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Dose optimization: a review of CT imaging for PET attenuation correction

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Abstract

Purpose

Review limitations and benefits of various options for CT-based attenuation correction for PET/CT studies.

Methods

With the combination of PET and CT, came the combination of patient radiation dose from the two imaging modalities. Modern advances in CT technology provide opportunities to design CT acquisitions for attenuation correction allowing for the optimization of the attenuation correction acquisition for specific clinical purposes. We reviewed published literature, accepted practices, and the authors’ experience, to identify and classify various tailored approaches for CT attenuation correction of PET emission data.

Results

ImageWisely recommends three broad categories for dose optimization of attenuation correction in PET/CT imaging: (1) attenuation correction at diagnostic CT quality (PET/CTD); (2) attenuation correction for anatomic localization only of PET images (PET/CTAL); and (3) for PET attenuation correction only (PET/CTAC). The advantages, disadvantages, and dosimetry for each approach are considered.

Conclusions

Modern dose reduction techniques allow some CTAL and CTAC exams to have a sufficient image quality for anatomic localization at radiation dose levels equivalent to the previous radionuclide attenuation correction method with [68-Ge/68-Ga] transmission sources. Thus, the major justifications for combining diagnostic quality CTD with PET would be to provide excellent anatomic image correlation in the cases, where subtle functional or lesion uptake requires greater localization refinement, and to reduce patient dose by removing the CTAC or CTAL exam in conjunction with a separate diagnostic CT in lieu of a single CTD exam. The choice of method depends on a variety of factors, including institutional and physician preference and experience, and technology availability.

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References

  1. Bailey DL (1998) Transmission scanning in emission tomography. Eur J Nucl Med 25:774–787

    Article  CAS  PubMed  Google Scholar 

  2. Zaidi H, Hasegawa B (2003) Determination of the attenuation map in emission tomography. J Nucl Med 44:291–315

    PubMed  Google Scholar 

  3. Kinahan PE, Hasegawa BH, Beyer T (2003) X-ray-based attenuation correction for positron emission tomography/computed tomography scanners. Semin Nucl Med 33:166–179

    Article  PubMed  Google Scholar 

  4. Portnow LH, Vaillancourt DE, Okun MS (2013) The history of cerebral PET scanning: from physiology to cutting-edge technology. Neurology 80:952–956

    Article  PubMed  PubMed Central  Google Scholar 

  5. Nutt R (2002) The history of positron emission tomography. Mol Imag Biol 4:11–26

    Article  Google Scholar 

  6. Bergstrom M, Litton J, Eriksson L, Bohm C, Blomqvist G (1982) Determination of object contour from projections for attenuation correction in cranial positron emission tomography. J Comput Assist Tomogr 6:365–372

    Article  CAS  PubMed  Google Scholar 

  7. Carson RE, Daube-Witherspoon ME, Green MV (1988) A method for postinjection PET transmission measurements with a rotating source. J Nucl Med 29:1558–1567

    CAS  PubMed  Google Scholar 

  8. Kinahan PE, Townsend DW, Beyer T, Sashin D (1998) Attenuation correction for a combined 3D PET/CT scanner. Med Phys 25:2046–2053

    Article  CAS  PubMed  Google Scholar 

  9. Karp JS, Muehllehner G, Qu H, Yan XH (1995) Singles transmission in volume-imaging PET with a 137Cs source. Phys Med Biol 40:929–944

    Article  CAS  PubMed  Google Scholar 

  10. Wu TH, Huang YH, Lee JJ, Wang SY, Wang SC, Su CT, Chen LK, Chu TC (2004) Radiation exposure during transmission measurements: comparison between CT- and germanium-based techniques with a current PET scanner. Eur J Nucl Med Mol Imaging 31:38–43

    Article  PubMed  Google Scholar 

  11. Ostertag H, Kubler WK, Doll J, Lorenz WJ (1989) Measured attenuation correction methods. Eur J Nucl Med 15:722–726

    Article  CAS  PubMed  Google Scholar 

  12. Bacharach SL (2007) PET/CT attenuation correction: breathing lessons. J Nucl Med 48:677–679

    Article  PubMed  Google Scholar 

  13. deKemp RA, Nahmias C (1994) Attenuation correction in PET using single photon transmission measurement. Med Phys 21:771–778

