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European Radiology

, Volume 28, Issue 5, pp 1818–1825 | Cite as

Tin-filtered low-dose chest CT to quantify macroscopic calcification burden of the thoracic aorta

  • Christoph Schabel
  • Daniele Marin
  • Dominik Ketelsen
  • Alfredo E. Farjat
  • Georg Bier
  • Mario Lescan
  • Fabian Bamberg
  • Konstantin Nikolaou
  • Malte N. Bongers
Computed Tomography
  • 195 Downloads

Abstract

Objectives

To compare a low-dose, tin-filtered, nonenhanced, high-pitch Sn100 kVp CT protocol (Sn100) with a standard protocol (STP) for the detection of calcifications in the ascending aorta in patients scheduled for cardiac surgery.

Methods

Institutional Review Board approval for this retrospective study was waived and the study was HIPAA-compliant. The study included 192 patients (128 men; age 68.8 ± 9.9 years), of whom 87 received the STP and 105 the Sn100 protocol. Size-specific dose estimates (SSDE) and radiation doses were obtained using dose monitoring software. Two blinded readers evaluated image quality on a scale from 1 (low) to 5 (high) and the extent of calcifications of the ascending aorta on a scale from 0 (none) to 10 (high), subdivided into 12 anatomic segments.

Results

The Sn100 protocol achieved a mean SSDE of only 0.5 ± 0.1 mGy and 0.20 ± 0.04 mSv compared with the mean SSDE of 5.4 ± 2.2 mGy achieved with the STP protocol (p < 0.0001). Calcification burden was associated with age (p < 0.0001), but was independent of protocol with mean calcification scores of 0.48 ± 1.23 (STP) and 0.55 ± 1.25 (Sn100, p = 0.18). Reader agreement was very good (STP κ = 0.87 ± 0.02, Sn100 κ = 0.88 ± 0.01). The STP protocol provided a higher subjective image quality than the Sn100 protocol: STP median 4, interquartile range 4–5, vs. SN100 3, 3–4; p < 0.0001) and a slightly better depiction of calcification (STP 5, 4–5, vs. Sn100 4, 4–5; p < 0.0001).

Conclusions

The optimized Sn100 protocol achieved a mean SSDE of only 0.5 ± 0.1 mGy while the depiction of calcifications remained good, and there was no systematic difference in calcification burden between the two protocols.

Key points

• Tin-filtered, low-dose CT can be used to assess aortic calcifications before cardiac surgery

• An optimized Sn100 protocol achieved a mean SSDE of only 0.5 ± 0.1 mGy

• The depiction of atherosclerosis of the thoracic aorta was similar with both protocols

• The depiction of relevant thoracic pathologies before cardiac surgery was similar with both protocols

Keywords

Multidetector computed tomography Imaging Radiation exposure Aorta Arteriosclerosis 

Abbreviations

CI

Confidence interval

CTDI

CT dose index

CT

Computed tomography

DLP

Dose–length product

PACS

Picture archiving and communication system

RD

Radiation dose

Sn100

Low-dose, tin-filtered Sn100 kVp CT protocol

SSDE

Size-specific dose estimates

STP

Standard protocol

Notes

Funding

The authors state that this work did not receive any funding.

Compliance with ethical standards

Guarantor

The scientific guarantor of this publication is Dr. Malte Bongers, M.D.

Conflict of interest

The authors declare general relationships with Siemens Healthcare, Forchheim, Germany. Siemens Healthcare was not involved in this study at any time.

Statistics and biometry

Dr. Alfredo Farjat, Ph.D. kindly provided statistical advice for this study and he is listed as one of the authors.

Informed consent

Written informed consent was waived by the Institutional Review Board.

Ethical approval

Institutional Review Board approval was obtained.

