Conclusion: SAM provides the following benefits: (1) images are acquired in only few minutes without requirement for staining, (2) imaging pattern is similar to that of light microscope, and (3) speed of sound from each lesion is digital and statistical analysis is possible among diseases. Although resolution of SAM is little lower than that of light microscope, the SAM can be an ancillary tool for histological diagnosis and clinical research. Objective: Parkinson's disease (PD) is considered one of the major neurological disorders of the population, and there is increasing data provides enough evidences confirming the involvement of free radicals and other reactive oxygen species (ROS) in a number of physiological and pathological processes. The aim of the present study was to evaluate, the effect of therapy in patients with Parkinson disease on biomarkers of oxidative stress, such as products of lipid peroxidation by two different methods: Electron Paramagnetic Resonance and visible spectrophotometry. Method: The study was performed in blood samples of patients with PD -with therapy, patients with PD -without therapy and healthy volunteers as controls. The products of lipid peroxidation were measured as malondialdehid (MDA), spectrophotometrically by thiobarbituric acid (TBA) method. The levels of lipid radicals were determinated ex vivo at room temperature on an X-band EMX-micro spectrometer, Bruker, Germany.