title: Comparative Performance of ¹⁸F-FDG PET/MRI and ¹⁸F-FDG PET/CT in Detection and Characterization of Pulmonary Lesions in 121 Oncologic Patients.
abstract: Our objective was to compare (18)F-FDG PET/MRI (performed using a contrast-enhanced T1-weighted fat-suppressed volume-interpolated breath-hold examination [VIBE]) with (18)F-FDG PET/CT for detecting and characterizing lung lesions in oncologic patients.
  
  
  METHODS
  In 121 oncologic patients with 241 lung lesions, PET/MRI was performed after PET/CT in a single-injection protocol (260 ± 58 MBq of (18)F-FDG). The detection rates were computed for MRI, the PET component of PET/CT, and the PET component of PET/MRI in relation to the CT component of PET/CT. Wilcoxon testing was used to assess differences in lesion contrast (4-point scale) and size between morphologic datasets and differences in image quality (4-point scale), SUVmean, SUVmax, and characterization (benign/malignant) between PET/MRI and PET/CT. Correlation was determined using the Pearson coefficient (r) for SUV and size and the Spearman rank coefficient (ρ) for contrast.
  
  
  RESULTS
  The detection rates for MRI, the PET component of PET/CT, and the PET component of PET/MRI were 66.8%, 42.7%, and 42.3%, respectively. There was a strong correlation in size (r= 0.98) and SUV (r= 0.91) and a moderate correlation in contrast (ρ = 0.48). Image quality was better for PET/CT than for PET/MRI (P< 0.001). Lesion measurements were smaller for MRI than for CT (P< 0.001). SUVmax and SUVmean were significantly higher for PET/MRI than for PET/CT (P< 0.001 each). There was no significant difference in lesion contrast (P= 0.11) or characterization (P= 0.076).
  
  
  CONCLUSIONS
  In the detection and characterization of lung lesions 10 mm or larger, (18)F-FDG PET/MRI and (18)F-FDG PET/CT perform comparably. Lesion size, SUV and characterization correlate strongly between the two modalities. However, the overall detection rate of PET/MRI remains inferior to that of PET/CT because of the limited ability of MRI to detect lesions smaller than 10 mm. Thus, thoracic staging with PET/MRI bears a risk of missing small lung metastases.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, Essen, Germany; and linomorris.sawicki@med.uni-duesseldorf.de.
authors.forename: Lino M
authors.initials: LM
authors.lastname: Sawicki
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, Essen, Germany; and.
authors.forename: Johannes
authors.initials: J
authors.lastname: Grueneisen
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Buchbender
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Benedikt M
authors.initials: BM
authors.lastname: Schaarschmidt
authors.affiliation: Department of Nuclear Medicine, University Duisburg-Essen, Essen, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Gomez
authors.affiliation: Department of Nuclear Medicine, University Duisburg-Essen, Essen, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Ruhlmann
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, Essen, Germany; and.
authors.forename: Axel
authors.initials: A
authors.lastname: Wetter
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, Essen, Germany; and.
authors.forename: Lale
authors.initials: L
authors.lastname: Umutlu
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Heusch
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: MRI; PET/CT; PET/MRI; lesion; lung