Preliminary Assessment Of Dual-energy Scan In Differential Diagnosis Of Lymphoma And Metastatic Lymph Nodes

Objective:(1) Analysis the dual-energy CT data of patients with lymphoma and metastatic lymph nodes,compare the different kinds energy parameters (for example CT value of iodine overlay、iodineconcentration、Iodine concentration difference and Normalized iodine concentration) to screenthe best index that can help to differentiate the diagnosis of lymphoma and metastatic lymphnodes disease.(2) Analysis the dual-energy CT data of patients with lymphoma and metastatic lymph nodes,compare the energy spectral curves of lymphoma and metastatic lymph nodes lesion.(3) Through the research on analysis index, to probe into the clinical value of Dual-sourceComputed Tomography Dual-energy scan in the differential diagnosis of metastatic andlymphoma lymph nodes lesions.Methods:(1) The all patients with lymphoma and metastatic lymph nodes underwent the dual-energy scanusing Dual-energy computed tomography, choose the optimization energy scanning method and scanning parameters, in order to achieve high imaging quality, low radiation dose, and rebuildthe dual energy date for further analysis.(2) To obtain the dual-energy CT imaging of30cases with lymphoma patients and28cases withmetastatic lymph nodes, and import the data to dual-energy post-processing workstation. Thenwe can get the iodine map of arterial and venous phase, a series mono-energetic imaging of40-190kev and the energy spectral curves of the both kinds lesion, respectively. By using thedual-energy CT function of separation and quantitative analysis of iodine substance to measurethe CT overlay value、the iodine concentration of lymph nodes and the big vessels which werein the same level with lesions; Meanwhile measure the CT value of lymph nodes in theunenhanced image、mixed-energy image and mono-energetic imaging. Analysis the above indexand the follow index through using two independent samples t-test.Results:(1) The CT value of the unenhanced phase image、the difference between arterial phase andunenhanced phase（the pure enhanced CT value in arterial phase）、the difference between venousphase and unenhanced phase（the pure enhanced CT value in venous phase）of lymphoma arehigher than the relevant data of metastatic lymph nodes, and the data of the three groups havesignificant difference (P＜0.05).(2) The region of interest in the iodine map of arterial phase, the CT value of overlay (CTOA)、the iodine concentration (ICAP)、 the iodine concentration normalized ratio (NICAP) oflymphoma and metastatic lymph nodes were （31.86±11.98）HU、（1.75±0.77）mg/ml、(0.20±0.13) and（11.53±10.43）HU、（0.60±0.46）mg/ml、（0.07±0.06）, respectively；The regionof interest in the iodine map of venous phase, the CT value of overlay (CTOV)、the iodineconcentration (ICVP)、the iodine concentration normalized ratio (NICVP) of lymphoma andmetastatic lymph nodes were（40.09±10.68）HU、（2.18±0.66）mg/ml、（0.41±0.18） and（20.64±13.17）HU、0.92±0.57）mg/ml、（0.24±0.16）, respectively. The difference betweenthe six groups of data were statistically significant (P＜0.05). And the energy parameters oflymphoma group which measure in the arterial phase and venous phase were higher than that ofmetastatic lymph nodes.(3) The average iodine concentration difference (ICD) in the arterial phase and venous phase of lymphoma were both higher than that of metastatic lymph nodes. The data of lymphoma andmetastatic lymph nodes were （0.43±0.73）mg/ml and0.32±0.61）mg/ml, respectively; but nosignificant difference (P＞0.05).(4) The CT value of lesions in the lymph nodes of lymphoma which measured in a seriesmono-energetic imaging of40-190kev in arterial phase that is relatively higher than metastaticlymph nodes, but only in mono-energetic imaging of40-120kev, the CT value was statisticallysignificant (P＜0.05). The energy spectral curves of lymphoma and metastatic lymph nodes isdifferent.Conclusion:(1) Dual-source Computed Tomography Dual-energy scan can identify the imaging diagnosis oflymphoma and metastatic lymph nodes from the CT performance.(2) The dual-energy CT Dual-energy scan function of separation and quantitative analysis ofiodine substance has a certain clinical value to the identification of two lesions on properties oflymphoma and metastatic lymph nodes.(3) Integrated application of a series of derivative imaging from Dual-source ComputedTomography Dual-energy scan can improve the accuracy of lesions imaging diagnosis, and has acertain guiding value for clinical treatment scheme. The Dual-energy scan is simple and can bewidely used in clinical.