Incidental 18F-FDG uptake in the colon: value of contrast-enhanced CT correlation with colonoscopic findings

  • Julian KirchnerEmail author
  • Benedikt M. Schaarschmidt
  • Firas Kour
  • Lino M. Sawicki
  • Ole Martin
  • Johannes Bode
  • Stephan vom Dahl
  • Verena Keitel
  • Dieter Häussinger
  • Christina Antke
  • Christian Buchbender
  • Gerald Antoch
  • Philipp Heusch
Original Article
Part of the following topical collections:
  1. Oncology – Digestive tract



To evaluate the impact of morphological information derived from contrast-enhanced CT in the characterization of incidental focal colonic uptake in 18F-FDG PET/CT examinations.


A total of 125 patients (female: n = 53, male: n = 72) that underwent colonoscopy secondary to contrast-enhanced, full-dose PET/CT without special bowel preparation were included in this retrospective study. PET/CT examinations were assessed for focal colonic tracer uptake in comparison with the background. Focal tracer uptake was correlated with morphological changes of the colonic wall in the contrast-enhanced CT images. Colonoscopy reports were evaluated for benign, inflammatory, polypoid, precancerous, and cancerous lesions verified by histopathology, serving as a reference standard. Sensitivity, specificity, PPV, NPV, and accuracy for detection of therapeutic relevant findings were calculated for (a) sole focal tracer uptake and (b) focal tracer uptake with correlating CT findings in contrast-enhanced CT.


In 38.4% (48/125) of the patients, a focal 18F-FDG uptake was observed within 67 lesions. Malignant lesions were endoscopically and histopathologically diagnosed in eleven patients, and nine of these were detected by focal 18F-FDG uptake. A total of 34 lesions with impact on short- or long-term patient management (either being pre- or malignant) were detected. Sensitivity, Specificity, PPV, NPV, and accuracy for sole 18F-FDG uptake for this combined group were 54%, 69%, 29%, 85%, and 65%. Corresponding results for focal 18F-FDG uptake with correlating CT findings were 38%, 90%, 50%, 86%, and 80%. This resulted in a statistically significant difference for diagnostic accuracy (p = 0.0001)


By analyzing additional morphological changes in contrast-enhanced CT imaging, the specificity of focal colonic 18F-FDG uptake for precancerous and cancerous lesions can be increased but leads to a considerate loss of sensitivity. Therefore, every focal colonic uptake should be followed up by colonoscopy.


18F-FDG Colon Contrast-enhanced CT 



This publication contains parts of the MD thesis of Firas Kour and is therefore in partial fulfillment of the requirements for an MD thesis at the Medical Faculty of the Heinrich-Heine University, Düsseldorf.

Compliance with ethical standards

Conflicts of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed were in accordance with the ethical standards of the institutional research committee and with the principles of the 1964 Declaration of Helsinki and its later amendments.

Informed consent

Informed consent was waived by the IRB for this retrospective analysis.


