Nuclear medicine communications
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Comparative Study Clinical Trial Controlled Clinical Trial
Comparison of quantitative 99mTc-HMPAO and 67Ga citrate lung scans in patients with active diffuse infiltrative lung disease.
Diffuse infiltrative lung disease (ILD) is a heterogeneous group of disorders that predominantly affect the lung parenchyma and spare the airway. To objectively assess the degree of pulmonary vascular endothelium damage in active ILD, lung/liver uptake ratios (L/L ratios) on 99mTc hexamethylpropylene amine oxime (99mTc-HMPAO) lung scans were determined in 21 patients with active ILD. Meanwhile, the 67Ga citrate uptake index (GUI) on 67Ga lung scans was measured in order to evaluate the severity of lung inflammation in active ILD. ⋯ In addition, no correlation between the degree of damage to the pulmonary vascular endothelium and the severity of lung inflammation was found. In conclusion, L/L ratios on 99mTc-HMPAO lung scans and GUI on 67Ga lung scans are different to the findings of chest X-rays and have the potential to objectively detect the degree of damage to the pulmonary vascular endothelium and the severity of lung inflammation in active IDL. However, the relationship between L/L ratio and GUI in active ILD is not significant.
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Comparative Study Clinical Trial
Usefulness of 99mTc ethyl cysteinate dimer brain SPECT to detect abnormal regional cerebral blood flow in patients with acute carbon monoxide poisoning.
99mTc ethyl cysteinate dimer (99mTc-ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in patients with acute carbon monoxide (CO) poisoning. Ten patients with acute CO poisoning and no past histories of psychoneurological disorders were enrolled in this study. ⋯ Only three of the 10 patients had normal 99mTc-ECD brain SPECT findings. This study suggests that, in comparison with brain CT scan, 99mTc-ECD brain SPECT is a better tool for the early detection of hypoperfusion brain lesions in acute CO poisoning in patients with normal brain CT findings.
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Comparative Study Clinical Trial
Narrow time-window dual-point 18F-FDG PET for the diagnosis of thoracic malignancy.
Dual time-point imaging has been proposed as a means of improving the accuracy of 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) for the diagnosis of malignant pulmonary nodules. The purpose of this study was to evaluate a dual time-point protocol that has a narrow time window between its initial and its delayed imaging sessions. All patients examined during a 16-month time period, either for the diagnosis of a radiographically indeterminate thoracic lesion or for the staging of non-small-cell carcinoma, were included in the study provided that they completed the dual-point protocol and had either biopsy evidence of malignancy, biopsy evidence of a benign condition involving the thoracic lesion of concern, or clinical and radiographic follow-up consistent with the absence of malignancy. ⋯ The best performance was achieved when the BSA corrected dSUV was at least 2.4, or when the fSUV showed at least a 5% increase from initial to delayed imaging. With the optimal combined dSUV/fSUV strategy, the area under the ROC curve was 0.99, as opposed to 0.96 for dSUV alone, or 0.93 for iSUV alone. The ability of 18F-FDG PET to discriminate between benign and malignant conditions of the central thorax can be improved by correcting the SUV for BSA and by increasing the 'incubation time' between 18F-FDG injection and imaging, or by performing narrow time-window dual-point imaging.
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Recent advances in the treatment of acute coronary syndromes has raised awareness in the community that prompt presentation for chest pain may be life saving. Each year in the United States, more than 6 million people present to the hospital with an acute chest pain, making this the most common presenting chief complaint second only to abdominal pain. Most patients presenting with chest discomfort have a non-ischaemic electrocardiogram on presentation. ⋯ As an approach to this dilemma, many hospitals have created protocols as a means of facilitating the identification of infarction and ischaemia and the safe and effective triage of patients with a chief complaint of chest pain. Myocardial perfusion imaging at rest has been shown to be highly sensitive for the detection of acute myocardial infarction, and can be supplemented with provocative testing after infarction has been excluded. Diagnostic strategies that utilize myocardial perfusion imaging for the evaluation of acute chest pain have successfully improved the triage of these patients by avoiding inadvertent discharge of patients with myocardial infarctions, and reducing unnecessary hospital admissions and overall cost and expenditure.
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Clinical Trial
Implementation of myocardial perfusion imaging in the early triage of patients with suspected acute coronary syndromes.
The risk of overlooking an underlying acute coronary syndrome remains an important challenge in patients complaining of chest pain but who have a non-diagnostic ECG (CP). Indeed, myocardial scintigraphy associated with exercise testing (exercise SPET) represents a valuable tool for excluding coronary artery disease (CAD) especially in patients with CP and delayed presentation to the emergency department. We sought to implement diagnoses of CAD in the early triage of CP patients by exercise gated SPET and compare diagnoses with outcomes. ⋯ Patients with positive scans (34%, n=105) had documented coronary stenoses in 43% (n=45); patients with negative scans (66%, n=201) had evidence of non-fatal coronary events at 6 months in 1.5% (n=3). When imaging was analysed with gating by the presence of transmural perfusion defects associated with wall motion abnormalities (n=86), only one patient, among 19 excluded, was recognized as having coronary stenosis by angiography (SPET vs gated SPET: negative predictive value 98.5% and 98%, respectively, P=NS; diagnostic accuracy 79% and 85%, respectively; P< or =0.03). Therefore, implementation of myocardial perfusion imaging in the early triage of patients with suspected acute coronary syndromes was effectively obtained by early exercise gated SPET, especially in patients with transmural myocardial perfusion defects associated with wall motion abnormalities.