title: Correlation of the apparent diffusion coefficient (ADC) with the standardized uptake value (SUV) in hybrid 18F-FDG PET/MRI in non-small cell lung cancer (NSCLC) lesions: initial results.
abstract: OBJECTIVE
  To compare the apparent diffusion coefficient (ADC) in non-small cell lung cancer lesions with standardized uptake values (SUV) derived from combined 18F-fluoro-deoxy-glucose-positron emission tomography/magnetic resonance imaging (FDG-PET/MRI) and those derived from FDG-PET/CT.
  
  
  METHODS
  In 18 consecutive patients with histologically proven NSCLC (17 men, 1 woman; mean age, 61 ± 12 years), whole-body FDG-PET/MRI was performed after whole-body FDG-PET/CT. Regions of interest (ROI) encompassing the entire primary tumor were drawn into FDG-PET/CT and FDG-PET/MR images to determine the maximum and mean standardized uptake value (SUVmax; SUVmean) and into ADC parameter maps to assess mean ADC values. Pearson's correlation coefficients were calculated to compare SUV and ADC values.
  
  
  RESULTS
  The SUVmax of NSCLC was 12.3 ± 4.8 [mean ±SD], and the SUVmean was 7.2 ± 2.8 as assessed by FDG-PET/MRI. The SUVmax and SUVmean derived from FDG-PET/CT and FDG-PET/MRI correlated well (R = 0.93; p < 0.001 and R = 0.92; p < 0.001, respectively). The ADCmean of the pulmonary tumors was 187.9 ± 88.8 × 10-5 mm²/s [mean ± SD]. The ADCmean exhibited a significant inverse correlation with the SUVmax (R = -0.72; p < 0.001) as well as with the SUVmean assessed by FDG-PET/MRI (R = -0.71; p < 0.001).
  
  
  CONCLUSIONS
  This simultaneous PET/MRI study corroborates the assumed significant inverse correlation between increased metabolic activity on FDG-PET and restricted diffusion on DWI in NSCLC.Citation Format:
authors.affiliation: Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany, Univ Dusseldorf, Medical Faculty, Düsseldorf.
authors.forename: P
authors.initials: P
authors.lastname: Heusch
authors.forename: C
authors.initials: C
authors.lastname: Buchbender
authors.forename: J
authors.initials: J
authors.lastname: Köhler
authors.forename: F
authors.initials: F
authors.lastname: Nensa
authors.forename: K
authors.initials: K
authors.lastname: Beiderwellen
authors.forename: H
authors.initials: H
authors.lastname: Kühl
authors.forename: R S
authors.initials: RS
authors.lastname: Lanzman
authors.forename: H J
authors.initials: HJ
authors.lastname: Wittsack
authors.forename: B
authors.initials: B
authors.lastname: Gomez
authors.forename: T
authors.initials: T
authors.lastname: Gauler
authors.forename: M
authors.initials: M
authors.lastname: Schuler
authors.forename: M
authors.initials: M
authors.lastname: Forsting
authors.forename: A
authors.initials: A
authors.lastname: Bockisch
authors.forename: G
authors.initials: G
authors.lastname: Antoch
authors.forename: T A
authors.initials: TA
authors.lastname: Heusner
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D015588:Observer Variation; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18