Pulmonary nodules: CT evaluation of enhancement with iodinated contrast material.
OBJECTIVE
To determine if the degree of enhancement of pulmonary nodules is directly related to the likelihood of malignancy and to the vascularity of the nodule.


METHODS
Uncalcified 6-40-mm-diameter pulmonary nodules were studied in 163 patients with malignant neoplasm (n = 111), granuloma (n = 43), and benign neoplasm (n = 9). Serial thin-section computed tomography (CT) was performed before and after injection of 100 mL of nonionic contrast material at 2 mL/sec. The maximum level of enhancement was recorded. Eighteen histologic specimens were graded after vascular staining.


RESULTS
Malignant neoplasms enhanced (median, 40.0 HU; range, 20-108 HU) significantly more than granulomas and benign neoplasms (median, 12.0 HU; range, -4 to 58 HU) (P < .001). With 20 HU as the threshold for a positive test, sensitivity was 100%; specificity, 76.9%; positive predictive value, 90.2%; negative predictive value, 100%; and accuracy, 92.6% (prevalence of malignancy, 68.1%). Degree of enhancement was significantly related to amount of central vascular staining (P = .003).


CONCLUSIONS
Enhancement is an indicator of malignancy and vascularity.
Swensen
S J
SJ
Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905.
Brown
L R
LR
Colby
T V
TV
Weaver
A L
AL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006099:Granuloma / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007472:Iohexol; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed
D007472:Iohexol