 600 people for October - November 2 months of 2006 to customer whole that get CT examination on source. Data getting through questionnaire investigated examination comprehension and satisfaction through questionnaire after experiment Scan Positioning to 500 coming to help customers to be source CT examination for 3 months February December - 2007 year in 2006 manufacturing Voice and Visual announce media for reference. To customer who interest degree appeared, and answers preparatory audit from preparatory audit about curiosity of CT examination customer to order of examination time required(43%), contrast media side effect(26%), examination region(20%), breath(10%), etc..(1.5%) audio-visual materials in questionnaire that attain after do reclamation among examination age, sex, reception type of irrelatively in 91% of target increase of hailing degree and examination satisfaction appear. Searched that customer hailing and satisfaction are increased greatly when use of audio-visual materials in satisfaction result that use CT Positioning delay time. In experiment process, It took lacking part by method that use hearing in case of do not use sight as is unavoidable in subject position or old age. Through this, audio-visual materials could analogize that it is more useful method that use sight and hearing at the same time.

• 한국의학물리학회지:의학물리
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• 제17권1호
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• pp.32-39
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• 2006

CT 검사에서 조영제의 혈관외유출을 예방하기 위해 EDA시스템을 증폭기, ADC, 스트레인 게이지로 구성하여 개발하였고, 스트레인 게이지의 신호의 수치를 나타내도록 프로그램을 설계하였다. 신호비율은 500/1000 sec, 분해능 값은 0에서 4,096범위로 표시하고, 입력범위 $0{\sim}5$ V이다. 혈관외유출 검출 문턱 값은 50으로 하였고, 10 간격으로 조정하도록 하였다. 개발된 EDA 시스템을 성인 50명을 대상으로 적용하였다. 2명의 환자에서 혈관외유출이 검출되었고, 조영제 주입속도는 2.0 mL/sec, 2.5 mL/sec, 압력은 137 psi, 158 psi, 혈관외유출된 조영제 용량은 22 mL, 25 mL였다. 설정된 주입 조영제에 비해 20% 정도의 적은 용량이 혈관외유출되었다. 개발된 EDA 시스템은 소량의 조영제를 검출하여 혈관외유출을 예방하는 효과가 있다.

• 대한임상독성학회지
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• 제15권2호
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• pp.122-130
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• 2017

Purpose: To evaluate the effects of low-dose intravenous N-acetylcysteine on the prevention of contrast-induced nephropathy (CIN) in patients undergoing computed tomography (CT). Methods: All patients presenting to our emergency department and undergoing CT with intravenous contrast media between August 2014 and April 2016 were retrospectively enrolled. We included hospitalized patients with renal dysfunction [estimated glomerular filtration rate (GFR) between 30 and $89mL/min/1.73m^2$]. A 600-mg injection of N-acetylcysteine was given to patients once before and once immediately after CT, depending on the preference of physician. The primary outcome was CIN defined as an increase in creatinine level of ${\geq}25%$ or ${\geq}0.5mg/dL$ from the baseline within 48 to 72 hours after CT. A trained person blindly reviewed all medical records. Results: Of the 1903 admitted patients, CIN occurred in 9.8% of patients who received 1200 mg intravenous N-acetylcysteine (24/244) and 6.8% of patients who did not (113/1659, p=0.090). In a multivariable regression analysis, N-acetylcystine was not relevant to the prevention of CIN (odds ratio=1.42 [95% CI, 0.90-2.26]). Even in the stratified analysis using the propensity score matching, N-acetylcysteine was irrelevant (GFR 30-59: odds ratio=1.06 [95% CI, 0.43-2.60]; GFR 60-89: odds ratio=1.76 [95% CI, 0.75-4.14]). After adjustment, crystalloids were significantly associated with the reduction in CIN compared with dextrose water (odds ratio=0.60 [95% CI, 0.37-0.97]). Conclusion: No effect was found when low-dose intravenous N-acetylcysteine was used to prevent CIN. However, there seems to be an association between crystalloids and reduction in CIN.

