title: Diagnostic accuracy of CT-guided automated needle biopsy of lung nodules.
abstract: OBJECTIVE
  The purpose of this study was to determine the factors influencing diagnostic accuracy in CT-guided automated needle biopsies of lung nodules.
  
  
  METHODS
  One hundred thirty-eight consecutive CT-guided automated needle biopsy procedures were performed in 123 patients (124 pulmonary nodules). Factors for diagnostic accuracy were evaluated through analysis of the procedures, which were classified into a success group (true-positive and true-negative) and a failure group (false-positive and false-negative).
  
  
  RESULTS
  Final diagnoses were 81 malignant lesions (91 biopsies) and 43 benign lesions (47 biopsies). More than two CT-guided biopsies were performed for 13 lesions. Seventy lesions were true-positive, 44 were true-negative, three were false-positive, and 21 were false-negative. The overall diagnostic accuracy was 82.6%. The sensitivity for malignancy and specificity for benign lesions were 76.9% and 93.6%, respectively. Positive and negative predictive values were 95.9% and 67.7%, respectively. Lesion size was a significant factor contributing to diagnostic accuracy (p = 0.014). Mean diameters of lesions (+/-SD) in the success and failure groups were 24.1+/-12.4 mm and 17.6+/-7.8 mm, respectively. For lesions 6-10 mm in diameter, diagnostic accuracy was 66.7%; for lesions 11-20 mm in diameter, 78.9%; for lesions 21-30 mm in diameter, 86.7%; for lesions 31-50 mm in diameter, 93.3%; and for lesions 51-70 mm in diameter, 100%.
  
  
  CONCLUSIONS
  Lesion size was a determining factor in diagnostic accuracy. Diagnostic accuracy decreased in proportion to the decrease in the lesion diameter.
authors.affiliation: Department of Radiology, Nagaoka Central General Hospital, Nagaoka-city, Niigata, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tsukada
authors.forename: T
authors.initials: T
authors.lastname: Satou
authors.forename: A
authors.initials: A
authors.lastname: Iwashima
authors.forename: T
authors.initials: T
authors.lastname: Souma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D001707:Biopsy, Needle / Q000379:methods*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed