the Comparison of Radiation Dose and Image Quality from Using automatic tube Current Modulation system and Fixed tube Current technique for Chest Computed tomography examination
Keywords:
Radiation dose, CT Image quality, Chest CT, Automatic tube current modulationAbstract
At the present time, automatic tube current modulation (ATCM) system for computed tomography (CT) scanner is widely used. Department of radiation diagnostic, Lopburi cancer hospital has been used the ATCM system for a Chest CT examination. The aim of this research was to compare radiation dose and image noise from the use of a fixed tube current time product of 250 mAs and those from using the Toshiba ATCM system with different image noise levels such as high quality (HQ), quality (Q), standard (STD), low dose (LD) and screening (S). The experiment was carried out in a phantom. The tube current times products, volume computed tomography dose index (CTDIvol), dose length product (DLP) obtained from the scans were recorded and the effective dose was calculated. The skin dose was also measured using NanodotTM dosimeters and the image noise was measured using ImageJ. The results reveal that the setting up of image noise levels of HQ, Q, STD, LD and S, when compared to the fixed 250 mAs, resulted in reductions of the average CTDIvol, DLP and E by 14%, 33%, 47%, 80% and 86%, but increases the image noise by 8%, 13%, 22% ,69% and 91% respectively. Although the lowest value of E of 2.7 mSv from the image noise of “S” level was 7 times lower than that obtained from the fixed mAs technique, it was 2 times higher than the value recommended by the national lung screening trial research, U.S. In the future, the use of Iterative reconstruction technique with ATCM system should be studied, in order to reduce the radiation dose while maintaining the image quality. Moreover, the complete quantitative image quality assessment and qualitative assessment by radiologists should be performed to select an appropriate protocol used for a specific lesion detection.
References
Mettler FA Jr, Huda W, Yoshizumi TT, Mahesh M. Effective doses in radiology and diagnostic nuclear medicine: a catalog Radiology. 2008; 248: 254–63.
Greess H, Wolf H, Baum U, Lell M, Pirkl M, Kalender W, et al. Dose reduction in computed tomography by attenuation-based online modulation of tube current: evaluation of six anatomical regions. Eur Radiol 2000; 10:391-4.
Kalra MK, Maher MM, Toth TL, Schmidt B, Westerman BL, Morgan HT, et al. Techniques and applications of automatic tube current modulation for CT. Radiology 2004; 233:649-57.
Mulkens TH, Bellinck P, Baeyaert M, Ghysen D, Van Dijck X, Mussen E, et al. Use of an automatic exposure control mechanism for dose optimization in multi-detector row CT examinations: clinical evaluation. Radiology 2005; 237:213–23.
McCollough CH, Bruesewitz MR, Kofler JM Jr. CT dose reduction and dose management tools: overview of available options. Radio Graphics 2006; 26:503–12.
Gudjónsdóttir J, Ween B, Olsen DR. Optimal use of AEC in CT: a literature review. Radiol Technol 2010; 81:309-17.
Moro L, Panizza D, D’Ambrosio D, Carne I. Considerations on an automatic computed tomography tube current modulation system. Radiat Prot Dosimetry 2013; 156:525-30.
Papadakis AE, Perisinakis K, Damilakis J. Automatic exposure control in pediatric and adult multidetector CT examinations: a phantom study on dose reduction and image quality. Med Phys 2008; 35:4567-76.
American Academy of Family Physicians. Lung cancer clinical recommendations.[Internet].[cite 2016 Sep 9]. Available from: http://www.aafp.org/patient-care/ clinical-recommendations/all/lung-cancer.html.
Jaklitsch MT, Jacobson FL, Austin JH, Field JK, Jett JR, Keshavjee S, ea al. The American Association for Thoracic Surgery guidelines for lung cancer screening using low-dose computed tomography scans for lung cancer survivors and other high-risk groups. J Thorac Cardiov Surg 2012; 144:33–8. นายสิริชัย เธียรรัตนกุล บริษัท นากาเซ่ (ประเทศไทย) จำกัด ที่ให้ความอนุเคราะห์อ่านค่าปริมาณรังสีจาก NanodotsTM นายชาคร เหลืองทองคำ และนายเอกชัย ธุวะคำ นิสิตรังสีเทคนิค คณะสหเวชศาสตร์ มหาวิทยาลัยนเรศวร ที่ให้ความช่วยเหลือในการเก็บข้อมูล
Smith RA, Andrews K, Brooks D, DeSantis CE, Fedewa SA, Lortet-Tieulent J, et al. Cancer screening in the United States, 2016: A review of current American Cancer Society guidelines and current issues in cancer screening.
CA Cancer J Clin 2016; 66:96–114.
Soderberg M, Gunnarsson M. Automatic exposure control in computed tomography—an evaluation of systems from different manufacturers. Acta Radiologica 2010; 51:625–34.
Singh S, Kalra MK, Thrall JH, Mahesh M. Automatic exposure control in CT: applications and limitations. J am Coll Radiol 2011; 8:446–9.
Shrimpton PC, Hillier MC, Lewis MA, Dunn M. National survey of doses from CT in the UK: 2003. Br J Radiol 2006; 79:968–80.
The National Lung Screening Trial Research Team. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med 2011; 365:395-409.
Larke FJ, Kruger RL, Cagnon CH, Flynn MJ, McNitt-Gray MM, Wu X, et al. Estimated radiation dose associated with low-dose chest CT of average-size participants in the National Lung Screening Trial. AJR Am J Roentgenol 2011; 197:1165–9.
Yanagawa M, Gyobu T, Leung AN, Kawai M, Kawata Y, Sumikawa H, et al. Ultra-low-dose CT of the lung: effect of iterative reconstruction techniques on image quality. Acad Radiol 2014; 21:695–703.
Kim Y, Kim YK, Lee BE, Lee SJ, Ryu YJ, Lee JH, et al. Ultra-low-dose CT of the thorax using iterative reconstruction: evaluation of image quality and radiation dose reduction. AJR Am J Roentgenol 2015; 204:1197–1202.
Neroladaki A, Botsikas D, Boudabbous S, Becker CD, Montet X. Computed tomography of the chest with model-based iterative reconstruction using a radiation exposure similar to chest X-ray examination: preliminary observations. Eur Radiol 2013; 23:360–6.
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