Abstract
PURPOSE: To evaluate enhancement dynamics of solitary pulmonary nodules at multi–detector row computed tomography (CT) and to correlate results with extent of tumor angiogenesis in pathologic specimens.
MATERIALS AND METHODS: One hundred thirty-one patients with solitary pulmonary nodules underwent unenhanced thin-section CT, followed by dynamic helical CT (throughout the nodule for 30 mm along the z-axis [13 images] and at 20-second intervals for 3 minutes [130 images total]) after intravenous injection of 120 mL of contrast medium. Diagnosis of malignancy or benignancy was assigned in 109 patients, and follow-up imaging suggested benignancy in the remaining 22. CT findings were analyzed for peak attenuation, net enhancement, and enhancement dynamics. In 54 patients with surgical diagnoses, Pearson correlation coefficient was used to correlate enhancement pattern with extent of microvessel density and vascular endothelial growth factor (VEGF) staining.
RESULTS: With 30 HU or more of net enhancement as a cutoff value in differentiation of malignant and benign nodules, sensitivity for malignant nodules was 99% (69 of 70 malignant nodules), specificity was 54% (33 of 61 benign nodules), positive predictive value was 71% (69 of 97 malignant readings), negative predictive value was 97% (33 of 34 benign readings), and accuracy was 78% (102 of 131 nodules). Peak attenuation was correlated positively with extent of microvessel density (r = 0.369, P = .006) and VEGF staining (r = 0.277, P = .042). Malignant nodules showed significantly higher VEGF expression (P = .009) than that of benign nodules.
CONCLUSION: Dynamic enhancement with multi–detector row CT shows high sensitivity and negative predictive values for diagnosis of malignant nodules but low specificity because of highly enhancing benign nodules. Extent of enhancement reflects underlying nodule angiogenesis.
© RSNA, 2004
References
- 1 Erasmus JJ, Connolly JE, McAdams HP, Roggli VL. Solitary pulmonary nodules. Part I. Morphologic evaluation for differentiation of benign and malignant lesions. RadioGraphics 2000; 20:43-58.
- 2 Swensen SJ, Morin RL, Schuleler BA, et al. Solitary pulmonary nodule: CT evaluation of enhancement with iodinated contrast material—a preliminary report. Radiology 1992; 182:343-347.
- 3 Swensen SJ, Brown LR, Colby TV, Weaver AL. Pulmonary nodules: CT evaluation of enhancement with iodinated contrast material. Radiology 1995; 194:393-398.
- 4 Yamashita K, Matsunobe S, Tsuda T, et al. Solitary pulmonary nodule: preliminary study of evaluation with incremental dynamic CT. Radiology 1995; 194:399-405.
- 5 Yamashita K, Matsunobe S, Takahashi R, et al. Small peripheral lung carcinoma evaluated with incremental dynamic CT: radiologic-pathologic correlation. Radiology 1995; 196:401-408.
- 6 Murayama S, Murakami J, Hashimoto S, Torii Y, Masuda K. Noncalcified pulmonary tuberculomas: CT enhancement patterns with histologic correlation. J Thorac Imaging 1995; 10:91-95.
- 7 Swensen SJ, Brown LR, Colby TV, Weaver AL, Midthun DE. Lung nodule enhancement at CT: prospective findings. Radiology 1996; 201:447-455.
- 8 Zhang M, Kono M. Solitary pulmonary nodules: evaluation of blood flow patterns with dynamic CT. Radiology 1997; 205:471-478.
- 9 Swensen SJ, Viggiano RW, Midthun DE, et al. Lung nodule enhancement at CT: multicenter study. Radiology 2000; 214:73-80.
- 10 Hu H, He HD, Foley WD, Fox SH. Four multidetector-row helical CT: image quality and volume coverage speed. Radiology 2000; 215:55-62.
- 11 Weidner N, Semple JP, Welch WR, Folkman J. Tumor angiogenesis and metastasis-correlation in invasive breast carcinoma. N Engl J Med 1991; 324:1-8.
- 12 Fontanini G, Bigini D, Vignati S, et al. Microvessel count predicts metastatic disease and survival in non–small cell lung cancer. J Pathol 1995; 177:57-63.
- 13 Fontanini G, Vignati S, Boldrini L, et al. Vascular endothelial growth factor is associated with neovascularization and influences progression of non–small cell lung carcinoma. Clin Cancer Res 1997; 3:861-865.
- 14 Shibusa T, Shijubo N, Abe S. Tumor angiogenesis and vascular endothelial growth factor expression in stage I lung adenocarcinoma. Clin Cancer Res 1998; 4:1483-1487.
- 15 Miles KA. Tumour angiogenesis and its relation to contrast enhancement on computed tomography: a review. Eur J Radiol 1999; 30:198-205.
- 16 Ahn MJ, Jang SJ, Park YW, et al. Clinical prognostic values of vascular endothelial growth factor, microvessel density, and P53 expression in esophageal carcinomas. J Korean Med Sci 2002; 17:201-207.
- 17 Jung KJ, Lee KS, Kim SY, Kim TS, Pyeun YS, Lee JY. Low-dose, volumetric helical CT. Image quality, radiation dose, and usefulness for evaluation of bronchiectasis. Invest Radiol 2000; 35:557-563.
- 18 Ohno Y, Hatabu H, Takenaka D, Adachi S, Kono M, Sugimura K. Solitary pulmonary nodules: potential role of dynamic MR imaging in management-initial experience. Radiology 2002; 224:503-511.
- 19 Ohta Y, Endo Y, Tanaka M, et al. Significance of vascular endothelial growth factor messenger RNA expression in primary lung cancer. Clin Cancer Res 1996; 2:1411-1416.
- 20 McNitt-Gray MF. AAPM/RSNA physics tutorial for residents: topics in CT—radiation dose in CT. RadioGraphics 2002; 22:1541-1553.
- 21 Kim H, Kang SJ, Suh GY, et al. Predictors for benign solitary pulmonary nodule in tuberculosis-endemic area. Korean J Intern Med 2001; 16:236-241.