Methodology

• retrospective

• case-control study

• performed at one institution

References

  1. 1.
    Blauth CI, Cosgrove DM, Webb BW et al (1992) Atheroembolism from the ascending aorta. An emerging problem in cardiac surgery. J Thorac Cardiovasc Surg 103:1104–1111 discussion 1111-1102PubMedGoogle Scholar
  2. 2.
    van der Linden J, Hadjinikolaou L, Bergman P, Lindblom D (2001) Postoperative stroke in cardiac surgery is related to the location and extent of atherosclerotic disease in the ascending aorta. J Am Coll Cardiol 38:131–135CrossRefPubMedGoogle Scholar
  3. 3.
    Selim M (2007) Perioperative stroke. N Engl J Med 356:706–713CrossRefPubMedGoogle Scholar
  4. 4.
    DeLoach SS, Joffe MM, Mai X, Goral S, Rosas SE (2009) Aortic calcification predicts cardiovascular events and all-cause mortality in renal transplantation. Nephrol Dial Transplant 24:1314–1319CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    den Harder AM, de Heer LM, Meijer RC et al (2016) Effect of computed tomography before cardiac surgery on surgical strategy, mortality and stroke. Eur J Radiol 85:744–750CrossRefGoogle Scholar
  6. 6.
    Anyanwu AC, Filsoufi F, Salzberg SP, Bronster DJ, Adams DH (2007) Epidemiology of stroke after cardiac surgery in the current era. J Thorac Cardiovasc Surg 134:1121–1127CrossRefPubMedGoogle Scholar
  7. 7.
    Gold JP, Torres KE, Maldarelli W, Zhuravlev I, Condit D, Wasnick J (2004) Improving outcomes in coronary surgery: the impact of echo-directed aortic cannulation and perioperative hemodynamic management in 500 patients. Ann Thorac Surg 78:1579–1585CrossRefPubMedGoogle Scholar
  8. 8.
    Sharony R, Bizekis CS, Kanchuger M et al (2003) Off-pump coronary artery bypass grafting reduces mortality and stroke in patients with atheromatous aortas: a case control study. Circulation 108(Suppl 1):II15–II20PubMedGoogle Scholar
  9. 9.
    Royse AG, Royse CF (2009) Epiaortic ultrasound assessment of the aorta in cardiac surgery. Best Pract Res Clin Anaesthesiol 23:335–341CrossRefPubMedGoogle Scholar
  10. 10.
    Akhtar NJ, Markowitz AH, Gilkeson RC (2010) Multidetector computed tomography in the preoperative assessment of cardiac surgery patients. Radiol Clin North Am 48:117–139CrossRefPubMedGoogle Scholar
  11. 11.
    den Harder AM, de Heer LM, Maurovich-Horvat P et al (2016) Ultra low-dose chest CT with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery (CRICKET study): rationale and design of a multicenter randomized trial. J Cardiovasc Comput Tomogr 10:242–245CrossRefGoogle Scholar
  12. 12.
    Kirmani BH, Brazier A, Sriskandarajah S, Azzam R, Keenan DJ (2016) A meta-analysis of computerized tomography scan for reducing complications following repeat sternotomy for cardiac surgery. Interact Cardiovasc Thorac Surg 22:472–479CrossRefPubMedGoogle Scholar
  13. 13.
    Nishi H, Mitsuno M, Tanaka H, Ryomoto M, Fukui S, Miyamoto Y (2010) Who needs preoperative routine chest computed tomography for prevention of stroke in cardiac surgery? Interact Cardiovasc Thorac Surg 11:30–33CrossRefPubMedGoogle Scholar
  14. 14.
    Lee R, Matsutani N, Polimenakos AC, Levers LC, Lee M, Johnson RG (2007) Preoperative noncontrast chest computed tomography identifies potential aortic emboli. Ann Thorac Surg 84:38–41 discussion 42CrossRefPubMedGoogle Scholar
  15. 15.
    Hogue CW Jr, Murphy SF, Schechtman KB, Davila-Roman VG (1999) Risk factors for early or delayed stroke after cardiac surgery. Circulation 100:642–647CrossRefPubMedGoogle Scholar
  16. 16.
    Mack M (2015) Can we make stroke during cardiac surgery a never event? J Thorac Cardiovasc Surg 149:965–967CrossRefPubMedGoogle Scholar
  17. 17.
    Roques F, Nashef SA, Michel P et al (1999) Risk factors and outcome in European cardiac surgery: analysis of the EuroSCORE multinational database of 19030 patients. Eur J Cardiothorac Surg 15:816–822 discussion 822-813CrossRefPubMedGoogle Scholar
  18. 18.
    Huber A, Landau J, Ebner L et al (2016) Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging. Eur Radiol 26:3643–3652CrossRefPubMedGoogle Scholar
  19. 19.
    Park JE, Kim Y, Lee SW, Shim SS, Lee JK, Lee JH (2016) The usefulness of low-dose CT scan in elderly patients with suspected acute lower respiratory infection in the emergency room. Br J Radiol 89:20150654CrossRefPubMedPubMedCentralGoogle Scholar
  20. 20.
    Haubenreisser H, Meyer M, Sudarski S, Allmendinger T, Schoenberg SO, Henzler T (2015) Unenhanced third-generation dual-source chest CT using a tin filter for spectral shaping at 100kVp. Eur J Radiol 84:1608–1613CrossRefPubMedGoogle Scholar
  21. 21.
    Braun FM, Johnson TR, Sommer WH, Thierfelder KM, Meinel FG (2015) Chest CT using spectral filtration: radiation dose, image quality, and spectrum of clinical utility. Eur Radiol 25:1598–1606CrossRefPubMedGoogle Scholar
  22. 22.
    Dewes P, Frellesen C, Scholtz JE et al (2016) Low-dose abdominal computed tomography for detection of urinary stone disease - impact of additional spectral shaping of the X-ray beam on image quality and dose parameters. Eur J Radiol 85:1058–1062CrossRefPubMedGoogle Scholar
  23. 23.
    Vonder M, Pelgrim GJ, Huijsse SE et al (2017) Feasibility of spectral shaping for detection and quantification of coronary calcifications in ultra-low dose CT. Eur Radiol 27:2047–2054CrossRefPubMedGoogle Scholar
  24. 24.
    Gordic S, Morsbach F, Schmidt B et al (2014) Ultralow-dose chest computed tomography for pulmonary nodule detection: first performance evaluation of single energy scanning with spectral shaping. Invest Radiol 49:465–473CrossRefPubMedGoogle Scholar
  25. 25.
    Lim HK, Ha HI, Hwang HJ, Lee K (2016) Feasibility of high-pitch dual-source low-dose chest CT: reduction of radiation and cardiac artifacts. Diagn Interv Imaging 97:443–449CrossRefPubMedGoogle Scholar
  26. 26.
    Hutt A, Duhamel A, Deken V et al (2016) Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT. Eur Radiol 26:1521–1528CrossRefPubMedGoogle Scholar
  27. 27.
    Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics:159–174Google Scholar

Copyright information

© European Society of Radiology 2017

Authors and Affiliations

  1. 1.Department of Diagnostic and Interventional RadiologyUniversity Hospital of TuebingenTuebingenGermany
  2. 2.Department of RadiologyDuke University Medical CenterDurhamUSA
  3. 3.Department of Biostatistics and BioinformaticsDuke University School of MedicineDurhamUSA
  4. 4.Department of NeuroradiologyUniversity Hospital of TuebingenTuebingenGermany
  5. 5.Department of Cardiovascular and Thoracic SurgeryUniversity Hospital of TuebingenTuebingenGermany

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