• 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.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.575-584
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• 2021

The aim of this study was to achieve optimal portal phase while reducing contrast medium by applying weight-based dose protocol compared to standard fixed dose protocol to performing of pediatric abdominal CT examination. Discovery 750HD (General Electric Medical Systems, Milwaukee, USA) was used, and a total of 167 children consisting of 85 men and 82 women under the age of 18 were studied. The group in which the 300 mgI/ml(Xenetix, Guerbet, France) contrast medium was fixedly injected at twice body weight and the group injected with physiological saline while gradually decreasing the injection amount by 10% while applying the weight-based protocol were distinguished. Also, the CT number and SNR of abdominal organs were compared and evaluated while changing the scan delay time. Subjective image quality of enhancement and beam-hardening artifacts of around the heart was assessed with five-point criterion. The group adapted weight-based protocol with 20% reduction in contrast medium was most similar in contrast enhancement in the group with fixed injection at twice body weight. Furthermore, the group with a delay time of 20% had the highest contrast enhancement effect, and the difference in CT attenuation coefficient from the group scanned immediately after injection of the contrast media. Therefore, the appropriate delay time after injection of the contrast agent increased the contrast enhancement of the parenchymal organ. In addition, the weight-based injection protocol with normal saline reduced artifacts around the heart, and the effect of contrast enhancement could be maintained. In conclusion, it is possible to reduce dosage of contrast media through the application of weight-based injection protocols and appropriate latency, and to characterize optimal portal phase imaging on pediatric abdominal CT.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.337-345
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• 2014

The purpose of this study is to evaluate exposure dose and absorbability according to differences in the content of iodine in contrast media used in interventional procedure and angiography. There were 7 levels of iodine content as 240, 270, 300, 320, 350, 370, and 400 I $mg/m{\ell}$. The higher iodine content was, the more elevated exposure dose and absorbability were. The output dose was about 8.5% from iodine content with 350I $mg/m{\ell}$ higher than that with 270 I $mg/m{\ell}$ in TACE. These results mean that contrast media can have an effect on patient's exposure dose and high iodine content contrast media results in elevation of patient's exposure dose.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.589-595
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• 2017

This study evaluated the effect of gadolinium contrast agents on the spectrum of metabolites during $^1H-MRS$ of brain and to investigate whether the contrast agents injected before MR spectroscopy significantly affect the estimated peaks of MRS. From January to May 2017, brain MR spectroscopy was performed on 30 patients to compare the spectrum before and after contrast injection of the brain white matter tissue. As a result, the spectrum of metabolites decreased after the paramagnetic contrast agents injected. However, it was not statistically significant which indicated that the use of contrast agent did not meaningfully affect the spectrum of metabolites. In conclusion, the use of the paramagnetic contrast before the acquisition of the spectroscopy may aid voxel positioning especially when it is difficult to determine the exact location of the lesion or the contrast is low.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.7
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• pp.297-300
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• 2015

In medical ultrasonography, transit time and contrast enhancement patterns are considered as important parameters to analyze liver diseases. In many recent researches, time-intensity curves(TIC) have been used for calculating the transit time of the contrast agents. However, the intensity curve may include the variations which are caused by the micro-bubble effect of contrast agents. In this paper, we propose a complementary approach to diagnostic parameter extraction which utilizes a density information as well as the intensity data. The proposed technique improves the accuracy in extraction of the transit time and velocity of contrast agents for detection and characterization of focal liver lesions. Through the experiments using a set of clinical data, we show that the proposed methods can improve the reliability of the parametric image data.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.87-94
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• 2022

In this study, 61 patients who underwent coronary angiography from March 2018 to August 2019 were divided into Group I (Radial, n=34 patients) and Group II (Femoral, n=27 patients), and compared and analyzed methods using radial and femoral arteries when coronary angiography was performed. As a result of comparative analysis, Catheter usage was reduced in the examination using radial artery, and in the abnormal shape of blood vessels, Loops arterial abnormalities were more in the radial artery (20.6% vs, 0%, p<0.05), and it was found that the abnormal shape of the radial vessels increased with age. 60s, 70s, 80s, 90s or older (0%, 18.2%, 25.0%, 100%)

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.589-595
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• 2023

If complete coronary artery occlusion occurs due to severer coronary spasm, malignant arrhythmias can lead to death. Therefore, early screening for coronary artery spasm angina is essential. Among the test methods, the drug injection test through coronary angiography is generally performed. Therefore, the purpose of this study was to evaluate the advantages of ergonovine drug test for vasospasitc angina examination during coronary angiography, such as the relationship between the procedure time, contrast medium usage, and radiation exposure effects of coronary angiography. Follow-up data of 142 patients who underwent coronary angiography and variant angina examination from september 2021 to february 2023 were used. As a result of analyzing contrast usage dose and dose area product and air kerma dose and number of imaging series and procedure time, variant angina examination was statistically significantly higher than coronary angiography. (p<0.001) In conclusion, variant angina examination other than coronary artery angiography are radiologically negative. Therefore, we think it is better to avoid excessive inspection. Nevertheless, in the case of the provocation test, the longer the examination time, the higher the fluoroscopy time and the amount of contrast medium used, so it is better to conduct the test as quickly as possible or shorten it.

• 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.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.436-443
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• 2015

The purpose of this study was to develop a self-diagnostic linearity quality control techniques of computed tomography (CT) by using measured CT number values from the various concentrations of iodine contrast media (CM) is diluted with distilled water under each condition of the tube voltage. The equipment was used for four-channel MDCT, the iodine concentration were using 300 mgI/ml, 350 mgI/ml, 370 mgI/ml and 400mgI/ml. Dilution of CM in distilled water was increased by each 5% until the maximum CT number values were measured. We applied the tube voltages for 90 kVp, 120 kVp, 140 kVp. As a result, we was obtained to the nearest linearity as 0.993 of correlation coefficient between the iodinated CM from 5% to 25% in 400 mgI/ml and the CT number values by 90 kVp. In conclusion, the proposed self-diagnostic linearity quality assurance technique by using iodine CM can be utilized to replace the AAPM CT performance phantom.