• 한국방사선학회논문지
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• 제15권1호
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• pp.29-35
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• 2021

본 연구의 목적은 주기적으로 follow up CT를 촬영하는 뇌출혈 환자에게 조영제의 양을 줄임으로써 줄이기 전과 후의 영상의 화질의 차이가 있는지에 관하여 조사하는 것이었고, 줄이기 전과 후의 영상을 검사한 후 MMWP 프로그램을 이용하여 각각의 혈관 위치에 ROI를 설정하여 화질을 평가하였다. 먼저 Rt. CCA, Lt.CCA. Rt.MCA, Lt.MCA, Basilar artery에 각각 ROI를 잡았다. 둘째, 잡은 ROI에 대한 평균값과 표준편차값을 구하였다. 셋째, 구해진 평균값과 표준편차 값을 통하여 SNR과 CNR을 구하였다. 구하여진 SNR값과 CNR값을 T-test 통계를 구한 결과 SNR에 대한 결과 값은 Rt.CCA 0.765, Lt.CCA 0.871, Rt.MCA 0.343, Lt.MCA 0.235, Basilar artery 0.916이며, CNR에 대한 결과 값은 Rt.CCA 0.088, Lt.CCA 0.069, Rt.MCA 0.818, Lt.. MCA 0.579, Basilar artery 0.878로 나타났다. 구해진 SNR값과 CNR값을 통하여 통계를 구한 결과값이 조영제를 줄이기 전과 후의 영상의 화질에 차이가 없는 것으로 나타났다. 따라서 본 연구가 주기적으로 CT검사를 하는 환자들에게 조영제에 대한 부담이 덜어질 수 있는 지표가 되기를 바랍니다.

• Nuclear Medicine and Molecular Imaging
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• 제40권3호
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• pp.169-176
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• 2006

목적 : 현재 PET/CT에서 CT의 역할은 단순히 감쇠 보정만을 위한 도구에서 진단을 위한 도구로 그 역할이 발전해 가고 있다. 따라서 양질의 CT 영상을 얻기 위한 정맥 조영제의 사용과 고선량의 CT 촬영이 요구되고 있으며 최근 조영제가 감쇠 보정한 PET 영상에 크게 영향을 미치지 않는다는 보고가 나오고 있다. 이에 본 연구에서는 고선량 CT에서 정맥 조영제의 사용이 감쇠 보정에 미치는 영향을 알아보았다. 대상 및 방법 : 총 13명의 환자에게 PET/CT 검사를 시행하였다. $^{18}F$-FDG를 주사하고 1시간 후에 촬영하였고, 첫 번째로 조영제의 사용 없이 CT(NECT-120 kVp, 130 mAs)를 촬영하고 이어서 바로 조영제를 사용하여 CT(CECT)를 촬영한 후 PET을 시행하였다. 각 환자마다 NECT와 CECT에 의해 각각 보정된 PET 영상에서 10곳의 신체 부위(병변이 없는 폐첨부, 폐기저부, 상행대동맥, 간의 상부 및 하부, 비장, 척추, 대퇴골두, 장요근과 10번 척추와 척추 인접 근육) 에서 HU와 maxSUV 값을 구하였고, 종양과 임파선 병변의 값도 함께 측정하였다. 결과: 조영제를 사용하였을 때 국소적으로 섭취가 증가된 곳은 관찰되지 않았다. 총 130개의 정상 조직의 maxSUV값을 측정하여 비교하였을 때, 조영제를 사용한 군과 사용하지 않은 군의 평균 maxSUV 값은 각각 $1.1{\pm}0.5,\;1.0{\pm}0.5$이고 두 군 사이에 p<0.001로 통계적으로 유의한 차이를 보였다. 정상 조직에 대해 Bland-Altman 분석을 시행하였을 때 일치의 한계 범위는 $0.1{\pm}0.3$ 이었다. 10개의 대상 영역 중 폐첨부, 폐하부, 상행대동맥, 간의 상부와 하부, 비장에서 maxSUV 값이 두군에서 유의한 차이(p<0.05)가 있었다. 총 39개 병변의 maxSUV 값을 측정하여 비교하였을 때, 조영제를 사용한 군과 사용하지 않은 군의 평균 maxSUV값은 각각 $4.7{\pm}2.0,\;4.4{\pm}2.0$이고 두 군 사이에 p<0.001로 통계적으로 유의한 차이를 보였다. 병변에 대해 Bland-Altman 분석을 시행하였을 때 일치의 한계 범위는 $0.4{\pm}0.8$ 이었다. 결론: 조영제로 인해 maxSUV의 값은 증가되었으나 정상 조직과 병변에서 일치의 한계 범위가 매우 좁았다. 따라서 진단용 고선량 CT를 이용한 PET/CT 촬영 시에 조영제의 사용이 임상 상황에서 판독에 큰 영향을 미치지 않는 것으로 생각된다.