  1. 1.
    Rigo P, Paulus P, Kaschten BJ, Hustinx R, Bury T, Jerusalem G, et al. Oncological applications of positron emission tomography with fluorine-18 fluorodeoxyglucose. Eur J Nucl Med. 1996;23:1641–74.CrossRefGoogle Scholar
  2. 2.
    Bar-Shalom R, Valdivia AY, Blaufox MD. PET imaging in oncology. Semin Nucl Med. 2000;30:150–85.CrossRefGoogle Scholar
  3. 3.
    Sobic-Saranovic D, Grozdic I, Videnovic-Ivanov J, Vucinic-Mihailovic V, Artiko V, Saranovic D, et al. The utility of 18F-FDG PET/CT for diagnosis and adjustment of therapy in patients with active chronic sarcoidosis. J Nucl Med. 2012;53:1543–9. Scholar
  4. 4.
    Meller J, Sahlmann CO, Scheel AK. 18F-FDG PET and PET/CT in fever of unknown origin. J Nucl Med. 2007;48:35–45.PubMedGoogle Scholar
  5. 5.
    Israel O, Yefremov N, Bar-Shalom R, Kagana O, Frenkel A, Keidar Z, et al. PET/CT detection of unexpected gastrointestinal foci of 18F-FDG uptake: incidence, localization patterns, and clinical significance. J Nucl Med. 2005;46:758–62.PubMedGoogle Scholar
  6. 6.
    Even-Sapir E, Lerman H, Gutman M, Lievshitz G, Zuriel L, Polliack A, et al. The presentation of malignant tumours and pre-malignant lesions incidentally found on PET-CT. Eur J Nucl Med Mol Imaging. 2006;33:541–52. Scholar
  7. 7.
    Agress H Jr, Cooper BZ. Detection of clinically unexpected malignant and premalignant tumors with whole-body FDG PET: histopathologic comparison. Radiology. 2004;230:417–22. Scholar
  8. 8.
    Weston BR, Iyer RB, Qiao W, Lee JH, Bresalier RS, Ross WA. Ability of integrated positron emission and computed tomography to detect significant colonic pathology: the experience of a tertiary cancer center. Cancer. 2010;116:1454–61. Scholar
  9. 9.
    Tatlidil R, Jadvar H, Bading JR, Conti PS. Incidental colonic fluorodeoxyglucose uptake: correlation with colonoscopic and histopathologic findings. Radiology. 2002;224:783–7. Scholar
  10. 10.
    Peng J, He Y, Xu J, Sheng J, Cai S, Zhang Z. Detection of incidental colorectal tumours with 18F-labelled 2-fluoro-2-deoxyglucose positron emission tomography/computed tomography scans: results of a prospective study. Colorectal Dis. 2011;13:e374–8. Scholar
  11. 11.
    van Kouwen MC, Nagengast FM, Jansen JB, Oyen WJ, Drenth JP. 2-(18F)-fluoro-2-deoxy-D-glucose positron emission tomography detects clinical relevant adenomas of the colon: a prospective study. J Clin Oncol. 2005;23:3713–7. Scholar
  12. 12.
    Treglia G, Calcagni ML, Rufini V, Leccisotti L, Meduri GM, Spitilli MG, et al. Clinical significance of incidental focal colorectal (18)F-fluorodeoxyglucose uptake: our experience and a review of the literature. Colorectal Dis. 2012;14:174–80. Scholar
  13. 13.
    Kei PL, Vikram R, Yeung HW, Stroehlein JR, Macapinlac HA. Incidental finding of focal FDG uptake in the bowel during PET/CT: CT features and correlation with histopathologic results. AJR Am J Roentgenol. 2010;194:W401–6. Scholar
  14. 14.
    Kamel EM, Thumshirn M, Truninger K, Schiesser M, Fried M, Padberg B, et al. Significance of incidental 18F-FDG accumulations in the gastrointestinal tract in PET/CT: correlation with endoscopic and histopathologic results. J Nucl Med. 2004;45:1804–10.PubMedGoogle Scholar
  15. 15.
    Gutman F, Alberini JL, Wartski M, Vilain D, Le Stanc E, Sarandi F, et al. Incidental colonic focal lesions detected by FDG PET/CT. AJR Am J Roentgenol. 2005;185:495–500. Scholar
  16. 16.
    Oh JR, Min JJ, Song HC, Chong A, Kim GE, Choi C, et al. A stepwise approach using metabolic volume and SUVmax to differentiate malignancy and dysplasia from benign colonic uptakes on 18F-FDG PET/CT. Clin Nucl Med. 2012;37:e134–40. Scholar
