Evaluation of Radiation Dose in Computed Tomography Angiography before Transcatheter Aortic Valve Implantation
DOI:
https://doi.org/10.31584/jhsmr.2022910Keywords:
transcatheter aortic valve implantation, computed tomography angiography, radiation dose, computed tomographyAbstract
Objective: To investigate the effective radiation dose and image quality of computed tomography angiography (CTA) before transcatheter aortic valve implantation (TAVI).
Material and Methods: This study involved 65 participants, diagnosed with aortic valve stenosis and examined with CTA before TAVI. The total mAs, kVp, volume CT dose index (CTDIvol), and dose–length product (DLP) in each scanning phase were recorded. The effective dose was calculated by multiplying the DLP by the conversion coefficient (k=0.015 mSv/[mGy.cm]). For quantitative image analysis, circular regions of interest were placed on six levels of the aorta in the axial images. The CT attenuation value, image noise, signal-to-noise ratio, and contrast-to-noise ratio were measured. For qualitative analysis, two radiologists rated the image quality of the aortic root and aortoiliac pathway.
Results: The mean CTDIvol and DLP were 23.59±5.19 mGy and 881.01±193.41 mGy.cm., respectively. The mean effective dose was 13.22±2.90 mSv; the whole-aorta CTA phase received the highest dose, followed by the coronary CTA and coronary artery calcium scoring phases (9.62±2.60, 2.44±1.13, and 1.16±0.55 mSv, respectively). Image quality ranged from good to excellent in all segments of the aorta.
Conclusion: The mean effective radiation dose of the pre-TAVI CT examination using 256-multidetector CT was 22.91± 5.03 mSv. The image quality in the aorta was good to excellent. The main factors that affected the radiation dose were: body mass index, total mAs, and kVp.
References
Latsios G, Spyridopoulos TN, Toutouzas K, Synetos A, Trantalis G, Stathogiannis K, et al. Multi-slice CT (MSCT) imaging in pretrans-catheter aortic valve implantation (TAVI) screening. How to perform and how to interpret. Hellenic J Cardiol 2018;59:3-7. doi: 10.1016/j.hjc.2017.09.013.
Shnayien S, Bressem KK, Beetz NL, Asbach P, Hamm B, Niehues SM. Radiation dose reduction in preprocedural CT imaging for TAVI/TAVR using a novel 3-phase protocol: a single institution’s experience. Rofo 2020;192:1174-82. doi: 10.1055/a-1150-7646.
Annoni AD, Andreini D, Pontone G, Mancini ME, Formenti A, Mushtaq S, et al. CT angiography prior to TAVI procedure using third-generation scanner with wide volume coverage: feasibility, renal safety and diagnostic accuracy for coronary tree. Br J Radiol 2018;91:20180196. doi: 10.1259/bjr.20180196.
Schicchi N, Fogante M, Pirani PE, Agliata G, Piva T, Tagliati C, et al. Third generation dual source CT with ultra-high pitch protocol for TAVI planning and coronary tree assessment: feasibility, image quality and diagnostic performance. Eur J Radiol 2020;122:108749. doi: 10.1016/j.ejrad.2019.108749.
Harries I, Weir-McCall JR, Williams MC, Shambrook J, Roditi G, Bull R, et al. CT imaging prior to transcatheter aortic valve implantation in the UK. Open Heart 2020;7:e001233. doi: 10.1136/openhrt-2019-001233.
Huda W, Mettler FA. Volume CT dose index and dose-length product displayed during CT: what good are they? Radiology 2011;258:236-42. doi: 10.1148/radiol.10100297.
Trattner S, Halliburton S, Thompson CM, Xu Y, Chelliah A, Jambawalikar SR, et al. Cardiac-specific conversion factors to estimate radiation effective dose from dose-length product in computed tomography. JACC Cardiovasc Imaging 2018;11:64- 74. doi: 10.1016/j.jcmg.2017.06.006.
Kok M, Turek J, Mihl C, Reinartz SD, Gohmann RF, Nijssen EC, et al. Low contrast media volume in pre-TAVI CT examinations. Eur Radiol 2016;26:2426-35. doi: 10.1007/s00330-015-4080-x.
Mayurasakorn S, Siriapisith T, Wasinrat J. Influence of heart rate on image quality to identify the best cardiac phase in 16-slice coronary CT angiography. J Med Assoc Thai 2008;91:1076-81.
Villecourt A, Faroux L, Blanpain T, Kinnel M, Mora C, Tassan-Mangina S, et al. Exposure to ionizing radiation in patients undergoing transfemoral transcatheter aortic valve implantation. Am J Cardiol 2020;125:114-9. doi: 10.1016/j. amjcard.2019.09.028.
Miller DL, Schauer D. The ALARA principle in medical imaging. Philosophy 1983;44:595-600.
Lewis S. Exposure technique factors in digital X-ray imaging systems: demonstrating the effect of mAs. Afr J Health Prof Educ 2020;12:50. doi: 10.7196/AJHPE.2020.v12i2.1261.
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