Dynamic enhancement patterns of solitary pulmonary nodules at multi-detector row CT and correlation with vascular endothelial growth factor and microvessel density.
OBJECTIVE
Differential diagnosis of malignant solitary pulmonary nodules (SPNs) from benign ones is difficult based on imaging manifestations. This study was to assess dynamic enhancement patterns of SPNs detected with multi-detector row computed tomography (MDCT), correlate SPN manifestations of MDCT to the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD), thus to explore the potential value of MDCT imaging in the diagnosis of SPNs.


METHODS
Fifty pathologically and one clinically confirmed patients with SPNs (diameter <or= 4 cm) undergoing MDCT plain and dynamic enhancement scans were enrolled in the study. The entire lung was scanned at 15 s after injection of the contrast agent; dynamic enhancement scans of SPNs were performed at 45 s, 75 s, 135 s, 195 s and 255 s after contrast injection. The enhancement patterns, pre-, peak and net enhancement of SPNs were assessed. Pearson correlation coefficient was used to correlate peak enhancement, net enhancement to the expression of VEGF and MVD.


RESULTS
The peak and net enhancements were significantly higher in malignant nodules (mean attenuation, 69.9 Hu and 32.9 Hu) than in benign nodules (mean attenuation, 51.7 Hu and 17.2 Hu) (p < 0.001). When net enhancement of 20 Hu was set as the cutoff value to differentiate malignant nodules from benign ones, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 96.43%, 69.57%, 79.41%, 94.12% and 84.31%, respectively. The enhancement patterns between malignant and benign SPNs were significantly different. Homogeneous enhancement or heterogeneous tending to homogeneous enhancement appeared mostly in malignant nodules (78.57%). Benign nodules were almost not enhanced (52.17%). Expressions of MVD and VEGF were significantly different between malignant and benign SPNs. VEGF was positively correlated to the peak enhancement value (r = 0.505, p = 0.014) and the net enhancement value (r = 0.565, p = 0.005). Similarly, MVD was also positively correlated to the peak enhancement value (r = 0.819, p < 0.001) and the net enhancement value (r = 0.845, p < 0.001).


CONCLUSIONS
Net enhancement value is an important indicator for differential diagnosis of malignant and benign SPNs. Characteristic enhancement patterns are different between malignant and benign SPNs. Peak enhancement and net enhancement values are positively correlated with VEGF and MVD, both of which reflect the extent of angiogenesis in SPNs to some extent.
Jiang
Nan-Chuan
NC
Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Han
Ping
P
Zhou
Cheng-Kai
CK
Zheng
Jin-Long
JL
Shi
He-Shui
HS
Xiao
Jie
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006222:Hamartoma / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism; D006801:Humans; D007089:Image Enhancement; D007150:Immunohistochemistry; D008171:Lung Diseases / Q000175:diagnosis / Q000378:metabolism; D008175:Lung Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism; D008297:Male; D055806:Microvessels / Q000473:pathology*; D008875:Middle Aged; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000098:blood supply / Q000175:diagnosis* / Q000378:metabolism; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D055815:Young Adult
D003287:Contrast Media; D042461:Vascular Endothelial Growth Factor A