| Objective: To probe into the value that high-resolution multi-slice CT scan, CT perfusion imaging, magnetic resonance imaging diffusion sequence diagnose early lung cancer. Through compared the sensitivity and specificity of diagnosis of lung cancer with means of each detection, we determined the optimum detection or some combination, meanwhile we can obtain each parameter of CT perfusion imaging ,optimum b value and ADC threshold.Methods: All patients underwent unenhanced CT scanning including 5mm-thick transverse sections through the lesion with GE Light-Speed 64 CT scanner. Then the location and the largest scan of the lesion were chosen to be performed by local single-lung field high-resolution and CT perfusion scanning on the target sections. High resolution scanning parameters: 120 kV, 300 mA, bone algorithm reconstruction pulmonary window, standard algorithm built mediastinal window. CT perfusion imaging parameters: 120 kV, 180-220 mA, 1 s/circle, 2.5 mm/16i,Iohexol (350 mg I/ml) 50 ml, infusion rate of 5ml /sec, scanning started at 5 seconds after the beginning of injection and acquisition time of 120 seconds were used. Data analysis was performed with body tumor protocol of CT Perfusion 3 (the imaging workstation of Advantage Windows 4.2, GE Medical Systems). Aorta descendens were placed as inflow artery. The computer could automatically create maps of blood flow (BF), blood volume (BV), mean transit time (MTT),and permeability surface (PS). With3-5 regions of interest (ROI) of each lesion were placed at the color parameter maps of ROIs were created simultaneously and then the perfusion parameter values were recorded and the means were calculated respectively. 33 patients in neck and abdomen coil, underwent unenhanced MRI scanning with Germany Siemens Avanto Magnetom 1.5T MRI scanner, TR/TE:6800/70 ms, 3 mm-thick, 1 ~ 2 mm-spacing, scans of client to quiet breathing, b values at 0, 600s/mm2, 800s/mm2, 1000s/mm2 acquisition image, using EPI sequence scanning mode for the horizontal axis bit DWI scanning.Results: After statistic analyzing the data of high-resolution scaning,perfusion parameters and DWI result, we came to following conclusions: 1 Subject to these conditions of a total of 50 cases, of which 2 cases of atypical adenoma, 7 cases of tuberculosis, 3 cases sclerosing hemangioma, 3 cases of inflammatory pseudotumor, 23 cases of adenocarcinoma, 2 cases of small cells and differentiation of squamous cell carcinoma, 2 cases of gland spike cell carcinoma, 2 cases of small cell carcinoma, 1 large cell carcinoma, 1 case of lymphatic cancer, more than 4 cases diagnosed cancer, but no specific pathological type. According to the case itself with the statement made by the check method and requires different parts, divided into two groups (malignant and benign group) or three (malignant group, benign group and inflammatory group).2 Lung cancer group of thin Burr, deep leaf, bronchial truncated and pleura are implicated in rates are higher than benign groups and statistically significance (p﹤0.05), lung cancer group of vascular convergence of display rate higher than benign group, but does not have statistical significance (p﹥0.05).3 With three and more features for the diagnosis of lung cancer of the standard, the osis efficiency,sensitivity,specificity, positive predictive value and negative predictive value were 80%,82.9%,73.3%,87.9%,64.7%4 BV and PS from the malignant were significantly higher than those of the benign (p<0.01). No statistically significant differences in BV and PS were found between the malignant and the inflammatory (p>0.05).5 When BV≥4.70ml.100 g-1 ,PS≥15 ml.min-1.100g-1 ,BV≥4.70ml.100 g- 1 and PS≥15 ml.min-1.100g-1 were set as a diagnostic threshold , the sensitivity respectively were 91.7%,66.7%,66.7%,the specificity respectively were 66.7%,77.8%,88.9%.6 The ADC mean value of low lung cancer b value group is higher than the ADC mean value of high b value. (P <0.05)7 By ROC curve analyzing,ADC values obtained from each b value were profit for differentiating between benign lesions and malignant tumors,and the osis efficiency with b value of 800s/mm2 was the largest. The optimal threshold value of ADC was1.366×l0-3mm2/s,the sensitivity and specificity was 80.8% and71.4% respectively.8 The distinction will distinguish high-resolution CT and CTPI, distinguishes high-resolution CT and DWI, CTPI and DWI carries on the series diagnosis test, obtains the sensitivity respectively is 66.7%, 80.8% and 57.1%; The specificity respectively is 88.9%, 85.7% and 75%; The positive predictive value respectively is 94.1%, 95.5% and 88.9%; The positive predictive value respectively is 50%, 54.5% and 33.3%; The diagnosis accuracy respectively is 72.7%, 81.8% and 68.8%.9 The various checks and various union tests two pair respectively canrry on Chi-square test, high-resolution CT scan union DWI and single high-resolution CT scan have statistical differences (p <0.05),others have no statistical differences.Conclusion:1 MPR and VR combination axial helps peripheral nodules diagnosis and differential diagnosis, but along with the increase in non-typical case and, if necessary, in combination with other methods required diagnostic nodule.2 BV and PS which are CTPI index can contribute to the discrimination of the benign nodles from the lung cancer.3 When BV≥4.7ml.100 g- 1,or PS≥12.58 ml.min-1.100g-1 were set as a diagnostic threshold , the sensitivity, specificity and osis efficiency were hight. It is shown that BV and PS have high value in diagnosing lung cancer. When BV≥4.70ml.100 g-1 and PS≥12.58 ml.min-1.100g-1were set as a diagnostic threshold Diagnosis of lung cancer specificity increases. And combination of results from perfusion imaging can enhance the accuracy of the diagnosis of the solitary pulmonary nodule.4 This study found when optimal b value are 0,800 s/mm2 , ADC value is highest diagnostic effectiveness. The best threshold of ADC value evaluation nodules is 1.366×10-3mm2/s. its sensitivity and specificity are respectively 80.8% and71.4 %.5 This study found that, although the simple use of magnetic resonance DWI, measurement of ADC value differential pulmonary nodules of sensitivity and specificity are relatively high, but still there are still some cases of benign nodles and lung cancer of value have overlapping parts, so you cannot use it as a diagnostic criteria, and can be used as a complement to some standards.6 This study found that the diagnostic value of combination of the high-resolution CT scanning and DWI are better than simple high-resolution CT scanning, but did not consider other check method and union test diagnostic results are different.combination of the high-resolution CT scanning and DWI, the diagnosis of lung cancer of value is the highest, so we think the high-resolution CT scanning and DWI are the optimal early lung cancer check. |
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