• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.445-450
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• 2019

This study proves that syringe reuse of automated injection system entails a risk of contrast media reflux and saline solution contamination which are pumped by a piston into the patients' venous cannula in the dynamic MR images, we will be aware of the serious problem. To quantify the contrast media contamination effect on the saline solution, identical volume of the saline solution was collected before and after the contrast injection to the patients' venous cannula following T1 weighted image scanning to verify whether signal intensities differences are observed. The signal intensity of saline solution after the contrast injection was significantly higher than that of saline before injection by 523.43%. This result is due to the backflow that contaminates the saline solution on the opposite side when the contrast agent is injected. In conclusion, the syringe used to inject contrast medium. causes cross-contamination due to contrast reflux. Therefore, even if the same patient's examination is used for quantitative analysis, the error should be avoided by changing the acquisition sequence or replacing the syringe.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.171-171
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• 2001

목적： 뇌 자기공명영상에서 Z-score를 이용한 관류 영상과 조영전후의 감산에 의한 역동 영상의 관류 양상을 비교 관찰 하고자 한다. 대상 및 방법： 뇌 자기공명영상에서 이상 소견이 없는 젊은 환자 1명, Moya moya 환자 1, 중대뇌동맥 폐색 환자 1명, 외상후 증후군 1명, 뇌종양 1예를 대상으로 하여, 뇌의 routine 자기공명 영상과 함께 Gd-DTPA 0.1 mmol/kg를 급속 주사 후 자화율 대조 EPI 영상을 얻었다. 영상 기기는 Magnetom Vision(Siemens Medical Systems, Erlangen, Germany)이며, EPI 영상 지표들은 TR/TE는 0.8/29 msec, slice 두께 6 mm, slice 수 10, 화소수 128 $\times$ 128, FOV 215 $\times$ 215 mm, 영상획득 1 회, 1회 검사시간 1.32 초, 검사수 30 회로서, 총 검사시간은 40 초였다. 검사 후 영상처리(post processing)는 Magnetom Vision의 VB31D 자체 프로그램을 이용하였는데, 2-score를 이용한 관류영상은 조영제 유입전 영상들, 조영제 최대 유입기 영상들, 그리고 조영제 배출기 영상들 4-5 회를 각각 한 군으로 하여, Z-score 1.2에서 2.0 사이에서 여러번 반복하여 영상을 재구성하였다. 감산에 의한 역동영상은 조영제 도달 전의 영상으로부터 조영제 유입 후의 영상을 차례로 빼어서 영상을 재구성하였으며, 이들 영상을 재정리하여 각 단면의 시간 경과에 따른 관류 양상을 연속하여 관찰하였다 두 방법에 의한 영상 재구성은 각각 약 10분 정도가 소요되었다.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.261-266
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• 2015

Intravenous urography (IVU) for urolithiasis is a radiologic examination to diagnosis stone in the ureter path using iodine contrast media, which is radioopacity material. The method includes compression on the upper iliac crest. The compression band prevents outlet of the contrast media through the bladder and enables easier movement to upper urinary tract. This usage depends on the policy of a hospital. Therefore, this study aimed to review and compare the characteristic of progress of contrast media either in compression and non-compression. The retrospective image measurement on 60 cases of intravenous pyelography was conducted at a hospital with the identical type and amount of contrast media as well as criteria for testing. Image measurement was limited to 5 minutes clip, which is optimal for progress of contrast media depending on usage of the compression band. Also, anatomical regions were set as following: "RP" is from renal pyramid to renal pelvis, "PL" is from renal pelvis to lumbar three endplate, and "IU" and "IL" for upper and lower parts from both iliac crests. Analysis has been conducted through the statistical method based on Fisher's Exact Test to find if there are differences of distribution with the anatomical regions with compression or no compression. It has been confirmed that there is no statistical significant difference as the video measurement on 30 cases of compression and non-compression group respectively resulted in P value of 0.580 from left and 0.711 from right (both 0.960). Therefore, it has been concluded that application of a compression band on an intravenous pyelography for urolithiasis patient does not meaningfully affect the progress of contrast media.

• The Korean Journal of Nuclear Medicine
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• v.34 no.3
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• pp.228-233
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• 2000

Purpose: The aim of this study is to better understand the pattern and nature of reverse redistribution (RR) in myocardial perfusion imaging. Materials and Methods: In consecutive 20 acute myocardial infarction (MI) patients, frequency of RR was correlated with that of subendocardial MI that was detected by myocardial contrast echocardiography (MCE). RR was judged to be present when there was more than one grade of worsening in perfusion at 24 hr delayed images compared with the initial rest images. MCE evaluated the significant lack of opacification in the subendocardial myocardium relative to the subepicardial myocardium to suggest the subendocardial MI. Kendall's nonparametric correlation coefficiency was calculated. Results: Concordant cases were 15 of 20 (75%) and correlation was statistically significant (p=0.0285). Conclusion: Our results suggested that RR was correlated with MCE-detected nontransmural MI.

• Journal of the Korean Society of Radiology
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• v.2 no.1
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• pp.17-21
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• 2008

Because of the reason that the meningioma is enhanced lately, we started the study to maximally enhance the meningioma. we were to know the relation between meningioma and vessels in the skull and compared 3D CT angiography with the conventional angiography. we got the data from 6 patients performed by both 3D CT angiography and there were 5 cases in sphenoidal ridge and 1 case parasagittal sinus. Injecting the contrast media at 3 ml/sec, 120 ml and then the CT number reached 100, we started the study using the medical system Program(smart prep). The scan parameters were HS-Mode(1.25 mm / 7.5 mm) right after being injected all and reconstructed with 0.5 mm interval. We compared the study with the conventional angiography after reconstructing the images required by using 3D-Med software Program(Rapidia). Seeing the consequences, the maximum enhancing time in the menigioma is about 120~180 seconds after injecting the contrast media and we distinguished the relation between vessels and tumors at the time and 1 case showed us the aneurysm with a tumor clearly at the time too. It was very helpful to the operation that the 3D images required by injecting the contrast media to the patients with meningioma distingushed between tumors and vessels dimensionally.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5124-5130
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• 2014

Dilution of the contrast agent by analyzing the change in the signal intensity during MR angiography in accordance with the viscosity and osmotic pressure minimizes the side effects, and improves the image quality. The contrast agent molarity changes by the dilution of the contrast agent in the blood, as it is injected, which leads to a change in signal intensity. Based on this principle, a phantom was prepared and experiments were performed. After the phantom experiment, a clinical experiment was conducted using the results of the phantom experiment. From November 2013 to January 2014, a group of patients were classified into diluted contrast agent (30 persons) and undiluted (30 persons), and the signal intensity of the cerebral vessels was compared. The signal intensity of the phantom according to the molarity of the contrast agent increased sharply from 0.0125 mmol, reached a peak at 20 mmol, and achieved equilibrium from 200 mmol. Based on the study results, the signal intensity of the blood vessels in the brain through were compared in a clinical experiment. All the brain vessels in the imaging range with diluting a high content of the gadolinium contrast agent showed high signal intensity. This result supports the phantom experiment and means that using the 500mmol diluted contrast agent is better than using 1000mmol undiluted contrast agent because it is easier to approach the 20mmol level needed to achieve the highest signal intensity. This study has significance in that it can minimize the high viscosity and osmotic pressure, which can cause side effects and improve the image quality using the method of the dilution rate.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.217-218
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• 2013

급성기 허혈성 뇌졸중 증상이 있는 뇌 관류 CT검사를 시행한 환자를 대상으로 장비사가 제시한 고정 시간 기법(fixed time technique)과 조영제 추적 기법(bolus tracking technique)을 비교하여 환자의 피폭선량을 분석하고자 하였으며 조영제 추적 기법의 유용성과 최적의 조영증강 구간을 구현하는 Time graph를 알아보기 위한 것이다.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.134-141
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• 2015

