Avaliação da qualidade de imagens adquiridas em câmara dedicada a estudos cardíacos com detectores de estado sólido

Abstract

Myocardial Perfusion Imaging (MPI) used in nuclear cardiology have been widely applied in clinical practice, because its value is documented in the diagnosis and prognosis of coronary artery disease. Due to the increasing use, the industry has developed projects for dedicated cardiac chambers that restrict the detection area just to the heart. Two detection systems for tomographic acquisitions in nuclear cardiology, using solid-state detectors, specifically cadmium zinc telluride crystals (CZT) are currently marketed. Although resulting in a short acquisition time and reduced radiation dose to the patient, there are doubts about the assessment procedures of equipment performance and the influence of the acquisition parameters and processing quality of the images. The aim of this study is to assess the impacts of changes in acquisition parameters and processing as cardiac SPECT equipment with solid and stationary gantry detectors. For this evaluation have been acquired images of an anthropomorphic experimental simulator with heart insert into a SPECT camera with solid state CZT detector type, to evaluate the quality and visibility of injuries. The images obtained were evaluated by quantitative quality indicators, such as the standard deviation normalization, contrast between the wall of the ventricle and the cavity, contrast-to-noise ratio and effective contrast of the lesion. As a result of the survey, variations in the time of acquisition does not affect the quality indicators values, unlike the reconstruction parameters and administered activity. The reconstruction parameter is what most affects the indicators, it is necessary to define a protocol of acquisition value for each activity to be administered in accordance with the characteristics of the patient.