title: A 16-channel MR coil for simultaneous PET/MR imaging in breast cancer.
abstract: OBJECTIVE
  To implement and evaluate a dedicated receiver array coil for simultaneous positron emission tomography/magnetic resonance (PET/MR) imaging in breast cancer.
  
  
  METHODS
  A 16-channel receiver coil design was optimized for simultaneous PET/MR imaging. To assess MR performance, the signal-to-noise ratio, parallel imaging capability and image quality was evaluated in phantoms, volunteers and patients and compared to clinical standard protocols. For PET evaluation, quantitative (18) F-FDG PET images of phantoms and seven patients (14 lesions) were compared to images without the coil. In PET image reconstruction, a CT-based template of the coil was combined with the MR-acquired attenuation correction (AC) map of the phantom/patient.
  
  
  RESULTS
  MR image quality was comparable to clinical MR-only examinations. PET evaluation in phantoms showed regionally varying underestimation of the standardised uptake value (SUV; mean 22 %) due to attenuation caused by the coil. This was improved by implementing the CT-based coil template in the AC (<2 % SUV underestimation). Patient data indicated that including the coil in the AC increased the SUV values in the lesions (21 ± 9 %).
  
  
  CONCLUSIONS
  Using a dedicated PET/MR breast coil, state-of-the-art MRI was possible. In PET, accurate quantification and image homogeneity could be achieved if a CT-template of this coil was included in the AC for PET image reconstruction.
  
  
  CONCLUSIONS
  • State-of-the-art breast MRI using a dedicated PET/MR breast coil is feasible. • A multi-channel design facilitates shorter MR acquisition times via parallel imaging. • An MR coil inside a simultaneous PET/MR system causes PET photon attenuation. • Including a coil CT-template in PET image reconstruction results in recovering accurate quantification.
authors.affiliation: Nuklearmedizinische Klinik, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany, isabel.dregely@gmail.com.
authors.forename: Isabel
authors.initials: I
authors.lastname: Dregely
authors.forename: Titus
authors.initials: T
authors.lastname: Lanz
authors.forename: Stephan
authors.initials: S
authors.lastname: Metz
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Mueller
authors.forename: Marika
authors.initials: M
authors.lastname: Kuschan
authors.forename: Manoj
authors.initials: M
authors.lastname: Nimbalkar
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Bundschuh
authors.forename: Sibylle I
authors.initials: SI
authors.lastname: Ziegler
authors.forename: Axel
authors.initials: A
authors.lastname: Haase
authors.forename: Stephan G
authors.initials: SG
authors.lastname: Nekolla
authors.forename: Markus
authors.initials: M
authors.lastname: Schwaiger
mesh_terms: D001940:Breast / Q000000981:diagnostic imaging / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis*; D004867:Equipment Design; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18