Evaluation of ¹⁸F-FDG uptake in lung parenchyma compensating for tissue fraction: Comparison between non-enhanced low dose CT and intravenous contrast-enhanced diagnostic CT

Abstract

Aim To determine how the presence of intravenous (IV) contrast-enhanced CT influences SUV measurements corrected for both attenuation and tissue fraction.

Material and Methods Eighteen patients with different malignancies, free from lung disorders, lung cancer or metastasis, were prospectively recruited when referred for staging with combined ¹⁸F-FDG-PET/CT examination. A non-enhanced low-dose CT over the chest was immediately followed by a whole-body IV contrast-enhanced diagnostic CT and finally the PET acquisition. PET data were reconstructed with attenuation correction based on the two CT data sets. The lungs were segmented in the CT images and lung density was measured. Uptake of ¹⁸F-FDG in lung parenchyma was recorded using both non-enhanced and IV contrast-enhanced CT as well as with and without compensation for lung aeration. A comparison of SUV values of corrected and uncorrected PET images was performed.

Results There was no significant difference between low dose PET/CT and IV contrast-enhanced PET/CT when removing the impact of air fraction (p = 0.093 for the right lung and p = 0.085 for the left lung). When tissue fraction was not corrected for, there was a significant difference between low dose PET/CT and IV contrast enhanced PET/CT used for attenuation correction (p = 0.006 for the right lung and p = 0.015 for the left lung).

Conclusion There was only a marginal effect on the assessement of SUV in the lung tissue when using IV contrast enhanced CT for attenuation correction when the air fraction was accounted for.

Zusammenfassung

Ziel Bestimmung, inwiefern die intravenöse (IV) kontrastverstärkte CT Einfluss auf die SUV-Messungen mit Korrektur von beiden, der Schwächung und des Gewebeanteils, hat.

Material und Methoden Es wurden 18 Patienten mit verschiedenen Malignomen, ohne Lungenerkrankungen, Lungenkarzinome oder Metastasen, prospektiv rekrutiert, bei denen ein Staging mittels kombinierter 18F-FDG-PET/CT-Untersuchung durchgeführt wurde. Auf eine nicht-verstärkte Niedrigdosis-CT der Brust folgte unmittelbar darauf eine Ganzkörper IV kontrastverstärkte diagnostische CT und schließlich die PET-Akquisition. Die PET-Daten wurden mit Schwächungskorrektur auf Basis der beiden CT-Datensätze rekonstruiert. Die Lungen wurden in den CT-Aufnahmen segmentiert und die Lungendichte gemessen. Die Aufnahme von 18F-FDG in das Lungenparenchym wurde sowohl mit nicht-verstärkter als auch mit IV kontrastverstärkter CT sowie mit und ohne Kompensation der Lungenbelüftung erfasst. Die SUV-Werte der korrigierten und nicht-korrigierten PET-Bilder wurden verglichen.

Ergebnisse Es gab keinen signifikanten Unterschied zwischen Niedrigdosis PET/CT und IV kontrastverstärkter PET/CT wenn man den Einfluss der Luftfraktion entfernt (p = 0,093 für die rechte Lunge und p = 0,085 für die linke Lunge). Wenn nicht nach Gewebeanteil korrigiert wurde, gab es einen signifikanten Unterschied beim Einsatz von Niedigdosis PET/CT und IV kontrastverstärkter PET/CT zur Schwächungskorrektur (p = 0,006 für die rechte Lunge und p = 0,015 für die linke Lunge).

Schlussfolgerung Es gab es nur einen marginalen Effekt auf die Beurteilung des SUV im Lungengewebe bei Verwendung von IV kontrastverstärkter CT zur Schwächungskorrektur, wenn der Luftanteil berücksichtigt wurde.