    Article  CAS  PubMed  Google Scholar 

  14. Townsend DW (2008) Combined positron emission tomography-computed tomography: the historical perspective. Semin Ultrasound CT MR 29:232–235

    Article  PubMed  PubMed Central  Google Scholar 

  15. Beyer T, Townsend DW, Brun T, Kinahan PE, Charron M, Roddy R, Jerin J, Young J, Byars L, Nutt R (2000) A combined PET/CT scanner for clinical oncology. J Nucl Med 41:1369–1379

    CAS  PubMed  Google Scholar 

  16. O’Connor MK, Kemp BJ (2006) Single-photon emission computed tomography/computed tomography: basic instrumentation and innovations. Semin Nucl Med 36:258–266

    Article  PubMed  Google Scholar 

  17. Brix G, Lechel U, Glatting G, Ziegler SI, Munzing W, Muller SP, Beyer T (2005) Radiation exposure of patients undergoing whole-body dual-modality 18F-FDG PET/CT examinations. J Nucl Med 46:608–613

    CAS  PubMed  Google Scholar 

  18. Fahey FH (2009) Dosimetry of pediatric PET/CT. J Nucl Med 50:1483–1491

    Article  CAS  PubMed  Google Scholar 

  19. Sureshbabu W, Mawlawi O (2005) PET/CT imaging artifacts. J Nucl Med Technol 33:156–161

    PubMed  Google Scholar 

  20. Mawlawi O, Erasmus JJ, Pan T, Cody DD, Campbell R, Lonn AH, Kohlmyer S, Macapinlac HA, Podoloff DA (2006) Truncation artifact on PET/CT: impact on measurements of activity concentration and assessment of a correction algorithm. AJR Am J Roentgenol 186:1458–1467

    Article  PubMed  Google Scholar 

  21. Antoch G, Freudenberg LS, Beyer T, Bockisch A, Debatin JF (2004) To enhance or not to enhance? 18F-FDG and CT contrast agents in dual-modality 18F-FDG PET/CT. J Nucl Med 45(Suppl 1):56S–65S

    CAS  PubMed  Google Scholar 

  22. Berthelsen AK, Holm S, Loft A, Klausen TL, Andersen F, Hojgaard L (2005) PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients. Eur J Nucl Med Mol Imaging 32:1167–1175

    Article  CAS  PubMed  Google Scholar 

  23. Cronin CG, Prakash P, Blake MA (2010) Oral and IV contrast agents for the CT portion of PET/CT. AJR Am J Roentgenol 195:W5–W13

    Article  PubMed  Google Scholar 

  24. Yau YY, Chan WS, Tam YM, Vernon P, Wong S, Coel M, Chu SK (2005) Application of intravenous contrast in PET/CT: does it really introduce significant attenuation correction error? J Nucl Med 46:283–291

    PubMed  Google Scholar 

  25. Alessio AM, Kinahan PE, Manchanda V, Ghioni V, Aldape L, Parisi MT (2009) Weight-based, low-dose pediatric whole-body PET/CT protocols. J Nucl Med 50:1570–1577

    Article  PubMed  Google Scholar 

  26. Brady SL, Shulkin BL (2015) Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction. Med Phys 42:558–566

    Article  PubMed  Google Scholar 

  27. Brix G, Lechel U, Glatting G, Ziegler SI, Munzing W, Muller SP, Beyer T (2005) Radiation exposure of patients undergoing whole-body dual-modality 18F-FDG PET/CT examinations. J Nucl Med 46:608–613

    CAS  PubMed  Google Scholar 

  28. Huang B, Law MW, Khong PL (2009) Whole-body PET/CT scanning: estimation of radiation dose and cancer risk. Radiology 251:166–174

    Article  PubMed  Google Scholar 

  29. NCRP (2009) NCRP Report No 160: ionizing radiation exposure of the population of the United States, pp 1–387

  30. Boellaard R, O’Doherty MJ, Weber WA, Mottaghy FM, Lonsdale MN, Stroobants SG, Oyen WJ, Kotzerke J, Hoekstra OS, Pruim J, Marsden PK, Tatsch K, Hoekstra CJ, Visser EP, Arends B, Verzijlbergen FJ, Zijlstra JM, Comans EF, Lammertsma AA, Paans AM, Willemsen AT, Beyer T, Bockisch A, Schaefer-Prokop C, Delbeke D, Baum RP, Chiti A, Krause BJ (2010) FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0. Eur J Nucl Med Mol Imaging 37:181–200

    Article  PubMed  Google Scholar 

  31. Kamel E, Hany TF, Burger C, Treyer V, Lonn AH, von Schulthess GK, Buck A (2002) CT vs 68Ge attenuation correction in a combined PET/CT system: evaluation of the effect of lowering the CT tube current. Eur J Nucl Medicine Mol Imaging 29:346–350

    Article  CAS  Google Scholar 

  32. Jackson J, Pan T, Tonkopi E, Swanston N, Macapinlac HA, Rohren EM (2011) Implementation of automated tube current modulation in PET/CT: prospective selection of a noise index and retrospective patient analysis to ensure image quality. J Nucl Med Technol 39:83–90

    Article  PubMed  Google Scholar 

  33. Xia T, Alessio AM, De Man B, Manjeshwar R, Asma E, Kinahan PE (2012) Ultra-low dose CT attenuation correction for PET/CT. Phys Med Biol 57:309–328

    Article  PubMed  Google Scholar 

  34. Yu L, Li H, Fletcher JG, McCollough CH (2010) Automatic selection of tube potential for radiation dose reduction in CT: a general strategy. Med Phys 37:234–243

    Article  PubMed  Google Scholar 

  35. Fahey FH, Palmer MR, Strauss KJ, Zimmerman RE, Badawi RD, Treves ST (2007) Dosimetry and adequacy of CT-based attenuation correction for pediatric PET: phantom study. Radiology 243:96–104

    Article  PubMed  Google Scholar 

  36. Mattsson S, Andersson M, Soderberg M (2015) Technological advances in hybrid imaging and impact on dose. Radiat Prot Dosim 165:410–415

    Article  Google Scholar 

  37. Rui X, Cheng L, Long Y, Fu L, Alessio AM, Asma E, Kinahan PE, De Man B (2015) Ultra-low dose CT attenuation correction for PET/CT: analysis of sparse view data acquisition and reconstruction algorithms. Phys Med Biol 60:7437–7460

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Matsutomo N, Nagaki A, Sasaki M (2015) Validation of the CT iterative reconstruction technique for low-dose CT attenuation correction for improving the quality of PET images in an obesity-simulating body phantom and clinical study. Nucl Med Commun 36:839–847

    Article  PubMed  Google Scholar 

  39. De Man B, Nuyts J, Dupont P, Marchal G, Suetens P (2001) An iterative maximum-likelihood polychromatic algorithm for CT. IEEE Trans Med Imaging 20:999–1008

    Article  PubMed  Google Scholar 

  40. Alessio AM, Kinahan PE. CT protocol selection in PET-CT imaging,” (ImageWisely.org, http://www.imagewisely.org/~/media/ImageWisely-Files/NucMed/CT-Protocol-Selection-in-PETCT-Imaging.pdf, 2012)

  41. Alessio AM, Kinahan PE, Cheng PM, Vesselle H, Karp JS (2004) PET/CT scanner instrumentation, challenges, and solutions. Radiol Clin North Am 42:1017–1032

    Article  PubMed  Google Scholar 

  42. Delbeke D, Coleman RE, Guiberteau MJ, Brown ML, Royal HD, Siegel BA, Townsend DW, Berland LL, Parker JA, Hubner K, Stabin MG, Zubal G, Kachelriess M, Cronin V, Holbrook S (2006) Procedure guideline for tumor imaging with 18F-FDG PET/CT 1.0. J Nucl Med 47:885–895

