Nuclear medicine communications
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Comparative Study
Assessment of left ventricular volume and ejection fraction: comparison of QGS and MBGS analyses of ECG-gated myocardial perfusion SPECT imaging.
The purpose of this study was to compare quantitative ECG-gated single-photon emission computed tomography (SPECT) (QGS) and model-based ECG-gated single-photon emission computed tomography (MBGS) for determination of end-diastolic cardiac volume (EDV), end-systolic cardiac volume (ESV), and left ventricular ejection fraction (LVEF). The accuracy of both methods was evaluated by measurements obtained from contrast left ventriculography (LVG). ⋯ Measurements of LV volumes and LVEF by QGS and MBGS showed close agreement with each other and with results from LVG. However, both methods measure lower values for EDV and higher values for ESV and thus underestimate LVEF compared with LVG.
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The purpose of this study was to evaluate the performance of F-fluorodeoxy-D-glucose (FDG)-PET/computed tomography (CT) and contrast-enhanced CT (CECT) in the detection and characterization of hepatic metastases. ⋯ Many studies have been conducted on the impact of FDG-PET/CT in the evaluation of hepatic metastases, especially from colorectal primary. Very few prospective studies, however, have been conducted on its role in evaluation of hepatic metastases from nongastrointestinal primaries. Despite its superior performance, it cannot replace CECT for this purpose, owing to the low but definite risk of false positivity based on PET-CT findings alone. Inclusion of CECT in PET/CT protocols may enable us to achieve a higher diagnostic accuracy. This suggests the need for a large prospective study with serial evaluations and pathological correlation.
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Optimal treatment for chronic total occlusion (CTO) in the infarct-related coronary artery is not clear. Our aim was to assess myocardial perfusion, left ventricular ejection fraction (EF), and left ventricular size using gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile in patients with CTO before and 1 year after recanalization. ⋯ Myocardial perfusion and EDV may significantly improve 1 year after PCI provided recanalization of CTO was successful. Our preliminary findings suggest that successful recanalization of CTO may have favorable outcome on left ventricular perfusion and function, particularly in patients with viable myocardium before PCI. The gated SPECT myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile may be useful for monitoring long-term functional outcome of PCI in patients with CTO.
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Septal perfusion abnormalities are frequently observed in patients with left bundle branch block (LBBB). The aim of this study was to compare myocardial perfusion imaging obtained from ungated and diastolic thallium gated single-photon emission computed tomography (SPECT) images in patients with LBBB. ⋯ In patients with LBBB, diastolic imaging did not provide additional information to ungated perfusion imaging, but left ventricular dysfunction was associated with CAD.
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Review Case Reports
FDG-PET and PET/CT in the clinical management of gastrointestinal stromal tumor.
The management of gastrointestinal stromal tumors (GISTs) has been revolutionized in recent years by two major developments: the introduction of imatinib mesylate as a targeted therapeutic agent and the dramatic change in the tumor metabolic activity following successful therapy making in fluorodeoxyglucose (FDG)-PET as the modality of choice for monitoring therapeutic response. In the present communication, we have explored the current role of PET/computed tomography (CT) imaging in GIST on the basis of a brief overview of the published studies and our experience on the subject gained in a large tertiary care setting. ⋯ The findings of detection of disease recurrence on discontinuing imatinib and acquired resistance to imatinib provide insight into the issue of therapeutic endpoint definition. On the basis of the experience gained in recent times, the future potential of this powerful modality in this setting is hypothesized.