Key words

PET/CT - attenuation correction - lung parenchyma - IV contrast agent

Schlüsselwörter

PET/CT - Schwächungskorrektur - Lungenparenchym - IV Kontrastmittel

• References

• 1 Scherer PM, Chen DL. Imaging Pulmonary Inflammation. J Nucl Med: official publication, Society of Nuclear Medicine 2016; 57 (11) 1764-1770
• 2 Boellaard R, Delgado-Bolton R, Oyen WJ. et al. FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0. Eur J Nucl Med Mol Imaging 2015; 42 (02) 328-354
• 3 Antoch G, Freudenberg LS, Beyer T. et al. To enhance or not to enhance? ¹⁸F-FDG and CT contrast agents in dual-modality ¹⁸F-FDG PET/CT. J Nucl Med 2004; 45 (Suppl. 01) 56s-65s
• 4 Lardinois D, Weder W, Hany TF. et al. Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography. N Engl J Med 2003; 348 (25) 2500-2507
• 5 Cronin CG, Prakash P, Blake MA. Oral and IV contrast agents for the CT portion of PET/CT. Am J Roentgenol 2010; 195 (01) W5-W13
• 6 Garrett PR, Meshkov SL, Perlmutter GS. Oral contrast agents in CT of the abdomen. Radiology 1984; 153 (02) 545-546
• 7 Nakamoto Y, Chin BB, Kraitchman DL. et al. Effects of nonionic intravenous contrast agents at PET/CT imaging: phantom and canine studies. Radiology 2003; 227 (03) 817-824
• 8 Antoch G, Freudenberg LS, Egelhof T. et al. Focal tracer uptake: a potential artifact in contrast-enhanced dual-modality PET/CT scans. J Nucl Med 2002; 43 (10) 1339-1342
• 9 Mawlawi O, Erasmus JJ, Munden RF. et al. Quantifying the effect of IV contrast media on integrated PET/CT: clinical evaluation. Am J Roentgenol 2006; 186 (02) 308-319
• 10 Bunyaviroch T, Turkington TG, Wong TZ. et al. Quantitative effects of contrast enhanced CT attenuation correction on PET SUV measurements. Mol Imaging Biol 2008; 10 (02) 107-113
• 11 Berthelsen AK, Holm S, Loft A. et al. PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients. Eur J Nucl Med Mol Imaging 2005; 32 (10) 1167-1175
• 12 Townsend DW. Positron emission tomography/computed tomography. Semin Nucl Med 2008; 38 (03) 152-166
• 13 Aschoff P, Plathow C, Beyer T. et al. Multiphase contrast-enhanced CT with highly concentrated contrast agent can be used for PET attenuation correction in integrated PET/CT imaging. Eur J Nucl Med Mol Imaging 2012; 39 (02) 316-325
• 14 Yau YY, Chan WS, Tam YM. et al. Application of intravenous contrast in PET/CT: does it really introduce significant attenuation correction error?. J Nucl Med 2005; 46 (02) 283-291
• 15 Rhodes CG, Wollmer P, Fazio F. et al. Quantitative measurement of regional extravascular lung density using positron emission and transmission tomography. J Comput Assist Tomogr 1981; 5 (06) 783-791
• 16 Wollmer P, Pride NB, Rhodes CG. et al. Measurement of pulmonary erythromycin concentration in patients with lobar pneumonia by means of positron tomography. Lancet 1982; 2 (8312): 1361-1364
• 17 Holman BF, Cuplov V, Millner L. et al. Improved correction for the tissue fraction effect in lung PET/CT imaging. Phys Med Biol 2015; 60 (18) 7387-7402
• 18 Lambrou T, Groves AM, Erlandsson K. et al. The importance of correction for tissue fraction effects in lung PET: preliminary findings. Eur J Nucl Med Mol Imaging 2011; 38 (12) 2238-2246
• 19 Wollmer P, Rhodes CG, Hughes JM. Regional extravascular density and fractional blood volume of the lung in interstitial disease. Thorax 1984; 39 (04) 286-293
• 20 Wang W, Hu Z, Gualtieri EE. et al., editors. Systematic and Distributed Time-of-Flight List Mode PET Reconstruction. 2006 IEEE Nuclear Science Symposium Conference Record 2006 29 Oct.–1 Nov. 2006.
• 21 Surti S. Update on time-of-flight PET imaging. J Nucl Med 2015; 56 (01) 98-105
• 22 Torigian DA, Dam V, Chen X. et al. In vivo quantification of pulmonary inflammation in relation to emphysema severity via partial volume corrected (18)F-FDG-PET using computer-assisted analysis of diagnostic chest CT. Hell J Nucl Med 2013; 16 (01) 12-18
• 23 Cohade C, Osman M, Marshall LN. et al. PET-CT: accuracy of PET and CT spatial registration of lung lesions. Eur J Nucl Med Mol Imaging 2003; 30 (05) 721-726
• 24 Gilman MD, Fischman AJ, Krishnasetty V. et al. Optimal CT breathing protocol for combined thoracic PET/CT. Am J Roentgenol 2006; 187 (05) 1357-1360
• 25 Pantin CF, Valind SO, Sweatman M. et al. Measures of the inflammatory response in cryptogenic fibrosing alveolitis. Am Rev Respir Dis 1988; 138 (05) 1234-1241
• 26 Hansson L, Ohlsson T, Valind S. et al. Glucose utilisation in the lungs of septic rats. Eur J Nucl Med 1999; 26 (10) 1340-1344
• 27 Motegi SI, Fujiwara C, Sekiguchi A. et al. Clinical value of (18) F-fluorodeoxyglucose positron emission tomography/computed tomography for interstitial lung disease and myositis in patients with dermatomyositis. J Dermatol 2019; 46 (03) 213-218
• 28 Kouranos V, Hansell DM, Sharma R. et al. Advances in imaging of cardiopulmonary involvement in sarcoidosis. Curr Opin Pulm Med 2015; 21 (05) 538-545
• 29 Ito K, Minamimoto R, Yamashita H. et al. Evaluation of Wegener’s granulomatosis using ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography. Ann Nucl Med 2013; 27 (03) 209-216
• 30 Tateishi U, Hasegawa T, Seki K. et al. Disease activity and ¹⁸F-FDG uptake in organising pneumonia: semi-quantitative evaluation using computed tomography and positron emission tomography. Eur J Nucl Med Mol Imaging 2006; 33 (08) 906-912
• 31 Garpered S, Minarik D, Diaz S. et al. Measurement of airway inflammation in current smokers by positron emission tomography. Clin Physiol Funct Imaging 2019; 36 (06) 393-398