Effective and organ doses from common CT examinations in one general hospital in Tehran, Iran

• Autorzy: Khoramian D. , Hashemi B.

Identyfikatory

DOI

10.1515/pjmpe-2017-0013

• Języki publikacji: EN

Abstrakty

EN

Purpose: It is well known that the main portion of artificial sources of ionizing radiation to human results from X-ray imaging techniques. However, reports carried out in various countries have indicated that most of their cumulative doses from artificial sources are due to CT examinations. Hence assessing doses resulted from CT examinations is highly recommended by national and international radiation protection agencies. The aim of this research has been to estimate the effective and organ doses in an average human according to 103 and 60 ICRP tissue weighting factor for six common protocols of Multi-Detector CT (MDCT) machine in a comprehensive training general hospital in Tehran/Iran. Methods: To calculate the patients' effective dose, the CT-Expo2.2 software was used. Organs/tissues and effective doses were determined for about 20 patients (totally 122 patients) for every one of six typical CT protocols of the head, neck, chest, abdomen-pelvis, pelvis and spine exams. In addition, the CT dosimetry index (CTDI) was measured in the standard 16 and 32 cm phantoms by using a calibrated pencil ionization chamber for the six protocols and by taking the average value of CT scan parameters used in the hospital compared with the CTDI values displayed on the console device of the machine. Results: The values of the effective dose based on the ICRP 103 tissue weighting factor were: 0.6, 2.0, 3.2, 4.2, 2.8, and 3.9 mSv and based on the ICRP 60 tissue weighting factor were: 0.9, 1.4, 3, 7.9, 4.8 and 5.1 mSv for the head, neck, chest, abdomen-pelvis, pelvis, spine CT exams respectively. Relative differences between those values were -22, 21, 23, -6, -31 and 16 percent for the head, neck, chest, abdomen-pelvis, pelvis, spine CT exams, respectively. The average value of CTDI_v calculated for each protocol was: 27.32 ± 0.9, 18.08 ± 2.0, 7.36 ± 2.6, 8.84 ± 1.7, 9.13 ± 1.5, 10.42 ± 0.8 mGy for the head, neck, chest, abdomen-pelvis and spine CT exams, respectively. Conclusions: The highest organ doses delivered by various CT exams were received by brain (15.5 mSv), thyroid (19.00 mSv), lungs (9.3 mSv) and bladder (9.9 mSv), bladder (10.4 mSv), stomach (10.9 mSv) in the head, neck, chest, and the abdomen-pelvis, pelvis, and spine respectively. Except the neck and spine CT exams showing a higher effective dose compared to that reported in Netherlands, other exams indicated lower values compared to those reported by any other country.

Słowa kluczowe

EN

effective dose; organ dose; computed tomography dose index; CTDI; MDCT; CT protocols

• Wydawca: Polskie Towarzystwo Fizyki Medycznej
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2017
• Tom: Vol. 23, Iss. 3
• Strony: 73--79
• Opis fizyczny: Bibliogr. 30 poz., rys., tab.

Twórcy

autor

Khoramian D.

• Department of Medical Physics, Tarbiat Modares University, Tehran, Iran

autor

Hashemi B.

• Department of Medical Physics, Tarbiat Modares University, Tehran, Iran

Bibliografia

• [1] Durand DJ, Mahesh M. Understanding CT dose display. J Am Coll Radiol. 2012;9(9):669-671.
• [2] Saltybaeva N, Jafari ME, Hupfer M, Kalender WA. Estimates of effective dose for CT scans of the lower extremities. Radiology. 2014;273(1):153-159.
• [3] Deak PD, Smal Y, Kalender WA. Multisection CT protocols: Sex-and age-specific conversion factors used to determine effective dose from dose-length product. Radiology. 2010;257(1):158-166.
• [4] Haddadi G, Mehdizadeh S, Haddadi MB, Meshkibaf MH. Evaluation of Absorbed Dose of Critical Organ in Rando Phantom under Head, Abdomen and Pelvis Spiral CT Scan by Thermo Luminescent Dosimetery - TLD. J Fasa Univ Med Sci. 2011;1(3):131-135.
• [5] Zarb F, McEntee M, Rainford L. Maltese CT doses for commonly performed examinations demonstrate alignment with published DRLs across Europe. Radiat Prot Dosimetry. 2012;150(2):198-206.
• [6] Shrimpton P, Hillier M, Lewis M, Dunn M. Doses from computed tomography (CT) examinations in the UK-2003 review: National Radiological Protection Board. Chilton, UK; 2005.
• [7] Hart D, Wall B, Hillier M, Shrimpton P. Frequency and collective dose for medical and dental x-ray examination in the UK, 2008: Health Protection Agency. Chilton, UK; 2010.
• [8] van der Molen AJ, Schilham A, Stoop P, et al. A national survey on radiation dose in CT in The Netherlands. Insights Imaging. 2013;4(3):383-390.
• [9] ICRP Publication 103, Valentin J. The 2007 recommendations of the international commission on radiological protection: Elsevier Oxford; 2007.
• [10] Friberg EG, Widmark A, Hauge IHR. National collection of local diagnostic reference levels in Norway and their role in optimization of X-ray examinations. Norwegian Radiation Protection Authority, Osteras, Norway. 2008.
• [11] Treier R, Aroua A, Verdun F, et al. Patient doses in CT examinations in Switzerland: implementation of national diagnostic reference levels. Radiat Prot Dosimetry. 2010;142(2-4):244-254.
• [12] Brenner DJ, Hall EJ. Computed tomography - an increasing source of radiation exposure. N Engl J Med. 2007;357(22):2277-2284.
• [13] Foley SJ, McEntee MF, Rainford L. Establishment of CT diagnostic reference levels in Ireland. Br J Radiol. 2014;85(1018):1390-1397.
• [14] Saravanakumar A, Vaideki K, Govindarajan K, Jayakumar S. Establishment of diagnostic reference levels in computed tomography for select procedures in Pudhuchery, India. J Med Phys/Association of Medical Physicists of India. 2014;39(1):50-55.
• [15] Matsunaga Y, Kawaguchi A, Kobayashi K, et al. Effective radiation doses of CT examinations in Japan: a nationwide questionnaire-based study. Br J Radiol. 2016;89(1058):20150671.
• [16] Somatom Emotion Technical Specifications. available at: http://www.healthcare.siemens.com/.
• [17] CT systems and hardware. 2002. available at: http://www.impactscan.org/.
• [18] Pantos I, Thalassinou S, Argentos S, et al. Adult patient radiation doses from non-cardiac CT examinations: a review of published results. Br J Radiol. 2011;84(1000):293-303.
• [19] Hsieh J, Computed tomography: principles, design, artifacts, and recent advances, 2009: SPIE Bellingham, WA.
• [20] Mutic S, Palta JR, Butker EK, et al. Quality assurance for computed-tomography simulators and the computed-tomography-simulation process: report of the AAPM Radiation Therapy Committee Task Group No. 66. Med Phys. 2003;30(10):2762-92.
• [21] Yates SJ, Pike LC, Goldstone KE. Effect of multislice scanners on patient dose from routine CT examinations in East Anglia. Br J Radiol. 2004;77(918):472-478.
• [22] Ngaile JE, Msaki P. Estimation of Patient Organ Doses from Computed Tomography Examinations in Tanzania. J Appl Clin Med. Phys. 2006;7(3):80-94.
• [23] Lee E, Lamart S, Little MP, Lee C. Database of normalised computed tomography dose index for retrospective CT dosimetry. J Radiol Prot. 2014;34(2):363-388.
• [24] Stamm G, Nagel HD. [CT-expo--a novel program for dose evaluation in CT]. RoFo: Fortschr Röntgenstr. 2002;174(12):1570-1576.
• [25] ICRP Publication 60: 1990 Recommendations of the International Commission on Radiological Protection: Elsevier Health Sciences; 1991.
• [26] Shrimpton MCH, Meeson S, Golding SJ. Doses from Computed Tomography (CT) Examinations in the UK – 2011 Review.
• [27] Palorini F, Origgi D, Granata C, et al. Adult exposures from MDCT including multiphase studies: first Italian nationwide survey. Eur Radiol. 2014;24(2):469-483.
• [28] Muhogora W, Nyanda A, Ngoye W, Shao D. Radiation doses to patients during selected CT procedures at four hospitals in Tanzania. Eur J Radiol. 2006;57(3):461-467.
• [29] Hiles PA, Brennen SE, Scott SA, Davies JH. A survey of patient dose and image quality for computed tomography scanners in Wales. J Radiol Prot. 2001;21(4):345.
• [30] Christner JA, Kofler JM, McCollough CH. Estimating Effective Dose for CT Using Dose–Length Product Compared With Using Organ Doses: Consequences of Adopting International Commission on Radiological Protection Publication 103 or Dual-Energy Scanning. AJR Am J Roentgenol. 2010;194(4):881-889.