Related Experiment Videos
Left ventricular thrombi: in vivo detection by indium-111 platelet imaging and two dimensional echocardiography
Insights
Indium-111 platelet imaging and echocardiography both detect left ventricular thrombi noninvasively. Platelet imaging may identify more active thrombi, aiding risk assessment for embolization.
Area of Science:
- Cardiology
- Nuclear Medicine
- Diagnostic Imaging
Background:
- Left ventricular thrombi pose an embolic risk, particularly after myocardial infarction or in cardiomyopathy.
- Noninvasive detection methods are crucial for patient management and risk stratification.
Purpose of the Study:
- To compare the diagnostic accuracy of Indium-111 platelet imaging and two-dimensional echocardiography for detecting left ventricular thrombi.
- To evaluate the utility of these techniques in patients at risk for thrombus formation.
Main Methods:
- 44 men at risk for left ventricular thrombi underwent Indium-111 platelet imaging.
- 35 patients also underwent two-dimensional echocardiography.
- Comparison with surgical or autopsy findings in seven patients.
Main Results:
- Indium-111 platelet imaging identified thrombi in 10 patients, with positive findings typically at 48-72 hours post-labeling.
- Echocardiography confirmed intraventricular masses in nine patients.
- Platelet imaging missed one thrombus when performed only at 24 hours; echocardiography findings agreed with pathology in all cases.
Conclusions:
- Both Indium-111 platelet imaging and echocardiography can detect left ventricular thrombi noninvasively.
- Platelet imaging may be more sensitive to hematologically active thrombi.
- These methods can aid in identifying patients at risk of embolization and assessing antithrombotic therapies.
Abstract:
Indium-111 platelet imaging, which can identify sites of active intravascular platelet deposition, and two dimensional echocardiography, which can identify intracardiac masses, can both be used to detect left ventricular thrombi noninvasively. We compared these techniques in 44 men at risk for thrombi from remote transmural myocardial infarction (31 patients) or cardiomyopathy (13 patients). All 44 patients underwent platelet imaging; 35 underwent echocardiography. On platelet imaging nine patients had thrombi and one had a possible thrombus. Of these 10 studies, none were positive at 2 hours, 5 were positive at 24 hours and all were positive 48 or 72 hours after platelet labeling. Nine of these patients underwent echocardiography, and all had an intraventricular mass. The findings on platelet scanning were negative in six patients who had positive (four patients) or equivocally positive (two patients) findings on echocardiography. All patients with thrombi detected by either noninvasive method had transmural anterior myocardial infarction with ventricular aneurysm. Of the seven patients who underwent cardiac surgery or autopsy, three had thrombi. Platelet imaging failed to identify one thrombus in a patient in whom imaging was performed only at 24 hours after labeling. There were no false positive platelet images in this group. Five of these seven patients (two with thrombi, three without) underwent echocardiography; in all cases the echocardiographic findings agreed with the pathologic findings. Both platelet imaging and echocardiography detect ventricular thrombi. Platelet imaging may detect only the most hematologically active thrombi. Both techniques may help define patients at risk of embolization and may be useful for in vivo assessment of antithrombotic drugs.