Accurate small animal surface reconstruction is important for full angle non-contact fluorescence molecular tomography （FMT） systems. In this letter, an optimal surface reconstruction method for FMT is proposed. The proposed method uses a line search method to minimize the mismatch between the reconstructed three- dimensional （3D） surface and the projected object silhouette at different angles. The results show that the mean mismatches of the 3D surfaces generated on three live anesthetized mice are all less than two charge coupled device （CCD） pixels （0.154 mm）. With the accurately reconstructed 3D surface, in-vivo FMT is also performed.
The inverse black body radiation problem, which is to reconstruct the area temperature distribution from the measurement of power spectrum distribution, is a well-known ill-posed problem. In this paper, a variational expectation-maximization （EM） method is developed and its convergence is studied. Numerical experiments demonstrate that the variational EM method is more efficient and accurate than the traditional methods, including the Tikhonov regularization method, the Landweber method and the conjugate gradient method.
The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistribution in BALB/C nude mice bearing MCF-7 tumor was measured.After t-butyloxycarbonyl(Boc)-modification,the 131I-Boc-YG5 was quite resistant to deiodination in vivo,resulting in negligible radioactivity accumulation in thyroid.The radiotracer clearance in tumor became faster,the absolute tumor uptake decreased for 131I-Boc-YG5,but the tumor-to-tissue uptake ratios increased.The uptake ratios of tumor to muscle,blood,heart,and lung at 1 h post injection reached 4.73,1.70,4.09 and 1.70,respectively.It is demonstrated that Boc-group is an effective prosthetic one to prevent deiodination in vivo and improve tumor imaging for radioiodinated NGR.
