Preliminary Study On Diagnosis Value Of Energy Spectrum CT For Benign And Malignant Pulmonary Mass

Objective To discuss the clinical diagnosis value of imaging in distinguishingbetween benign pulmonary masses and malignant pulmonary masses preliminarily by theenergy spectral CT imaging technology.Material and methods A retrospective selection of53cases with pulmonary masslesions (mass diameter larger than3cm) confirmed by pathology were collected,they weredivided into benign pulmonary masses group: A total of16cases (including6cases ofspherical pneumonia,4cases of tuberculoma,3cases of inflammatory pseudotumor,2cases of organized pneumonia,1case of hamartoma);malignant pulmonary masses group: Atotal of37cases (including20cases of adenocarcinoma,11cases of squamous cellcarcinoma,5cases of small cell lung cancer,1case of adenosquamous carcinoma). All thecases underwent GSI imaging of Gem energy spectrum CT(Discovery CT750HD),andwere by the Application of spectrum scan mode (GSI) for data mining scanning. The scanrange was from thoracic entrance to the diaphragm level.High pressure syringe infusion ofnonionic contrast agent60ml was used,and by the injection rate of3.5ml/s. Then thearterial phase and venous phase scan were taken, the CT values, slope values, iodine basedimages and water based images on40~140keV in arterial phase and venous phase weregot by the post processing software GSI-viewer. Then the data was analyzed and compared.To observe the effects of different lung mass lesions in the single energy image obtained inspectral attenuation curve differences and the content of different substances,and comparedifferences of CT values, slope values, iodine based images and water based images.Thenwe use Independent samples T test to analysis the data.Results (1) In the CT values on40~140keV of energy spectrum CT enhancementimaging in arterial phase and venous phase,the CT values on40~80keV in benignpulmonary mass group were lower than that in malignant pulmonary mass group,and thelower single energy,the greater difference between CT values.(2) Slope value withen thetumor region of interest on40~70keV in arterial phase was (2.38±0.31) vs (2.96±0.39), statistical significant difference of slope value was found between the two groups(P<0．05).(3)In arterial phase and venous phase, iodine concentration on iodine based image ofbenign group were lower than that of malignant group, statistical significant difference wasfound(P<0．05);And significant difference was not found in differences of water basedvalues between two groups(P>0．05).(4)In malignant pulmonary masses group, compareslope values of adenocarcinoma, squamous cell carcinoma and small cell lung cancer on40~70keV in arterial phase. We found that the slope values of adenocarcinoma group weremore than that of squamous cell carcinoma group and that of small cell lung cancer group,statistical significant differences were both found in comparison between groups(P<0．05);the slope values of squamous cell carcinoma group were more than that of small cell lungcancer group, and statistical significant difference was not found(P>0．05).Conclusion Iodine substances contents of pulmonary benign masses and malignantmasses have different characteristics in energy spectral imaging. Energy Spectrum CT ishelpful in differential diagnosis.It has potential value to speculate some pathological typesof lung cancer by using spectral curve slope.