title: N staging of lung cancer patients with PET/MRI using a three-segment model attenuation correction algorithm: initial experience.
abstract: OBJECTIVE
  Evaluate the performance of PET/MRI at tissue interfaces with different attenuation values for detecting lymph node (LN) metastases and for accurately measuring maximum standardised uptake values (SUVmax) in lung cancer patients.
  
  
  METHODS
  Eleven patients underwent PET/CT and PET/MRI for staging, restaging or follow-up of suspected or known lung cancer. Four experienced readers determined the N stage of the patients for each imaging method in a randomised blinded way. Concerning metastases, SUVmax of FDG-avid LNs were measured in PET/CT and PET/MRI in all patients. A standard of reference was created with a fifth experienced independent reader in combination with a chart review. Results were analysed to determine interobserver agreement, SUVmax correlation between CT and MRI (three-segment model) attenuation correction and diagnostic performance of the two techniques.
  
  
  RESULTS
  Overall interobserver agreement was high (κ = 0.86) for PET/CT and substantial (κ = 0.70) for PET/MRI. SUVmax showed strong positive correlation (Spearman's correlation coefficient = 0.93, P < 0.001) between the two techniques. Diagnostic performance of PET/MRI was slightly inferior to that of PET/CT, without statistical significance (P > 0.05).
  
  
  CONCLUSIONS
  PET/MRI using three-segment model attenuation correction for LN staging in lung cancer shows a strong parallel to PET/CT in terms of SUVmax, interobserver agreement and diagnostic performance.
  
  
  CONCLUSIONS
  •F18-FDG PET/MRI shows similar performance to F18-FDG PET/CT in lung cancer N staging. •PET/MRI has substantial interobserver agreement in N staging. •A three-segment model attenuation correction is reliable for assessing the mediastinum.
authors.affiliation: Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH, USA, andreskohan1@gmail.com.
authors.forename: A A
authors.initials: AA
authors.lastname: Kohan
authors.forename: J A
authors.initials: JA
authors.lastname: Kolthammer
authors.forename: J L
authors.initials: JL
authors.lastname: Vercher-Conejero
authors.forename: C
authors.initials: C
authors.lastname: Rubbert
authors.forename: S
authors.initials: S
authors.lastname: Partovi
authors.forename: R
authors.initials: R
authors.lastname: Jones
authors.forename: K A
authors.initials: KA
authors.lastname: Herrmann
authors.forename: P
authors.initials: P
authors.lastname: Faulhaber
mesh_terms: D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*