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[Reverse redistribution in dipyridamole-loading thallium-201 images using single photon emission computed tomography]
Journal of Cardiography
|June 1, 1986
Summary
Reverse redistribution in thallium (Tl) myocardial imaging indicates potential pathology. This finding, observed in 21.6% of patients, suggests a combination of scarred and metabolically affected heart muscle, correlating with poorer cardiac function.
Area of Science:
- Cardiology
- Nuclear Medicine
- Diagnostic Imaging
Background:
- Reverse redistribution on thallium (Tl) myocardial imaging, defined as decreased Tl activity in redistribution images compared to stress images, has clinical significance.
- Understanding the underlying myocardial conditions associated with reverse redistribution is crucial for accurate diagnosis and patient management.
Purpose of the Study:
- To investigate the clinical significance and prevalence of reverse redistribution in patients undergoing dipyridamole stress and redistribution Tl myocardial imaging.
- To correlate reverse redistribution patterns with specific cardiac conditions, myocardial perfusion, and left ventricular function.
Main Methods:
- 125 patients underwent dipyridamole stress and redistribution Tl myocardial imaging, analyzed by single photon emission computed tomography.
- Myocardial washout rate was calculated using the segmental region of interest (ROI) method.
- Myocardial function and left ventricular wall motion were assessed using 99mTc-RBC-gated cardiac pool imaging.
Main Results:
- Reverse redistribution was observed in 27 (21.6%) patients, with higher prevalence in those with supraventricular arrhythmia (62.5%), subendocardial infarction (60.0%), hypertension (42.8%), and diabetes mellitus (40.0%).
- Patients with reverse redistribution (Group 2) showed significantly greater Tl washout rates compared to normal perfusion areas.
- Group 2 patients exhibited more extensive left ventricular wall motion abnormalities and lower ejection fractions than Group 1 (normal perfusion).
Conclusions:
- Reverse redistribution may indicate regions with combined scarred and normal myocardium, metabolically affected myocardium, or increased myocardial blood flow.
- Patients exhibiting reverse redistribution, particularly those with reduced perfusion during stress, appear to have more pathological myocardium and impaired cardiac function.