Objective To explore the clinical value of dual-energy CT lung perfusion imaging and perfusion scintigraphy in acute pulmonary embolism (PE) rabbit models. Methods Acute PE models were established in 20 rabbits with femoral vein injection of sponge as embolus materials, and 4 rabbits were injected saline as control group. Two hours after embolization, dual-energy CT and perfusion scintigraphy imaging were performed respectively. Taking the pathologicall findings as the reference standards, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of both imaging methods were compared. CT values and enhancement degree (overlay value) of the embolic areas and normal pulmonary parenchyma were measured in DEPI image after embolization. Results Normal lung was color-coded as homogeneously yellowish red, perfusion scintigraphy displayed rarefaction or absence. The sensitivity, specificity, PPV, NPV of DEPI was 100%, 97.50%, 95.24%, 100%, and of perfusion scintigraphy was 67.50%, 81.25%, 64.29%, 83.33%, respectively. Increased CT values and overlay values of embolism areas in DEPI images were lower than those of normal pulmonary parenchyma (P<0.05). Conclusion DEPI has higher sensitivity and specificity than perfusion scintigraphy for detection of pulmonary emboli in an acute PE rabbit models.

Objective To discuss the value of digital tomosynthesis for detection of pulmonary nodules. Methods Thirty patients suspected of having pulmonary nodules underwent chest radiography, digital tomosynthesis and CT examination. Above image data were transferred to postprocessing work station and were reviewed by 2 radiologists with 3 years of chest-radiology diagnosis experience in a double-blind method. The number, location and size of nodules were recorded. Then, 2 radiologists reviewed the all images once more, and discuss in consensus. The sensitivities of chest radiography and digital tomosynthesis for detection of pulmonary nodules were respectively calculated according to the CT results. Chi-square test was used for radiography, digital tomosynthesis and CT examination. Results Of 30 patients, 21 were detected having pulmonary nodules by X-ray radiography and 9 were negative, the total number of 40 nodules was detected, while 89 nodules in 26 patients were detected by digital tomosynthesis, and only 4 patients were negative. CT demonstrated 102 nodules in 27 patients, and 3 patients were negative. Taking CT as "gold standard", the sensitivities of X-ray radiography and digital tomosynthesis were 27.4%(28/102)and 87.2%(89/102), X~2=4.35, P<0.05, respectively. Conclusion Digital tomosynthesis has a high sensitivity for detection of pulmonary nodules compared with X-ray radiography, and could be an excellent and necessary supplementary technique of X-ray radiography.

Objective To evaluate the feasibility and value of dual-energy perfusion imaging (DEPI) of dual-source CT(DSCT) in the diagnosis of acute experimental pulmonary embolism. Methods Acute pulmonary embolism ( PE ) model was made in 8 New Zealand rabbits, and non-enhanced and enhanced DSCT scans were performed before and after embelization. Postprocessing of image data was made on the workstation, and CT pulmonary angiography ( CTPA ), DEal and fusion images were obtained. The location and number of the emboli were recorded. The rabbits were killed immediately after DSCT scan, the location and number of the lung lobes with pulmonary emboli were evaluated pathologically. Based on the pathological results, the sensitivity, specificity, positive predictive value ( PPV), and negative predictive value (NPV) of CTA, DEal and fusion images for the diagnosis of PE were calculated. Weighted Kappa values were calculated to evaluate the consistency between CTPA and DEal. Results PE model was made successfully in 7 rabbits. Six rabbits with 30 lobes were evaluated with one exception because of the catheter affecting the quality of lung peffusian image. PE was found pathologically in 18 lobar arteries. On DEPI, the region with PE showed low peffusion area comparing with the normal parenchyma and CTPA showed the filling defect within corresponding pulmonary artery or interruption of the artery. The sensitivity, specificity, PPVand NPV of CTPA were 66. 7% (12/18), 100.0% (12/12), 100.0% (12/12) and 66. 7% (12/18), respectively. The Kappa value was 0. 651 indicating moderate correlation with pathology. The sensitivity, specificity, aPv, and NPV of DEal were 88. 9% ( 16/18), 91.7% ( 11/12, 94. 1% (16/17) and 84. 6% ( 11/13 ), respectively. The Kappa value was 0. 795 indicating excellent correlation with pathology. Conclusion Dual-energy lung perfusion imaging of DSCT can display the blood distribution of rabbit's lung and has a high sensitivity for the diagnosis of acute pulmonary embolism.