• Korean Journal of Radiology
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• 제2권1호
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• pp.28-36
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• 2001

Objective: To provide a systematic overview of the effects of various parameters on contrast enhancement within the same population, an animal experiment as well as a computer-aided simulation study was performed. Materials and Methods: In an animal experiment, single-level dynamic CT through the liver was performed at 5-second intervals just after the injection of contrast medium for 3 minutes. Combinations of three different amounts (1, 2, 3 mL/kg), concentrations (150, 200, 300 mgI/mL), and injection rates (0.5, 1, 2 mL/sec) were used. The CT number of the aorta (A), portal vein (P) and liver (L) was measured in each image, and time-attenuation curves for A, P and L were thus obtained. The degree of maximum enhancement (Imax) and time to reach peak enhancement (Tmax) of A, P and L were determined, and times to equilibrium (Teq) were analyzed. In the computed-aided simulation model, a program based on the amount, flow, and diffusion coefficient of body fluid in various compartments of the human body was designed. The input variables were the concentrations, volumes and injection rates of the contrast media used. The program generated the time-attenuation curves of A, P and L, as well as liver-to-hepatocellular carcinoma (HCC) contrast curves. On each curve, we calculated and plotted the optimal temporal window (time period above the lower threshold, which in this experiment was 10 Hounsfield units), the total area under the curve above the lower threshold, and the area within the optimal range. Results: A. Animal Experiment: At a given concentration and injection rate, an increased volume of contrast medium led to increases in Imax A, P and L. In addition, Tmax A, P, L and Teq were prolonged in parallel with increases in injection time The time-attenuation curve shifted upward and to the right. For a given volume and injection rate, an increased concentration of contrast medium increased the degree of aortic, portal and hepatic enhancement, though Tmax A, P and L remained the same. The time-attenuation curve shifted upward. For a given volume and concentration of contrast medium, changes in the injection rate had a prominent effect on aortic enhancement, and that of the portal vein and hepatic parenchyma also showed some increase, though the effect was less prominent. A increased in the rate of contrast injection led to shifting of the time enhancement curve to the left and upward. B. Computer Simulation: At a faster injection rate, there was minimal change in the degree of hepatic attenuation, though the duration of the optimal temporal window decreased. The area between 10 and 30 HU was greatest when contrast media was delivered at a rate of 2 3 mL/sec. Although the total area under the curve increased in proportion to the injection rate, most of this increase was above the upper threshould and thus the temporal window was narrow and the optimal area decreased. Conclusion: Increases in volume, concentration and injection rate all resulted in improved arterial enhancement. If cost was disregarded, increasing the injection volume was the most reliable way of obtaining good quality enhancement. The optimal way of delivering a given amount of contrast medium can be calculated using a computer-based mathematical model.