Preliminary Study Of Gemstone Spectral Imaging (GSI) In The Differential Diagnosis Of Different Types Of Lymph Nodes In Neck

Background and purpose:Cervical lymph node enlargement is a common clinical manifestations, the etiology is of the following three:first, inflammatory lymph node change, including lymph node tuberculosis and lymphadenitis; second, a variety of malignant cervical lymph node metastasis, including head and neck squamous cell carcinoma, Aden carcinoma of lymph node metastasis, upper respiratory tract, digestive tract squamous cell carcinoma of cervical lymph node metastasis. Third, the lymphoma. Treatment options and prognosis are not the same in the concern of the different nature of the lymphadenopathy. To determine the nature of right cervical lymph nodes before treatment and lymph nodes the number of estimates has a very important clinical significance for clinical treatment program development, follow-up after treatment and prognosis assessment.The purpose of this study is to explore the role of CT spectroscopy imaging in the different nature of the identification of neck lymph node lesions, the results were compared with pathological and it provides more diagnostic information for clinical. Materials and Methods1Object of studySpectrum scanning56patients between April2011February2012in Affiliated Hospital of Zhengzhou University of cervical lymph node enlargement2Scanning equipment and medicationUsing GE gem spectroscopy, CT (Discovery CT750HD),CT high pressure injector made by Medrad in USANon-ionic contrast medium iohexol300mgI/ml3scanning methodsConventional positioning:the scan range is from the base of the skull to the thoracic inlet. All patients underwent CT scan and dual-phase enhanced scan, first use the spiral sweep, the scanning parameters of120kVp tube voltage, tube current of220-650mA, layer reaches5-mm thick, rack speed of0.8s/week, pitch1.375. Then use the spectroscopy imaging and dual-phase enhanced scan, the scan parameters as follows:the voltage of the tube switch form140kVp to80kVp instantaneous (0.5ms), the tube current is about600mA, thickness and layer spacing are5mm, gantry rotation time of0.6s/week and a pitch of1.375, the detector width is0.625mmX64. Non-ionic contrast agent to enhance the scanning contrast agent (Omnipatient,300mgI.ml-1), use intelligent tracking (Smart Prep) to trigger scanning technology, the amount is in accordance with10ml/kg, rate of3-4ml/s. After the start of the injection, scan in25s (arterial phase) and60s (venous phase)4Data processing and image analysisGet single-energy image of arteriovenous of QC hybrid image and MONO, and iodine-based images. Use spectroscopy spectrum analysis the images, select the region of interest measurements of the same size of the lesions of lymph nodes in the three different types of lymph nodes iodine-based image in arterial phase iodine concentration, venous phase iodine concentration, dynamic venous lesions lymph node concentration of iodine difference, and arteriovenous lesions, lymph nodes, and the iodine concentration of carotid artery ratio (ie, standardized iodine concentration ratio of the iodine concentration of lesions of lymph nodes and internal carotid artery), the pairwise comparison, is approached in p<0.05which has statistically significant. 5Statistical AnalysisThree different types of lymph node concentration of iodine, iodine concentration of the difference between the iodine concentration and homogenization were statistically analyzed using SPSS17.0statistical software for analysis of various quantitative indicators. By using single factor analysis of variance statistics and using the mean±standard deviation, expressed as difference of p<0.05was considered statistically significant.Result1In the highest average concentration is of iodine (ICAP) in arterial phase lymphoma of cervical lymph node, lymphadenitis is followed by the average and iodine concentration is the lowest, difference of the minimum iodine concentration of lymph node metastasis, lymph node inflammation in average and lymphoma have no statistically significant (P<0.05), the average iodine content of lymph node metastasis and lymphadenitis average iodine content differences were statistically significant (p<0.05)2Vein of lymphoma slightly higher than the concentration of iodine (ICVP) lymphatic metastases and lymph node inflammation, iodine concentration, but no significant difference (P>0.05).3Lymphoma, lymphadenitis, lymph nodes switch to move the vein of the average iodine concentration difference (ICD) were statistically significant (p<0.05)4Cervical lymph node inflammation, neck lymphoma and cervical lymph node metastasis homogenization of the arterial phase iodine concentration ratio (NICAP) was statistically significant, cervical lymphadenitis, lymphoma, and cervical lymph node metastasis of the iodine content of the venous phase homogenization ratio (NICVP) has no statistical significance.Conclusion1CT spectroscopy imaging can identify the different natures of the lymphadenopathy. 2CT spectroscopy imaging arteriovenous degree of enhancement of lesions of lymph node type has a certain clinical significance.3CT spectroscopy imaging is simple and can be widely used in clinical.