title: Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion.
abstract: OBJECTIVE
  To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients.
  
  
  METHODS
  Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed.
  
  
  RESULTS
  According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images, as compared to the reference magnetic resonance images. The difference in accuracy was statistically significant (P = 0.02).
  
  
  CONCLUSIONS
  New generation CT scanner, using high resolution MPR images, represents a reliable diagnostic tool in assessment of loco-regional and whole body staging of advanced rectal cancer, especially in patients with MRI contraindications.
authors.affiliation: Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, School of Medicine, University of Milano-Bicocca, Milan, 20900 Monza (MB), Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Ippolito
authors.affiliation: Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, School of Medicine, University of Milano-Bicocca, Milan, 20900 Monza (MB), Italy.
authors.forename: Silvia Girolama
authors.initials: SG
authors.lastname: Drago
authors.affiliation: Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, School of Medicine, University of Milano-Bicocca, Milan, 20900 Monza (MB), Italy.
authors.forename: Cammillo Talei
authors.initials: CT
authors.lastname: Franzesi
authors.affiliation: Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, School of Medicine, University of Milano-Bicocca, Milan, 20900 Monza (MB), Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Fior
authors.affiliation: Davide Ippolito, Silvia Girolama Drago, Cammillo Talei Franzesi, Davide Fior, Sandro Sironi, School of Medicine, University of Milano-Bicocca, Milan, 20900 Monza (MB), Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Sironi
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D004867:Equipment Design; D005205:Fascia / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000295:instrumentation; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015898:Tomography Scanners, X-Ray Computed
keywords: Magnetic resonance; Mesorectal fascia; Multi detector computed tomography; Multiplanar reconstructions; Rectal cancer