|
KMID : 1149020190210020067
|
|
Journal of Korean Society of Computed Tomographic Technology
2019 Volume.21 No. 2 p.67 ~ p.75
|
|
|
Evaluation of GSI(Gemstone Spectral Imaging) Mode for Contrast Reduction in Chest CT
|
|
So Eun-Sup
Shim Ji-Na
Kim Hong-Sik
Yoon Soo-Jung
Kim Yoon-Kuk
Park Soon-Kyoo
|
|
|
Abstract
|
|
|
PURPOSE: Contrast-enhanced CT is on the increase with the development of CT. However, the use of contrast has caused side effects, and various studies have been conducted to minimize side effects. In order to reduce the amount of contrasts used in dual energy CT, we investigated the characteristics of the contrast in each energy region using GSI mode image, and the ways to minimize the use of contrast.
MATERIAL AND METHODS: We performed both phantom and patient study. In the phantom study, monochromatic images of each energy region were obtained by GSI (gemstone spectral imaging) mode in a dual energy CT using phantom which consist of contrast and normal saline in a ratio of 1:5. In addition, the polychromatic images using a single source under the same were obtained and compared with HU, SNR, and CNR values of images in GSI mode. In the patient study, we compared the HU values at six-ROI in monochromatic images of each energy region. The subject of patient study was 30 patients in normal BMI group who underwent chest CT in GSI mode at Yonsei medical center.
RESULT: In phantom study, high HU value was observed in the low energy region. The SNR and CNR of 50 keV monochromatic images were higher than those of single source images by 1.71 times and 1.40 times, respectively. At that time, the HU value of GSI mode was higher than single source by 1.92 times. In the patient study, the HU values of peripheral tissues or organs except for bones were not changed by 40 ~ 140 keV monochromatic images, and the HU values of the contrast showed large changes in 40 ~ 70keV monochromatic images.
CONCLUSIONS: The quality of reconstructed image with GSI mode in 50 keV was similar to that of single source image. In addition, HU values of contrast increased while keeping HU values of muscles, bronchi, and lung parenchyma which contain air. Therefore, chest CT using GSI mode can decrease the dose of contrast so it might contribute to the reduction of contrast side effects.
|
|
|
KEYWORD
|
|
|
GSI, Monochromatic, Contrast
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|