Objective To design and establish a set of diffusion optical tomography(DOT) system.Methods Near-infrared(NIR) laser was employed as the light source and only one photomultiplier tube(PMT) as the detector.An optical multiplexer was used to alter the detector channels.The 32 channels of the system,which are consisted of 16 launch channels and 16 detector channels,worked under the continuous-wave(CW) model and were used to acquire 256 boundary data.Results Experiments were performed based on the proposed imaging system.The intralipid was used as the tissue-like medium and the India ink as the absorber.Two sets of data on the boundary were sampled,respectively,before and after the absorber was embedded inside the tissue-like medium.The two sets of data were normalized and then used to reconstruct the absorption coefficient distribution.The recovered image reflected the real location and size of the absorber.Conclusion The proposed imaging platform can image the tissue optical parameters effectively.However the resolution of the reconstructed image was not high because the inverse problem was gravely underdetermined and the noise was not considered in the reconstruction algorithm.The recovered result in the next generation system could be improved by making more use of prior information and enhancing the performance of the system.

ObjectiveTo investigate the serum tumor markers level of carcinoembryonic antigen(CEA) ,cytokeratin fragment antigen21-1 (CYFRA21-1),neuron specific enolase (NSE) in patients with lung cancer, and the change after chemotherapy on them. Methods Radioimmunoassay was applied to detect the levels of CEA, CYFRA21-1 ,NSE in 45 patients with advanced NSCLC before and after chemotherapy,and the tumor markers were also detected in 20 patients with SCLC and 20 patients with benign lung diseases of control groups. ResultsThe levels of CEA, CYFRA21-1, NSE in lung cancer group before chemotherapy were much higher than benign group, but there was no difference of CYFRA21-1 between the SCLC group and benign group. The same result of NSE was found between NSCLC and benign group(P ＞0. 05). The value of NSE was lower in the patients with SCLC after chemotherapy than before(P ＜0. 01 ). The level of CYFRA21-1 was lower in squamous carcinoma than before( P ＜0. 01 ). But in the adenocarcinoma group only NSE's level was lower after chemotherapy( P ＞0. 05) ,there were no differences in CEA and CYFRA21-1 ( P ＞ 0. 05 ). ConclusionThe levels of the three tumor markers rise obviously in advanced NSCLC and decrease after chemotherapy. The differences were significant with NSE in SCLC and CYFRA21-1 in squamous cell carcinoma and CEA in adenocarcinoma. The levels of serum CEA,CYFRA21-1 and NSE could be a tumor marker in progressive lung cancer. And the decrease of the levels could be used to evaluate the chemotherapeutic response respectively in different pathologic types of lung cancer.