Reducing contrast media dosage by dual-energy simulated monochromatic spectral CT for liver dynamic contrast enhanced study

• Main Authors: Chieh-Chung Ho, 何介中
• Other Authors: Ran-Chou Chen
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/teug92

碩士 === 國立陽明大學 === 生物醫學影像暨放射科學系 === 106 === Since the advent of the computed tomography (CT) in 1971, computed tomography tends to be an increasingly important examination by clinicians in the world. The numbers of contrast medium usage have been elevated with the increase of inspection volume in CT scan. With the increased use of iodinated contrast medium, contrast-induced nephropathy(CIN) has become an important issue of iatrogenic acute renal failure. Noticeable, reducing the dosage of iodinated contrast medium is the cornerstone to the prevention of the contrast-induced nephropathy. The purpose of this study is to evaluate the feasibility of reducing routine iodine contrast medium dosage by using dual energy computed tomography(DECT) simulated monochromatic spectral imaging in liver dynamic imaging examination. Between August 2017 and February 2018, a total of 60 patients who were suspected with focal liver lesions were enrolled in our study for liver dynamic contrast enhanced examination. The subjects were divided into two groups: traditional single energy computed tomography(SECT) and dual energy spectral computed tomography, each group has 30 subjects with different contrast medium dosage. The effects of different scanning techniques and contrast medium dosage to the imaging quality of liver dynamic enhanced scan were evaluated by measuring the CT number of abdominal aorta, hepatic portal vein and liver parenchyma in different scanning phases. The results showed that there were significant differences in the mean total dosage of the contrast medium administered in the two groups (27.3±4.92 g I vs. 22.6±4.39 g I; p<0.001). In liver dynamic enhanced imaging, the image quality is significantly better by using dual energy spectrum computed tomography with lower contrast medium dosage than the traditional single energy computed tomography. The contrast to noise ratio(CNR) of abdominal aorta during arterial phase is better in DECT (36.5±10.19) compare to the SECT (27.5±6.82) (p<0.001). The CNR of liver parenchyma during portal venous phase is also better in DECT (5.1±1.66) than in the SECT (4.2±1.23) (p=0.03). While in the image quality to radiation dose assessment, the figure of merit (FOM) of the abdominal aorta were (79.0 ±58.27 vs. 138.5±94.43; p=0.005), respectively and the FOM of the liver parenchyma were (0.12±0.14 vs. 0.32±0.39; p=0.012), respectively, during the arterial phase. In the portal venous phase, the FOM of the liver parenchyma is (1.8±1.34 vs. 2.7±1.86; p=0.03) between SECT and DECT. According to the results of our present study. In the implementation of liver dynamic enhanced imaging, dual energy spectrum computed tomography could be used to obtain a better image quality with lower dosage of iodinated contrast medium than the conventional single energy computed tomography without increasing the radiation dose to the patients.