    PubMed  Google Scholar 

  43. Xia T, Alessio AM, Kinahan PE(2010) Limits of ultra-low dose CT attenuation correction for PET/CT. In: IEEE Nuclear Science Symposium Conference Record, vol 1997: pp 3074–3079

  44. Lecomte R (2009) Novel detector technology for clinical PET. Eur J Nucl Med Mol Imaging 36(Suppl 1):S69–S85

    Article  PubMed  Google Scholar 

  45. Budinger TF (1998) PET instrumentation: what are the limits? Semin Nucl Med 28:247–267

    Article  CAS  PubMed  Google Scholar 

  46. Nehmeh SA, Erdi YE, Rosenzweig KE, Schoder H, Larson SM, Squire OD, Humm JL (2003) Reduction of respiratory motion artifacts in PET imaging of lung cancer by respiratory correlated dynamic PET: methodology and comparison with respiratory gated PET. J Nucl Med 44:1644–1648

    PubMed  Google Scholar 

  47. Callahan J, Kron T, Schneider-Kolsky M, Hicks RJ (2011) The clinical significance and management of lesion motion due to respiration during PET/CT scanning. Cancer Imaging 11:224–236

    PubMed  PubMed Central  Google Scholar 

  48. Hope TA, Verdin EF, Bergsland EK, Ohliger MA, Corvera CU, Nakakura EK (2015) Correcting for respiratory motion in liver PET/MRI: preliminary evaluation of the utility of bellows and navigated hepatobiliary phase imaging. EJNMMI Phys 2:21

    Article  PubMed  PubMed Central  Google Scholar 

  49. Matsuzaki Y, Fujii K, Kumagai M, Tsuruoka I, Mori S (2013) Effective and organ doses using helical 4DCT for thoracic and abdominal therapies. J Radiat Res 54:962–970

    Article  PubMed  PubMed Central  Google Scholar 

  50. Krishnasetty V, Bonab AA, Fischman AJ, Halpern EF, Aquino SL (2008) Comparison of standard-dose vs low-dose attenuation correction CT on image quality and positron emission tomographic attenuation correction. J Am Coll Radiol 5:579–584

    Article  PubMed  Google Scholar 

  51. Brady S, Moore B, Yee B, Kaufman R (2014) Implementation of ASiR™ reconstruction for substantial dose reduction in pediatric CT without affecting image noise. Radiology 270:223–231

    Article  PubMed  Google Scholar 

  52. Brady SL, Yee BS, Kaufman RA (2012) Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: a pediatric oncology perspective. Med Phys 39:5520–5531

    Article  CAS  PubMed  Google Scholar 

  53. Hara AK, Paden RG, Silva AC, Kujak JL, Lawder HJ, Pavlicek W (2009) Iterative reconstruction technique for reducing body radiation dose at CT: feasibility study. AJR Am J Roentgenol 193:764–771

    Article  PubMed  Google Scholar 

  54. Prakash P, Kalra MK, Digumarthy SR, Hsieh J, Pien H, Singh S, Gilman MD, Shepard JA (2010) Radiation dose reduction with chest computed tomography using adaptive statistical iterative reconstruction technique: initial experience. J Comput Assist Tomogr 34:40–45

    Article  PubMed  Google Scholar 

  55. Silva AC, Lawder HJ, Hara A, Kujak J, Pavlicek W (2010) Innovations in CT dose reduction strategy: application of the adaptive statistical iterative reconstruction algorithm. AJR Am J Roentgenol 194:191–199

    Article  PubMed  Google Scholar 

  56. Singh S, Kalra MK, Gilman MD, Hsieh J, Pien HH, Digumarthy SR, Shepard JA (2011) Adaptive statistical iterative reconstruction technique for radiation dose reduction in chest CT: a pilot study. Radiology 259:565–573

    Article  PubMed  Google Scholar 

  57. Yang B-H, Wu N-Y, Chen G-L, Wu T-H (2016) The optimal protocols of low-dose CT with iterative reconstruction CT in PET/CT scan. J Nucl Med 57:2675