  17. 17.
    Luboldt W, Volker T, Wiedemann B, Zophel K, Wehrmann U, Koch A, et al. Detection of relevant colonic neoplasms with PET/CT: promising accuracy with minimal CT dose and a standardised PET cut-off. Eur Radiol. 2010;20:2274–85. Scholar
  18. 18.
    Keyzer C, Dhaene B, Blocklet D, De Maertelaer V, Goldman S, Gevenois PA. Colonoscopic findings in patients with incidental colonic focal FDG uptake. AJR Am J Roentgenol. 2015;204:W586–91. Scholar
  19. 19.
    Strum WB. Colorectal adenomas. N Engl J Med. 2016;375:389–90. Scholar
  20. 20.
    Stoop EM, de Haan MC, de Wijkerslooth TR, Bossuyt PM, van Ballegooijen M, Nio CY, et al. Participation and yield of colonoscopy versus non-cathartic CT colonography in population-based screening for colorectal cancer: a randomised controlled trial. Lancet Oncol. 2012;13:55–64. Scholar
  21. 21.
    Schoen RE, Pinsky PF, Weissfeld JL, Yokochi LA, Church T, Laiyemo AO, et al. Colorectal-cancer incidence and mortality with screening flexible sigmoidoscopy. N Engl J Med. 2012;366:2345–57. Scholar
  22. 22.
    Nishihara R, Wu K, Lochhead P, Morikawa T, Liao X, Qian ZR, et al. Long-term colorectal-cancer incidence and mortality after lower endoscopy. N Engl J Med. 2013;369:1095–105. Scholar
  23. 23.
    Chin BB, Wahl RL. 18F-Fluoro-2-deoxyglucose positron emission tomography in the evaluation of gastrointestinal malignancies. Gut. 2003;52(Suppl 4):iv23–9.PubMedPubMedCentralGoogle Scholar
  24. 24.
    Chen LB, Tong JL, Song HZ, Zhu H, Wang YC. (18)F-DG PET/CT in detection of recurrence and metastasis of colorectal cancer. World J Gastroenterol. 2007;13:5025–9.CrossRefGoogle Scholar
  25. 25.
    Shim JH, JH O, Oh SI, Yoo HM, Jeon HM, Park CH, et al. Clinical significance of incidental colonic 18F-FDG uptake on PET/CT images in patients with gastric adenocarcinoma. J Gastrointest Surg. 2012;16:1847–53. Scholar
  26. 26.
    Kim S, Chung JK, Kim BT, Kim SJ, Jeong JM, Lee DS, et al. Relationship between Gastrointestinal F-18-fluorodeoxyglucose accumulation and gastrointestinal symptoms in whole-body PET. Clin Positron Imaging. 1999;2:273–9.CrossRefGoogle Scholar
  27. 27.
    Maruyama M, Koizumi K, Kai S, Kazami A, Handa T. Radiographic diagnosis of early colorectal cancer, with special reference to the superficial type of invasive carcinoma. World J Surg. 2000;24:1036–46. Scholar
  28. 28.
    Klein JL, Okcu M, Preisegger KH, Hammer HF. Distribution, size and shape of colorectal adenomas as determined by a colonoscopist with a high lesion detection rate: Influence of age, sex and colonoscopy indication. United European Gastroenterol J. 2016;4:438–48. Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Julian Kirchner
    • 1
    Email author
  • Benedikt M. Schaarschmidt
    • 1
  • Firas Kour
    • 1
  • Lino M. Sawicki
    • 1
  • Ole Martin
    • 1
  • Johannes Bode
    • 2
  • Stephan vom Dahl
    • 2
  • Verena Keitel
    • 2
  • Dieter Häussinger
    • 2
  • Christina Antke
    • 3
  • Christian Buchbender
    • 1
  • Gerald Antoch
    • 1
  • Philipp Heusch
    • 1
  1. 1.Department of Diagnostic and Interventional Radiology, Medical FacultyUniversity DusseldorfDusseldorfGermany
  2. 2.Clinic for Gastroenterology, Hepatology and Infectious Diseases, Medical FacultyUniversity Hospital Düsseldorf, Heinrich-Heine-UniversityDüsseldorfGermany
  3. 3.Department of Nuclear Medicine, Medical FacultyUniversity DusseldorfDusseldorfGermany

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