title: Lung nodule enhancement at CT: multicenter study.
abstract: OBJECTIVE
  To test the hypothesis that absence of statistically significant lung nodule enhancement (< or =15 HU) at computed tomography (CT) is strongly predictive of benignity.
  
  
  METHODS
  Five hundred fifty lung nodules were studied. Of these, 356 met all entrance criteria and had a diagnosis. On nonenhanced, thin-section CT scans, the nodules were solid, 5-40 mm in diameter, relatively spherical, homogeneous, and without calcification or fat. All patients were examined with 3-mm-collimation CT before and after intravenous injection of contrast material. CT scans through the nodule were obtained at 1, 2, 3, and 4 minutes after the onset of injection. Peak net nodule enhancement and time-attenuation curves were analyzed. Seven centers participated.
  
  
  RESULTS
  The prevalence of malignancy was 48% (171 of 356 nodules). Malignant neoplasms enhanced (median, 38.1 HU; range, 14.0-165.3 HU) significantly more than granulomas and benign neoplasms (median, 10.0 HU; range, -20.0 to 96.0 HU; P < .001). With 15 HU as the threshold, the sensitivity was 98% (167 of 171 malignant nodules), the specificity was 58% (107 of 185 benign nodules), and the accuracy was 77% (274 of 356 nodules).
  
  
  CONCLUSIONS
  Absence of significant lung nodule enhancement (< or = 15 HU) at CT is strongly predictive of benignity.
authors.affiliation: Dept of Diagnostic Radiology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Swensen
authors.forename: R W
authors.initials: RW
authors.lastname: Viggiano
authors.forename: D E
authors.initials: DE
authors.lastname: Midthun
authors.forename: N L
authors.initials: NL
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Sherrick
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: D P
authors.initials: DP
authors.lastname: Naidich
authors.forename: E F
authors.initials: EF
authors.lastname: Patz
authors.forename: T E
authors.initials: TE
authors.lastname: Hartman
authors.forename: J R
authors.initials: JR
authors.lastname: Muhm
authors.forename: A L
authors.initials: AL
authors.lastname: Weaver
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media