Nuclear medicine is one of the fundamental, noninvasive imaging techniques through which radionuclides are used for both diagnostic and treatment purposes. Scintigraphic images of radionuclide distributions provide information about anatomical structure by showing physiological processes and metabolic disturbance, including the assessment of lesions at the molecular level. Scintigraphic analyses can be applied in estimating xenophobic toxicity that has caused disturbance on the metabolic level without structural damage, but with substantial functional disturbance of various organs. In clinical practice, radiotracers emitting gamma radiation are administered and the technique of single photon emission computed tomography (SPECT) is applied. The SPECT technique provides functional and morphological information about organs through the imaging of thin slices of radionuclide distributions. The SPECT technique produces images of slices of radionuclide distributions with image contrast that is higher than that obtained with conventional planar imaging. Among other capabilities, SPECT can measure regional cerebral blood flow and indirectly estimate the metabolism of the nervous system, since metabolic processes are connected with blood perfusion. This article describes the procedures used by the Department of Clinical Toxicology and Nuclear Medicine in measuring myocardial perfusion in acute carbon monoxide (CO) and paracetamol poisoning. Analysis of toxicological indicators of CO poisoning revealed a significant relationship between the blood lactate concentration and the degree of scintigraphic changes, which were confirmed by logistic regression analysis. 1 table, 3 figures, and 23 references