RESUMO
OBJECTIVE: We introduced a method to measure the extent of myocardial ischemia and steal with SPECT MBF quantitation. METHODS: Eighty-seven patients who received rest/Dipyridamole-stress 99mTc-Sestamibi (MIBI) dynamic SPECT scans and coronary angiography were included. Dynamic SPECT images were reconstructed with full physical corrections. The one-tissue kinetic model was utilized to quantify K1 and further converted to MBF with required corrections. Rest MBF, stress MBF and myocardial flow reserve (MFR) were converted to a flow status polar map by a flow diagram. Extents of 7 flow statuses were verified their cutoff points for detecting stenoses. The diagnostic performance (DP) was compared to that of MFR. RESULTS: Cutoff point of the extent to detect ≥ 50% stenosis was 3.01% for ischemia-steal status and 20.3% for the combined status of ischemia-steal and moderate. Using these criteria, sensitivity, specificity and accuracy to detect ≥ 50% stenosis were (80%, 75%, 79%) and (86%, 68%, 80%) for ≥ 70% stenosis. The DP was superior to that of MFR < 2.0 criterion (≥ 50%: 70%, 63%, 69%; ≥ 70%: 73%, 61%, 69%) (all p < 0.015). CONCLUSION: SPECT MBF quantitation integrated with the flow diagram can measure the extent of myocardial ischemia and steal which appeared more accurate to detect angiographic stenoses than the single MFR parameter.
Assuntos
Circulação Coronária , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Angiografia Coronária , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Reprodutibilidade dos Testes , Descanso , Fatores de Risco , Estresse FisiológicoRESUMO
Recently, myocardial blood flow quantitation with dynamic SPECT has been validated to enhance the detection of multivessel coronary artery disease (CAD) and conclude equivocal SPECT myocardial perfusion study. This advance opened an important clinical application to utilize the tool in guiding CAD management for area where myocardial perfusion tracers for PET are unavailable or unaffordable. We present a clinical patient with ongoing recursive angina who underwent multiple nuclear stress tests for a sequence of CAD evaluation in 26 months and demonstrated that SPECT myocardial blood flow quantitation properly guided CAD management to warrant patient outcome.
Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Tomografia Computadorizada de Emissão de Fóton Único , Doença da Artéria Coronariana/terapia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.
