title: Dynamic multi-echo DCE- and DSC-MRI in rectal cancer: Low primary tumor Ktransand ΔR2* peak are significantly associated with lymph node metastasis.
abstract: To implement a dynamic contrast-based multi-echo MRI sequence in assessment of rectal cancer and evaluate associations between histopathologic data and the acquired dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) -MRI parameters.
  
  
  
  This pilot study reports results from 17 patients with resectable rectal cancer. Dynamic contrast-based multi-echo MRI (1.5T) was acquired using a three-dimensional multi-shot EPI sequence, yielding both DCE- and DSC-data following a single injection of contrast agent. The Institutional Review Board approved the study and all patients provided written informed consent. Quantitative analysis was performed by pharmacokinetic modeling on DCE data and tracer kinetic modeling on DSC data. Mann-Whitney U-test and receiver operating characteristics curve statistics was used to evaluate associations between histopathologic data and the acquired DCE- and DSC-MRI parameters.
  
  
  
  For patients with histologically confirmed nodal metastasis, the primary tumor demonstrated a significantly lower Ktransand peak change in R2*, R2*-peakenh, than patients without nodal metastasis, showing a P-value of 0.010 and 0.005 for reader 1, and 0.043 and 0.019 for reader 2, respectively.
  
  
  
  This study shows the feasibility of acquiring DCE- and DSC-MRI in rectal cancer by dynamic multi-echo MRI. A significant association was found between both Ktransand R2*-peakenhin the primary tumor and histological nodal status of the surgical specimen, which may improve stratification of patients to intensified multimodal treatment.
  
  
  
  4 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:194-206.
authors.affiliation: Oslo University Hospital, The Intervention Centre, Oslo, Norway.|University of Oslo, Department of Physics, Blindern, Oslo, Norway.
authors.forename: Endre
authors.initials: E
authors.lastname: Grøvik
authors.affiliation: Akershus University Hospital, Department of Oncology, Lørenskog, Norway.
authors.forename: Kathrine Røe
authors.initials: KR
authors.lastname: Redalen
authors.affiliation: Oslo University Hospital, The Intervention Centre, Oslo, Norway.
authors.forename: Tryggve Holck
authors.initials: TH
authors.lastname: Storås
authors.affiliation: Akershus University Hospital, Department of Radiology, Lørenskog, Norway.
authors.forename: Anne
authors.initials: A
authors.lastname: Negård
authors.affiliation: Akershus University Hospital, Department of Radiology, Lørenskog, Norway.
authors.forename: Stein Harald
authors.initials: SH
authors.lastname: Holmedal
authors.affiliation: Akershus University Hospital, Department of Oncology, Lørenskog, Norway.|University of Oslo, Faculty of Medicine, Blindern, Oslo, Norway.
authors.forename: Anne Hansen
authors.initials: AH
authors.lastname: Ree
authors.affiliation: Akershus University Hospital, Department of Oncology, Lørenskog, Norway.|University of Oslo, Faculty of Medicine, Blindern, Oslo, Norway.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Meltzer
authors.affiliation: Oslo University Hospital, The Intervention Centre, Oslo, Norway.|University of Oslo, Department of Physics, Blindern, Oslo, Norway.
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
authors.affiliation: Akershus University Hospital, Department of Radiology, Lørenskog, Norway.|Sunnmøre MR-klinikk, Ålesund, Norway.
authors.forename: Kjell-Inge
authors.initials: KI
authors.lastname: Gjesdal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging; D010865:Pilot Projects; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000071036:Sentinel Lymph Node / Q000000981:diagnostic imaging* / Q000473:pathology*
chemical_list: D003287:Contrast Media
keywords: 
  R2*; DCE-MRI; DSC-MRI; multi-echo dynamic MRI; rectal cancer