The purpose on this research is quantitatively comparing and analyzing signal intensity of 1.0mol and 0.5mol contrast agent. For this study, two MR phantoms were produced. One of them is used with 1.0mol Gadobutrol. The other is used with 0.5mol Gadoteridol. These two phantoms respectively have been scanned by SE T1 sequence which is used to get a general contrast-enhanced image in 1.5T MRI and 3D FLASH sequence which is used as enhanced angio MRI. Signal intensity was measured by scanned images as per contrast agent dilution ratio. The results were as follow: RSP(Reaction Starting Point) of the two sequences(2D SE, 3D FLASH) was respectively 6.0%, 60.0% in 0.5mol contrast and 2.0%, 20.0% in 1.0mol contrast, which means in 0.5mol contrast, RSP was formed faster than the one in 1.0mol contrast. MPSI was respectively 1358.8[a.u], 1573[a.u] in 0.5mol contrast and 1374[a.u], 1642.4[a.u] in 1.0mol contrast, which means 0.5mol contrast's MPP (0.4%, 10.0%) was formed faster than 1.0mol contrast's MPP (0.16%, 1.8%). Lastly, RA as per contrast agent dilution ratio was 27.4%, 11.8% wider in 0.5mol contrast(20747.4[a.u], 23204.6[a.u]) than in 1.0mol contrast(12691.9[a.u], 20747.4[a.u]). According to the study, we are able to assure that signal reaction time of 1.0mol contrast is slower than the one of 0.5mol contrast in contrast-enhanced MRI at two different sequences(2D SE, 3D FLASH). Furthermore, owing to the fact that there are not any signal intensity differences between 1.0mol and 0.5mol contrast, it is not true that high concentration gadolinium MR contrast agent does not always mean high signal intensity in MRI.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.619-627
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• 2016

The purpose of this study is to investigate the effect of CT contrast agent and MRI contrast agent on the area dose in the body when using automatic exposure control system in general radiography. After making rectangular holes in the center of the abdominal thickness paraffin phantom, CT contrast agent and MRI contrast agent were respectively diluted with physiological saline solution for contrast medium dilution ratio of 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, 0:10%. Each experiment was set to 78 kVp, 320 mA, which is the proper condition for KUB photography, and thereafter a total of 30 inspections were made for each dilution ratio using an automatic exposure control device, and the area dose corresponding to the dilution ratio of each contrast agent, Average comparison and correlation analysis were performed on the exposure index. As a result, the CT contrast agent and the MRI contrast agent appeared different in area dose according to the dilution ratio(p<0.05), and as the dilution ratio increased, the area dose increased for CT contrast agent and MRI contrast agent(P<0.05). In each test, the exposure index showed the manufacturer's recommendation of 200-800 EI value, and the exposure index and area dose increased as the area dose increased(p<0.05). In conclusion, CT contrast agent and MRI contrast agent confirmed to increase the area dose by general imaging test using all automatic exposure control device. Therefore, it is considered that it is necessary to perform it after the contrast medium has been excreted sufficiently when using usual imaging test after using the contrast agent in CT and MRI examination.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.879-887
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• 2019

The purpose of this study is to establish a physiological injection protocol according to body weight, in order to minimize amount of contrast medium and optimize contrast enhancement in pediatric patients performing thoracic CT examinations. The 80 pediatric patients under the age of 10 were studied. Intravenous contrast material containing 300 mgI/ml was used. The group A injected with a capacity of 1.5 times its weight, and groups B, C and D added 5 to 15 ml of normal saline with a 10% decrease in each. The physiologic model which can be calculated by weight about amount of injection of contrast medium and normal saline, flow rate and delay time were applied. To assess image quality, measured average HU value and SNR of superior vena cava, pulmonary artery, ascending and descending aorta, right and left atrium, right and left ventricle. CT numbers of subclavian vein and superior vena cava were compared to identify the effects of reducing artifacts due to normal saline. Comparing SNR according to the contrast medium injection protocol, significant differences were found in superior vena cava and pulmonary artery, descending aorta, right and left ventricle, and CT numbers showed significant differences in all organs. In particular, B group with a 10% decrease in contrast medium and an additional injection of saline showed a low degree of contrast enhancement in groups with a decrease of more than 20%. In addition, the group injected with normal saline greatly reduced contrast enhancement of subclavian vein and superior vena cava, and the beam hardening artifact by contrast medium was significantly attenuated. In conclusion, the application of physiological protocol for injection of contrast medium in pediatric thoracic CT examinations was able to reduce artifacts by contrast medium, prevent unnecessary use of contrast medium and improve the effect of contrast enhancement.