    Article  Google Scholar 

  58. Palmer MR, Fahey FH (2012) Attenuation correction in PET/CT from ultra-low dose CT: photon starvation and iterative CT reconstruction. J Nucl Med 53:2360

    Google Scholar 

  59. Fa-Shun Tsa S-C, Wang H-H, Chou T-L, Jiang L-COu (2014) SAFIRE improves CT image quality in PET/CT scans: An ACR CT phantom test. Ann Nucl Med Mol Imaging 27:3–11

    Google Scholar 

  60. Wong TZ, Paulson EK, Nelson RC, Patz EF Jr, Coleman RE (2007) Practical approach to diagnostic CT combined with PET. AJR Am J Roentgenol 188:622–629

    Article  PubMed  Google Scholar 

  61. Kuehl H, Veit P, Rosenbaum SJ, Bockisch A, Antoch G (2007) Can PET/CT replace separate diagnostic CT for cancer imaging? Optimizing CT protocols for imaging cancers of the chest and abdomen. J Nucl Med 48(Suppl 1):45S–57S

    PubMed  Google Scholar 

  62. Gollub MJ, Hong R, Sarasohn DM, Akhurst T (2007) Limitations of CT during PET/CT. J Nucl Med 48:1583–1591

    Article  PubMed  Google Scholar 

  63. Brechtel K, Klein M, Vogel M, Mueller M, Aschoff P, Beyer T, Eschmann SM, Bares R, Claussen CD, Pfannenberg AC (2006) Optimized contrast-enhanced CT protocols for diagnostic whole-body 18F-FDG PET/CT: technical aspects of single-phase versus multiphase CT imaging. J Nucl Med 47:470–476

    PubMed  Google Scholar 

  64. Beyer T, Antoch G, Bockisch A, Stattaus J (2005) Optimized intravenous contrast administration for diagnostic whole-body 18F-FDG PET/CT. J Nucl Med 46:429–435

    PubMed  Google Scholar 

  65. Nakamoto Y, Chin BB, Kraitchman DL, Lawler LP, Marshall LT, Wahl RL (2003) Effects of nonionic intravenous contrast agents at PET/CT imaging: phantom and canine studies. Radiology 227:817–824

    Article  PubMed  Google Scholar 

  66. Joshi U, Raijmakers PG, Riphagen II, Teule GJ, van Lingen A, Hoekstra OS (2007) Attenuation-corrected vs. nonattenuation-corrected 2-deoxy-2-[F-18]fluoro-d-glucose-positron emission tomography in oncology: a systematic review. Mol Imaging Biol 9:99–105

    Article  PubMed  PubMed Central  Google Scholar 

  67. Blodgett TM, Mehta AS, Mehta AS, Laymon CM, Carney J, Townsend DW (2011) PET/CT artifacts. Clin Imaging 35:49–63

    Article  PubMed  PubMed Central  Google Scholar 

  68. Sun T, Mok GS (2012) Techniques for respiration-induced artifacts reductions in thoracic PET/CT. Quant Imaging Med Surg 2:46–52

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Schilham A, van der Molen AJ, Prokop M, de Jong HW (2010) Overranging at multisection CT: an underestimated source of excess radiation exposure. Radiographics 30:1057–1067

    Article  PubMed  Google Scholar 

  70. Boellaard R, Delgado-Bolton R, Oyen WJ, Giammarile F, Tatsch K, Eschner W, Verzijlbergen FJ, Barrington SF, Pike LC, Weber WA, Stroobants S, Delbeke D, Donohoe KJ, Holbrook S, Graham MM, Testanera G, Hoekstra OS, Zijlstra J, Visser E, Hoekstra CJ, Pruim J, Willemsen A, Arends B, Kotzerke J, Bockisch A, Beyer T, Chiti A, Krause BJ, European Association of Nuclear M (2015) FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0. Eur J Nucl Med Mol Imaging 42:328–354

