Integrated versus separate reading of F-18 FDG-PET/CT and MRI for abdominal malignancies: effect on staging outcomes and diagnostic confidence

Lisa A. Min, Wouter V. Vogel, Max J. Lahaye, Monique Maas, Maarten L. Donswijk, Erik Vegt, Miranda Kusters, Henry J. Zijlmans, Katarzyna Jozwiak, Sander Roberti, Regina G. H. Beets-Tan, Doenja M. J. Lambregts*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Objective Abdominal cancer patients increasingly undergo multimodality imaging. This study evaluates effects of integrated reading of PET/CT and abdominal MRI on staging outcomes and diagnostic confidence compared to "routine" separate reading.

Methods In total, N=201 patients who underwent abdominal MRI and whole-body F-18 FDG-PET/CT within 14 days were retrospectively analyzed. Original MRI and PET/CT reports were retrieved and reported findings translated into a 5-point confidence score (1=definitely benign to 5=definitely malignant) for 7 standardized regions (primary tumor/regional lymph nodes/distant lymph nodes/liver/lung/bone/peritoneum) per patient. Two-reader teams (radiologist + nuclear medicine physician) then performed integrated reading of the images using the same scoring system.

Results Integrated reading led to discrepant findings in 59 of 201 (29%) of patients, with potential clinical impact in 25 of 201 (12%). Equivocal scores decreased from 5.7% (PET/CT) and 5.4% (MRI) to 3.2% (p=0.05 and p=0.14). Compared to the original PET/CT reports, integrated reading led to increased diagnostic confidence in 8.9% versus decreased confidence in 6.6% (p=0.26). Compared with the original MRI reports, an increase in confidence occurred in 9.6% versus a decrease in 6.9% (p=0.18). The effect on diagnostic confidence was most pronounced in lymph nodes (p=0.08 vs. MRI), cervical cancer (p=0.03 vs. MRI), and recurrent disease staging (p=0.06 vs. PET/CT).

Conclusions Integrated PET/CT+MRI reading alters staging outcomes in a substantial proportion of cases with potential clinical impact in 1 out of 9 patients. It can also have a small positive effect on diagnostic confidence, particularly in lymph nodes and cervical cancer, and in post-treatment settings. These findings support further collaboration between radiology and nuclear medicine disciplines.

Original languageEnglish
Pages (from-to)6900-6910
Number of pages11
JournalEuropean Radiology
Issue number12
Publication statusPublished - 22 May 2019


  • Positron emission tomography computed tomography
  • Magnetic resonance imaging
  • Multimodal imaging
  • Neoplasms

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