title: Pulmonary metastasis from renal cell carcinoma: characterization using contrast-enhanced CT attenuation value measurements.
abstract: OBJECTIVE
  To retrospectively assess the usefulness of contrast-enhanced computed tomographic (CT) attenuation measurements for differentiating renal cell carcinoma pulmonary metastasis from primary lung cancer.
  
  
  METHODS
  The authors retrospectively evaluated 39 pulmonary nodules in 36 patients with pulmonary metastasis from renal cell carcinoma (RCC; 29 men and 7 women; mean age +/- SD, 56.9 +/-10.0 years; range, 38-76 years) and 30 pulmonary nodules in 42 patients with primary lung cancer (33 men and 9 women; mean age +/- SD, 62.9 +/- 9.8 years; range, 38-81 years). Contrast-enhanced scans were obtained 35 seconds after injecting contrast medium intravenously. Pulmonary nodules were retrospectively analyzed by determining nodule attenuation values in contrast-enhanced CT scans. The Mann-Whitney U test was used to compare pulmonary nodule mean attenuation values in these 2 patient groups.
  
  
  RESULTS
  The mean attenuation value of metastatic pulmonary nodules from RCC (mean +/- SD, 73.6 +/- 40.6 Hounsfield units) was greater than that of primary lung cancer nodules (mean +/- SD, 47.8 +/-17.9 Hounsfield units) (P < 0.001).
  
  
  CONCLUSIONS
  Pulmonary nodule attenuation measurements obtained by contrast-enhanced CT are useful for differentiating pulmonary metastasis from RCC and primary lung cancer.
authors.affiliation: Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Korea.
authors.forename: Dae Chul
authors.initials: DC
authors.lastname: Jung
authors.forename: Hyuck Jae
authors.initials: HJ
authors.lastname: Choi
authors.forename: Hyae Young
authors.initials: HY
authors.lastname: Kim
authors.forename: Kang Hyun
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000556:secondary*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging / Q000556:secondary; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide