Comparison of Size specific dose estimates (SSDE) and CTDIvol values in patients undergoing CT examinations of abdomen and pelvis
DOI:
https://doi.org/10.7577/radopen.5326Emneord (Nøkkelord):
SSDE, CTDIvol, Weight, Effective diameter, f-sizeSammendrag
Introduction: Computed Tomography Dose Index volume (CTDIvol) is a measure of radiation output of the CT scanner and does not represent patient dose. It often underestimates the radiation dose being given to small children and smaller adults and overestimates the dose to larger patients. The use of Size Specific Dose Index (SSDE) helps convert CTDIvol into more patient size specific radiation dose and is a better measure of estimated patient dose than CTDIvol.
Methods: This cross-sectional study was conducted in the Department of Radiology and Imaging of Tribhuvan University Teaching Hospital (TUTH), Maharajgunj, Nepal. CT scans were performed on the Siemens Somaton Definition AS+ 128 slice scanner. During 96 CT examinations of the abdomen and pelvis collected over a period of 4 months, effective diameters were calculated from the AP and Lateral diameters at the mid-liver region. These were used to determine the conversion factors which were then used to convert the CTDIvol values to SSDE. Obtained SSDE values were compared with the displayed CTDIvol values.
Results: The average CTDIvol was found to be 9.42 ± 3.26 mGy and the average SSDE was found to be 13.48 ± 3.53 mGy. Moderate positive correlation (r=+0.52, p<0.001) was found between CTDIvol and patient weight and low positive correlation (r=+0.17, p=0.08) was found between SSDE and patient weight. Similarly, moderate positive correlation (r=+0.5, p<0.001) was found between CTDIvol and patient BMI and low positive correlation (r=+0.14, p=0.15) was found between SSDE and patient BMI.
Conclusion: In comparison with SSDE, CTDIvol seemed to underestimate the patient dose estimate by 30.11%. CTDIvol values showed dependency with patient weight and BMI, this dependency was significantly reduced when those values were converted into SSDE (i.e. r=+0.52, p<0.001 (CTDIvol and Patient weight) vs. r=+0.17, p=0.08 (SSDE and Patient weight) and r=+0.5, p<0.001 (CTDIvol and BMI) vs. r=+0.14, p=0.15 (SSDE and BMI). Thus, providing more concrete evidence to the fact that SSDE values are a more reliable patient dose estimate since it addresses the patient’s size.
Referanser
Pierce DA, Preston DL, Pierce DA, Preston DL. Radiation-Related Cancer Risks at Low Doses among Atomic Bomb Survivors Radiation-Related Cancer Risks at Low Doses among Atomic Bomb Survivors. 2000;154(2):178–86. https://doi.org/10.1667/0033-7587(2000)154[0178:rrcral]2.0.co;2
Brenner DJ, Elliston CD, Hall EJ, Berdon WE. Estimated Risks of Radiation-. Am Roentgen Ray Soc. 2001;176(February):289–96. https://doi.org/10.2214/ajr.176.2.1760289
Albert JM. Radiation risk from CT: Implications for cancer screening. Am J Roentgenol. 2013;201(1):81–7. https://doi.org/10.2214/ajr.12.9226
Brenner DJ, Hall EJ. Computed Tomography — An Increasing Source of Radiation Exposure. N Engl J Med [Internet]. 2007 Nov 29;357(22):2277–84. https://doi.org/10.1056/nejmra072149
Pearce MS, Salotti JA, Little MP, McHugh K, Lee C, Kim KP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet. 2012 Aug;380(9840):499–505. https://doi.org/10.1016/s0140-6736(12)60815-0
Bushberg J, Siebert JA. The Essential Physics of Medical Imaging , 3rd ed. 2012 Mar;387–9.
Bauhs JA, Vrieze TJ, Primak AN, Bruesewitz MR, McCollough CH. CT dosimetry: Comparison of measurement techniques and devices. Radiographics. 2008;28(1):245–53. https://doi.org/10.1148/rg.281075024
Huda W, Mettler FA. Volume CT Dose Index and Dose-Length Product Displayed. Radiology. 2011;258(1):236–42. https://doi.org/10.1148/radiol.10100297
AAPM. Size-Specific Dose Estimates (SSDE) in Pediatric and Adult Body CT Examinations 2011 Jan. https://www.aapm.org/pubs/reports/detail.asp?docid=143
McCollough CH, Leng S, Yu L, Cody DD, Boone JM, McNitt-Gray MF. CT dose index and patient dose : They are not the same thing. Radiology. 2011;259(2):311–6. https://doi.org/10.1148/radiol.11101800
McCollough C, Cody D, Edyvean S, Geise R, Gould B, Keat N, et al. The Measurement, Reporting, and Management of Radiation Dose in CT. 2008 Jan. https://www.aapm.org/pubs/reports/detail.asp?docid=97
Seibert JA, Boone JM, Wootton-Gorges SL, Lamba R. Dose is not always what it seems: Where very misleading values can result from volume CT dose index and dose length product. J Am Coll Radiol. 2014;11(3):233–7. https://doi.org/10.1016/j.jacr.2013.10.010
Brink JA, Morin RL. Size-specific dose estimation for CT: How should it be used and what does it mean? Radiology. 2012;265(3):666–8. https://doi.org/10.1148/radiol.12121919
Pourjabbar S. Size-specific dose estimates: Localizer or transverse abdominal computed tomography images? World J Radiol. 2014;6(5):210–7. https://doi.org/10.4329/wjr.v6.i5.210
Supanich M, Peck D. Size-Specific Dose Estimate as an Indicator of Absorbed Organ Dose in CT Abdomen and Pelvis Studies. Med Phys. 2012. https://doi.org/10.1118/1.4736074
Moore BM, Brady SL, Mirro AE, Kaufman RA. Size-specific dose estimate (SSDE) provides a simple method to calculate organ dose for pediatric CT examinations. Med Phys. 2014;41(7). https://doi.org/10.1118/1.4884227
American Association of Physicists in Medicine, Todd. AAPM TG 220: Use of water equivalent diameter for calculating patient size and size-specific dose estimates (SSDE) in CT. AAPM Rep 220. 2014;(220):1–23.
Christner JA, Braun NN, Jacobsen MC, Carter RE, Kofler JM, McCollough CH. Size-specific Dose Estimates for Adult Patients at CT of the Torso. Radiology 2012 Dec;265(3):841–7. https://doi.org/10.1148/radiol.12112365
Brady SL, Kaufman RA. Investigation of American Association of Physicists in medicine report 204 size-specific dose estimates for pediatric CT implementation. Radiology. 2012;265(3):832–40. https://doi.org/10.1148/radiol.12120131
Brady SL, Mirro AE, Moore BM, Kaufman RA. How to appropriately calculate effective dose for CT using either size-specific dose estimates or dose-length product. Am J Roentgenol. 2015;204(5):953–8. https://doi.org/10.2214/ajr.14.13317
Leng S, Shiung M, Duan X, Yu L, Zhang Y, McCollough CH. Size-specific dose estimates for chest, abdominal, and pelvic CT: Effect of intrapatient variability in water-equivalent diameter. Radiology. 2015;276(1):184–90. https://doi.org/10.1148/radiol.15142160
Tsujiguchi T, Obara H, Ono S, Saito Y, Kashiwakura I. Consideration of the usefulness of a size-specific dose estimate in pediatric CT examination. J Radiat Res. 2018;59(4):430–5. https://doi.org/10.1093/jrr/rry022
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Opphavsrett 2024 Sweta Joshi, Sharma Paudel, Shanta Lall Shrestha, Surendra Maharjan
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