title: Extranodal spread in the neck: MRI detection on the basis of pixel-based time-signal intensity curve analysis.
abstract: OBJECTIVE
  We evaluated dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for the preoperative detection of extranodal spread (ENS) in metastatic nodes in the neck.
  
  
  METHODS
  The time-signal intensity curve (TIC) profiles of 54 histologically proven metastatic nodes (26 ENS-positive and 28 ENS-negative) from 43 patients with head and neck squamous cell carcinoma (SCC) were retrospectively analyzed to determine the effective TIC criteria for ENS-positive nodes. The TICs were semiautomatically classified into four distinctive patterns (flat, slow uptake, rapid uptake with low washout ratio, and rapid uptake with high washout ratio) on a pixel-by-pixel basis.
  
  
  RESULTS
  A number of the MRI findings were significantly correlated with ENS. However, multivariate logistic regression analysis revealed that only a short-axis diameter and an area with slow uptake TIC patterns were significantly and independently indicative of the presence of ENS. The combined MRI criteria of nodal size (>25 mm) or TIC profile (>44% nodal areas with slow-uptake TIC patterns) yielded the best results for differentiation between ENS-positive and ENS-negative nodes, providing 96% sensitivity, 100% specificity, 98% accuracy, and 100% positive, and 97% negative predictive values.
  
  
  CONCLUSIONS
  When combined with size criteria, pixel-based MR factor analysis may be a promising tool for detecting ENS.
authors: Department of Radiology and Cancer Biology, Nagasaki University School of Dentistry, Nagasaki, Japan.
authors: Misa
authors: M
authors: Sumi
authors: Takashi
authors: T
authors: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology; D005260:Female; D019786:Gadolinium DTPA / Q000494:pharmacology; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA