[Reconstruction of images in emission tomography]. / Rekonstruktsiia izobrazheniia v émissionnoi tomografii.

The algorithm of back projection with filtration for exponential Radon transform leads to strong distortion for big diameter objects. The main reason for this distortion is mainly the exponential increase of errors in the quadrature formula for a weighed back projection operator. So it is sometimes more convenient to use the back Radon transform R-1 and then to correct the result, taking into account attenuation. For this purpose, the approximation formulas are given, which connect f and R-1 R mu f. An appropriate iteration reconstruction algorithm is also considered. Application exponential Radon identities for projection data analysis are also discussed.

[Single-photon emission-computed tomography with the Testascan multidetector gamma tomograph in neurologic practice]. / Odnofotonnaia émissionnaia komp'iuternaia tomografiia s mnogodetektornym gamma-tomografom TESTASKAN v nevrologicheskoi praktike.

The paper is concerned with the results of single-photon emission tomography and gamma-topography in patients with cerebral tumors, cerebral circulatory disorders and pathology of the liquor system. Tomographic investigation was shown to enhance the accuracy and reliability of the detection of cerebral tumors. Single-photon emission computerized gamma-tomography (SPECT) permitted the detection of structural and morphological cerebral changes in disturbed cerebral circulation of various etiology. SPECT together with computerized tomography and radionuclide cisternography was shown to be an auxiliary method for visualization of the cerebral cisterns. Radionuclide tomographic images as compared to gamma-topographic findings of the brain possessed a high statistical significance and good resolution.