    Article  CAS  PubMed  Google Scholar 

  71. Beyer T, Antoch G, Muller S, Egelhof T, Freudenberg LS, Debatin J, Bockisch A (2004) Acquisition protocol considerations for combined PET/CT imaging. J Nucl Med 45(Suppl 1):25S–35S

    PubMed  Google Scholar 

  72. Elstrom RL, Leonard JP, Coleman M, Brown RK (2008) Combined PET and low-dose, noncontrast CT scanning obviates the need for additional diagnostic contrast-enhanced CT scans in patients undergoing staging or restaging for lymphoma. Ann Oncol 19:1770–1773

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  73. Acuff S, Osborne DR (2016) Clinical workflow considerations for implementation of continuous bed motion PET/CT. J Nucl Med Technol 44:55–58. doi:10.2967/jnmt.116.172171

    Article  PubMed  Google Scholar 

  74. Jeong SW, Kim HG, Gwon JB, Shin YM, Kim YH (2014) Effect of the dose reduction applied low dose for PET/CT according to CT attenuation correction method. J Nucl Med 55:2635

    Google Scholar 

  75. Berker Y, Li Y (2016) Attenuation correction in emission tomography using the emission data—a review. Med Phys 43:807–832

    Article  PubMed  PubMed Central  Google Scholar 

  76. Daftary A (2010) PET-MRI: challenges and new directions. Indian J Nucl Med 25:3–5

    Article  PubMed  PubMed Central  Google Scholar 

  77. Judenhofer MS, Wehrl HF, Newport DF, Catana C, Siegel SB, Becker M, Thielscher A, Kneilling M, Lichy MP, Eichner M, Klingel K, Reischl G, Widmaier S, Rocken M, Nutt RE, Machulla HJ, Uludag K, Cherry SR, Claussen CD, Pichler BJ (2008) Simultaneous PET-MRI: a new approach for functional and morphological imaging. Nat Med 14:459–465

    Article  CAS  PubMed  Google Scholar 

  78. Pichler BJ, Kolb A, Nagele T, Schlemmer HP (2010) PET/MRI: paving the way for the next generation of clinical multimodality imaging applications. J Nucl Med 51:333–336

    Article  PubMed  Google Scholar 

  79. Spick C, Herrmann K, Czernin J (2016) 18F-FDG PET/CT and PET/MRI perform equally well in cancer: evidence from studies on more than 2300 patients. J Nucl Med 57:420–430

    Article  PubMed  PubMed Central  Google Scholar 

  80. Zaidi H, Becker M (2016) The Promise of Hybrid PET\/MRI: technical advances and clinical applications. IEEE Signal Process Mag 33:67–85

    Article  Google Scholar 

  81. Vogelius E, Shah S (2017) Pediatric PET/MRI: a review. J Am Osteopath Coll Radiol 6:15–27

    Google Scholar 

  82. Wagenknecht G, Kaiser HJ, Mottaghy FM, Herzog H (2013) MRI for attenuation correction in PET: methods and challenges. Magma 26:99–113

    Article  PubMed  Google Scholar 

  83. Schafer JF, Gatidis S, Schmidt H, Guckel B, Bezrukov I, Pfannenberg CA, Reimold M, Ebinger M, Fuchs J, Claussen CD, Schwenzer NF (2014) Simultaneous whole-body PET/MR imaging in comparison to PET/CT in pediatric oncology: initial results. Radiology 273:220–231

    Article  PubMed  Google Scholar 

  84. Defrise M, Rezaei A, Nuyts J (2012) Time-of-flight PET data determine the attenuation sinogram up to a constant. Phys Med Biol 57:885–899

    Article  PubMed  Google Scholar 

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  1. Department of Diagnostic Imaging, St Jude Children’s Research Hospital, 262 Danny Thomas Pl, Memphis, TN, 38105, USA

    Samuel L. Brady & Barry L. Shulkin

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  1. Samuel L. Brady
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Brady, S.L., Shulkin, B.L. Dose optimization: a review of CT imaging for PET attenuation correction. Clin Transl Imaging 5, 359–371 (2017). https://doi.org/10.1007/s40336-017-0232-0

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