Lung nodule enhancement at CT: prospective findings.
OBJECTIVE
To determine if lung nodule enhancement measured with computed tomography (CT) is directly related to the likelihood of malignancy and to nodule vascularity.


METHODS
Radiologically indeterminate 7-30-mm pulmonary nodules were studied in 107 patients with malignant neoplasms (n = 52), granulomas (n = 51), and benign neoplasms (n = 4). Attenuation was recorded from serial thin-section CT scans before and after injection of contrast material. Twenty-four histologic specimens were graded after immunoperoxidase vascular staining with antibody to factor VIII-associated antigen.


RESULTS
Malignant neoplasms were enhanced (median, 46.5 HU; range, 11-110 HU) statistically significantly more than granulomas and benign neoplasms (median, 8 HU; range, -10 to 94 HU) (P < .001). With 20 HU as the threshold for a positive test result, the sensitivity was 98%, specificity was 73%, and accuracy was 85% (prevalence of malignancy, 49% ¿52 of 107 nodules]). The degree of enhancement was statistically significantly related to the amount of central vascular staining (P < .001).


CONCLUSIONS
Enhancement appears to be an indicator of malignancy and vascularity. These prospective findings corroborate previously reported results.
Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905, USA.
S J
SJ
Swensen
L R
LR
Brown
T V
TV
Colby
A L
AL
Weaver
D E
DE
Midthun
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006099:Granuloma / Q000000981:diagnostic imaging; D006801:Humans; D007479:Iopamidol; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D007479:Iopamidol