1.Exposure Conditions in Measurement of Visceral Adipose Tissue by CT
Taku FUDEYA ; Yoshitake ITO ; Akitoshi YOSHIKAWA ; Shoichiro OTAKE
Journal of the Japanese Association of Rural Medicine 2009;58(2):68-72
[Purposes] In 2005, criteria for diagnosing the metabolic syndrome was officially announced. Accumulation of fat tissue in and around the abdomen is one of the metabolic syndrome. To assess the excess fat tissue, the waist circumference is measured. Computed tomography can work out the area of the intra-abdominal fat tissue. In this study, we examined exposure conditions with a view to reducing dose and radiation risk.[Methods] A CT phantom model simulating the abdominal area at the level of the umbilicus was made for obtaining the pictures of the intra-abdominal fat tissue with the tube current ranging from 10 mA to 250 mA set at intervals of 10 mA. The average CT value for the area of mimic fat tissue obtained by each scan and standard deviations were worked out.[Results] The size of fat tissue and the mean CT value were constant with a tube current of 100 mA or over. [Conclusions] It was found possible to measure the area of intra-abdominal fat tissue with a tube current of 100 mA. Therefore, our findings showed that the radiation exposure could be reduced by 60% when compared with the 250 mA CT used at a clinical setting.
Adipose tissue
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X-Ray Computed Tomography
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mA
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Radiation
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Accident due to exposure to weather conditions
2.Fundamental Study of Reduced Radiation Exposure of Virtual Endoscopy by 16 DAS MDCT
Yasuji YAMADA ; Masanori KATOH ; Makoto NAGAI ; Shingo OKAZAKI ; Shunichi NAKAMURA ; Tsukasa SUGAWARA ; Norio KONDOH ; Kencho MIYASHITA ; Akira FUJINAGA
Journal of the Japanese Association of Rural Medicine 2006;55(5):459-464
Our aim was to study the scan protocol of 16 DAS (Data Acquisition System) multidetector-row CT (MDCT) and to ascertain whether we could reduce radiation exposure and scanning time, while maintaing image quality in the Virtual endoscopy (VE).We made a mimic gastrointestinal tract and examined the result by changing a scan protocol of 16 DAS MDCT.We found that a reduction of radiation exposure and scanning time depended on slice width, angle of the table, rotation time, table speed, mAs/slice and resolution.The study confirmed that it was possible to use the scan protocol of MDCT with a radiographic dose of 40% and scanning time of 50%, without changing image quality in the VE.
Radiation
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amsonic acid
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Protocols documentation
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Endoscopy
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Accident due to exposure to weather conditions