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1.
J Nucl Cardiol ; 24(2): 698-707, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-26846369

RESUMO

BACKGROUND: A phantom assembly that simulates the respiratory motion of the heart was used to investigate artifacts and their impact on defect detection. METHODS: SPECT/CT images were acquired for phantoms with and without small and large cardiac defects during normal and deep breathing, and also at four static respiratory phases. Acquisitions were reconstructed with and without AC, and with misalignment of transmission and emission scans. A quantitative analysis was performed to assess artifacts. Two physicians reported on defect presence or absence and their results were evaluated. RESULTS: All large defects were correctly reported. Attenuation reduced uptake in the basal LV walls, increasing FN physicians' reports for small defects. Respiratory motion reduced uptake mainly in the anterior and inferior walls increasing FP and FN reports on images without and with small defects, respectively. Artifacts due to misalignment between CT and SPECT scans in normal breathing phantoms did not influence the physicians' reports. CONCLUSIONS: Attenuation and respiratory motion correction should be applied to reduce artifacts before reporting on small defects in deep breathing conditions. Artifacts due to misalignment between CT and SPECT scans do not affect defect detection in normal breathing when the LV is co-registered in SPECT and CT images prior to AC.


Assuntos
Artefatos , Cardiopatias/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/instrumentação , Imagens de Fantasmas , Mecânica Respiratória , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Movimento (Física) , Imagem de Perfusão do Miocárdio/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão de Fóton Único/métodos
2.
J Nucl Cardiol ; 24(4): 1216-1225, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-26676030

RESUMO

BACKGROUND: The aim of this study was to determine the impact of respiratory motion correction on SPECT MPI and on defect detection using a phantom assembly. METHODS: SPECT/CT data were acquired using an anthropomorphic phantom with inflatable lungs and with an ECG beating and moving cardiac compartment. The heart motion followed the respiratory pattern in the cranio-caudal direction to simulate normal or deep breathing. Small or large transmural defects were inserted into the myocardial wall of the left ventricle. SPECT/CT images were acquired for each of the four respiratory phases, from exhale to inhale. A respiratory motion correction was applied using an image-based method with transformation parameters derived from the SPECT data by a non-rigid registration algorithm. A report on defect detection from two physicians and a quantitative analysis on MPI data were performed before and after applying motion correction. RESULTS: Respiratory motion correction eliminated artifacts present in the images, resulting in a uniform uptake and reduction of motion blurring, especially in the inferior and anterior regions of the LV myocardial walls. The physicians' report after motion correction showed that images were corrected for motion. CONCLUSIONS: A combination of motion correction with attenuation correction reduces artifacts in SPECT MPI. AC-SPECT images with and without motion correction should be simultaneously inspected to report on small defects.


Assuntos
Cardiopatias/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Imagens de Fantasmas , Respiração , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Humanos , Movimento (Física)
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