The Clinical Utility Of DSCT With Dual Energy Scan In In The Differentiation Of Benign And Malignant Solitary Pulmonary Nodules(SPN)

Part One The clinical utility of virtual nonenhanced in SPN diagnosisObjective: To discuss the correlation of the CT numbers on virtual nonenhanced and nonenhanced weighted average images,and the clinical utility of virual nonenhanced in SPN diagnosis.Methods: To collect 36 cases with solitary pulmonary nodules(SPN) in Hebei Tumor Hospital with all patients accepted the thoracic enhanced examination from September,2010 to March,2011. All the cases were confirmed by pathohistology, operation or clinic follow-up. 36 cases (30 men, 6 women, age range:30-70, mean age:56) with pulmonary nodules 1.9-3.0cm (mean,2.7cm) in diameter were inclued into study. In 36 cases,24 were malignant(adenocarcinoma, n=16; squamous cell carcinoma, n=5; bronchioa- lveolar carcinoma,n=2;adenoacanthoma,n=1),and 12 were benign(tuberculosis, n=3;hamartoma,n=2; sclerosing hemangioma, n=2;inflammatory pseudotumor, n=2; inflammatory nodules, n=2;solitary fibrous tumor, n=1).Firstly, all patients were performed routine scan(tube voltage 100KV, 140KV,slice thickness is 5mm) using DSCT with dual energy mode, then underwent the dynamic enhanced scanning after injection of iodinated contrast material(iohexol, 300mg/ml,1.5-2ml/kg, injective rate 3ml/s, at 25s,90s,120s, 180s). Choose"Liver VNC"mode to obtained the virtual nonenhanced and iodine-enhanced images. CT numbers of SPN on virtual nonenhanced, nonenhanced weighted average images were measured.Results: CT number on virtual nonenhanced and nonenhanced weighted average images showed good correlation (Pearson Correlation coefficients were 0.780 for maglinant nodules ,0.896 and 0.900 for benign nodules ). Conclusion: The correlation of virtual nonenhanced and nonenhanced weighted average images was good. In routine practice, optional reconstru- ction of a virtual nonenhanced image after DECT scanning might replace the additional nonenhanced CT scan, and reduced the amount of radiation of an additional nonenhanced scanning.Part Two The clinical efficacy by using multi-phase enhanced CT scanning in the differentiation of benign and malignant solitary pulmonary nodulesObjective: To respectively compare the enhanced features of benign and malignant solitary pulmonary nodules(SPN) by using multi-phase enhanced CT scanning, discuss the clinical efficacy with multiple parameters in the differentiation of benign and malignant solitary pulmonary nodules. Methods: The same to Part One.The CT value of SPN was measured before and after enhancement. The largest number of the CT values minus CT values before enhancement was regarded as the largest increased CT value , then draw the time-attenuation curves.Results:1 The enhanced peak CT values of malignant nodules, inflammatory nodules and the benign nodules with enriched blood supply were obviously higher than other benign nodules. To differentiate between the malignant and benign nodules, the peak height of 20HU was considered as threshold (higher than 20HU were considered as malignant), and sensitivity and specificity were 90.5% and 72.7% respectively.2 There was statistically significant difference in the time which reached to enhanced peak CT value (P<0.05). The time of benign nodules when reached to enhanced peak CT value was earlier than malignant nodules.3 The TDC appeared differently for the benign and malignant nodules. The TDC appeared continuously slow-moving rise. Benign nodules appeared mild type, which showed no peak value or showed prompt rise and then slow-moving descent.Conclusion:1 The technique of multi-phase enhanced scanning was helpful for the differential diagnosis.2.2 The peak increased CT values, the time which reached to enhanced peak CT value and TDC were helpful for the differential diagnosis of SPN.Part Three The clinical utility of iodine-enhanced image of dual-energy computed tomography(CT) in evaluating the benign and malignant SPNObjective: To determine the clinical utility of iodine-enhanced image of dual-energy computed tomography(CT) in evaluating the benign and malignant SPN。Methods: The same to Part One. Choose"Liver VNC"mode to obtained the virtual nonenhanced and iodine-enhanced images. CT numbers of SPN on virtual nonenhanced, nonenhanced weighted average, iodine-enhanced weighted average images were measured.Results: CT number on the iodine-enhanced image and degree of enhancement images showed good correlation. The CT number of 20HU was selected as threshold in the iodine-enhanced image, sensitivity and specificity were 0.925 and 0.824.Conclusion:1 Iodine component could be differentiated from the enhanced soft tissue by using dual energy technique.2 Iodine-enhanced images with DECT may be a feasible tool for the measurement of the degree of enhancement ,and it could increased the sensitivity and specificity of benign and malignant SPN differential diagnosis.Part Four The clinical utility of dual-energy energy spectrum analyzing in evaluating the benign and malignant SPNObjective: To determine the clinical utility of dual-energy computed tomography(CT) in evaluating the benign and malignant SPN,and some preliminary experiences in energy spectrum analyzing using dual-energy scanning.Methods: The same to Part One. And transfer the two groups dual energy data into Dual-Energy software of the workstation , choose"Monoenergetic"mode to obtained images under different Kev, measured the CT value of SPN of multi-phase ,then made energy spcetrum analysis.Results: According the changes and tendency of CT value company with the different Kev after drawing the energy spectrum, some speacial materials as fat and iodine can be differentiated.Conclusion: Dual-energy energy spectrum analysis could provide some valuable information for differentiation of SPN.