ObjectiveTo explore the effect of Tongxie Yaofang on the immune microenvironment of colorectal cancer in mice under chronic stress and the underlying mechanism. MethodA total of 40 male SPF BABL/C mice were randomized into normal group， stress group， Tongxie Yaofang group （13.65 g·kg^-1）， and Tongxie Yaofang-stress group （13.65 g·kg^-1）， with 10 in each group. Chronic restraint stress was induced in mice and administration （ig） of Tongxie Yaofang began after 7 days of stress. On the 14^th day， forced swim and tail suspension tests were used to examine the behavioral changes of mice after stress and the subcutaneous colorectal tumor was implanted in each group of mice. The effect of this prescription on the body mass and tumor volume of mice was observed. After the last administration， mouse serum and tumor samples were collected. The content of T lymphocytes （CD3⁺， CD4⁺， CD8⁺， and CD4⁺/CD8⁺） in tumor was detected by immunohistochemistry and flow cytometry and levels of corticosterone （CORT） in peripheral blood， and interleukin （IL）-2， interferon-γ （IFN-γ）， IL-6， and IL-10 in the serum were determined by enzyme-linked immunosorbent assay （ELISA）. The protein expression of inhibitor of nuclear factor-κB（IκB） kinase α/β （IKKα/β）， nuclear factor-κB （NF-κB）α （IκBα）， NF-κB p65， and phosphorylated （p）-NF-κB p65 was measured by Western blot. ResultCompared with the normal group， the stress group had large tumor volume （P<0.05）， low content of CD3⁺， CD4⁺， and CD4⁺/CD8⁺ （P<0.05， P<0.01）， high content of CD8⁺， low content of T helper 1 （Th1）-secreted IFN-γ （P<0.05）， high content of T helper 2 （Th2）-secreted IL-10 （P<0.05） and CORT （P<0.05）， high protein expression of p-NF-κB p65， NF-κB p65， and IKKα/β （P<0.05）， and low protein expression of IκBα （P<0.05）. Compared with the normal group， the Tongxie Yaofang group showed slow tumor growth， high content of CD3⁺， CD4⁺， and CD4⁺/CD8⁺ （P<0.01）， low content of CD8⁺ （P<0.05）， high content of Th1-secreted IL-2 and IFN-γ （P<0.05）， low content of Th2-secreted IL-6 and IL-10 （P<0.05）， low content of CORT， low protein expression of p-NF-κB p65， NF-κB p65， and IKKα/β （P<0.05）， and high protein expression of IκBα （P<0.01）. Tongxie Yaofang-stress group demonstrated slower tumor growth， higher content of CD3⁺， CD4⁺， and CD4⁺/CD8⁺ （P<0.01）， smaller content of CD8⁺ （P<0.05）， higher content of IL-2 and IFN-γ （P<0.05）， lower content of IL-6， IL-10 （P<0.05）， and CORT （P<0.05）， lower protein expression of p-NF-κB p65， NF-κB p65， and IKKα/β （P<0.05，P<0.01）， and higher protein expression of IκBα （P<0.01） than the stress group. ConclusionTongxie Yaofang can delay the growth of colorectal cancer under chronic stress and alleviate the deterioration of the immune microenvironment， possibly by inhibiting NF-κB signaling pathway， regulating the function of T lymphocyte subsets， and thus suppressing the secretion of pro-inflammatory factors.