• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.83-91
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• 2024

The purpose of this study was to determine the doppler fluid effects of carbonated water (CBW) in a bi-directional flow phantom model. A bi-directional flow phantom model was chosen to realize arterial and venous flow, and the structure of the inner and outer tanks allowed for fluid circulation and also made the size of the phantom small. Carbonated water (CBW), salt fluid (SAF), sugar fluid (SUF), and distilled water (DW) were used as fluids, and ultrasound scans were performed at depths of 1.5 cm and 3.0 cm from the surface of the tank, using B-mode and color Doppler effects. All fluids tested showed color Doppler effects, but CBW had the highest doppler shift and the least variation with depth. In conclusion, we determined that CBW was the most suitable fluid to be used as a doppler fluid and confirmed that the bubbles dissolved in CBW act as doppler scatterers, just like red blood cells inside human blood. Therefore, it is possible that CBW can be used as a blood-mimicking fluid in doppler ultrasound phantoms through further research, and this study will provide basic data.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.965-973
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• 2020

The purpose of this study was to quantitatively correlate the change of flow velocity and signal voiding in TOF-MRA. We made our phantom to control the flow velocity, and changed the flow velocity in 16 steps from 8.0 to 127.3 mc/s. The TOF-MRA test was performed using a 3.0T MRI system and the signal intensity was measured by classifying the signal voiding length and image into the In flow, Mid flow, and Out flow. The length of signal voiding was the longest when the flow velocity was 127.3 cm/s and the signal intensity decreased with increasing flow velocity(p<0.05). In flow(-.547) and Mid flow(-.643) were negatively correlated with flow velocitys(p<0.05). In conclusion, it was confirmed that the increase in flow velocity was a major factor causing signal voiding in TOF-MRA. In the future, this study will provide basic data when studying sequences and parameters to reduce signal voiding in models with a high flow velocity.

• Polymer(Korea)
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• v.32 no.1
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• pp.90-93
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• 2008

We developed a variety of polymeric jelly phantoms that can be used in hyperthermia using an electromagnetic wave as an auxiliary cancer therapy. Particularly, using an appropriate material composed of polyethylene, deionized water, and sodium chloride, jelly phantoms for brain was prepared. Also, their electrical properties were characterized by measuring the dielectric constant and conductivity. As the results, overall electrical values of the phantoms decreased with increasing the amount of the components of the materials, excepted for sodium chloride. Additionally, storage characteristics of the phantoms showed a sustainable stability up to 6 months. Based on the experimental results, it can be proposed that jelly phantoms containing a ferro-magnetic particle could be a potential material for cancer therapy following the further study on the temperature elevation effect and the evaluation of electromagnetic properties of the materials.

• Polymer(Korea)
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• v.30 no.6
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• pp.572-575
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• 2006

In this work, a variety of polymer based jelly phantoms suitable for the hyperthermia operations to human organs was synthesized in order to confirm the possibility of auxiliary cancer therapy. Specifically, using an appropriate material composition including polyethylene, Jelly phantoms for brain was prepared and characterized their electrical properties suitable for the monitoring the effect of electromagnetic wave from code division multiple access (CDMA) and personal communication service (PCS) on the human body. In the future, after injection of ferromagnetic nanoparticle into the jelly phantoms, new approach to propose the cancer therapy can be anticipated by monitoring the degree of temperature rise in human body using the photograph of Infrared camera.

• Progress in Medical Physics
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• v.13 no.4
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• pp.209-217
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• 2002

There have been many studies on the application of the reciprocal advantages of multimodality image to define accurate target volume in the Process of radiation treatment planning. For the proper use of the multimodality images, the registration works between different modality images should be performed in advance. In this study, we selected chamfer matching method and mutual information method as most popular methods in recent image registration studies considering the registration accuracy and clinical practicality. And the two registration methods were analyzed to deduce the optimal registration method according to the characteristics of images. Lung phantom of which multimodality images could be acquired was fabricated and CT, MRI and SPECT images of the phantom were used in this study. We developed the registration program which can perform the two registration methods properly and analyzed the registration results which were produced by the developed program in many different images' conditions. Although the overall accuracy of the registration in both chamfer matching method and mutual information method was acceptable, the registration errors in SPECT images which had lower resolution and in degraded images of which data were removed in some part were increased when chamfer matching method was applied. Especially in the case of degraded reference image, chamfer matching methods produce relatively large errors compared with mutual information method. Mutual information method can be estimated as more robust registration method than chamfer matching method in this study because it did not need the prerequisite works, the extraction of accurate contour points, and it produced more accurate registration results consistently regardless of the images' characteristics. The analysis of the registration methods in this study can be expected to provide useful information to the utilization of multimodality images in delineating target volume for radiation treatment planning and in many other clinical applications.